Research Reports

Effect of different dietary protein levels on nitrogen retention in weanling, growing, and finishing pigs

Soybean meal (SBM) is the primary plant-protein source in diets for pigs and provides both amino acids (AA) and energy to the diets. Current estimates for net energy in SBM are less than for cereal grains, based on the assumption that there is more nitrogen to be deaminated if ingredients are high in protein because deamination and excretion of nitrogen via the urea cycle are energy-requiring processes, and therefore, reduce energy efficiency. It has been suggested that pigs retain only 45 to 50% of absorbed nitrogen, which corresponds to 40 to 45% of ingested nitrogen. Modern genotypes of pigs, however, have improved the capacity for protein synthesis and may retain more nitrogen than older genotypes, which would result in less AA deamination and, therefore, less energy loss to deaminate AA and excrete nitrogen. Indeed, results of recent research indicate that pigs fed corn-SBM based diets retain more than 60% of ingested nitrogen, indicating that protein retention by modern genotypes of pigs is more efficient than by older genotypes. It is likely that as breeding companies have selected for leaner pigs, they have also selected genotypes that are more efficient in converting dietary protein into body protein. It is, however, not known if the greater nitrogen retention that has been recently reported is experienced by all pigs regardless of body weight (BW) and if it is true for all types of diets regardless of the dietary level of protein. Therefore, the objective of this experiment was to test the hypothesis that nitrogen retention, measured as a percent of nitrogen consumed, is greater than 50% regardless of the dietary protein level and the BW of pigs.

Keywords: 
Amino acids, nitrogen balance, nitrogen retention, Pigs, Soybean meal
Authors: 
Ibagon, Lee, Stein
Publication Type: 
Research Reports

Impact of soybean hulls on net energy and nitrogen balance in group-housed pigs allowed ad libitum access to feed

Diets for pigs may vary in composition and in their concentration of the energy containing nutrients (i.e., protein, fat, starch and sugars, and dietary fiber). To our knowledge, however, there is no information on how concentration of net energy (NE) is affected by dietary fiber concentrations in diets fed to group-housed pigs. Therefore, the objective of this experiment was to test the hypothesis that increasing soybean hulls in diets for group-housed growing pigs decreases NE and nitrogen balance.

Keywords: 
Fiber, Net energy, nitrogen balance, nitrogen retention, Pigs, Soybean hulls
Authors: 
Lee, Stein
Publication Type: 
Research Reports

Effect of Pistachio Blanks on Growth Performance of Weanling Pigs

Pistachio blanks are co-products from pistachio production and consist of unmarketable pistachio components including the hard outer shells, undersized or unripe kernels, hull fragments, and occasionally woody debris from pruning or sorting operations. As global pistachio production of pistachios increases increased quantities of pistachio byproducts are generated and interest in utilizing some of the co-products in livestock feeding has increased. Data from previous research indicated that pistachio shell powder can be utilized in diets for sows, but because pistachio shell powder and pistachio blanks are very high in fiber, the metabolizable energy in these ingredients fed to weanling pigs is expected to be less than in sows. However, weanling pigs may benefit from the insoluble dietary fiber in pistachio co-products to improve intestinal health, but there are no data to demonstrate effects of including pistachio blanks in diets for weanling pigs. Therefore, an experiment was conducted to test the null-hypothesis that pistachio blanks may be included in diets for weanling pigs without compromising pig growth performance. 

Keywords: 
pistachio blanks, Growth performance, Weanling pigs
Authors: 
Kim, Lee, Stein
Publication Type: 
Research Reports

Impact of soybean meal on nitrogen retention and concentrations of energy in diets fed to growing pigs

Soybean meal (SBM) is often included in cereal-based diets for growing pigs because it provides a well-balanced profile of digestible amino acids (AA), which maximizes growth performance and protein synthesis. However, in recent years, SBM has often been partially replaced by crystalline AA or alternative protein sources such as corn distillers dried grains with solubles (DDGS) or corn protein. These co-products are by-products of the ethanol and vegetable oil industries and are commonly used in swine diets due to their availability and lower cost. Although they provide some indispensable AA, they have a less balanced AA profile and greater fiber concentrations than SBM, which may result in reduced AA digestibility, nitrogen retention, and energy utilization in pigs. However, pigs have become leaner and have greater requirements for dietary AA to support protein synthesis. In addition, it is often assumed that replacing SBM with corn and crystalline AA increases the energy of the diet, but recent data indicate that SBM may provide as much or more digestible energy (DE) and metabolizable energy (ME) than previously estimated. Therefore, it is possible that replacing SBM with corn co-products and crystalline AA may result in a reduction of nitrogen and energy utilization and increase nitrogen excretion in manure. Therefore, the objective of this work was to test the hypothesis that feeding intact protein from SBM to growing pigs, instead of combinations of SBM with crystalline AA or co-products such as DDGS or corn protein, results in greater nitrogen retention and greater DE in the diet without affecting ME.

Keywords: 
Amino acids, Energy, nitrogen retention, Pigs, Soybean meal
Authors: 
Ibagon, Lee, Stein
Publication Type: 
Research Reports

Release of phosphorus and inositol from soybean meal by growing pigs fed diets with graded levels of microbial phytase

Soybean meal (SBM) is a source of P in diets for swine. However, the P in SBM is stored as part of phytate, and pigs have very limited production of endogenous phytase. Therefore, to improve P availability, commercial pig diets often include supplemental phytase. This practice increases P digestibility, decreases the need for added phosphate, reduces feed costs, and decreases phosphorus excretion in manure. The release of P from phytate in SBM is believed to be in a dose-response manor. In addition, the destruction of phytate that is caused by phytase will also result in release of inositol, which is a sugar that may improve growth performance of pigs. However, there is very limited knowledge about how different levels of phytase influence plasma concentrations of inositol in growing pigs. Therefore, the objective of this work was to test the hypothesis that inclusion of microbial phytase in diets for growing pigs containing SBM will improve the digestibility of P in a dose-response manner and that inclusion of microbial phytase in diets for growing pigs also will increase plasma inositol levels of pigs.

 

Keywords: 
Phosphorus, inositol, soybean meal phytase
Authors: 
Mallea, Lee, Stein
Publication Type: 
Research Reports

Standardized ileal digestibility of amino acids in pistachio blanks and soybean meal fed to growing pigs

Pistachio blanks are coproducts of pistachio processing and are discarded due to their hollow shells or immature nuts, which make them unusable as human food. Pistachio blanks float in water and the annual production is estimated to be between 50,000 and 70,000 metric tons. A similar coproduct, pistachio shell powder, was recently demonstrated to provide significant amounts of energy in diets for sows. However, there is no information about the digestibility of amino acids (AA) in pistachio blanks when fed to pigs. Although AA concentration in pistachio blanks is low, there is a need for determining standardized ileal digestibility (SID) of AA in pistachio blanks. Therefore, an experiment was conducted to test the hypothesis that the SID of AA in pistachio blanks are comparable to those in soybean meal (SBM) when fed to growing pigs.

Keywords: 
Standardized ileal digestibility, Amino acids, pistachio blanks, Soybean meal, Pigs
Authors: 
Kim, Lee, Stein
Publication Type: 
Research Reports

Impact of soybean oil on net energy and nitrogen balance in group-housed pigs allowed ad libitum access to feed

Diets for pigs may vary in composition and in their concentration of the energy containing nutrients (i.e., protein, fat, starch and sugars, and dietary fiber). To our knowledge, however, there is no information on how concentration of net energy (NE) is affected by dietary fat concentrations in diets fed to group-housed pigs. Therefore, the objective of this experiment is to test the hypothesis that increased soybean oil in diets for group-housed growing pigs will increase NE and nitrogen balance.

Keywords: 
Fat, Net energy, nitrogen balance, nitrogen retention, Pigs, Soybean oil
Authors: 
Lee, Stein
Publication Type: 
Research Reports

Determination of net energy and nitrogen balance in group-housed pigs fed diets containing varying levels of starch and fiber

Diets for pigs may vary in composition and in their concentration of the energy containing nutrients (i.e., protein, fat, starch and sugars, and dietary fiber). To our knowledge, however, there is no information on how concentration of net energy (NE) is affected by dietary starch and fiber concentrations in diets fed to group-housed pigs. Therefore, the objective of this experiment is to determine NE and nitrogen balance in diets containing various levels of starch and fiber fed to group-housed pigs.

 

Keywords: 
Distillers dried grains with solubles, Net energy, nitrogen retention, Pigs, Starch
Authors: 
Lee, Stein
Publication Type: 
Research Reports

Digestibility of energy by growing pigs and concentrations of digestible and metabolizable energy in diets containing pistachio blanks

As the production of pistachios grows globally, more co-products are produced every year. Pistachio blanks are pistachio fruits that float in water because the shells are hollow and therefore cannot be used for human food. Pistachio blanks is a high fiber ingredient, which is comparable to wheat middlings. The annual production is 50,000 to 70,000 tons, but is growing. Pistachio blanks have been viewed as a waste product from the pistachio processing sector, but it is possible this feed ingredient can provide nutrients for animals and be used in animal diets. Therefore, this experiment was conducted to test the hypothesis that the apparent total tract digestibility of energy, dry matter, ash, and total dietary fiber in pistachio blank powder is not different from that of wheat middlings if included in diets for growing pigs.

Keywords: 
Energy, pistachio blanks, Wheat middlings
Authors: 
Kim, Lee, Stein
Publication Type: 
Research Reports

Digestible and metabolizable energy in soybean meal and soybean hulls when fed to growing pigs or sows

Values for digestible energy (DE) and metabolizable energy (ME) in feed ingredients are usually determined in growing pigs and subsequently applied to all groups of pigs. Results of recent research, however, indicate that the energy content of soybean meal (SBM) is greater than previously thought when fed to growing pigs. This increase in energy may be due to changes in the pigs themselves or differences in methodology, but there are no recent experiments assessing DE and ME in SBM when fed to sows. Therefore, it remains unclear if sows also have greater DE and ME in SBM compared with current book values. Likewise, there are no recent data for the DE and ME in soybean hulls although soybean hulls are often added to diets for gestating sows. Therefore, an experiment was conducted to test the hypothesis that gestating and lactating sows have greater DE and ME in SBM and soybean hulls than growing pigs and that DE and ME in SBM fed to both growing pigs and sows are greater than current book values. The second hypothesis was that there is no difference in apparent total tract digestibility (ATTD) of gross energy (GE) and DE between gestating and lactating sows.

Keywords: 
Digestibility, Energy, Sows, Soybean hulls, Soybean meal
Authors: 
Yeonwoo, Lee, Stein
Publication Type: 
Research Reports

Effect of soy isoflavones and extra nitrogen on growth performance in low-protein diets fed to growing pigs

Soybean meal (SBM) is the primary source of amino acids (AA) and energy in diets for swine throughout the world. However, less SBM is often used in diets to decrease nitrogen excretion and environmental pollution. Nonetheless, it is demonstrated that lowering dietary protein does not consistently deliver the same performance of pigs as of pigs fed high protein diets, even though all indispensable AA meet the requirements of pigs. It is possible that soybean-derived bioactive compounds (i.e., soy isoflavones and saponins) in SBM act as immunomodulators, which improve the performance of pigs. It is also possible that low-protein diets contain nitrogen below the requirements for pigs to maximize growth. However, no data are available to prove this hypothesis. Therefore, the objective of this experiment was to test the hypothesis that reducing the dietary protein by decreasing the SBM and increasing crystalline AA in diets may have influence growth performance, carcass composition, and meat quality and that soy isoflavones act as immunomodulators, which may improve the immune system and thus results in better performance of pigs fed low-protein diets.

Keywords: 
Growth performance, Isoflavones, Nitrogen, Soybean meal
Authors: 
Ibagon, Lee, Stein
Publication Type: 
Research Reports

Effect of feeding intact protein from soybean meal instead of synthetic amino acids on growth performance, carcass composition, energy deposition, blood cytokines, or abundance of intestinal amino acid transporters by growing pigs

The use of synthetic amino acids (AA) in diets for pigs has increased in the past few decades due to increased availability and reduced prices of these AA. The increased use of synthetic AA has caused a reduced need for inclusion of soybean meal (SBM) in diets. For instance, a common grower pig diet without synthetic AA needs around 35% SBM to full fill the requirements for all indispensable AA, but a diet with 5 synthetic AA only requires 17% SBM. It has generally been assumed that pigs fed diets containing synthetic AA will have growth performance, protein deposition, and carcass quality that is no different from that of pigs fed diets based in which the majority of the AA are furnished by SBM as long as the requirements for all digestible AA are met. It has also been assumed that diets formulated with large amounts of synthetic AA, compared with diets based on SBM provide more net energy to pigs because these diets contain more corn and less SBM. However, some of these assumptions are not based on strong scientific evidence, and results of recent research has raised doubts about previously assumed effects of using synthetic AA. Therefore, the objective of this experiment was to test the hypothesis that the use of synthetic AA instead of some of the intact protein from SBM does not impact growth performance, carcass composition, energy deposition, blood cytokines or abundance of intestinal amino acid transporters when fed to growing pigs.

Keywords: 
Low-protein, Soybean meal, Growth, Retention, carcass
Authors: 
Cristobal, Lee, Stein
Publication Type: 
Research Reports

Diet protein concentration does not influence net energy by group-housed growing pigs offered ad libitum access to feed

Soybean meal (SBM) is the major source of amino acids (AA) and energy in diets for swine throughout the world because SBM has an AA profile that matches the requirements of pigs and AA in SBM have high digestibility. In the U.S., nearly 20% of all SBM produced is used to feed pigs. However, AA in diets can also be provided by feed-grade synthetic AA and diets based on corn and synthetic AA have been thought to also increase diet net energy and reduce N excretion and carbon footprint. With the addition of synthetic AA in diets, it is possible to reduce the inclusion of SBM and formulate diets with reduced crude protein. However, recent data indicate that pigs of modern genotypes utilize more dietary protein than older genotypes and the net energy may, therefore, not be increased in diets that contain less SBM and more corn and synthetic AA. Therefore, the objective of this experiment was to test the hypothesis that diets based on corn and SBM and limited quantities of synthetic AA contain net energy that is not different from diets based on corn and larger quantities of synthetic AA.

Keywords: 
Net energy, Metabolizable energy, Low-protein, Soybean meal, synthetic amino acids
Authors: 
Cristobal, Lee, Stein
Publication Type: 
Research Reports

Effect of dietary leucine concentration on the tryptophan requirement in diets for 25-50 kg growing pigs fed soybean meal or corn fermented protein as a protein sources

Diets with high inclusion of corn fermented protein (CFP) may have an excess of Leu, which has a negative impact on the growth performance of pigs. Tryptophan is a precursor of serotonin, which is a neurotransmitter that is critical for feed intake regulation, and excess dietary Leu may reduce synthesis of serotonin in the brain by preventing Trp from being transported to the brain. Reduced serotonin synthesis can result in reduced feed intake and pigs with reduced feed intake due to excess Leu also have reduced growth performance. As a consequence, if diets are formulated based on CFP instead of soybean meal (SBM), diets need to be fortified with extra Trp to account for the reduced efficiency of Trp due to the excess Leu in corn protein. However, a quantitative assessment of how much extra Trp is needed in diets based on CFP instead of SBM has not been conducted. Therefore, an experiment was conducted to test the hypothesis that the optimum Trp:Lys ratio in diets for growing pigs is greater if CFP rather than SBM is used as the protein source in the diets. 

Keywords: 
leucine, Tryptophan, Diets, Pigs, Soybean meal, Corn fermented protein
Authors: 
Mallea, Stein
Publication Type: 
Research Reports

Effect of feeding intact protein from soybean meal instead of synthetic amino acids on energy and nitrogen balance by growing pigs

Synthetic amino acids (AA) are often included in diets fed to pigs at the expense of SBM or other protein sources to provide a portion of the indispensable AA needed by pigs. Substituting SBM for synthetic AA may support pig growth performance, but daily N retention by pigs may be reduced if diets containing synthetic AA instead of some of the SBM are used. This indicates that there may either be an AA deficiency in diets with synthetic AA, or there are factors other than AA in SBM that are needed to maximize protein synthesis in pigs.

It has been speculated that synthetic AA are absorbed more rapidly than AA from intact protein, which may impair protein synthesis. It is, therefore, possible that if protein from SBM is replaced by synthetic AA, some of the synthetic AA will not be used for protein synthesis, which will result in reduced nitrogen retention by the pigs. Results of recent research also indicate that the DE in SBM is greater than in corn, and therefore, dietary DE may be reduced if SBM is reduced in the diet. However, at this time, no research has been conducted to confirm this assumption. Therefore, the objective of this experiment was to test the hypothesis that use of synthetic AA instead of some of the intact protein from SBM reduces N retention and also reduces DE of the diet if fed to growing pigs.

Keywords: 
Low-protein, Soybean meal, Nitrogen, Retention, metabolizable.
Authors: 
Cristobal, Lee, Stein
Publication Type: 
Research Reports

Effect of soy isoflavones and nitrogen-source on nitrogen balance in low-protein diets fed to growing pigs

Soybean meal (SBM) is the primary source of amino acids (AA) and energy in diets for swine throughout the world. However, less SBM is often used in diets to decrease nitrogen (N) excretion and environmental pollution. Nonetheless, it is demonstrated that lowering dietary protein does not consistently deliver the same performance of pigs as of pigs fed high protein diets, even though all indispensable AA meet the requirements of pigs. It is possible that soybean-derived bioactive compounds (i.e., soy isoflavones and saponins) in SBM act as immunomodulators, which improve the performance of pigs. It is also possible that low-protein diets contain N below the requirements for pigs to maximize growth. However, no data are available to prove this hypothesis. Therefore, the objective of this experiment was to test the hypothesis that N balance of pigs is not affected by reducing dietary protein if soy isoflavones or N source are supplemented in diets.

Keywords: 
nitrogen balance, Retention, Soybean meal
Authors: 
Ibagon, Stein, Lee
Publication Type: 
Research Reports

Growth performance, blood inositol levels, and immune characteristics of pigs fed diets containing soybean meal and high levels of phytase

Most of the P in corn and soybean meal (SBM) is stored as phytate. Phytase consists of one hydroxylated inositol ring with six phosphate groups. Therefore, phytase is often included at a standard level of 500 units (FTU) per kg in swine diets to increase the release of P from phytate. However, greater concentrations of phytase in diets for pigs may benefit growth and feed efficiency, which is likely a result of the inositol that is also released and can be absorbed by pigs. Inositol is believed to increase growth of animals by stimulating protein accretion. Inositol also improves gut health of pigs by enhancing intestinal epithelial cell functions. However, data from recent research demonstrated that weaning pigs at around 21 days of age results in a dramatic drop in plasma inositol and it is not until 6 weeks post-weaning that pigs will regain preweaning levels of inositol. Therefore, an experiment was conducted to test the hypothesis that microbial phytase will release sufficient inositol from corn and SBM and other ingredients in diets for newly weaned pigs to maintain pre-weaning levels of plasma inositol throughout the post-weaning phase and that this will result in improved growth performance of pigs.

Keywords: 
Growth performance, blood inositol levels, immune characteristics, Pigs, Soybean meal, Phytase
Authors: 
Mallea, Stein
Publication Type: 
Research Reports

25-hydroxy-vitamin D3 and microbial phytase may increase digestibility of calcium and phosphorus in diets fed to growing pigs

Vitamin D regulates a wide spectrum of genes responsible for Ca and P homeostasis and cell differentiation. Cholecalciferol, commonly known as vitamin D3, is a primary source of vitamin D3 in diets for growing pigs; however, it needs to be hydroxylated twice to be active. The first hydroxylation occurs in the liver at the 25-position, resulting in 25-hydroxycholecalciferol [25(OH)D3], whereas the second hydroxylation occurs in the kidneys at the 1-position, resulting in 1,25 dihydroxycholecalciferol [1,25(OH)2D3], which is the active form of vitamin D3 in the body. Supplementation of 25(OH)D3 to diets for sows in late gestation may increase the apparent total tract digestibility (ATTD) and retention of Ca and P, but there are no data to demonstrate this effect in growing pigs.

Cereal grains commonly used in diets for pigs have low digestibility of P because P is bound to phytate. Exogenous phytase increases the digestibility of both Ca and P in pigs by releasing the P from the phytate molecule within the gastrointestinal tract of pigs. However, there is limited information about the interaction between 25(OH)D3 and supplemental phytase in diets fed to growing pigs. Therefore, the objective of this experiment was to test the hypothesis that both 25(OH)D3 and microbial phytase independently and in combination may increase standardized total tract digestibility (STTD) of Ca and P by growing pigs.

Keywords: 
Calciferol, Calcium, Phosphorus, Phytase, Vitamin D, Vitamin D Metabolites
Authors: 
Jaramillo, Lee, Acosta, Stein
Publication Type: 
Research Reports

Digestible and metabolizable energy, and standardized total tract digestibility of phosphorus in five sources of full-fat soybeans fed to growing pigs

Whole soybeans, from which the oil is not extracted, are referred to as full-fat soybeans (FFSB) and may be used in diets for poultry and pigs because of it is high contents of protein, oil, linoleic acid, vitamin E, and lecithin. Unprocessed raw soybeans, however, contain several anti-nutritional factors including trypsin inhibitors that make them unsuitable as a feed for pigs and poultry, because the protein digesting enzymes are impaired by the trypsin inhibitors, which reduces digestibility, depresses growth rate, and decreases the efficiency of feed utilization when fed to swine. However, there is a lack of data for the nutritional value of FFSB. Therefore, two experiments were conducted to test the hypothesis that there is no difference among FFSB sources 01, 02, 03, 04, and 05 in the digestible energy (DE), the metabolizable energy (ME), and the standardized total tract digestibility (STTD) of P when fed to growing pigs.

Keywords: 
Digestible energy, Metabolizable energy, Standardized total tract digestibility
Authors: 
Ruiz-Arias, Lee, Stein
Publication Type: 
Research Reports

Effects of high fiber on gas production, nitrogen excretion, and net energy in diets fed to group-housed pigs

To reduce the cost of pork production, high-fiber ingredients are often used in diets, but an increase in the amount of dietary fiber in pig diets may have a negative impact on the digestibility of nutrients and energy. Carbon footprint from pork production is related to emissions of greenhouse gases including carbon dioxide, nitrous oxide, and methane from pigs. Emission of gases may be correlated with the composition of feeds, and it is thus possible that feeding pigs with diets containing high-fibrous feed ingredients affects the gas exchange, which also impacts concentration of net energy (NE) in diets.

Therefore, the objective of this experiment was to test the null hypothesis that feeding pigs with a high-fiber diet does not affect gas production, N excretion, and NE in diets fed to group-housed pigs.

Keywords: 
Greenhouse gas, Fiber, Net energy, Wheat middlings
Authors: 
Lee, Stein
Publication Type: 
Research Reports

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