Sveberg G, Rogers G W, Cooper J, Refsdal A O, Erhard H W, Kommisrud E, Buckley F, Waldmann A, Ropstad E
Department of Production Animals Clinical Sciences, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Science, N-0033 Oslo, Norway.
GENO Breeding and AI Association, N-2317 Hamar, Norway.
J Dairy Sci. 2015 Apr;98(4):2450-61. doi: 10.3168/jds.2014-8905. Epub 2015 Jan 23.
This study addressed the effect of breed on estrus length and estrous behavior by observing 20 Holstein-Friesian (HF) and 20 Norwegian Red (NRF) cows on an outdoor wood-chip pad through 1 estrous cycle (22d). Detailed behavioral data were collected by continuous (24 h) video monitoring of all cows. Accurate estimation of duration of estrous periods, behavioral signs (sum per period and counts per hour), and duration and number of sexually active groups were reported through all stages of mount estrus (prestand, standing estrus, and poststand). These dependent variables were analyzed with a basic statistical model that included fixed effects for breed and lactation group. Other independent variables (milk yield, body condition score, and number of cows in standing estrus) were added to the basic model one by one and included in an expanded model if they had an effect on the respective dependent variables. Estrus duration was considerably shorter in HF compared with NRF cows for all the major periods: mount estrus (11.2 ± 3.0 vs. 21.3 ± 2.7 h), standing estrus (7.1 ± 1.4 vs. 11.7 ± 1.3 h), mounting period (6.9 ± 2.7 vs. 18.2 ± 2.4 h), and mounted period (9.2 ± 2.8 vs. 17.5 ± 2.6 h). Additionally, the NRF cows spent more time in sexually active groups (36.1 ± 4.0 vs. 17.6 ± 4.8%) during standing estrus compared with HF cows. The NRF cows participated in a greater number of sexually active groups (9.6 ± 1.3 vs. 5.5 ± 1.3) with longer average duration (0.42 ± 0.04 vs. 0.20 ± 0.04 h) and continued to be more active in these groups through late stages of estrus (poststand) compared with the HF breed. Mounting activity differed between breeds as NRF mounted more times in total (46.3 ± 6.2 vs. 18.1 ± 6.3) and per hour (2.6 ± 0.4 vs. 1.5 ± 0.5) during mount estrus. In addition, NRF tended to express the primary estrous sign, standing when mounted, more often during standing estrus (32.4 ± 5.0 vs. 18.5 ± 5.2). The HF initiated more unsuccessful mounts (1.6 ± 0.3 vs. 0.6 ± 0.3) per hour than did NRF during mount estrus. A significant effect of milk yield was demonstrated only on this behavior. For other estrous signs, HF cows initiated chase-up (2.0 ± 0.5 vs. 0.5 ± 0.4) and anogenital sniff (3.7 ± 0.6 vs. 2.0 ± 0.5) more frequently (counts per hour), whereas NRF expressed more total head butt behavior (32.3 ± 4.7 vs. 14.2 ± 4.8) during mount estrus. Body condition score had a significant effect on receptive behavior. Measures of estrus duration, sexually active group activity, and behavior related to estrus should be subjected to larger studies for improved heat detection and possible implementation in breeding programs.
本研究通过在户外木屑垫上对20头荷斯坦-弗里生（HF）奶牛和20头挪威红牛（NRF）奶牛进行1个发情周期（22天）的观察，探讨了品种对发情持续时间和发情行为的影响。通过对所有奶牛进行连续（24小时）视频监测来收集详细的行为数据。报告了发情期各阶段（爬跨前期、站立发情期和爬跨后期）发情期持续时间、行为迹象（每个阶段的总和及每小时的次数）以及性活跃群体的持续时间和数量的准确估计值。这些因变量采用基本统计模型进行分析，该模型包括品种和泌乳组的固定效应。其他自变量（产奶量、体况评分和站立发情期的奶牛数量）逐一添加到基本模型中，如果它们对各自的因变量有影响，则纳入扩展模型。在所有主要阶段，HF奶牛的发情持续时间明显短于NRF奶牛：爬跨发情期（11.2±3.0小时对21.3±2.7小时）、站立发情期（7.1±1.4小时对11.7±1.3小时）、爬跨期（6.9±2.7小时对18.2±2.4小时）和被爬跨期（9.2±2.8小时对17.5±2.6小时）。此外，与HF奶牛相比，NRF奶牛在站立发情期处于性活跃群体的时间更长（36.1±4.0%对17.6±4.8%）。与HF品种相比，NRF奶牛参与性活跃群体的数量更多（9.6±1.3对5.5±1.3），平均持续时间更长（0.42±0.04小时对0.20±0.04小时），并且在发情后期（爬跨后期）在这些群体中仍然更活跃。不同品种的爬跨行为存在差异，在爬跨发情期，NRF奶牛总的爬跨次数（46.3±6.2对18.1±6.3）和每小时的爬跨次数（2.6±0.4对1.5±0.5）更多。此外，在站立发情期，NRF奶牛更倾向于表现出主要的发情迹象，即被爬跨时站立，频率更高（32.4±5.0对18.5±5.2）。在爬跨发情期，HF奶牛每小时发起的不成功爬跨次数（1.6±0.3对0.6±0.3）比NRF奶牛多。仅产奶量对这种行为有显著影响。对于其他发情迹象，在爬跨发情期，HF奶牛更频繁地发起追逐（2.0±0.5对0.5±0.4）和肛门生殖器嗅闻（3.7±0.6对2.0±0.5）（每小时次数），而NRF奶牛表现出更多的总头部顶撞行为（32.3±4.7对14.2±4.8）。体况评分对接受行为有显著影响。应对发情持续时间、性活跃群体活动以及与发情相关的行为进行更大规模的研究，以改进发情检测并可能应用于育种计划。
