Lactose improves gain through nursery period: the benefit of lactose levels of up to 7.5% during the third and fourth week postweaning was demonstrated in three different environments with different pig sources.(Nutrition & Health: Swine) - Feedstuffs

IT is known that providing lactose in diets the first few weeks postweaning improves pig feed intake and gain through the nursery period.

The importance of this response is the subsequent reduction in days to market and increase in throughput that results by making sure pigs get off to a good start and by adding weight in the nursery.

Research and field experience clearly demonstrate that pigs make the transition from sow's milk to dry feed much more easily when lactose is included in the diet, resulting in higher feed intakes, more gain and fewer starve-out pigs.

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The obvious nutritional benefit of providing lactose is that it has improved digestibility compared to starches from cereal grains due to the pig's natural state of development of digestive enzymes after weaning.

However, enhancement of feed palatability and improvements in intestinal health are likely equally important in explaining the observed response to lactose.

In 2007, the price of dairy products used in pig feeds to provide lactose reached unprecedented levels and pressured feed manufacturers and nutritionists to lower the lactose levels of pre-starter and starter diets to bare minimums in order to optimize the economic return of lactose inclusion.

Many factors have contributed to a softening of the lactose market in 2008, and whey prices are now, in many instances, 25% of the highs reached in mid-2007 (data not shown).

During this same time period, the price of corn and other cereal grains has soared.

These market swings have resulted in some of the smallest price differentials between the cost of corn and lactose ever observed in the swine feeding industry.

This situation provides an opportunity to re-evaluate optimal lactose levels in starter programs and to take full advantage of the positive relationship between lactose level and pig performance.

Gain

A recent cooperative effort by researchers at the University of Kentucky, the University of Missouri and The Ohio State University has reconfirmed the value of feeding aggressive levels of lactose to pigs during the third and fourth week postweaning.

At each of the three universities, a trial was conducted evaluating the response to 0, 2.5%, 5.0%, 7.5% or 10.0% lactose from day 14 to 28 postweaning.

Pigs were weaned at 15-20 days of age and averaged 13.7 lb. After one week of a common phase 1 diet containing 20% lactose and one week of a common phase 2 diet containing 15% lactose, pens of pigs were administered treatment diets.

Responses to increasing the lactose level in the diets from 14 to 28 days postweaning were observed at each of the three university research sites.

Figure 1 illustrates the average daily gain (ADG) response when data were combined for the three trials. Although the analysis indicated a linear response, it appears that the response was maximized at 7.5% lactose.

The improvement in ADG as pigs were fed higher levels of lactose was a result of increased feed intake (Figure 2).

The economics of feeding the various lactose levels from 22 to 40 lb. are presented in the Table. The added gain from each inclusion of lactose was calculated by comparing the total amounts of gain during weeks three and four to the total gain for pigs fed 0% lactose during this period.

The pigs fed 7.5% lactose gained approximately 1 lb. more than pigs on the diet without lactose.

The cost of gain for each treatment was calculated from the reported feed efficiency numbers and calculated diet costs for each treatment using $6/bu. for corn, $375 per ton for soybean meal and $400 per ton for whey permeate (lactose source) with realistic costs for other fixed ingredients.

Estimates of the relationship between differences in the nursery exit weight and the impact on market weight were variable; however, it is generally accepted that a 1 lb. advantage in weight at the end of the nursery will increase through the subsequent grow-finish period.

For this example, an estimate of reduced days to market was made by assuming that 1 lb. of extra weight out of the nursery would result in a 2 lb. heavier pig at marketing and that ADG in the finishing period would be 1.85 lb. per day.

A cost of 12 cents per day for yardage and a finishing feed conversion of 2.80 were used with an average cost of a medium-energy finishing feed that was assumed to be $280 per ton.

When the cost of gain in finishing and yardage costs were considered, the additional weight out of the nursery for pigs fed 7.5% lactose from days 14 to 28 resulted in a 19 centsperpig benefit compared to having no lactose in the diet during this period. In conclusion, the benefit of lactose levels of up to 7.5% during the third and fourth week postweaning for pigs that averaged 13.7 lb. at weaning and were fed diets with pharmacological levels of copper, 6% fish meal and antibiotics was demonstrated in three different environments with different pig sources.

Assuming 24 pigs per sow per year and a net benefit of 19 cents per pig by feeding 7.5% lactose from day 14 to day 28 postweaning, the net return to the producer would be $45,600 for every 10,000 sows in production.

The above calculation assumes feeding to a constant market weight and fewer days to achieve that weight due to feeding lactose longer in the starter period.

Using another scenario, if barn days are fixed, the additional 1 lb. out of the nursery would result in selling an additional 2 lb. of market weight, and the economics are even more favorable.

Using August 2008 lean hog prices and factoring in the added feed cost, the benefit would be more than 50 cents per pig (more than $120,000 per 10,000 sows).

Regardless of how the economics are calculated, the bottom line is that current lactose pricing provides an opportunity to be aggressive with lactose levels in starter diets to maximize performance through the nursery period and improve production efficiencies to market.

Reference

J. Anim. Sci., Vol. 86, No. 1.

TO YOUR HEALTH : TIME TO BACK OFF? TIPS FOR IMPROVING CARE CAN PRODUCE HUGE BENEFITS.(L.A. LIFE) - Daily News (Los Angeles, CA)

Did you know 200 million work days are lost each year due to back pain? That's second only to the common cold, according to a government statistic.

August is Be Good to Your Back Month, and Relax the Back Stores in the Los Angeles area are providing free seminars and free on-site workplace ergonomic assessments designed to ease the pain 80 percent of Americans will suffer at some point in their lives.

Here are some back-saving pointers:

To aid proper back alignment when driving, position your seat so your knees are level with your hips and support your lower back by placing a lumbar support behind your back.

Adjustable armrests on office chairs can reduce neck, shoulder and lower back pain. Also, use a footrest at your desk to reduce lower back pressure. To avoid lower back pain while sitting, place a pillow or a lumbar roll in the small of your back. Avoid sitting with a wallet in your back pocket.

Standing puts pressure on your spine. If you must stand for long periods, put one foot on a stool to take pressure off the spine and help keep natural curves aligned. Avoid high-heeled shoes.

When you sleep on your back, put a pillow under your knees and a small support underneath your lower back. If you sleep on your side, place a pillow between your bent knees and hug a second pillow to take some pressure off your back.

For more information, call Relax the Back Stores at (800) 971-2225.

Healthy books: ``The Lice-buster Book: What to Do When Your Child Comes Home With Head Lice!'' by Lennie Copeland, illustrated by Ashley Copeland Griggs (Warner Books; $8.99). Copeland, mother of two and self-made lice expert, delivers step-by-step procedures for detecting and treating head lice.

``Living Healthy in a Toxic World,'' by David Steinman and R. Michael Wisner (Perigee; $12). A book on how to protect yourself from common, everyday toxins - in food, household cleaners and cosmetics.

Baby help in Spanish: ``Su Bebe,'' the first Spanish-language publication designed to answer the needs of expectant and new parents in Los Angeles County, is available free to pregnant women at more than 200 distribution outlets - including hospitals, HMOs, individual practitioners and government outreach programs such as the Women, Infants and Children Program. The 56-page magazine focuses on local services and resources, as well as prenatal and infant care education. To receive ``Su Bebe'' by mail, call Four Corners Publishing at (310) 444-0184.

Putting feet first: ``The Foot Health Guide'' addresses eight common foot problems, how they're caused and how to treat them. Among the problems discussed in the guide are tired, aching feet; corns and calluses; athlete's foot; and lower back pain. Request the free, pocket-size guide by sending a postcard with your name and address to: Dr. Scholl's Foot Health Guide, P.O. Box Y-6148, Department 96P, Young America, Minn., 55558-6148.

CAPTION(S):

2 Photos

Photo: (1) no caption (Book cover - THE LICE-BUSTER BOOK )

Software provides feed cost savings with phytase; Danisco developed Phycheck, a program that gives nutritionists greater flexibility when formulating corn-based broiler diets with phytase and offers producers greater profitability through feed cost savings.(Nutrition & Health: Poultry) - Feedstuffs

IN 2003, Danisco Animal Nutrition launched Phyzyme XP, the first new generation Escherichia coli phytase produced in yeast Schizosaccharomyces pombe.

This new generation E. coli phytase has been proven to be at least 20% more effective than fungal phytases at releasing phosphorus and has shown further improvements in calcium, energy and amino acid release. The benefits to the poultry producer are even greater feed cost savings and reduced costs associated with environmental management.

Efficacy

Compared to fungal phytases, this new generation E. coli phytase is more resistant to breakdown by the animal's own proteases as well as having a higher relative activity over a wider pH range. This means the new generation phytase is more effective throughout the digestive tract compared to other leading phytase products (Tables 1 and 2).

Phytase

Phytate is not only a potential phosphorus source but also an anti-nutrient that can bind other costly nutrients, reducing the supply of energy and amino acids to the animal. The diet digestibility is reduced because these bound nutrients are less available.

As the level of dietary phytate increases, the digestibility of the diet is reduced (Figure 1).

[FIGURE 1 OMITTED]

Phytases release phytate-bound nutrients. This new generation E. coli phytase releases more energy and amino acids as dietary phytate levels increase (Figure 2).

[FIGURE 2 OMITTED]

Traditional use of 'fixed' nutrient matrix values for phytase in the feed formulation fails to consider that the response to phytase will vary with factors such as dietary phytate level, bird age and phytase dose rate.

Feed cost savings

Traditionally, phytases tend to be included in the feed at fixed inclusion rates. With increasingly competitive phytase prices, there will be cases where higher inclusion of phytase can release more phytate-bound nutrients, offering a higher return on investment to the feed producer (Figure 3).

[FIGURE 3 OMITTED]

To help nutritionists establish the most economic use of phytase in their feeds, Danisco has developed the Phycheck service. This service includes a unique software program initially focused on broiler feeds that calculates specific matrix values for phosphorus, calcium, amino acids and energy according to phytase dose rate, dietary phytate level and bird age.

By using these scientifically proven matrix values, nutritionists can op timize phytase in their diet formulations to maximize feed cost savings.

Scientific results

The software program is derived from extensive digestibility and bird performance trials conducted in the U.S., Canada, Brazil, U.K. and Australia/New Zealand that cumulatively contributed more than 100 individual data points.

The diets used in the trials were corn/soy based and varied in phytate level by using higher phytate raw materials such as rice bran and canola meal. The new generation E. coli phytase was added to the diets at 250, 500, 750 or 1,000 phytate units (FTU) per kilogram of feed. Daily gain, feed intake and feed conversion were measured, together with energy (AME), ileal amino acid digestibility and phosphorus and calcium retention at 21 and 42 days of age.

The digestibility and performance results were compared to birds fed diets reduced in phosphorus and calcium with no phytase supplemented.

A 'multi-factorial model' was then developed to describe the bird responses--like improvements in AME and amino acid digestibility--according to phytase dose rate (250-1,000 FTU/kg feed), dietary phytate phosphorus level (0.23-0.33%) and bird age (0-21 or 22-42 days).

Phytase improved dietary AME, ileal protein and amino acid digestibility at all concentrations. There were also significant interactions between phytate level and phytase dose rate and other complex interrelationships. The software accounts for these interrelationships when calculating specific matrix values for phosphorus, calcium, amino acids and energy.

The digestibility data supported Danisco's bird performance trials, indicating that this new generation E. coli phytase liberates at least 20% more digestible phosphorus than fungal phytases at a dose of 500 FTU/kg feed. Calcium release was around 10% higher for the same phytase addition rate. Amino acid and energy release was also higher and was influenced by the complex interaction of phytase dose rate, dietary phytate phosphorus level and bird age.

Efficacy

Matrix values derived from the new software were validated in broiler performance trials in the U.S. (Auburn University) and the U.K. (ADAS) using corn/soybean meal based-diets.

These trials demonstrated that adding the new generation E. coli phytase at varying levels to diets reduced in phosphorus, calcium, energy and amino acids (according to Phycheck) maintained performance, offering considerable feed cost savings.

Feed cost savings

In today's challenging and increasingly competitive market, broiler producers can benefit from this new advancement in phytase optimization. Producers aiming to maximize feed cost savings can now apply phosphorus, calcium, energy and amino acid matrix values to phytase to fully exploit its potential, without risk to bird performance.

What could this mean for broiler producers in the U.S.? According to recent feed ingredient prices, and assuming 'simple' corn/soybean meal-based diets, feed costs could be reduced by $6 per ton--$1.50-2.00 more than using fungal phytases with fixed matrix values for calcium, phosphorus, energy and amino acids.

As phytase use continues to grow throughout the world and product choice for poultry producers and feed manufacturers becomes more diverse, so does the need for reliable tools to compare and optimize phytase use for maximum economic benefit.

JANET REMUS *

Corn germ byproduct may serve as fat source for finishing cattle. (Nutrition and Health/Beef).(full-fat corn germ use in finishing diets ) - Feedstuffs

With the increased production of ethanol in the Midwest, many corn byproducts have received much attention as potential ingredients for the animal feed industry.

At Kansas State University's 2003 Cattlemen's Day last month, S.P. Montgomery, J.S. Drouillard, J.J. Sindt, M.A. Greenquist, B.E. Depenbusch, E.J. Good, E.R. Loe, M.J. Sulpizio and T.J. Kessen presented research on the use of full-fat corn germ (FFG) as a lipid source in finishing diets containing steam-flaked corn as well as the effects of added vitamin E in finishing diets containing various concentrations of added fat on finishing performance and carcass characteristics of beef heifers.

They said FFG, a byproduct of corn wet milling, has traditionally been used for corn oil production and contains 45% lipid and 12% crude protein (dry matter basis). They noted that FFG has been used successfully as a fat source in finishing diets containing dry-rolled corn.

Procedures

Montgomery et al. utilized 888 crossbred beef heifers with an initial weight of 837 lb. in the trial. The heifers were processed (including vaccination against respiratory and clostridial diseases and implanting) over eight days. Immediately following processing, heifers were randomly assigned to dirt-surfaced pens so that each pen contained between 14 and 23 heifers each, depending on pen size. Each pen served as the experimental unit, and pens were blocked by date of implanting.

They reported that the dietary treatments consisted of finishing diets formulated to provide no added fat (Control), 4% tallow or 10% or 15% FFG on a dry matter basis (10% FFG and 15% FFG, respectively) with or without 2,000 IU of additional vitamin E per heifer daily. Treatments were assigned randomly to pens within each block.

Heifers were maintained on the control diet until all heifers were processed, upon which time heifers were weighed and their respective dietary treatments were initiated, the researchers said. Diets were fed once daily and were offered for ad libitum consumption.

At the end of the 105-day finishing period, each pen of heifers was weighed and transported to a commercial slaughter facility. Hot carcass weights and the incidence of liver abscesses were recorded at time of slaughter, Montgomery et al. reported, and other carcass traits were measured following a 24-hour chill.

Results, discussion

The effects of fat addition and FFG on finishing performance and carcass characteristics are shown in Table 1. Fat addition decreased (P < 0.01) dry matter intake (DMI) and tended (P < 0.09) to improve, gain efficiency when compared to the control, Montgomery et al. reported, although marbling score and the percentage of carcasses grading U.S. Department of Agriculture Choice were decreased (P < 0.01) in response to supplemental fat. They said it was not known whether this was an effect of decreased feed intake or an effect of fat on marbling.

Tallow and 10%FFG yielded similar finishing performance and carcass characteristics, they said, which suggests that including FFG at 10% in finishing diets can effectively replace 4.2% tallow as a fat source.

According to the researchers, increasing FFG decreased DMI (linear, P < 0.01), daily gains (linear, P < 0.03), final bodyweight (linear, P < 0.02), hot carcass weight (linear, P < 0.02), as well as marbling score (linear, P < 0.01) and the number of carcasses grading USDA Choice (linear, P < 0.01).

Mongtomery et al. reported that gain efficiency was improved when 10% FFG was added to the diet, but this benefit was lost when it was increased to 15% of the diet (quadratic, P < 0.03). They said increasing FFG tended (linear, P < 0.06) to reduce the incidence of liver abscesses, which could be a result of decreased feed intake or possibly some antimicrobial property of the FFG that suppressed the growth of bacteria responsible for liver abscesses.

According to the group, vitamin E addition did not affect finishing performance but did marginally increase (P < 0.04) the number of carcasses grading USDA Select and decrease (P < 0.05) the number of carcasses grading USDA Standard (Table 2). They said this effect might have been due to the antioxidant properties of vitamin E.

So what?

According to Montgomery et al., this study suggests that FFG can serve as a supplemental fat source for finishing cattle and result in a performance response similar to that obtained from an equal amount of tallow.

High moisture tempering

Also at this year's Kansas State Cattlemen's Day, B.E. Depenbusch, J.S. Drouillard, R.K. Phebus, A.B. Broce, C.M. Gordon and J.J. Sindt presented their research on the role of high-moisture tempering in the spread of pathogens.

They said visual observations suggest that houseflies (Musca dornestica) have an affinity for tempered steam-flaked corn compared to nontempered steam-flaked corn. High-moisture tempering of whole shelled corn prior to flaking resulted in significantly higher moisture content (37%) of the flaked corn as compared to industry standards (20%).

Depenbusch et al. pointed out that recent research has shown that houseflies are a common carrier of pathogens such as salmonella and Escherichia coli O157:H7. They said, in light of these observations, one might conclude that tempering steam-flaked corn may attract more flies and pathogens resulting in higher number of foodborne pathogens shed by the cattle.

To test their theory, they tempered whole shelled corn by mixing corn with water in a stationary mixer periodically for 24 hours. The tempered corn was then flaked to a bulk density of 26 lb./bu., resulting in final moisture content of 37%. Nontempered whole shelled corn was also flaked to the same bulk density as the tempered steam-flaked corn samples. To determine initial bacterial counts, 250-g aliquots of tempered and nontempered corn were sampled directly from the steam faker following completion of the flaking process and immediately refrigerated.

Depenbusch et al. said additional samples of each corn treatment was acquired and left exposed to the environment and flies for the next 21 hours; samples were then aseptically mixed completely and thoroughly by hand. Random grab samples were used to acquire a 250-g aliquot, which was refrigerated prior to enumeration of microbial populations.

To determine whether tempering and exposure to flies had any effect on fecal shedding, Depenbusch et al. fed steers total mixed rations containing either tempered or nontempered steam-flaked corn and collected fecal samples on day 56 of the feeding period.

According to. these researchers, tempered steam-flaked corn samples had numerically higher generic E. coli coliforms, total coliforms and total plate counts. Non-E. coli coliforms, generic E. coli coliforms, total coliforms and total plate counts were all numerically higher for the tempered total mixed rations than for their nontempered counterparts, they reported.

Also, fly exposure significantly increased non-E. coli coliforms, genenc E. coli, total coliforms and total plate counts for the tempered and non-tempered steam-flaked corn samples (P < 0.05) but not the total mixed rations.

When fed to steers, Depenbusch et al. reported that those cattle that received nontempered rations actually shed more acid-resistant coliforms than cattle fed rations containing tempered steam-flaked corn. They said this was contrary to their hypothesis because cattle on the tempered rations had a greater intake of coliforms.

U STUDY: CORN ETHANOL NO BETTER THAN GAS; The U research that the biofuel takes a heavy toll on the environment and health was greeted by skepticism by ethanol producers.(NEWS) - Star Tribune (Minneapolis, MN)

Byline: TOM MEERSMAN; STAFF WRITER

Corn ethanol is no better fuel than gasoline, and it may even be worse for air quality, according to a new University of Minnesota study.

The study, released Monday, is the first one to estimate the economic costs to human health and well-being from three different fuels -- gasoline, corn-based ethanol and cellulosic (plant-based) ethanol -- its authors say.

Scientists and economists looked at life-cycle emissions of growing, harvesting, producing and burning different fuels, and concluded that ethanol made from switchgrass and other plant materials is far better than either corn ethanol or gasoline.

'Our study shows that if we're really going to make choices in the best interest of the public, we need to look not only at what's cheapest to produce, but what are the costs to the public in terms of environmental and health effects,' said Jason Hill, research associate in applied economics and a resident fellow at the U's Institute on the Environment.

Ethanol is a $6 billion industry in Minnesota, according to state estimates. The Minnesota Department of Agriculture calculated that the 17 ethanol plants in the state produced 670 million gallons of ethanol in 2007 and provided 26,000 'direct impact' jobs.

The university's study will be published in this week's issue of the Proceedings of the National Academy of Sciences and was posted online on Monday afternoon at the PNAS site.

No love from ethanol backers

Ethanol advocates said they haven't seen the study and will need time to understand how the conclusions were reached.

'I'm stifling a yawn,' said Mark Hamerlinck, communications director for the Minnesota Corn Growers Association. 'It would be news if the university had anything positive to say about corn ethanol. It's how they make a living over there.'

His comment was an apparent reference to a controversial paper published by the university a year ago that said the exploding demand for biofuels will change the landscape and worsen global warming if farmers around the world clear forests and grasslands to grow more corn, soybeans and sugar cane.

In the latest study, the health concern comes mainly from microscopic particulates in the air, which are produced when fossil fuels are burned. They accumulate in the lungs and can cause a variety of respiratory and other problems.

The fine particles, similar to soot, are produced from the earliest stages by the farm equipment used to plant, fertilize and harvest the corn, or the drills and pumps used to extract and transport crude oil to refineries.

From 19 cents to $1.45 a gallon

The study concluded that the total environmental and health costs of making a gallon of gasoline was about 71 cents, compared with a range of 72 cents to $1.45 for corn-based ethanol, and 19 to 32 cents for cellulosic ethanol, depending upon the technology and type of plants used.

A major difference between corn-based and 'cellulosic' ethanol is that biorefineries producing corn ethanol need to purchase electricity, while those producing cellulosic ethanol can burn the plant waste and generate their own power, the study said. That adds another source of air pollution to corn ethanol as well.

Whatever its benefits, Hamerlinck said, cellulosic ethanol cannot yet be made on a large scale.

He doesn't understand why researchers 'bash' corn ethanol. It's a domestic source of fuel, he said, and farmers should be given more credit for developing and investing in it.

'If folks in their ivory towers at the university continue to pummel this industry, it doesn't do anyone any good' except perhaps for oil-rich countries around the world, Hamerlinck said.

Hill said that the study is not biased against corn ethanol.

'We're not coming at this with any preconceived notions of what the best fuel should be,' he said. 'We're just investigating and trying to take an independent look at the underlying factors and consequences of global energy and food use.'

Net energy system may have benefits for performance.(Nutrition And Health/Swine) - Feedstuffs

Net energy provides the closest estimate of the true energy available for maintenance and production. The nutritional and economic ranking of feedstuffs depends on the energy system. For practical purposes, the superiority of the net energy System (in comparison with the digestible or metabolizable systems) for predicting performance and carcass quality can be demonstrated.

The effect of reducing the protein level in diets for growing pigs has been investigated in a number of experiments, showing no detrimental effect on performance and nitrogen retention--but markedly reduced nitrogen excretion--when sufficient amounts of the essential amino acids are supplied to this type of diet (Bourdon et al., 1995; Canh et al., 1998). However, there is a trend for fatter carcasses when pigs are fed low protein diets supplemented with amino acids (Kerr et al., 1995; Tuitoek et al., 1997; Raj et al., 2000).

Lowering the dietary crude protein (CP) level is accompanied by a more efficient utilization of energy, due to a significant reduction in heat production and energy lost in urine. This results in a greater quantity of retained energy with low protein diets at identical digestible (DE) or metabolizable energy (ME) intake. The net energy (NE) system is able to take this effect into account. The superiority of the NE system for predicting performance and carcass quality has been confirmed especially when reduced protein diets are fed (Dourmad et al., 1993; Le Bellego et al., 2000 and 2001).

The following article will discuss the applicability of the NE system in comparison to the DE and ME system. Special emphasis is placed on the effects of energy system on performance, carcass quality, nitrogen excretion as well as least-cost diet formulation.

Comparison of energy systems

In theory, a reduced protein, amino acid-supplemented diet should be nutritionally superior to an all-intact protein diet. By feeding low-protein, amino acid-supplemented diets with less excess of amino acids, fewer amino acids are deaminated, converted to urea and excreted in the urine. As a result, less energy is needed for these energy requiting metabolic processes. However the savings in energy as a result of not having to deaminate excess amino acids is, in some cases, simply deposited as body fat in pigs fed low-protein diets. The reason for the increase in carcass back fat is likely due to a higher NE content of the low-protein, amino acid-supplemented diet.

Although the ME content in corn and soybean meal is the same (3,650 kcal/kg; Table 1), the NE content in corn is considerably higher (2,970 versus 1,930 kcal/kg; Table 1). Therefore in the case of a corn-soybean meal diet a reduction of 2 percentage units in dietary protein results in an increase in dietary NE content by about 2%.

The data in Table 1 shows that the efficiency of utilization of DE or ME for NE is not constant. Therefore, the hierarchy among feedstuffs is different in the DE, ME or NE system. Comparing some typical feedstuffs clearly illustrates that both the DE and ME system in general overestimate the energy value of high-protein and high-fiber feedstuffs, whereas feedstuffs high in starch or fat are underestimated.

NE values are defined as ME minus heat increment associated with metabolic utilization of ME and the energy cost of ingestion and digestion of the feed (Noblet, 1996). NE values provide the closest estimate of the 'true' energy available for maintenance and production purposes.

Energy utilization, performance

The increase in fat deposition in pigs fed low-protein, amino acid-supplemented diets can be prevented by maintaining the same ratio of digestible amino acids to NE as in the intact protein diet (Dourmad et al., 1993; Le Bellego et al., 2000 and 2001).

In a performance trial (Canh et al., 1998), the effect of three levels of dietary protein (16.5, 14.5 and 12.5%) on performance and carcass characteristics of growing-finishing pigs (52 to 104 kg bodyweight) were examined. All diets were formulated to contain 0.76 g digestible lysine/MJ NE. The level of dietary CP did not influence feed intake, daily gain, .feed conversion and carcass characteristics (Table 2, p. 13).

With the reduction in dietary CP level--at similar DE or ME intakes--Le Bellego et al. (2001) observed a significant reduction in heat production and urinary energy loss (Table 3).

The significantly lower heat production was due to a reduction of the thermic effect of feed, which is reduced when the dietary protein level is lowered, and corresponded to 18.7 ,and 15.2% of ME intake for the high- and low-CP diets, respectively. Due to the reduction of urinary energy losses and heat production, the efficiencies of DE and ME for NE are improved when dietary CP level is reduced (Table 4). The NE system is able to take this effect into account.

For each 1 g decrease in protein intake (and its replacement by starch), urinary energy and heat loss are reduced 3.5 and 7.0 kJ, respectively (Le Bellego et al., 2001).

Le Bellego et al. (2000) conducted a study to determine the effect of low-protein diets with or without fat addition on growth performance and body composition of growing-finishing pigs in thermoneutral (22[degrees]C) or high (29[degrees]C) ambient temperature.

Daily weight gain, lean meat and fat tissue (Table 4) were not affected by treatment. Feed conversion was significantly affected by diet with best feed conversion observed for the low CP + fat diet.

The effect of heat stress on performance of pigs is shown in Table 5. Feed intake was significantly reduced 15% by increasing the ambient temperature from 22 to 29[degrees]C. Weight gain was not affected by diet but by temperature with a significant reduction of 13% at high ambient temperature. Feed conversion was not affected by temperature but by diet with a significant advantage for the low CP and low CP + fat diets. The increase of ambient temperature also resulted in a reduction in fat tissue (-8%).

Pigs under heat stress showed a significant reduction in feed intake and daily gain. However, the depression in feed intake (Figure 1) and weight gain (Figure 2) tended to be higher for the high CP diet-than for the low CP or low CP + fat diet.

[FIGURES 1-2 OMITTED]

This effect holds especially true for the finishing phase (64-100 kg bodyweight), showing a clear advantage of feeding low-protein diets under heat stress conditions.

Practical diet formulation

For least-cost formulation purposes, it is important to predict the energy values of the different feed ingredients. Today, it is well accepted that NE is the closest estimate of the true energy value of ingredients. Since the NE value of feedstuffs and diets cannot be measured routinely, regression equations can be used for predicting the dietary NE content from DE or ME and chemical characteristics (Table 6). The NE value of free amino acids is 75% of their gross energy content (Noblet et al., 1994).

It is important to express the energy requirement of the animal on the same basis as the energy value of the feed. In order to transfer energy requirements expressed on a DE or ME basis to NE requirements, one should simply multiply the present DE or ME specification by 0.71 or 0.74, respectively (Noblet et al., 1994).

Results of least-cost formulation will depend on the energy system. For instance, diets formulated based on the NE concept generally have a lower CP content and subsequent higher supplementation of amino acids, while dietary costs can be reduced.

The potential effect of the energy system on least-cost formulation is shown in Table 7. In this example, corn-soybean meal diets were formulated based on ME or NE for the growing (25-40 kg bodyweight) and finishing (70-105 kg bodyweight) phases, respectively.

Within each phase, diets were formulated on ME basis and standardized digestible amino acids. In the growing phase, diet 1 was formulated to contain 13.5 MJ/kg ME, which resulted in dietary NE and CP contents of 9.88 MJ/ kg and 18.7%, respectively.

Formulating diet 2 with the same ingredients to a NE content of 9.88 MJ/ kg as well as equal levels of amino acids compared with diet 1 resulted in a slight reduction in dietary CP content. The actual diet composition moved to a lower level of soybean meal with elevated inclusion levels of corn and amino acids.

The same principles were applied and observations were made for the finishing phase (diet 3 versus diet 4).

The economic benefit of formulating diets based on NE versus ME can also be deducted from Table 7. Feed costs are reduced about 2% in both phases when diets are formulated on NE basis.

Conclusions

NE provides the closest estimate of the true energy available for maintenance and production. The nutritional and economic ranking of feedstuffs depends on the energy system; therefore, the result of least-cost formulation depends on the energy system as well. DE and ME systems systematically overestimate the energy content of protein-or fiber-rich feeds and underestimate the energy value of starch- or fat-rich feeds.

For practical purposes, the superiority of the NE system (in comparison with the DE or ME system) for predicting performance and carcass quality--especially when reduced-protein diets are fed--can be demonstrated. Diets formulated according to the NE concept are characterized by a lower CP content, a higher supplementation of amino acids and reduced dietary costs.

 TABLES  1. Energy values (kcal/kg) of some ingredients in DE, ME and NE system (Noblet et al., 1994)  Ingredients    DE     ME     NE    ME:DE  NE:ME  Corn          3,780  3,650  2,970  0.97   0.81 Wheat         3,870  3,780  2,900  0.98   0.77 Tapioca       3,790  3,720  3,080  0.98   0.83 Peas          3,880  3,750  2,640  0.97   0.70 Soybean meal  3,910  3,650  1,930  0.93   0.53  2. Effect of reducing dietary protein on performance and carcass characteristics of pigs (52-104 kg bodyweight; Canh et al., 1998)                                High     Medium     Low      Diet Dietary CP (%)               (16.5)    (14.5)    (12.5)   effect  Weight gain, g per day        805       805       797       NS Feed intake, g per day      2,249     2,245     2,257       NS Feed:gain ratio                 2.75      2.75      2.79    NS Back fat thickness, mm         15.2      15.4      15.9     NS Lean meat, %                   57.2      57.1      56.7     NS Muscle thickness, mm           56.9      56.5      57.0     NS Digestible lysine, g/MJ NE         0.76 for all treatments  TABLES  3. Effect of dietary CP level on energy balance and utilization in growing pigs (50-70 kg bodyweight; Le Bellego et al., 2001)  CP (%)                            18.9        16.7        14.6  Energy intake (2)  DE intake                         2.74        2.75        2.76  ME intake                         2.61        2.65        2.67  Urinary energy, % DE intake       3.80 (a)    3.32 (a)    2.87 (c)  Heat production, % ME intake     56.7 (a)    55.2 (ab)   53.2 (bc)  Thermic effect of feed,   % ME intake                     18.7        16.9        16.9 Energy utilization  NE/DE, %                         69.6 (a)    72.1 (b)    73.2 (bc)  NE/ME, %                         72.8 (a)    74.9 (ab)   75.8 (b)  N[E.sub.measured]/   N[E.sub.calculated] (3), %      97.9       100.0       100.3  CP (%)                             12.3          Diet effect (1)  Energy intake (2)  DE intake                          2.67               NS  ME intake                          2.60               NS  Urinary energy, % DE intake        2.27 (d)           **  Heat production, % ME intake      52.8 (c)            **  Thermic effect of feed,   % ME intake                      15.2                NS Energy utilization  NE/DE, %                          74.5 (c)            **  NE/ME, %                          76.6 (b)            **  N[E.sub.measured]/   N[E.sub.calculated] (3), %      101.0                NS  (1) Statistical significance: analysis of variance with diet as main effect. Statistical significance: NS: P > 0.05; **: P < 0.01. Different superscripts indicate significantly different means (P < 0.05).  (2) MJ per day per kilogram [bodyweight.sup.0.60].  (3) Calculated according to Noblet et al. (1994).  4. Effect of low heat increment diets on feed intake, performance and body composition of pigs (27-100 kg bodyweight; Le Bellego et al., 2000)  Temperature                       22[degrees]C Diet CP level (%)         High,        Low,          Low, (27-64 kg BW/             19.7/        15.3/        + fat, 64-100 kg BW)             17.5         12.5       16.4/13.3  Feed intake  g per day              2,752 (a)    2,575 (b)     2,544 (b)  MJ NE per day          28.14 (a)    27.02 (a)     28.26 (a) Performance  ADG, g per day         1,098 (a)    1,057 (a)     1,078 (a)  Feed conv. ratio        2.52 (a)     2.44 (ab)     2.36 (bc) Body composition at slaughter  Lean meat,   % of carcass           58.7 (a)     59.7 (ac)     59.7 (ac)  Fat tissues,   % of carcass           25.7 (a)     24.1 (ac)     24.5 (ac)  Temperature                       29[degrees]C Diet CP level (%)         High,        Low,           Low, (27-64 kg BW/             19.7/        15.3/         + fat, 64-100 kg BW)             17.5         12.5        16.4/13.3  Feed intake  g per day              2,265 (c)    2,243 (c)     2,202 (c)  MJ NE per day          23.16 (c)    23.55 (bc)    24.45 (b) Performance  ADG, g per day           930 (b)      917 (b)       955 (b)  Feed conv. ratio        2.46 (ab)    2.45 (ab)     2.30 (c) Body composition at slaughter  Lean meat,   % of carcass           61.4 (b)     60.6 (bc)     60.3 (bc)  Fat tissues,   % of carcass           22.0 (b)     23.1 (bc)     23.3 (bc)  Temperature Diet CP level (%)               Statistics (1) (27-64 kg BW/                                   Diet x 64-100 kg BW)           Diet         Temp.       Temp.  Feed intake  g per day               **           **          NS  MJ NE per day           **           **          NS Performance  ADG, g per day          NS           **          NS  Feed conv. ratio        **           NS          NS Body composition at slaughter  Lean meat,   % of carcass           NS           **           *  Fat tissues,   % of carcass           NS           **          NS  Diets based on wheat, corn and soybean meal, with 0.85 g standardized ileal digestible lysine per MJ NE.  (1) Statistical significance: analysis of variance with diet as the main effect. Statistical significance: NS: P > 0.05; *: P < 0.05; **: P < 0.01. Different superscripts indicate statistically different means (P < 0.05).  5. Effect of heat stress on performance of pigs (27-100 kg bodyweight; Le Bellego et al., 2000)  Temperature                   22[degrees]C   29[degrees]C  Feed intake, g per day        2,624 (1)      2,237 Daily bodyweight gain, g      1,078 (1)        934 Feed conversion                   2.44           2.40 Lean meat, % carcass             59.4 (1)       60.8 Fat tissues, % carcass           24.8 (1)       22.8                                29 vs. 22[degrees]C, Temperature                      % difference  Feed intake, g per day              -15 Daily bodyweight gain, g            -13 Feed conversion                      +2 Lean meat, % carcass                 +2 Fat tissues, % carcass               -8  (1) P < 0.01.  6. Prediction of NE content (kcal/kg DM) of diets from DE or ME content (kcal/kg DM) and/or chemical characteristics (g/kg DM; Noblet et al., 1994) (1)  Number                         Equation [R.sup.2]  1    NE = 0.703 x DE  + 1.58 x EE + 0.47 x        ST - 0.97 x CP - 0.98 x CF                          0.97 2    NE = 0.700 x DE  + 1.61 x EE + 0.48 x        ST - 0.91 x CP - 0.87 x ADF                         0.97 3    NE = 0.730 x ME  + 1.31 x EE + 0.37 x        ST - 0.67 x CP - 0.97 x CF                          0.97 4    NE = 0.726 x ME  + 1.33 x EE + 0.39 x        ST - 0.62 x CP - 0.83 x ADF                         0.97 5    NE = 2875 + 4.38 x EE + 0.67 x        ST - 5.50 x Ash - 2.01 x (NDF - ADF) - 4.02 x ADF   0.93  (1) EE, ST, CF, ADF, NDF for ether extract, starch, crude fiber, acid detergent fiber and neutral detergent fiber, respectively.  7. Effect of energy system on least-cost formulation                                               Growing phase                                           (25-40 kg bodyweight)  Ingredients (%)                       Diet 1 (ME)    Diet 2 (NEb)  Corn                                     60.06          66.16- Wheat middlings                          10.00           5.83 Soybean meal (48% CP)                    24.86          24.67 DL-methionine (99%)                       0.04           0.04 L-lysine hydrochloride                    0.11           0.12 L-threonine                              --             -- Soybean oil                               1.82          -- Dicalcium phosphate                       1.01           1.14 Calcium carbonate                         0.78           0.71 Sodium chloride                           0.32           0.33 Premix                                    1.00           1.00  Nutrients (%)  ME, MJ/kg (kcal/kg)                 13.50 (3,230)   13.31 (3,180) NE, MJ/kg (kcal/kg)                  9.88 (2,360)    9.88 (2,360) CP                                      18.7            18.5 Std. digestible lysine (a)               0.90            0.90 Std. digestible methionine (a)           0.31            0.31 Std. digestible methionine + cysteine (a)                0.57            0.57 Std. digestible threonine (a)            0.59            0.59 Std. digestible tryptophan (a)           0.17            0.17 Cost ($/100 kg) (c)                     13.59           13.38                                              Finishing phase                                          (70-105 kg bodyweight)  Ingredients (%)                       Diet 3 (ME)     Diet 4 (NE)  Corn                                     58.17          63.97 Wheat middlings                          20.00          19.57 Soybean meal (48% CP)                    17.30          13.06 DL-methionine (99%)                       0.01           0.03 L-lysine hydrochloride                    0.07           0.20 L-threonine                              --              0.06 Soybean oil                               1.40          -- Dicalcium phosphate                       0.80           0.89 Calcium carbonate                         0.95           0.93 Sodium chloride                           0.31           0.31 Premix                                    1.00           1.00  Nutrients (%)  ME, MJ/kg (kcal/kg)                  13.00 (3,100)   12.75 (3,050) NE, MJ/kg (kcal/kg)                  9.62 (2,300)    9.62 (2,300) CP                                      16.4            15.0 Std. digestible lysine (a)               0.71            0.71 Std. digestible methionine (a)           0.25            0.25 Std. digestible methionine + cysteine (a)                0.49            0.48 Std. digestible threonine (a)            0.50            0.50 Std. digestible tryptophan (a)           0.15            0.14 Cost ($/100 kg) (c)                     12.11           11.91  (a) Ratios of standardized digestible methionine + cystine, threonine and tryptoptnan to lysine were at least 62:, 65: and 19:100 or 65:, 70: and 19:100 for the growing and finishing period, respectively, with methionine:methionine + cysteine set at 55:100.  (b) Formulated to contain equal NE and standardized digestible amino acid levels as diet formulated on ME.  (c) Basis: U.S. ingredient prices, spring 2001. 

REFERENCES

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Canh, T.T., A.J.A. Aarnink, J.B. Schutte, A. Sutton, D.J. Langhout and M.W.A. Verstegen. 1998. Dietary protein affects nitrogen excretion and ammonia emission from slurry of growing-finishing pigs. Livest. Prod. Sci. 56:181-191.

Dourmad, J.Y., Y. Henry, D. Bourdon, N: Quiniou and D. Guillou. 1993. Effect of growth potential and dietary protein input on growth performance, carcass characteristics and nitrogen output in growing-finishing pigs. In: M.W.A. Verstegen, L.A. den Hartog, G.J.M. van Kempen and J.H.M. Metz (eds.). Nitrogen flow in pig production and environmental consequences. Pudoc. Wageningen, The Netherlands. p. 206-211.

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Le Bellego, L., J. van Milgen, M. Rademacher, S. van Cauwenberghe and J. Noblet. 2000. Utilization of low heat increment diets at high ambient temperatures in growing pigs. J. Anita. Sci. 78 (Suppl. 1):186.

Le Bellego, L., J. van Milgen, S. Dubois and J. Noblet. 2001. Energy utilization of low-protein diets in growing pigs. J. Anim. Sci. 79:1259-1271.

Noblet, J. 1996. Digestive and metabolic utilization of dietary energy in pig feeds: Comparison of energy systems. In: P.C. Garnsworthy, J. Wiseman and W. Haresign (eds.). Recent advances in animal nutrition. Nottingham University Press, Nottingham, U.K. p. 207-231.

Noblet, J., H. Fortune, X.S. Shi and S. Dubois. 1994. Prediction of net energy value of feeds for growing pigs. J. Anita. Sci. 72:344-354..

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Tuitoek, K,, L.G. Young, C.F.M. de Lange and B.J. Kerr. 1997. The effect of reducing excess dietary amino acids on growing-finishing pig performance: An evaluation of the ideal protein concept. J. Anita. Sci. 75:1575-1583.

Optimum CP, WCGF levels suggested for finishing diets. (Nutrition and Health/Beef).(crude protein, wet corn gluten feed) - Feedstuffs

As the corn milling industries have continued to expand production, interest in using coproducts of these processes as livestock feedstuffs has also increased.

Many research trials, particularly at Midwest universities, are being conducted to determine the proper use of these feedstuffs to optimize animal performance.

One such experiment, reported in the 2002 Nebraska Beef Report, was conducted by Hushton Block, graduate student; Casey Macken, research technician, and Terry Klopfenstein, professor in the animal science department at the University of Nebraska, Lincoln, and Rob Cooper and Rick Stock of Cargill Corn Milling, Blair, Neb.

The objectives of their research were to determine the optimum level of corn steep liquor to include in yearling steer finishing diets based on steam-flaked corn and corn bran and to determine the optimum level of wet corn gluten feed (WCGF) and crude protein (CP) to include in steam-flaked corn finishing diets for steer calves.

According to the researchers, corn steep liquor (with or without distiller solubles) and corn bran (with or without solvent-extracted germ meal) are the primary components of WCGF. They said WCGF alleviates acidosis in dry-rolled corn finishing diets, thereby improving performance. Also, they noted that both steep liquor and WCGF supply degradable intake protein (DIP) as true protein, which may also improve performance compared to urea.

Procedures

Trial 1. Block et al. used 93 yearling steers in a 104-day finishing trial to investigate the effects of steep liquor inclusion level in steam-flaked corn! corn bran-based diets. They pointed out that the steep used in this trial was a combination of steep liquor and distillers solubles.

Treatments for this trial consisted of adding steep at 0, 10 and 20% of dietary dry matter (DM). Twelve pens of steers with seven or eight steers per pen were randomly allotted to the three treatments, resulting in four replicates per treatment, Block et al. said.

Trial 1 diets were formulated to contain (DM basis) a minimum of 13.0% CP, 0.70% calcium, 0.35% phosphorus and 0.70% potassium and included 27 g per ton monensin and 10 g per ton tylosin. Steers were adapted to the final diet by using four adaptation diets containing alfalfa hay at 45, 35, 25 and 15% of DM for three, four, seven and seven days, respectively. Steers were implanted and treated for internal and external parasites on day 1.

Trial 2. In this trial, Block et al. used 18 individually fed yearling steers in a 154-day individual feeding trial to investigate the effect of steep inclusion in steam-flaked corn/corn bran-based diets. Treatments consisted of adding steep at 0 or 10% of diet DM.

Trial 2 diets were formulated to contain a minimum of 13.4% CP, 0.70% calcium, 0.35% phosphorus and 0.70% potassium and included 28 g per ton monensin and 10 g per ton tylosin. Steer intakes were started at 11 lb. DM per day and increased 0.5 lb. DM per day to ad libitum intake Trial 2 steers were implanted on day 1 and re-implanted on day 41.

Trial 3. To investigate the effects of WCGF and CP levels in steam-flaked corn-based diets, the researchers used 360 steer calves in a 166-day finishing trial. They said treatments for this trial consisted of adding WCGF at 0, 20, 30 and 40% and CP levels of 13.0, 13.7 and 14.4% of diet DM. Block et al. pointed out that these CP levels were achieved with urea supplementation.

The researchers noted that the combination of 40% WCGF and 13.0% CP was infeasible due to the CP content of the feed ingredients, which, along with pen availability, resulted in the exclusion of this combination.

According to the report, CP variation in the feed ingredients resulted in 'higher-than-anticipated CP levels' (as reflected in the column headings for Table 2).

The researchers said the diets for this trial were formulated to contain (DM basis) a minimum of 0.70% calcium; 0.35% phosphorus and 0.70% potassium and included 27 g per ton monensin and 10 g per ton tylosin. Steers were vaccinated for respiratory disease, treated for internal and external parasites and implanted on day 1. On day 70, steers were retreated for external parasites and re-implanted.

Results

Trial 1. The researchers reported that the inclusion of steep at 0, 10 or 20% of diet DM did not affect (P > 0.05) feedlot performance or measured carcass evaluation variables (data not shown).

However, they noted that observed numerical differences suggested that hot carcass weight (HCW), average daily gain (ADG) and feed efficiency tended toward quadratic patterns in response to increased levels of steep inclusion. Block et al. said there was a numerical benefit in HCW (+3%), ADG (+9%) and feed efficiency (+5%) to increasing the inclusion of steep from 0 to 2 10% of DM. Conversely, they noted that increasing steep from 10 to 20% resulted in reduced ADG (-1%), no benefit for HCW (0%) and decreased feed efficiency (-3%).

Trial 2. The inclusion of steep at 10% of diet DM did not affect (P > 0.05) the feedlot performance parameters in this trial, Block et al. pointed out (Table 1). Similar to the trend observed in trial 1, they said the observed numerical values for feed efficiency in trial 2 tended to be improved with inclusion of steep at 10% of diet DM.

Therefore, Block et al. concluded that the results of these trials suggest that the inclusion of steep at 10% of diet DM in steam-flaked corn/corn bran-based finishing diets may be beneficial in improving feed efficiency.

Trial 3. For the third trial, the researchers reported that HCW, ADG and feed efficiency (Table 2) responded to increasing levels of WCGF in a quadratic fashion (P < 0.05) and dry matter intake (DMI) responded in a linear fashion (P < 0.05).

As a result of increasing CP levels, HCW, ADG and feed efficiency responded in a linear fashion (P < 0.05), the researchers said.

According to the researchers, net energy (NE) levels for trial 3 were calculated from feed energy values (Table 3). They conducted a nonlinear analysis using the 20 and 30% WCGF levels, and they determined a breakpoint of 8.6% DIP for ADG and 8.4% DIP for feed: gain.

The researchers predicted metabolizable protein and DIP levels for trial 3 (Table 3) according to the 2000 National Research Council (NRC) beef model using microbial efficiency values determined by balancing DIP requirements. They said inadequate DIP supply was indicated for 20% WCGF at 13.4% CP and 30% WCGF at 13.5% CP.

According to Block et al., the NRC predictions suggested that the CP requirement for the 20 and 30% WCGF levels was approximately 13.7%. There was a small response in efficiency (Table 2) for the 20% level of WCGF when CP was increased to levels more than 14.1%, but no response occurred with a similar increase for the 30% WCGF level, they said.

Block et al. said these results indicate that the level of WCGF to include in steam-flaked corn-based finishing diets to optimize ADG, feed efficiency and HCW of steer calves is in the range of 20-30% of dietary DM.

The researchers noted that the effect of WCGF on observed mean animal performance responses should only be evaluated at the higher CP levels where DIP is not limiting. Predicted treatment means were remarkably similar for HCW and ADG (not shown) between the 20 and 30% WCGF treatments.

Additionally, they said, if WCGF is priced lower than corn, WCGF's lower price may justify higher inclusion levels as the economic benefits may outweigh small performance losses.