Effects of a long-acting, trace mineral, reticulorumen bolus on range cow productivity and trace mineral profiles.

摘要: The objectives were to determine if strategic supplementation of range cows with a long-acting (6 mo), trace mineral, reticulorumen bolus containing Cu, Se, and Co would: (1) increase cow BCS BW, calf birth, weaning, postweaning weights, or weight per day age (WDA); (2) liver concentrations Cu Zn in cows, blood calves; (3) vary by breed for any these response variables. There 192 control 144 bolused Composite (C; 25% Hereford, Angus, Gelbevieh, Senepol Barzona); 236 158 Hereford (H) cows; 208 149 Brahman cross (B) used 3-yr experiment. Cows weighed scored body condition January, May, September, all received boluses January. Each year, from among the 3 groups subset 15 (n = 90) had samples obtained January May Zn, serum Zn. As calves sampled each year September was significant x treatment interaction (P 0.001) loss May. CalfWDA, weights did not differ > 0.40) between but there 0.022) birth weight. Liver deficient ( 75 90 ppm) cows. differed 0.1 except 2001 2002. no difference 0.50) Se greater < 0.01) Breed differences existed B having 0.05) than either C H also less 0.04) Calves 0.01). Supplementation via mineral successful increasing calves, responses varied year. Bolus administration variable effects on BW change early lactation, depending which may indicate need breed- year-specific programs.