The Effect of Lysine to Protein Ratio on Growth Performance and Efficiency of Nitrogen Utilization in Pigs

Li, Defa,Xi, Pengbin,Wang, Junxun,Wang, Jitan,Ren, Jiping,Kang, Yufan,Thacker, P. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.9

One feeding trial and two metabolic trials were conducted to investigate the effects of lysine to protein ratio in practical swine diets on growth performance and efficiency of nitrogen retention and utilization in different growing phases. In Trial one (the feeding trial), 90 mixed sex pigs weighing $9.1{\pm}1.4kg$ (Duroc ${\times}$ Landrance ${\times}$ Beijing Black) were used to study the effects of concentrations of 5.2, 5.3, 5.8, 6.4 and 7.2 g lysine/100 g CP in diets containing 1.2% lysine on growth performance and serum urea nitrogen. The results showed that feed conversion efficiency and economic efficiency were best for pigs fed the diet containing the lysine concentration of 5.8 g /100 g crude protein. Serum urea nitrogen concentration decreased linearly (p=0.0009) and serum free lysine content increased linearly (p=0.0017) as the lysine to protein ratio in diets increased from 5.2 to 7.2 g/100 g. In Trials two and three (the metabolic trials), five growing barrows (Duroc ${\times}$ Landrance ${\times}$ Beijing black), with initial body weights of approximately $26{\pm}2.4kg$ and $56.3{\pm}3.5kg$, respectively, were allotted to five dietary treatments according to a $5{\times}5$ Latin square design. Trial two contained 5.2, 5.7, 6.1, 6.7 and 6.8 g lysine/100 g CP treatments. Trial three contained 4.6, 5.0, 5.6, 6.1 and 6.6 g lysine/100 g CP treatments. The results showed that nitrogen retention in growing pigs decreased linearly (p=0.0011 in Trial two; p=0.0099 in Trial three) as the lysine to protein ratio in diets increased. The ratio of lysine to protein in diets resulting in maximum nitrogen retention was 5.2 g/100 g and 5.0 g/100 g in Trial two and Trial three, respectively. In Trial two, apparent biological value and gross nitrogen efficiency increased linearly (p=0.0135 and p=0.0192, respectively) as the lysine to protein ratio increased from 5.2 to 6.8 g lysine/100 g CP. In summary, we concluded that the optimal Lysine to Protein Ratios for 8-20 kg and 20-80 kg pigs were 5.8 g/100 g and 5.0 to 5.2 g/100 g, respectively.

Effects of Alpha-galactosidase Supplementation to Corn-soybean Meal Diets on Nutrient Utilization, Performance, Serum Indices and Organ Weight in Broilers

Wang, C.L.,Lu, W.Q.,Li, Defa,Xing, J.J. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.12

Effects of alpha-galactosidase (GAL) on broiler corn-soybean meal diet was investigated. In experiment 1, sixty cockerels were allocated to five groups, including three enzyme treatments (GAL added at 0, 500, and 1,000 mg/kg diet), a nitrogen-free diet group and a fast group. The true nitrogen-corrected ME (TME$_n$) and true amino acid availability were determined. In experiment 2, 324 day-old chicks were used in a 2${\times}$3 factorial design consisting of two energy contents (high and low) and three GAL levels (0, 250, and 500 mg/kg). Three feeding phases, comprising 0-21 d, 22-35 d and 36-48 d, were involved. GAL addition improved TME$_n$ and the availability of methionine and cystine (p<0.05). The apparent ME (AME) or nitrogen-corrected AME (AME$_n$) and digestibility of dry matter, organic matter, calcium, and phosphorus were improved significantly on d 21, so was crude protein and an interaction of energy and GAL on AME$_n$ (p<0.05) was found on d 35. However, daily intake and daily gain were significantly improved with GAL addition (p<0.05) during 21 d. The small intestine relative weight decreased at 250 mg/kg GAL (p<0.05) on d 35, whereas presented an interaction between GAL and energy on d 21 (p<0.05). Likewise, this treatment increased breast muscle ratio (p<0.05). On d 21, triglycerides level of broilers showed interaction between energy and enzyme levels (p<0.05). Uric acid level in 500 mg/kg GAL declined linearly (p<0.05). On d 35, quadratic effects (p<0.05) were observed in total protein, albumin, globulin and cholesterol content for enzyme supplementation. And the interactive effects of energy and GAL on serum values showed more obviously. The study implies that GAL improved energy and nutrient availability of corn-soybean meal diet in broiler. The GAL supplementation to corn-soybean meal based diet can improve performance of broilers in early stages of growth.

Current status, challenges and prospects for pig production in Asia

Wang Lu,Li Defa 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.4

Asia is not only the primary region for global pig production but also the largest consumer of pork worldwide. Although the pig production in Asia has made great progress in the past, it still is confronted with numerous challenges. These challenges include: inadequate land and feed resources, a substantial number of small-scale pig farms, escalating pressure to ensure environmental conservation, control of devastating infectious diseases, as well as coping with high temperatures and high humidity. To solve these problems, important investments of human and financial capital are required to promote large-scale production systems, exploit alternative feed resources, implement precision feeding, and focus on preventive medicine and vaccines as alternatives to antibiotics, improve pig breeding, and increase manure recycling. Implementation of these techniques and management practices will facilitate development of more environmentally-friendly and economically sustainable pig production systems in Asia, ultimately providing consumers with healthy pork products around the world.

Effect of L-Carnitine and Source of Dietary Fat on Growth Performance and Serum Biochemical Parameters of Piglets Weaned at 35 Days of Age

Li, Defa,Qiao, Q.,Johnson, E.W.,Jiang, J.,Wang, F.,Blum, R.,Allee, G. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.8

The effects of carnitine in diets with or without added fat (5% lard or soybean oil) were evaluated in 72 Large White ${\times}$ Landrace ${\times}$ Duroc pigs weaned at 35 days of age. Pigs were fed a 1.30% lysine corn-soybean basal diet+15% dried whey+4% fish meal with carnitine at 0 or 50 mg/kg and either 0% added fat, 5% soybean oil or 5% lard for 6 weeks in a $2{\times}3$ factorial trial (6 treatments, 3 pens per treatment, 4 pigs per pen). Addition of carnitine increased average daily gain (ADG) and average daily feed intake (ADFI) in the second two weeks of the six-week trial and overall, but had no significant effect on feed per gain (F/G). Lard alone depressed ADG (p<0.05) in the last two weeks of the trial and overall, but the ADG for pigs fed lard+carnitine was similar to the control. Lard reduced feed intake in the first two weeks of the trial (p<0.05). Carnitine reduced the percentage of pigs with poor (ADG<375 g/d) growth (15 vs 40%; p<0.05). The greater uniformity of growth was most evident in low-weaning-weight pigs in the second period (16 vs 62%, p<0.005). Addition of fat did not produce any positive effect on uniformity and had no interaction with carnitine on uniformity. Carnitine addition increased serum total carnitione and short-chain acyl-carnitine levels (p<0.05), but did not modify free carnitine levels. Serum carnitine levels were lower at weaning than at 14, 28, or 39 days after weaning (p<0.05). Carnitine increased serum protein levels on day 14 (p<0.05). Addition of fat in the form of soybean oil or lard did not improve piglet growth performance. Addition of 50 mg/kg of carnitine to the diet of weanling pigs enhanced postweaning performance.

The Effect of Calcium Level on Microbial Phytase Activity and Nutrient Balance in Swine

Li, Defa,Che, X.R.,Wang, Y.Q.,Qiao, S.Y.,Cao, H.,Johnson, W.,Thacker, P. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.2

Three barrows weighing 45.0 kg, fitted with simple T-cannulas in both the duodenum and terminal ileum, were assigned to diets in a $3{\times}3$ Latin Square design experiment to determine the effect of two calcium levels (0.8% vs 0.4%) on phytase activity and nutrient balance in growing pigs. The control diet contained 0.8% calcium, with no added inorganic phosphorus (0.45% total phosphorus) and no added phytase. The two additional experimental diets contained microbial phytase (750 phytase units/kg) and supplied either 0.8% or 0.4% calcium. With added microbial phytase, ileal and total tract digestibility of rotal phosphorus were improved by 20.9 and 13.8 percentage units, respectively (p=0.01). The apparent duodenal and ileal digestibility of phytate phosphorus were increased by 51.8 and 49.7 percentage units (p=0.01). Lowering dietary calcium in the presence of microbial phytase increased the digestibility of phytate phosphorus by an additional 10.9 (p=0.001) and 5.7 percentage units for duodenal and ileal digestibility, respectively. Supplementation with microbial phytase significantly reduced fecal excretion of nitrogen and phosphorus and increased the percentage of these nutrients retained by the pig. Lowering dietary calcium further increased the percentage of dietary phosphorus retained. Overall, reducing dietary calcium appeared to increase the effectiveness of added microbial phytase in degrading phytate phosphorus. As a result, care should be taken to avoid high levels of dietary calcium when supplementing swine diets with microbial phytase.

Additivity of values for phosphorus digestibility in corn, soybean meal, and canola meal in diets fed to growing pigs

She, Yue,Wang, Qiuyun,Stein, Hans H.,Liu, Ling,Li, Defa,Zhang, Shuai Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.8

Objective: This study was conducted to determine the apparent and standardized total tract digestibility (ATTD and STTD) of phosphorus (P) in corn, soybean meal (SBM), and canola meal (CM), and additivity of values for ATTD and STTD of P in corn, SBM, and CM in diets fed to growing pigs. Methods: Thirty-six growing barrows (initial body weight of $21.6{\pm}1.7kg$) were placed in metabolism crates and allotted to a completely randomized design with 6 diets and 6 pigs per diet. Six diets were formulated using corn, SBM or CM as the sole source of P, or corn and SBM, or corn and CM, or corn, SBM, and CM as the P source in each diet, respectively. Fecal samples were collected for 5 d following a 7 d adaptation period to the diets. Results: Values for ATTD and STTD of P in corn, SBM, and CM in growing pigs were 33.12% and 37.76%, 50.19% and 56.62%, 34.93% and 39.45%, respectively. The ATTD and STTD of P in SBM were greater (p<0.05) than those in corn and CM. However, there were no differences in the ATTD or STTD of P between corn and CM. The determined STTD of P in the mixture of corn and SBM, corn and CM, and corn, SBM, and CM is not different from the calculated STTD values. Conclusion: Values for STTD of P in corn, SBM, and CM are additive in their mixture fed to growing pigs.

Comparative digestibility of nutrients and amino acids in high-fiber diets fed to crossbred barrows of Duroc boars crossed with Berkshire×Jiaxing and Landrace×Yorkshire

Zhao, Jinbiao,Wang, Qiuyun,Liu, Ling,Chen, Yiqiang,Jin, Aiming,Liu, Guoliang,Li, Kaizhen,Li, Defa,Lai, Changhua Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.5

Objective: This experiment was conducted to determine the differences in the apparent ileal (AID) and total tract digestibility (ATTD) of nutrients and indispensable amino acids (IAA) in high-fiber diets with wheat middlings, rice bran or alfalfa meal fed to Duroc${\times}$(Landrace${\times}$Yorkshire) (DLY) and Duroc${\times}$ (Berkshire${\times}$Jiaxing) (DBJ) growing barrows. Methods: Eighteen DLY and 18 DBJ growing barrows were randomly allotted to a $2{\times}3$ factorial arrangement involving 2 crossbreeds and 3 high-fiber diets. The experiment lasted 15 d with 10 d for diets adaptation, 3 d for feces collection and 2 d for digesta collection. Three diets were based on corn and soybean meal with 25% wheat middlings, rice bran and alfalfa meal respectively. Results: DBJ had a greater (p<0.05) AID of isoleucine, leucine, lysine, phenylalanine and valine and a lower (p<0.05) AID of methionine than DLY. The hindgut disappearance of acid detergent fiber for DBJ was greater (p<0.05) than DLY. The ATTD of gross energy, dry matter, organic matter, neutral detergent fiber and acid detergent fiber in wheat middlings diet were greater (p<0.05) than in rice bran and alfalfa meal diets. The hindgut disappearance of neutral detergent fiber and acid detergent fiber in wheat middlings diet or rice bran diet were the highest or lowest (p<0.05), and those of alfalfa meal diet were the middle. Barrows fed rice bran diet had a greater (p<0.05) hindgut disappearance of gross energy, dry matter and organic matter and lower hindgut disappearance of neutral detergent fiber and acid detergent fiber than barrows fed alfalfa meal diet Conclusion: DBJ growing barrows showed a significant higher digestibility of fiber in the hindgut and most IAA in the small intestine compared with DLY barrows. The digestibilities of chemical constituents and IAA were affected by the diets formulated with different fiber sources.

Evaluation of Chinese Brown Rice as an Alternative Energy Source in Pig Diets

Piao, X.S.,Li, Defa,Han, In K.,Chen, Y.,Lee, J.H.,Wang, D.Y.,Li, J.B.,Zhang, D.F. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.1

A total of six crossbred barrows ($Duroc{\times}Landrace{\times}Large$ White, $44.17{\pm}1.94kg$ BW) were housed conducted to evaluate apparent fecal digestibilities of Brown Rice (BR) as an alternative energy source in growing pigs. Pigs were housed individually on metabolism crate on the basis of body weight. Four treatments contained: 1) 100% of corn-soybean meal (C100; Control diet), 2) 75% of corn-soybean meal diet plus 25% of corn meal (C25), 3) 100% of brown rice-soybean meal diet (BR100), 4) 75% of brown rice-soybean meal diet plus 25% of brown rice meal (BR25). Brown rice has an excellent gross energy and crude protein composition compared to corn. The BR used had 3,801 kcal of gross energy/kg, 8.0% crude protein, 2.6% of ether extract, 0.035% calcium and 0.35% total phosphorus. The best digestibilities of energy (87.75%), DM (81.71%) and CP (78.57%) were observed in BR 100 group and the worst were found in Corn 25 group. The nutrient digestibility was not significantly different in most nutrients. Through this experiment, BR appeared a good alternative energy source that can replace corn yellow to 100% in growing pigs. Therefore, the price relationship between corn and BR may provide an excellent opportunity for pork producers to use BR in order to reduce feed costs provided that diet has been balanced for digestible amino acids.

Effects of Casein and Protein-free Diets on Endogenous Amino Acid Losses in Pigs

Zhang, Yongcheng,Li, Defa,Fan, Shijun,Piao, Xiangshu,Wang, Jitan,Han, In K. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.11

Quantification of endogenous amino acid loss at the terminal ileum is an essential means for calculation of the true amino acid digestibility of a feedstuff. Since nitrogen appeared in the determined diet or not could shift the results very much, also, none of digestibility markers could be recovered with 100% rate at the terminal ileum, the objectives of the present study were: (1) to determine endogenous amino acid losses when fed either a casein diet or a protein-free diet and (2) to examine the reliability of chromic oxide or acid insoluble ash in the protein-free diet. Six ileal-cannulated pigs ($65{\pm}1.85 kg$ BW) with a simple T-cannula in the terminal ileum were used in a replicated $3{\times}3$ Latin square designed trial, after allowed a 14 d recuperation period. Each test period ran for 12 days comprised of a 10 d adjustment period and a 2 d collection period. The endogenous AA losses of His, Ile, Lys, Cys, Thr, Val, Trp, Asp, Glu, and Ser from pigs fed the casein diet were significantly higher than those of the protein-free diet (p<0.05). No significant difference was found in the amount of endogenous amino acid loss when determined with the different markers in the protein-free diet (p>0.05). These data suggest that endogenous amino acid loss could be underestimated when a protein-free diet is used. A direct effect of dietary peptides on the endogenous amino acid loss was found when the casein diet was fed. Our results also indicate that acid insoluble ash can be used as an inert marker as an alternative to chromic oxide when measuring endogenous amino acid loss.

Effects of Different Sources of Organic Chromium on Immune Function in Weaned Pigs

Tang, L.,Li, Defa,Wang, F.L.,Xing, J.J.,Gong, L.M. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.8

A five-week trial was conducted to evaluate the effect of organic chromium from different sources on growth performance, immune response and serum parameters of weaned pigs. One hundred and eighty Tianjin white pigs weaned at $35{\pm}1$ days of age, were allotted to three treatments with six replicates and10 pigs per pen. Pigs were fed corn-soybean-whey-fishmeal basal diets with either no supplemental Cr, $200{\mu}g/kg$ Cr as chromium picolinate (CrPi), or $200{\mu}g/kg$ Cr as chromium yeast (Cr-yeast). To assess humoral immune response, all pigs were immunized with swine fever virus on day 21 and two pigs from each pen were immunized with pure albumin on day 14. Cell-mediated immunity was measured by determining the double skinfold thickness (DST) of two pigs from each pen before and 24h after stimulation with phytohemagglutinin (PHA) on day 28. The results indicated that: (1) diets with Cr-yeast increased average daily gain (ADG, p<0.05) and tended to increase average daily feed intake (ADFI, p<0.10). Diets with CrPi did not increase ADG and ADFI (p>0.05). (2) Dietary CrPi or Cr-yeast supplementation did not affect blood urea nitrogen, glucose, or cholesterol (p>0.05), but blood urea nitrogen in CrPi and Cr-yeast supplemented groups and blood glucose in the Cr-yeast supplemented group were significantly influenced by sampling days (p<0.05). (3) Serum proteins (TP, ALB, and GLB) were influenced by sampling days (p<0.05), but not by dietary Cr treatment (p>0.10). (4) There were no significant differences among treatments in the titers of albumin antibody and swine fever virus antibody (p>0.05) or DST before and after PHA stimulation (p>0.05), indicating that organic chromium has no significant effect on the immune function of weaning pigs. Therefore, these results agree with other research that the effects of supplemental Cr are variable in weanling pigs.