Forty-one purebred Brahman cows were blocked to control (C; n = 20) or lasalocid (L; n = 21) treatments. Cow ADG was increased (P 0.01) in L cows prepartum and tended (P 0.11) to be increased from calving to d 56 after calving in L cows. Postpartum interval (PPI) was unaffected by treatment; however, a greater percentage (P .05) of L cows conceived by 90 d after calving (43% L vs 15% C). First service conception rate tended (P .08) to be greater in L than C (68% L vs 40% C), and pregnancy rate was numerically greater (P .12) in L (86% L vs 65% C). There was a negative correlation between leptin and PPI (r = −0.27; P 0.0001) and a positive correlation between leptin and body condition score (BCS; r = 0.29; P 0.06). Feeding an ionophore prior to calving and throughout the postpartum period increased the number of cows that rebreed to calve at a yearly interval. Cows with higher concentrations of leptin postpartum exhibited shorter PPI. Twenty crossbred heifers were blocked to C (n = 11) and L (n = 9) treatments. There was a significant treatment effect on age at puberty (P 0.03), with L heifers being older at puberty. There was a significant treatment by time (P 0.0001) interaction influencing serum concentrations of IGF-I. There was a positive correlation (r = 0.59; P 0.006) between IGF-I and age at puberty. Ingestion of lasalocid did not alter concentrations of IGF-I and increased age at puberty. Fifty-seven crossbred heifers were utilized to determine the effects of the fibrolytic enzyme preparation Cattle-Ase™ on heifer performance. Cattle-Ase™ did not improve ADG when fed with molasses-lick tanks to heifers grazing coastal bermudagrass pasture, but did increase ADG (P 0.04) when fed with a grain carrier to heifers consuming coastal bermudagrass hay. Cattle-Ase™ increased (P 0.04) the percentage of heifers estrous cycling prior to the start of the breeding season. Ingestion of Cattle-Ase™ when provided in a suitable carrier and with suitable forage improves heifer performance.
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机译：41头纯种婆罗门奶牛被封锁以进行对照（C; n = 20）或lasalocid（L; n = 21）处理。 L牛产犊后，产犊后ADG升高（P <0.01），从产犊到d 56趋于（P <0.11）升高。产后间隔（PPI）不受治疗影响；然而，产犊后90 d受孕的L母牛比例更高（P <.05）（43％L对15％C）。 L的首次服务受孕率倾向于（P <.08）高于C（68％L对40％C），L的怀孕率在数值上更高（P <.12）（L 86％vs 65％C） ）。瘦素与PPI之间呈负相关（r = -0.27; P <0.0001），瘦素与身体状况评分之间呈正相关（BCS; r = 0.29; P <0.06）。在产犊前和整个产后期间喂饲离子载体增加了每年间隔产犊的母牛的数量。产后瘦素浓度较高的母牛表现出较短的PPI。 20头杂种小母牛受C（n = 11）和L（n = 9）处理。青春期的年龄有显着的治疗效果（P <0.03），而小母牛在青春期的年龄更大。时间（P <0.0001）相互作用会影响IGF-I的血清浓度，治疗效果显着。 IGF-I与青春期年龄之间呈正相关（r = 0.59； P <0.006）。摄入拉沙菌素不会改变IGF-I的浓度并不会增加青春期的年龄。使用五十七个杂交小母牛来确定纤溶酶制剂Cattle-Ase™对小母牛性能的影响。当给在沿海百慕大草场放牧的小母牛喂食糖蜜-舔槽时，Cattle-Ase™不能改善ADG，但是当向食用沿海百慕大草的小母牛喂食谷物载体时，Cattle-Ase™却提高了ADG（P <0.04）。在繁殖季节开始之前，Cattle-Ase™增加了发情的小母牛的百分比（P <0.04）。当以适当的载体和适当的草料形式提供Cattle-Ase™时，其摄入可改善小母牛的性能。
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