Abstract：
Body-condition dynamics are known to affect the different steps of reproduction in cattle (cyclicity, estrus expression, fertilization, embryo development). This has led to a widespread idea that there is an ideal-target optimal body condition, but no clear profile has yet been identified. Here we investigated the relationships between body condition score (BCS) profiles and reproductive performance in dairy cows. Data were from Holstein or Normande herds in 6 French experimental farms. In the Holstein breed, we discriminated 4 BCS profiles based on combining BCS at calving (Low: around 2.6 points, or High: around 3.3 points) with BCS loss after calving (Moderate (M): ≤ 1.0 points, or Severe (S): > 1.0 points). The Low-M profile mostly included multiparous cows with higher milk yield and lower reproductive performance than cows in the 3 other profiles. Low-M cows that experienced abnormal ovarian activity had lower reproductive performance than their profile-mates. Moreover, 67% of Low-M cows kept the same profile at the following lactation. The High-S profile mostly included primiparous cows with lower milk yield and higher reproductive performance than cows in other profiles. In High-S cows, higher milk yields correlated to higher risk of failure to calf on first insemination. Moreover, 38% of High-S cows kept the same profile at the following lactation, and none changed to Low-M. The other 2 BCS profiles (Low-S and High-M) were intermediate in terms of milk yield and reproductive performance. In Normande, we discriminated 3 BCS profiles based on combining BCS at calving (Low: around 2.6 points, or High: around 3.5 points) with BCS loss after calving (Flat (F): flat with no loss, Moderate (M): around 0.5 points, or Severe (S): around 1.0 point). The Low-M and High-S profiles included cows with similar performance, even though High-S-profile cows showed better but not significantly different milk yield and reproduction performance. The High-F profile included cows that were more likely to experience abnormal ovarian activity and fail at first insemination than cows in other profiles. More than 50% of Normande cows with 2 successive lactations kept in the same BCS profile at the next lactation. Even though a low BCS at calving combined with severe BCS loss (more than 1 point) after calving was found to increase reproductive failure, there was no evidence of an optimal BCS profile for reproduction in dairy cows, and reproductive success or failure is multifactorial.
摘要：
已知身体状况动力学会影响牛的不同繁殖步骤(周期性，发情表情,受精,胚胎发育)。这导致了一个普遍的想法，即有一个理想的目标最佳身体状况，但还没有明确的侧写.在这里，我们调查了奶牛的身体状况评分（BCS）与繁殖性能之间的关系。数据来自6个法国实验农场的荷斯坦或诺曼德牧群。在Holstein品种中，我们根据产卵时的BCS组合区分了4个BCS配置文件(低：约2.6点，或高：约3.3点）产卵后BCS损失（中度（M）：≤1.0点，或严重（S）：>1.0分）。Low-M概况主要包括与其他3个概况中的奶牛相比具有更高的产奶量和更低的繁殖性能的多胎奶牛。经历卵巢活动异常的低M母牛的繁殖性能低于其同伴。此外，67%的低M奶牛在接下来的泌乳期保持相同的分布。High-S概况主要包括初产奶牛，其产奶量较低，繁殖性能高于其他概况。在高S奶牛中，较高的产奶量与第一次授精时小腿失败的风险较高相关。此外，38%的高S奶牛在接下来的泌乳期保持相同的轮廓，没有人更改为Low-M。其他2个BCS曲线（低S和高M）在产奶量和繁殖性能方面处于中等水平。在诺曼德,我们根据产卵时的BCS组合区分了3个BCS配置文件(低：约2.6点，或高：约3.5分）产卵后BCS损失（平坦（F）：平坦，无损失，中度（M）：约0.5点，或严重（S）：约1.0点）。低M和高S配置文件包括具有相似性能的奶牛，即使高S型奶牛表现出更好但没有显着差异的产奶量和繁殖性能。高F概况包括比其他概况中的母牛更可能经历卵巢活动异常并且在第一次授精时失败的母牛。超过50%的具有2次连续泌乳的诺曼德奶牛在下一次泌乳时保持在相同的BCS特征中。即使产卵时的BCS较低，产卵后的BCS严重丢失（超过1点）也会增加繁殖失败，没有证据表明奶牛繁殖的最佳BCS曲线，生殖的成功或失败是多因素的。
