Department of Animal Science, Division of Agriculture, University of Arkansas, Little Rock 72204, USA.
J Anim Sci. 2012 May;90(5):1583-8. doi: 10.2527/jas.2011-4088. Epub 2011 Dec 6.
The relationship between barometric pressure (BARO) and maximum (MAX_T) and minimum (MIN_T) environmental temperatures with the incidence of parturition in beef cows was examined through exploratory data analysis. Spring- and fall-calving records from a 5-yr period (2005 through 2009) collected at the University of Arkansas, Livestock and Forestry Research Station (Batesville) and the Department of Animal Science Savoy Research Unit (Savoy, AR) were used. All cows were multiparous, predominantly Angus, and naturally bred. During this period, 2,210 calves were born over a cumulative 1,547 d. Local weather station BARO and MAX_T and MIN_T data were obtained from the Southern Regional Climate Center, Louisiana State University, Baton Rouge. The combined calving record and climate variables were used to determine differences in BARO, MAX_T, and MIN_T on d 0 (d of calving) and -1, -2, or -3 d, respectively, before calving occurred (CALFD) or did not occur (NOCALFD). Location and season also were included in the model. For fall-calving cows, BARO on d 0 and -1, -2, or -3 was not different between CALFD and NOCALFD (P > 0.10). For spring-calving cows, BARO on d 0, -1, -2, and -3 was greater (P < 0.05) for CALFD compared with NOCALFD. The MAX_T was greater on d -1 (24.4 vs. 22.9°C) and -3 (24.8 vs. 23.4°C) for CALFD in the fall compared with NOCALFD (P < 0.05). No differences were detected in the fall for MAX_T on d 0 or -2 (P > 0.10). In the spring, a decreased MAX_T was associated with CALFD. Maximum environmental temperatures on d 0 (14.7 vs. 16.0°C), -1 (14.4 vs. 16.0°C), and -3 (14.0 vs. 15.7°C) were less for CALFD compared with NOCALFD (P < 0.05). No difference was detected on d -2 (P > 0.10). For fall, MIN_T was greater on d -1 (12.8 vs. 11.3°C), -2 (13.0 vs. 11.4°C), and -3 (13.1 vs. 11.7°C) for CALFD compared with NOCALFD (P < 0.05). In spring, MIN_T for d 0 (2.6 vs. 3.9°C), -1 (2.5 vs. 3.7°C), -2 (2.1 vs. 3.7°C), and -3 (1.8 vs. 3.8°C) were lesser (P < 0.05) for CALFD vs. NOCALFD. These data indicate that for spring-calving cows, a greater BARO and decreased MAX_T and MIN_T were associated with CALFD, whereas for fall-calving cows, an increase in MAX_T and MIN_T was associated with CALFD. Therefore, monitoring weather conditions may assist producers in preparing for the obstetric assistance of beef cattle.
通过探索性数据分析，研究了大气压力（BARO）和环境最高温度（MAX_T）和最低温度（MIN_T）与肉牛分娩之间的关系。本研究使用了阿肯色大学牲畜和林业研究站（贝茨维尔）和动物科学萨维奥研究单位（萨维奥，AR）在 5 年期间（2005 年至 2009 年）收集的春季和秋季分娩记录。所有的奶牛都是经产的，主要是安格斯牛，并且是自然繁殖的。在此期间，共有 2210 头犊牛在 1547 天内出生。当地气象站的 BARO 和 MAX_T 和 MIN_T 数据是从路易斯安那州立大学南方区域气候中心获得的。将分娩记录和气候变量结合起来，以确定分娩当天（d0）和分娩前 1、2 或 3 天（分别为 CALFD 和 NOCALFD）的 BARO、MAX_T 和 MIN_T 之间的差异。还包括位置和季节。对于秋季分娩的奶牛，CALFD 和 NOCALFD 之间的 d0 和-1、-2 或-3 日的 BARO 没有差异（P > 0.10）。对于春季分娩的奶牛，CALFD 的 d0、-1、-2 和-3 的 BARO 大于 NOCALFD（P < 0.05）。秋季分娩的奶牛，d-1 的 MAX_T 更高（24.4 对 22.9°C），d-3 的 MAX_T 更高（24.8 对 23.4°C）（P < 0.05），而 NOCALFD 则没有差异。在秋季，d0 或-2 的 MAX_T 没有差异（P > 0.10）。在春季，与 NOCALFD 相比，CALFD 的 MAX_T 较低。d0（14.7 对 16.0°C）、-1（14.4 对 16.0°C）和-3（14.0 对 15.7°C）的最大环境温度较低（P < 0.05）。在 d-2 没有差异（P > 0.10）。对于秋季，d-1（12.8 对 11.3°C）、-2（13.0 对 11.4°C）和-3（13.1 对 11.7°C）的 MIN_T 较高（P < 0.05），CALFD 比 NOCALFD 高。在春季，d0（2.6 对 3.9°C）、-1（2.5 对 3.7°C）、-2（2.1 对 3.7°C）和-3（1.8 对 3.8°C）的 MIN_T 较低（P < 0.05），CALFD 比 NOCALFD 低。这些数据表明，对于春季分娩的奶牛，BARO 增加和 MAX_T 和 MIN_T 减少与 CALFD 有关，而对于秋季分娩的奶牛，MAX_T 和 MIN_T 的增加与 CALFD 有关。因此，监测天气状况可能有助于生产者为肉牛的产科援助做好准备。
