PSI-18 Effects of supplementing polyunsaturated fatty acids during late gestation on performance of fall-calving cows

Abstract

Abstract The objective was to determine the effects of supplementing calcium salts of PUFA or SFA + MUFA during late gestation on performance of fall-calving beef cows through calving. Mature, Simmental x Angus cows confirmed pregnant to a synchronized artificial insemination (AI) and fetal sexed were selected prior to the start of the experiment. At 200 d of gestation, cows (n = 96; BW = 603 ± 72 kg) were stratified by age, AI service sire, fetal sex and BW and allotted to 8 groups. Groups were randomly assigned to 1 of 2 treatments (4 groups per treatment): SFA + MUFA (0.155 kg of EnerGII per cow per day on a DM basis) and PUFA (0.08 kg of Strata and 0.08 kg of Prequel per cow per day on a DM basis). The SFA + MUFA supplement included palmitic and oleic acid. The PUFA supplement included eicosapentaenoic acid, docosahexaenoic acid, and linoleic acid. All cows grazed endophyte-infected tall fescue and were supplemented 2 kg DM per cow per d of soybean hulls for 78 d during late gestation in addition to their treatment supplement. Body condition score and BW were collected at trial initiation, during supplementation, before calving, and after calving. Pen was the experimental unit and BW, BCS, and calf BW were analyzed using the MIXED procedure of SAS. The BW and BCS at trial initiation, during supplementation, before calving, and after calving of the cows supplemented PUFA were not different (P ≥ 0.38) than the BW and BCS of cows supplemented SFA + MUFA. Calf birth BW from cows supplemented with PUFA were not different (P = 0.87) than calf birth BW from cows supplemented with SFA + MUFA. Supplementing cows PUFA during late gestation in fall-calving cows did not affect BW, BCS or calf birth BW.