Departamento de Produção Animal, Faculdade de Medicina Veterinária e Zootecnia-UNESP, Botucatu-SP 18618-000, Brazil.
J Anim Sci. 2009 Dec;87(12):3935-43. doi: 10.2527/jas.2009-2201. Epub 2009 Aug 14.
Five experiments evaluated the effects of rumen-protected PUFA supplementation on reproductive function of Bos indicus beef cows. In Exp. 1, 910 lactating primiparous Nelore cows were randomly assigned to receive 0.4 kg/d of a protein-mineral mix in addition to 0.1 kg/d of a rumen-inert PUFA source (PF) or 0.1 kg/d of kaolin (rumen-inert indigestible substance; control), from the beginning of estrus synchronization protocol (d -11) until 28 d after fixed-time AI (TAI; d 28). Cows supplemented with PF had greater (P = 0.04) pregnancy rates compared with control cows (51.2 vs. 39.6%). In Exp. 2, 818 lactating primiparous Nelore cows were assigned to the same TAI schedule from Exp. 1 and randomly allocated to receive 1) control from d -11 to 28, 2) PF from d -11 to 16 and control from d 17 to 28, or 3) PF from d -11 to 28. Cows receiving PF until d 28 had greater (P = 0.02) pregnancy rates compared with control cows and tended to have greater (P = 0.10) pregnancy rates compared with cows receiving PF until d 16 (42.9, 31.3, and 35.8%, respectively). In Exp. 3, 435 nulliparous and multiparous lactating B. indicus-crossbred cows were randomly assigned to receive control or PF from the end of synchronization protocol (d 0) until 21 d after fixed-time embryo transfer (d 28). Cows supplemented with PF had greater (P = 0.07) pregnancy rates compared with control cows (49.6 vs. 37.7%). In Exp. 4, 504 lactating multiparous Nelore cows were randomly assigned to receive PF or a similar supplement containing a rumen-protected SFA source (SF) for 28 d beginning after TAI. Cows supplemented with PF had greater (P = 0.02) pregnancy rates compared with SF cows (47.9 vs. 35.5%). In Exp. 5, 9 nonlactating, nonpregnant, ovariectomized Gir x Holstein cows inserted with an intravaginal progesterone (P4)-releasing device were stratified by BW and BCS and divided into 3 squares. Squares were randomly assigned to receive control, PF, or a protein-mineral mix containing 0.2 kg/d of rumen-inert PUFA source (PF2), in a Latin square 3 x 3 design containing 3 periods of 14 d each. Cows supplemented with PF had greater (P = 0.03) mean serum P4 concentrations compared with control and PF2 cows (1.81, 1.66, and 1.68 ng/mL, respectively). These results indicate that supplementing 0.1 kg/d of rumen-inert PUFA to beef cows, particularly after breeding, may be a method of enhancing their reproductive performance, perhaps by increasing circulating P4 concentrations.
五项实验评估了瘤胃保护性 PUFA 补充对印度野牛肉牛繁殖功能的影响。在实验 1 中，910 头泌乳初产 Nelore 奶牛随机分为两组，一组在发情同步方案开始（d-11）至 28 天后固定时间人工授精（d 28）期间，每天额外添加 0.4 公斤蛋白质-矿物质混合物和 0.1 公斤瘤胃惰性 PUFA 源（PF）或 0.1 公斤高岭土（瘤胃惰性不可消化物质；对照）；另一组仅接受对照。与对照组相比，添加 PF 的奶牛妊娠率更高（P = 0.04）（51.2% vs. 39.6%）。在实验 2 中，818 头泌乳初产 Nelore 奶牛按实验 1 的相同 TAI 方案分配，并随机分为三组：1）从 d-11 到 28 接受对照，2）从 d-11 到 16 接受 PF，从 d 17 到 28 接受对照，或 3）从 d-11 到 28 接受 PF。直到 d 28 接受 PF 的奶牛妊娠率更高（P = 0.02），与对照组相比，且与 d 16 开始接受 PF 的奶牛相比，妊娠率也更高（P = 0.10）（42.9%、31.3%和 35.8%）。在实验 3 中，435 头初产和经产泌乳 B. indicus 杂交奶牛随机分为对照组或 PF 组，从同步方案结束（d 0）到 21 天后固定时间胚胎移植（d 28）。添加 PF 的奶牛妊娠率更高（P = 0.07）（49.6% vs. 37.7%）。在实验 4 中，504 头泌乳经产 Nelore 奶牛随机分为 PF 组或类似的含瘤胃保护 SFA 源（SF）的补充剂组，从 TAI 后开始补充 28 天。添加 PF 的奶牛妊娠率更高（P = 0.02）（47.9% vs. 35.5%）。在实验 5 中，9 头非泌乳、非妊娠、卵巢切除术的 Gir x Holstein 奶牛插入阴道内孕酮（P4）释放装置，按体重和体况指数分层，分为 3 个方块。每个方块随机分为对照组、PF 组或含 0.2 公斤/天瘤胃惰性 PUFA 源的蛋白质-矿物质混合物（PF2）组，采用包含 3 个 14 天期的拉丁方 3 x 3 设计。与对照组和 PF2 组相比，添加 PF 的奶牛平均血清 P4 浓度更高（P = 0.03）（1.81、1.66 和 1.68 ng/mL）。这些结果表明，每天补充 0.1 公斤瘤胃惰性 PUFA 可能是提高肉牛繁殖性能的一种方法，尤其是在配种后，这可能是通过增加循环 P4 浓度实现的。
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