TY - JOUR
T1 - Effect of whole-crop pea (Pisum sativum L.) silages differing in condensed tannin content as a substitute for grass silage and soybean meal on the performance, metabolism, and carcass characteristics of lambs
AU - Hart, K. J.
AU - Sinclair, L. A.
AU - Wilkinson, R. G.
AU - Huntington, J. A.
PY - 2011/11
Y1 - 2011/11
N2 - Two experiments were conducted to investigate the effect of inclusion of whole-crop pea (WCP) silages, differing in condensed tannin content, as a substitute for grass silage (GS) and soybean meal on lamb metabolism, performance, plasma metabolites, digestibility, and carcass characteristics. In both experiments lambs were offered either solely GS or a 50: 50 mix on a DM basis of GS with either low-tannin (LTPS) or high-tannin (HTPS) pea silage ad libitum. Each forage mix was fed with either 400 g/d of low-protein (LP) concentrate or 400 g/d of LP with an additional 200 g/d of pelletized soybean meal (HP), resulting in 6 dietary treatments. Experiment 1 examined the effects of the diets on metabolism, digestibility, and N balance using 6 lambs in 4 periods of 21 d in an incomplete crossover design. Experiment 2 used 48 lambs and examined the effects of the diets on ADG, plasma metabolites, and carcass characteristics over 56 d. Both experiments were analyzed using a 3 x 2 factorial arrangement of treatments. In Exp. 1, lambs offered the LTPS diets had a greater (P <0.05) digestibility of DM and OM than those offered the GS diets. Lambs offered the WCP silages had an increased (P <0.05) N intake, N output, and digestibility of GE compared with those offered GS. Mean N digestibility was greatest (P <0.05) in lambs offered LTPS. Lambs offered HP diets had increased (P <0.001) digestibility of DM, OM, GE and N, and N-intake, output, retention, and digestibility compared with those offered the LP diets. In Exp. 2, there was no effect (P > 0.05) of forage type on intake, slaughter BW, or feed conversion efficiency (FCE). However, lambs offered the LTPS had a greater (P <0.05) ADG than those offered the GS diets. Feeding diets containing HP increased (P <0.001) total DMI, slaughter BW, ADG, and FCE. Lambs offered the WCP had a greater (P <0.05) plasma beta-hydroxybutyrate and urea concentration compared with those offered the GS diets. Feeding lambs HP diets increased (P <0.05) plasma urea and total protein. Forage mix had no effect (P > 0.05) on carcass composition except for fat depth, which was greater (P <0.05) in lambs offered WCP silage. Diets containing the HP increased (P <0.05) carcass weight, hind leg circumference, chop dimensions, and kidney weight. It was concluded that lambs offered LTPS performed better than those offered GS and that LTPS has a concentrate sparing effect. Additionally, the increased tannin concentration in HTPS did not increase performance over lambs offered either GS or LTPS.
AB - Two experiments were conducted to investigate the effect of inclusion of whole-crop pea (WCP) silages, differing in condensed tannin content, as a substitute for grass silage (GS) and soybean meal on lamb metabolism, performance, plasma metabolites, digestibility, and carcass characteristics. In both experiments lambs were offered either solely GS or a 50: 50 mix on a DM basis of GS with either low-tannin (LTPS) or high-tannin (HTPS) pea silage ad libitum. Each forage mix was fed with either 400 g/d of low-protein (LP) concentrate or 400 g/d of LP with an additional 200 g/d of pelletized soybean meal (HP), resulting in 6 dietary treatments. Experiment 1 examined the effects of the diets on metabolism, digestibility, and N balance using 6 lambs in 4 periods of 21 d in an incomplete crossover design. Experiment 2 used 48 lambs and examined the effects of the diets on ADG, plasma metabolites, and carcass characteristics over 56 d. Both experiments were analyzed using a 3 x 2 factorial arrangement of treatments. In Exp. 1, lambs offered the LTPS diets had a greater (P <0.05) digestibility of DM and OM than those offered the GS diets. Lambs offered the WCP silages had an increased (P <0.05) N intake, N output, and digestibility of GE compared with those offered GS. Mean N digestibility was greatest (P <0.05) in lambs offered LTPS. Lambs offered HP diets had increased (P <0.001) digestibility of DM, OM, GE and N, and N-intake, output, retention, and digestibility compared with those offered the LP diets. In Exp. 2, there was no effect (P > 0.05) of forage type on intake, slaughter BW, or feed conversion efficiency (FCE). However, lambs offered the LTPS had a greater (P <0.05) ADG than those offered the GS diets. Feeding diets containing HP increased (P <0.001) total DMI, slaughter BW, ADG, and FCE. Lambs offered the WCP had a greater (P <0.05) plasma beta-hydroxybutyrate and urea concentration compared with those offered the GS diets. Feeding lambs HP diets increased (P <0.05) plasma urea and total protein. Forage mix had no effect (P > 0.05) on carcass composition except for fat depth, which was greater (P <0.05) in lambs offered WCP silage. Diets containing the HP increased (P <0.05) carcass weight, hind leg circumference, chop dimensions, and kidney weight. It was concluded that lambs offered LTPS performed better than those offered GS and that LTPS has a concentrate sparing effect. Additionally, the increased tannin concentration in HTPS did not increase performance over lambs offered either GS or LTPS.
KW - FINISHING LAMBS
KW - metabolism
KW - DIFFERENT PROTEIN SUPPLEMENTS
KW - DIETARY ENERGY
KW - IN-VIVO
KW - whole-crop peas
KW - MILK-PRODUCTION
KW - WHEAT INTERCROPS
KW - performance
KW - FORAGE LEGUMES
KW - CV BLANCA
KW - tannin
KW - RUMINANTS
KW - DAIRY-COWS
KW - silage
UR - http://hdl.handle.net/2160/9091
U2 - 10.2527/jas.2009-2617
DO - 10.2527/jas.2009-2617
M3 - Article
SN - 0021-8812
VL - 89
SP - 3663
EP - 3676
JO - Journal of Animal Science
JF - Journal of Animal Science
IS - 11
ER -