Department of Animal and Aquacultural Sciences,Norwegian University of Life Sciences,NO-1432 Ås,Norway.
Animal. 2018 Dec;12(12):2619-2626. doi: 10.1017/S175173111800037X.
Norwegian Red bulls, selected in Norway, have been used for crossbreeding with Israeli Holstein on commercial farms. The aim of this project was to investigate Norwegian Red×Israeli Holstein (NRX) performance to see how the daughters perform in a different environment than the one their sires were selected in. This was done by comparing health and fertility of NRX with their Israeli Holstein (HO) counterparts. The data consisted of 71 911 HO records and 10 595 NRX records from 33 855 cows in 23 Israeli dairy herds. Calving events took place between 2006 and 2016. Five postpartum disorders (mean frequency in HO v. NRX, %) recorded by veterinarians were analyzed: anestrus (37.4 v. 41.2), metritis (40.1 v. 28.6), ketosis (11.9 v. 7.1), lameness (7.1 v. 3.1) and retained placenta (6.2 v. 4.0). The incidence of abortions was also analyzed; HO had a mean frequency of 9.9% and NRX 8.2%. These traits were defined as binary traits, with '1' indicating that the disorder was present and a treatment took place at least once, or '0' if the cow did not show signs of that disorder. Days open (i.e. the number of days from calving to conception), body condition score (BCS) recorded on a 1 to 5 scale and changes in BCS from calving to peak lactation were also analyzed. A logistic model was used for the health traits, while days open and BCS were analyzed with linear models. The model included breed group, herd-year of calving, birth year and parity as fixed effects. There was a significantly higher risk (odds ratio for HO v. NRX in parentheses) of ketosis (1.46), metritis (1.78), lameness (2.07), retained placenta (1.41) and abortion (1.13) in HO compared with NRX. Israeli Holstein heifers and cows in parity 3 to 6 had fewer cases of anestrus than NRX but no differences were found between the groups in parities 1 and 2. Body condition score was higher for NRX than HO and there was less change in BCS from calving to peak lactation in NRX compared with HO. Likewise, NRX had fewer days open than HO. Results indicate that crossbreeding can produce cows with better fertility that are less susceptible to postpartum disorders.
挪威红牛在挪威被选中与以色列荷斯坦牛进行杂交，在商业农场中进行。该项目的目的是研究挪威红牛×以色列荷斯坦牛（NRX）的性能，看看它们的女儿在与其父亲选择的不同环境中表现如何。这是通过比较 NRX 与其以色列荷斯坦牛（HO）对应物的健康和生育能力来完成的。数据包括 23 个以色列奶牛场的 33855 头奶牛的 71911 头 HO 记录和 10595 头 NRX 记录。产犊事件发生在 2006 年至 2016 年之间。由兽医记录的五种产后疾病（HO 中的平均频率 v. NRX，%）进行了分析：乏情（37.4 v. 41.2）、子宫炎（40.1 v. 28.6）、酮病（11.9 v. 7.1）、跛行（7.1 v. 3.1）和胎衣不下（6.2 v. 4.0）。还分析了流产的发生率；HO 的平均频率为 9.9%，NRX 为 8.2%。这些特征被定义为二元特征，其中“1”表示存在疾病并且至少进行了一次治疗，或者“0”表示奶牛没有表现出该疾病的迹象。开产天数（即从产犊到配种的天数）、产犊时记录的体况评分（BCS）为 1 至 5 分以及从产犊到泌乳高峰时 BCS 的变化也进行了分析。使用逻辑模型对健康特征进行分析，而开产天数和 BCS 则使用线性模型进行分析。该模型包括品种组、产犊年份、出生年份和胎次作为固定效应。HO 患酮病（HO v. NRX 的优势比（OR）在括号中）、子宫炎（1.78）、跛行（2.07）、胎衣不下（1.41）和流产（1.13）的风险显著高于 NRX。以色列荷斯坦后备牛和 3 至 6 胎次的奶牛乏情病例比 NRX 少，但 1 胎次和 2 胎次的两组之间没有差异。NRX 的体况评分高于 HO，NRX 从产犊到泌乳高峰时 BCS 的变化小于 HO。同样，NRX 的开产天数少于 HO。结果表明，杂交可以产生具有更高生育力且更不易患产后疾病的奶牛。
