Institute of Animal Breeding and Genetics, University of Giessen, 35390Giessen, Germany.
Diamond V USA, Cedar Rapids, IA52404, USA.
J Dairy Res. 2021 May;88(2):147-153. doi: 10.1017/S0022029921000327. Epub 2021 Apr 30.
This research paper focuses on time-lagged heat stress (HS) effects from an across-generation perspective. Temperature × humidity indexes (THI) from the last 8 weeks of pregnancy were associated with subsequent female offspring performances. The offspring dataset considered 172 905 Holstein dairy cows from calving years 2002-2013 from 1,968 herds, located in the German federal state of Hesse. Production traits included milk yield (MKG), protein percentage (PRO%), fat percentage (FAT%), somatic cell score (SCS) and milk urea nitrogen (MUN) from the first official test-day in first lactation. Female fertility traits were the non-return-rate after 56 d (NRR56) in heifers and the interval from calving to first insemination (ICFI) in first parity cows. Longevity traits were the length of productive life (LPL), lifetime productivity in milk yield (LTP-MKG) and milk yield per day of life (MKG-DL). The association analyzes for 10 traits combined with meteorological data from 8 single weeks before calving implied in total 80 different runs. THI ≥50 from all single 8 weeks before calving had unfavorably significant effects on FAT%, ICFI and LPL. Heat stress in terms of THI ≥60 from the last 3 weeks before calving impaired MKG. NRR56 decreased with increasing THI, as observed for all 6 weeks before calving. LTP-MKG and MKG-DL decreased due to high THI in the last 4 weeks before calving. Heat stress (THI ≥60) during late pregnancy had no significantly unfavorable impact on PRO% and MUN. Interestingly, SCS in offspring declined with increasing THI during late pregnancy. In conclusion, for most of the primary and functional traits, unfavorable impact of HS from the dry period on time-lagged performances in offspring was identified, even on longevity. From a practical perspective, our data suggest to provide HS abatement to late gestation dams to avoid long-term adverse effects on the offspring.
本研究论文从跨代的角度关注滞后的热应激 (HS) 效应。妊娠最后 8 周的温度-湿度指数 (THI) 与随后的雌性后代表现相关联。后代数据集考虑了来自 1968 个牛群的 172905 头荷斯坦奶牛，其产犊年份为 2002-2013 年。生产性状包括首次泌乳的第一个官方测试日的产奶量 (MKG)、蛋白质百分比 (PRO%)、脂肪百分比 (FAT%)、体细胞评分 (SCS) 和牛奶尿素氮 (MUN)。雌性繁殖力性状是后备牛的 56 天返情率 (NRR56) 和第一胎次奶牛的产犊至首次配种间隔 (ICFI)。长寿性状是生产寿命的长度 (LPL)、产奶量终生生产力 (LTP-MKG) 和日产奶量 (MKG-DL)。对 10 个性状的联合关联分析与产犊前 8 周的气象数据相结合，总共涉及 80 个不同的运行。产犊前所有 8 周的 THI≥50 对 FAT%、ICFI 和 LPL 有不利的显著影响。产犊前最后 3 周 THI≥60 的热应激损害了 MKG。随着产犊前所有 6 周 THI 的增加，NRR56 降低。由于产犊前最后 4 周 THI 较高，LTP-MKG 和 MKG-DL 降低。怀孕期间晚期的热应激 (THI≥60) 对 PRO% 和 MUN 没有明显的不利影响。有趣的是，后代的 SCS 随着怀孕期间晚期 THI 的增加而下降。总之，对于大多数主要和功能性性状，即使对长寿性状，也发现了干期 HS 对后代滞后表现的不利影响。从实际的角度来看，我们的数据表明，为了避免对后代产生长期的不利影响，应向妊娠晚期的母畜提供缓解热应激的措施。
