Tags

Type your tag names separated by a space and hit enter

Heat-stress abatement during the dry period: does cooling improve transition into lactation?
J Dairy Sci. 2009 Dec; 92(12):5988-99.JD

Abstract

Environmental factors, especially temperature and light exposure, influence the health and productivity of dairy cows during lactation, possibly via similar physiological mechanisms. For example, heat stress is a critical component of decreased milk yield during summer. However, less is known about the effect of heat stress during the dry period. The objective of this study was to evaluate the effects of heat stress prepartum under a controlled photoperiod on lactation performance and hepatic metabolic gene expression of periparturient multiparous Holstein cows (n = 16). Cows were dried off approximately 46 d before expected calving date and assigned to treatment randomly after blocking by mature equivalent milk production and parity. Treatments consisted of either heat stress (HT) or cooling (CL) with fans and sprinklers, both under a photoperiod of 14L:10D. Rectal temperature was measured twice daily during the dry period. After calving, cows were housed in a freestall barn with cooling devices, and milk yield was recorded daily up to 210 d in milk. Blood samples were taken from dry off until +42 d relative to calving for metabolites and from -2 until +2 d relative to calving for hormone analysis. Daily dry matter intake was measured from -35 to +42 d relative to calving. Liver biopsies were collected at dry off, -20, +2, and +20 d relative to calving for cows on HT (n = 5) and CL (n = 4) to measure mRNA expression of suppressors of cytokine signaling-2 (SOCS-2), insulin-like growth factor binding protein-5 (IGFBP-5), a key transcription factor in lipid biosynthesis (SREBP-1c), and enzymes of lipid metabolism (FASN, ACACA, and ACADVL) by real-time quantitative PCR. Heat stress increased rectal temperatures (39.2 vs. 38.8 degrees C), plasma prolactin concentrations at -1 (171 vs. 79 ng/mL) and 0 d (210 vs. 115 ng/mL) relative to calving, and decreased dry matter intake at 0 and +14 d relative to calving and 3.5% fat-corrected milk postpartum (26.1 vs. 35.4 kg/d) compared with CL cows. Relative to CL cows, hepatic mRNA expression of SOCS-2 and IGFBP-5 was downregulated in HT cows. Expression of ACADVL was upregulated in CL cows at d +2 but downregulated at d +20 relative to HT cows. Concentrations of C16:0 and cis C18:1 were greater in the milk and liver of CL cows compared with HT cows, which reflects greater lipid mobilization. These results suggest that heat-stress abatement in the dry period improves subsequent lactation, possibly via suppression of plasma prolactin surge around calving, SOCS-2 expression, and regulation of hepatic lipid metabolism.

Authors+Show Affiliations

Department of Animal Sciences, University of Florida, Gainesville 32611, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

19923602

Citation

do Amaral, B C., et al. "Heat-stress Abatement During the Dry Period: Does Cooling Improve Transition Into Lactation?" Journal of Dairy Science, vol. 92, no. 12, 2009, pp. 5988-99.
do Amaral BC, Connor EE, Tao S, et al. Heat-stress abatement during the dry period: does cooling improve transition into lactation? J Dairy Sci. 2009;92(12):5988-99.
do Amaral, B. C., Connor, E. E., Tao, S., Hayen, J., Bubolz, J., & Dahl, G. E. (2009). Heat-stress abatement during the dry period: does cooling improve transition into lactation? Journal of Dairy Science, 92(12), 5988-99. https://doi.org/10.3168/jds.2009-2343
do Amaral BC, et al. Heat-stress Abatement During the Dry Period: Does Cooling Improve Transition Into Lactation. J Dairy Sci. 2009;92(12):5988-99. PubMed PMID: 19923602.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Heat-stress abatement during the dry period: does cooling improve transition into lactation? AU - do Amaral,B C, AU - Connor,E E, AU - Tao,S, AU - Hayen,J, AU - Bubolz,J, AU - Dahl,G E, PY - 2009/11/20/entrez PY - 2009/11/20/pubmed PY - 2010/2/18/medline SP - 5988 EP - 99 JF - Journal of dairy science JO - J Dairy Sci VL - 92 IS - 12 N2 - Environmental factors, especially temperature and light exposure, influence the health and productivity of dairy cows during lactation, possibly via similar physiological mechanisms. For example, heat stress is a critical component of decreased milk yield during summer. However, less is known about the effect of heat stress during the dry period. The objective of this study was to evaluate the effects of heat stress prepartum under a controlled photoperiod on lactation performance and hepatic metabolic gene expression of periparturient multiparous Holstein cows (n = 16). Cows were dried off approximately 46 d before expected calving date and assigned to treatment randomly after blocking by mature equivalent milk production and parity. Treatments consisted of either heat stress (HT) or cooling (CL) with fans and sprinklers, both under a photoperiod of 14L:10D. Rectal temperature was measured twice daily during the dry period. After calving, cows were housed in a freestall barn with cooling devices, and milk yield was recorded daily up to 210 d in milk. Blood samples were taken from dry off until +42 d relative to calving for metabolites and from -2 until +2 d relative to calving for hormone analysis. Daily dry matter intake was measured from -35 to +42 d relative to calving. Liver biopsies were collected at dry off, -20, +2, and +20 d relative to calving for cows on HT (n = 5) and CL (n = 4) to measure mRNA expression of suppressors of cytokine signaling-2 (SOCS-2), insulin-like growth factor binding protein-5 (IGFBP-5), a key transcription factor in lipid biosynthesis (SREBP-1c), and enzymes of lipid metabolism (FASN, ACACA, and ACADVL) by real-time quantitative PCR. Heat stress increased rectal temperatures (39.2 vs. 38.8 degrees C), plasma prolactin concentrations at -1 (171 vs. 79 ng/mL) and 0 d (210 vs. 115 ng/mL) relative to calving, and decreased dry matter intake at 0 and +14 d relative to calving and 3.5% fat-corrected milk postpartum (26.1 vs. 35.4 kg/d) compared with CL cows. Relative to CL cows, hepatic mRNA expression of SOCS-2 and IGFBP-5 was downregulated in HT cows. Expression of ACADVL was upregulated in CL cows at d +2 but downregulated at d +20 relative to HT cows. Concentrations of C16:0 and cis C18:1 were greater in the milk and liver of CL cows compared with HT cows, which reflects greater lipid mobilization. These results suggest that heat-stress abatement in the dry period improves subsequent lactation, possibly via suppression of plasma prolactin surge around calving, SOCS-2 expression, and regulation of hepatic lipid metabolism. SN - 1525-3198 UR - https://www.unboundmedicine.com/medline/citation/19923602/Heat_stress_abatement_during_the_dry_period:_does_cooling_improve_transition_into_lactation L2 - https://linkinghub.elsevier.com/retrieve/pii/S0022-0302(09)71316-5 DB - PRIME DP - Unbound Medicine ER -