31 Effect of polyunsaturated fatty acid and methionine supplementation during late gestation on offspring growth, glucose tolerance test, and carcass characteristic in sheep

Abstract

Abstract The objective of this study was to evaluate the effect of supplementing polyunsaturated fatty acids (PUFA), methionine (M) or both to ewes during late gestation on offspring growth, dry matter intake (DMI), carcass composition, and glucose and insulin metabolism (by conducting a glucose tolerance test (GTT)). Seventy-two post-weaned lambs (6 pens/treatment, 3 lambs/pen) born from ewes supplemented from gestation day 100 until lambing were used. Dam supplementation was: 1) no PUFA nor M supplementation (NFA-NM); 2) supplementation with PUFA (PUFA-NM, 1 % StrataG113); 3) supplementation with M (NFA-MET, 0.1 % rumen protected methionine, Smartamine); and 4) supplementation with PUFA and M (PUFA-MET). At weaning (60 days of age) lambs were fed a common finishing diet for 54 days, and DMI was measured daily. Lambs were weighed on weaning day (d0), d28, and d54. Twenty-four lambs (one per pen) were used for a GTT on d55. On d56, other 24 lambs were harvested for carcass characteristics measurements. Offspring data was analyzed as a 2x2x2 factorial (FA, M, and sex). Ewe supplementation affected (P < 0.1) lamb DMI. On d54 lambs born from No FA and methionine showed a greater DMI. There was a tendency for plasma glucose concentration for PUFA*MET*Time (P = 0.07) in the GGT. Lambs born from ewes supplemented with methionine had greater glucose concentration than NFA-NM born lambs, and lambs born from PUFA*MET had greater glucose concentration than the other lambs at 2m of the GGT. Dam MET supplementation decreased lamb’s insulin response (P = 0.06). Hot carcass weight (HCW) (P = 0.08) and Ribeye area (REA) (P = 0.02) were affected by treatment and sex. A tendency and a triple interaction FA*MET*Sex were observed; NFA-MET methionine had a greater HCW and a larger REA. In conclusion, lamb’s insulin response and carcass characteristics are affected by dam’s supplementation.