Effect of crambe meal on performance, reproduction, and thyroid hormone levels in gestating and lactating beef cows

Crambe meal was compared to a combination of sunflower and soybean meal as a protein supplement for mature beef cows in two experiments. In Exp. 1, co ws (n = 80, average BW 651 +/- 14.4 kg) were fed crambe meal at 9.86% of dr y matter intake (DMI) during the last trimester of gestation. No difference s (P < .05) were detected due to treatment for cow weight, condition score, thyroid hormones, calf birth weight, or calving interval. In Exp. 2, cows (n = 100, average BW 566 +/- 6.82 kg) were fed crambe meal at 7.44% of DMI during the last trimester of gestation and at 8.33% of DMI during early lac tation (53 +/- 6 d of lactation). Gains were greater during gestation (P =. 09) and throughout the supplementation period (P = .06), and days to first estrus were reduced (P < .01) for cows fed crambe meal. During lactation, serum triiodothyronine (T-3) concentrations did not decline as much (P = .0 3) in cows fed crambe meal as in cows fed sunflower-soybean meal-based supp lements. No differences (P > .10) were apparent for condition score, birth weight, calf growth rate, weaning weight, thyroid hormones during gestation , or calving interval. These data indicate that crambe meal fed at the leve ls used in this experiment can be used as a protein supplement for beef cow s without negatively affecting cows' performance.