Effects of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on the probability of conception in New York State Holstein dairy cows
Effects of clinical mastitis caused by gram-positive and gram-negative bacteria and other organisms on the probability of conception in New York State Holstein dairy cows
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DOI：
10.3168/jds.2009-2599
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发表时间：
2010-04-01
影响因子：
3.5
通讯作者：
Schukken, Y. H.
中科院分区：
文献类型：
--
作者：
Hertl, J. A.;Groehn, Y. T.;Schukken, Y. H.
本研究的目的是评估不同类型的临床型乳房炎（CM）对纽约州荷斯坦奶牛受孕概率的影响。在7个牛群的14，148头奶牛的23，695次泌乳中，获得了55，372次人工授精（AI）的数据。我们使用广义线性混合模型来模拟奶牛是否在特定AI之后受孕。自变量包括AI数（第一，第二，第三，第四），奇偶性，季节时，AI发生，农场，CM的类型（由于革兰氏阳性菌，革兰氏阴性菌，或其他生物体）在6周之前和之后的AI，和其他疾病的发生。年龄较大的奶牛不太可能怀孕。在夏季进行的授精最不可能成功。胎盘滞留会降低受孕的可能性。每次连续AT受孕的可能性也较小。与第一次人工授精相关的受孕概率为0.29。第二、第三和第四AI的受孕概率分别降至0.26、0.25和0.24。在AI前14天至AI后35天之间的任何时间发生的临床乳腺炎与较低的受孕概率相关;最大的影响是AT后一周发生的革兰氏阴性CM减少80%。一般来说，由于革兰氏阴性菌引起的CM比革兰氏阳性菌或其他微生物引起的CM对受孕概率的不利影响更大。此外，CM在AT前后对受孕概率的影响更大。关于CM的其他信息（即，其关于AI的时间，以及病原体是革兰氏阳性还是革兰氏阴性细菌，还是其他生物体）对于奶牛场工作人员确定为什么一些奶牛不能及时怀孕是有价值的。这些发现也有利于乳腺炎奶牛（特别是革兰氏阴性CM奶牛）在接近AI时发生乳腺炎的管理。
The objective of this study was to estimate the effects of different types of clinical mastitis (CM) on the probability of conception in New York State Holstein cows. Data were available on 55,372 artificial inseminations (AI) in 23,695 lactations from 14,148 cows in 7 herds. We used generalized linear mixed models to model whether or not a cow conceived after a particular AI. Independent variables included AI number (first, second, third, fourth), parity, season when AI occurred, farm, type of CM (due to gram-positive bacteria, gram-negative bacteria, or other organisms) in the 6 wk before and after an AI, and occurrence of other diseases. Older cows were less likely to conceive. Inseminations occurring in the summer were least likely to be successful. Retained placenta decreased the probability of conception. Conception was also less likely with each successive AT. The probability of conception associated with the first AI was 0.29. The probability of conception decreased to 0.26, 0.25, and 0.24 for the second, third, and fourth AI, respectively. Clinical mastitis occurring any time between 14 d before until 35 d after an AI was associated with a lower probability of conception; the greatest effect was an 80% reduction associated with gram-negative CM occurring in the week after AT. In general, CM due to gram-negative bacteria had a more detrimental effect on probability of conception than did CM caused by gram-positive bacteria or other organisms. Furthermore, CM had more effect on probability of conception immediately around the time of AT. Additional information about CM (i.e., its timing with respect to AI, and whether the causative agent is gram-positive or gram-negative bacteria, or other organisms) is valuable to dairy personnel in determining why some cows are unable to conceive in a timely manner. These findings are also beneficial for the management of mastitic cows (especially those with gram-negative CM) when mastitis occurs close to AI.