Across-generation effects of maternal heat stress during late gestation on production, female fertility and longevity traits in dairy cows

Abstract

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.

Genotype by heat stress interactions for production and functional traits in dairy cows from an across-generation perspective

“…In previous phenotypic association analyses, the last week before birth (d 0-7 before birth) was identified as the period with the strongest time-lagged sensitivity to intrauterine HS (Kipp et al, 2021). Therefore, in the present study, the THI during the last week of gestation was considered as HS indicator, also defined as intrauterine HS.…”

“…Additionally, cows with an age at first calving lower than 20 mo or higher than 40 mo were excluded from the ongoing analyses. Trait selection based on previous across-generation phenotypic association analyses (Kipp et al, 2021). Traits, which were significantly affected by intrauterine HS, were chosen for the present genetic study.…”

“…In dairy cattle, there is evidence that HS during late gestation induced carry-over effects (i.e., longlasting effects on traits recorded in offspring). In this regard, birth weight, BW up to 1 yr of age, calf immune functions, productivity, female fertility, and longevity in the offspring generation were affected (Tao et al, 2012;Monteiro et al, 2016;Kipp et al, 2021). Laporta et al (2020) reported impairments regarding productivity and survival to first breeding in the F 2 generation of heat-stressed grandmothers.…”

Direct genetic effects, maternal genetic effects, and maternal genetic sensitivity on prenatal heat stress for calf diseases and corresponding genomic loci in German Holsteins

“…Generally, wk 1 was identified as the most important week with regard to detrimental effects on calf diseases. Accordingly, Kipp et al (2021b) identified notable impaired female fertil-ity and productivity in lactating cows due to prenatal HS in wk 1. The immune system mechanisms have physiological explanations, such as lower IgG concentrations in heat-stressed calves during the dry period of their dams (Tao et al, 2012).…”

“…As a heat-sensitive breed, Holstein cows show variations in phenotypic performance and breeding values under heat stress (HS) conditions (Bohlouli et al, 2019;Gernand et al, 2019). In addition to the immediate effects, HS during late gestation or prenatal HS had unfavorable effects on the growth, immune competence, and functional traits of offspring (Tao and Dahl, 2013;Kipp et al, 2021b). The late-gestation period plays a crucial role in fetal growth, and carryover effects from dams exposed to HS during late gestation can influence the performance of their offspring (Monteiro et al, 2016).…”