Two 21 d-experiments were conducted to determine the optimum standardized ileal digestible(SID)threonine:lysine ratio(Thr:Lys) for weaned piglets reared under clean(Exp. 1) or unclean(Exp. 2) sanitary conditions and f...Two 21 d-experiments were conducted to determine the optimum standardized ileal digestible(SID)threonine:lysine ratio(Thr:Lys) for weaned piglets reared under clean(Exp. 1) or unclean(Exp. 2) sanitary conditions and fed antibiotic-free diets. In each experiment, 90 mixed-sex pigs(Duroc × [Yorkshire × Landrace]; initial BW 7.2 ± 0.3 kg) were randomly assigned to 5 dietary treatments each with 6 replicates(3 pigs per pen). The dietary treatments were 5 graded levels of SID Thr:Lys(55,59, 63, 67 and 71%). Diets were corn-wheat-soybean meal-based with a constant SID Lys of 1.18% that was set to be second limiting amino acid. In Exp. 1 and Exp. 2, plasma-free Thr increased(P = 0.05) with increasing dietary SID Thr:Lys. In Exp. 1, the SID Thr:Lys for gain-to-feed ratio(G:F) was optimized at 65%.In Exp. 2, the estimated optimal SID Thr:Lys for overall G:F was 66.5%. In conclusion, an average optimal SID Thr:Lys of 65 and 66.5% could be used to optimize feed efficiency for weaned pigs under clean and unclean sanitary conditions, respectively.展开更多
Two 14-day experiments,each with 90(Duroc×[Yorkshire×Landrace]; 7.3 ± 0.6 kg) piglets,were conducted to determine the optimum sulfur amino acid(SAA) to lysine(Lys) ratio(SAA:Lys) for piglets when reared...Two 14-day experiments,each with 90(Duroc×[Yorkshire×Landrace]; 7.3 ± 0.6 kg) piglets,were conducted to determine the optimum sulfur amino acid(SAA) to lysine(Lys) ratio(SAA:Lys) for piglets when reared under clean or unclean sanitary conditions using performance and non-performance response criteria. Piglets were randomly assigned to the following dietary treatments. The basal diet contained 1.18% standardized ileal digestible(SID) Lys, and the SAA:Lys was 52%. In diets 2 to 5, the basal diet was supplemented with 4 graded levels of DL-Met to make SAA:Lys of 56%, 60%, 64% and 68%. In Exp.1, piglets were housed in disinfected clean room. In Exp. 2, piglets were housed in a room previously occupied by other pigs and was not disinfected. On the last day, blood was collected to measure plasma urea nitrogen(PUN) and one pig per pen was euthanized to collect jejunal tissue to measure villus height(VH), crypt depth(CD), and VH:CD. In Exp. 1, increasing SAA:Lys linearly and quadratically increased VH and VH:CD(P < 0.05). In Exp. 2, increasing SAA:Lys linearly increased(P < 0.05) VH and VH:CD and linearly and quadratically decreased PUN(P < 0.05). Estimated PUN and VH-based optimum SAA:Lys requirements for clean and unclean sanitary condition were 60%, 63% and 66%, respectively.展开更多
基金Evonik Industries and Natural Science and Engineering Research Council
文摘Two 21 d-experiments were conducted to determine the optimum standardized ileal digestible(SID)threonine:lysine ratio(Thr:Lys) for weaned piglets reared under clean(Exp. 1) or unclean(Exp. 2) sanitary conditions and fed antibiotic-free diets. In each experiment, 90 mixed-sex pigs(Duroc × [Yorkshire × Landrace]; initial BW 7.2 ± 0.3 kg) were randomly assigned to 5 dietary treatments each with 6 replicates(3 pigs per pen). The dietary treatments were 5 graded levels of SID Thr:Lys(55,59, 63, 67 and 71%). Diets were corn-wheat-soybean meal-based with a constant SID Lys of 1.18% that was set to be second limiting amino acid. In Exp. 1 and Exp. 2, plasma-free Thr increased(P = 0.05) with increasing dietary SID Thr:Lys. In Exp. 1, the SID Thr:Lys for gain-to-feed ratio(G:F) was optimized at 65%.In Exp. 2, the estimated optimal SID Thr:Lys for overall G:F was 66.5%. In conclusion, an average optimal SID Thr:Lys of 65 and 66.5% could be used to optimize feed efficiency for weaned pigs under clean and unclean sanitary conditions, respectively.
基金Evonik IndustriesNatural Sciences and Engineering Research Council of Canada for funding this project
文摘Two 14-day experiments,each with 90(Duroc×[Yorkshire×Landrace]; 7.3 ± 0.6 kg) piglets,were conducted to determine the optimum sulfur amino acid(SAA) to lysine(Lys) ratio(SAA:Lys) for piglets when reared under clean or unclean sanitary conditions using performance and non-performance response criteria. Piglets were randomly assigned to the following dietary treatments. The basal diet contained 1.18% standardized ileal digestible(SID) Lys, and the SAA:Lys was 52%. In diets 2 to 5, the basal diet was supplemented with 4 graded levels of DL-Met to make SAA:Lys of 56%, 60%, 64% and 68%. In Exp.1, piglets were housed in disinfected clean room. In Exp. 2, piglets were housed in a room previously occupied by other pigs and was not disinfected. On the last day, blood was collected to measure plasma urea nitrogen(PUN) and one pig per pen was euthanized to collect jejunal tissue to measure villus height(VH), crypt depth(CD), and VH:CD. In Exp. 1, increasing SAA:Lys linearly and quadratically increased VH and VH:CD(P < 0.05). In Exp. 2, increasing SAA:Lys linearly increased(P < 0.05) VH and VH:CD and linearly and quadratically decreased PUN(P < 0.05). Estimated PUN and VH-based optimum SAA:Lys requirements for clean and unclean sanitary condition were 60%, 63% and 66%, respectively.
