Influence of on-farm measurements for heat stress indicators on dairy cow productivity, female fertility, and health

Abstract

The aim of the present study was to quantify the effect of heat stress (HS) from different points in time on production, female fertility, and health traits. In this regard, on-farm measurements for temperature and relative humidity were combined into temperature-humidity indexes (THI), and merged with longitudinal cow traits from electronic recording systems. The study included traits from 22,212 Holstein cows kept in 15 large-scale dairy co-operator herds. Trait and meteorological data recording spanned a period between May 2013 and November 2015. Longitudinal production traits considered 191,911 test-day records for protein yield, protein percentage, and milk urea nitrogen (MUN). Female fertility traits were the pregnancies per AI (P/AI) and the number of daily inseminations per herd cow (INS/ HCOW). Health traits considered clinical mastitis (MAST), retained placenta, puerperal disorders (PD) from d 0 to 10 postpartum, and the claw disorders digital phlegmona, digital dermatitis (DD), and interdigital hyperplasia from d 0 to 360 postpartum. For all traits, we analyzed the THI influence from the trait-recording day. In addition, we studied the time-lagged THI effect from the previous week. Linear mixed models were applied to estimate THI effects on Gaussian distributed production traits. For binary health and fertility traits, generalized linear mixed models with a logit link function were used. The continuous THI effect was either modeled linear, or via Legendre polynomials of order 4. Regression models for THI were validated via THI class effects (i.e., 5% percentiles for THI). Protein percentage decreased with increasing test-day THI, and with increasing THI from the previous week. Protein yield obviously decreased beyond THI 68 for both THI measurements (test-day THI and THI from previous week). For MUN, the visually identified test-day HS threshold was THI 70. Time-lagged THI effects on MUN were less obvious. For both THI measuring dates, INS/HCOW was highest at THI 57. Beyond THI 57, INS/HCOW substantially decreased. For P/AI, the visually identified HS threshold at the insemination date was THI 65. Temperature-humidity indexes from the previous week had a moderate detrimental effect on P/AI. Incidences for MAST, retained placenta, and PD during d 0 to 10 postpartum increased with increasing average THI from this period. Studying the whole lactation period, incidences for interdigital hyperplasia also increased with increasing THI from the previous week. An opposite THI response was identified for DD: DD decreased with increasing THI. For all health traits, associations between disease incidences and THI were almost linear. Hence, for health traits, no obvious HS thresholds were detected. Especially in early lactation, HS had a detrimental effect on cow productivity and female fertility. The influence of HS on cow health differed, depending on the disease pathogenesis.

Heat Stress Impacts Immune Status in Cows Across the Life Cycle

“…DuBois and Williams (105) examined seasonal incidence of retained placenta in a single herd, and found that the percentage of cows with a retained placenta (RP) doubled in the summer relative to the winter, and cows with an RP had an additional 24 days open compared with the reproductive performance of healthy cows. A recent study by Gernand et al (106) tied the relationship of RP and metritis more closely to increases in THI. With records from 22,000 cows, puerperal disorders and RP increased linearly with the average THI in the 5 days after calving.…”

Dietary supplementation with combined extracts from garlic (Allium sativum), brown seaweed (Undaria pinnatifida), and pinecone (Pinus koraiensis) improves milk production in Holstein cows under heat stress conditions

“…Heat stress causes changes in homeostasis and has been quantified by the measurement of milk production and physiological variables such as body temperature, respira tory rate, and behaviors of cows [23]. According to a study by Gernand et al [24], milk production is not affected by heat stress when mean THI values are under 68. However, milk production and feed intake begin to decline when be yond THI 68 [24,25].…”

Optimization of technological processes in animal husbandry

“…The developed technology can affect most parameters of the microclimate and maintain within the specified limits temperature and relative humidity of air, air velocity, concentration of harmful gases (ammonia, carbon dioxide, and hydrogen sulfide), dust and microorganisms [3,4,6,7,8,10,12,14,15,19]. The technological process of a microclimate system with air conditioning includes such operations as heating, cooling, humidification, drying and purification of air from harmful gases, dust and microorganisms.…”

“…The amount of metabolic energy yielding products other than the body's heat production is also reduced by so-called non-productive energy needs: the energy needs of the animal, consisting of thermoregulation, which is necessary to maintain constant body temperature, and the energy expended on movement [4, 6,12,14,19].…”

“…The impact of microclimate parameters on cow productivity and feed consumption[4,5,6,7,9,10,12,14,19].Taking into account the air velocity V in terms of temperature tВ, °С:…”