Machado-Ramos Maria G, Meza-Herrera Cesar A, De Santiago-Miramontes Angeles, Mellado Miguel, Véliz-Deras Francisco G, Arellano-Rodríguez Fernando, Contreras-Villarreal Viridiana, Arévalo José R, Carrillo-Moreno Dalia I, Flores-Salas Jessica M
Programa de Posgrado en Ciencias en Producción Agropecuaria, Universidad Autónoma Agraria Antonio Narro Unidad Laguna, Torreon 27054, Mexico.
Unidad Regional Universitaria de Zonas Áridas, Universidad Autónoma Chapingo, Bermejillo 35230, Mexico.
Animals (Basel). 2023 Jul 27;13(15):2431. doi: 10.3390/ani13152431.
Based on a circular economy approach, we evaluated the possible effect of targeted supplementation with leftover feed from dairy cows (i.e., intensive system) on the reproductive performance of crossbred/rangeland goats (i.e., extensive system) in arid Northern Mexico. During the deep-anestrous season (i.e., March-April, 25° North), multiparous goats ( = 38) with a similar body weight (BW) and body condition score (BCS) were randomly assigned to two groups: (1) supplemented group (SG; = 19; BCS: 1.76 ± 0.07; BW: 43.7 ± 1.8 kg), receiving 400 g goat d of dairy-cow-feed leftovers prior to grazing; and (2) non-supplemented group (NS; = 19; BCS: 1.76 ± 0.06; BW: 44.3 ± 2.5 kg). Both groups were directed to the rangeland for a period of ≈8 h. While the experimental period lasted 36 d, the experimental breeding considered 11 d (d0-d10). The anovulatory status of goats was ultrasonographically confirmed on days -20, -10, and -1 prior to male-female interaction. Previously, bucks were separated for 3 weeks from the experimental females and received exogenous testosterone every third day (i.e., 50 mg i.m.) prior to mating. With respect to the response variables, namely BW, BCS, blood glucose levels (BGLs), estrus induction (GIE, %), latency to estrus (LTE, h), estrus duration (ED, h), and luteal tissue volume (LTV, mm), no differences ( > 0.05) occurred between experimental groups. However, the response variables, namely goats ovulating (GO, %; 78.9 vs. 47.3), total number of corpuses luteum (TNCL, ; 27 vs. 13), ovulation rate (OR, ; 1.42 vs. 0.73), multiple ovulation (MO, %; 73.3 vs. 55.5), and pregnancy rate on d 36 (PRd36, %, 68.4 vs. 36.8), favored ( < 0.05) the SG over the NS goats. Our results demonstrate that connecting the circularity of two divergent ruminant production systems (i.e., cow-intensive and goat-extensive) by using dairy cows' feed leftovers as a targeted supplementation strategy in anestrous goats under a marginal-rangeland production system enhanced out-of-season reproductive outcomes (i.e., ovulation rate and pregnancy rate), thus benefiting marginal goat producers and their families.
基于循环经济方法，我们评估了在墨西哥北部干旱地区，用奶牛剩余饲料（即集约系统）对杂交/草原山羊（即粗放系统）进行定向补饲，对其繁殖性能可能产生的影响。在深度乏情期（即3月至4月，北纬25°），将体重（BW）和体况评分（BCS）相近的经产山羊（n = 38）随机分为两组：（1）补饲组（SG；n = 19；BCS：1.76±0.07；BW：43.7±1.8 kg），在放牧前每天补饲400 g奶牛剩余饲料；（2）未补饲组（NS；n = 19；BCS：1.76±0.06；BW：44.3±2.5 kg）。两组均被驱赶至牧场放牧约8小时。试验期持续36天，试验配种期为11天（d0 - d10）。在公母羊混群前第20天、第10天和第1天，通过超声检查确认山羊的无排卵状态。此前，将公羊与试验母羊分开3周，并在配种前每隔一天注射一次外源睾酮（即肌肉注射50 mg）。关于反应变量，即BW、BCS、血糖水平（BGLs）、发情诱导率（GIE，%）、发情潜伏期（LTE，小时）、发情持续时间（ED，小时）和黄体组织体积（LTV，mm），两组之间无差异（P>0.05）。然而，反应变量，即排卵山羊比例（GO，%；78.9对47.3）、黄体总数（TNCL，个；27对13）、排卵率（OR，个；1.42对0.73）、多排卵比例（MO，%；73.3对55.5）和第36天的妊娠率（PRd36，%，68.4对36.8），补饲组山羊优于未补饲组（P<0.05）。我们的研究结果表明，在边际牧场生产系统下，利用奶牛剩余饲料作为乏情期山羊的定向补饲策略，将两种不同的反刍动物生产系统（即奶牛集约型和山羊粗放型）的循环性联系起来，可提高季节性外繁殖效果（即排卵率和妊娠率），从而使边际山羊养殖户及其家庭受益。
