0719 Effects of heat stress and dietary zinc source on mammary tight junction of lactating dairy cows

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 344-345 ◽  
Author(s):  
X. Weng ◽  
A. P. A. Monteiro ◽  
J. Guo ◽  
J. K. Bernard ◽  
J. DeFrain ◽  
...  
Keyword(s):  
Heat Stress ◽  
Tight Junction ◽  
Dairy Cows ◽  
Dietary Zinc ◽  
Zinc Source ◽  
Lactating Dairy Cows

scholarly journals Effects of heat stress and dietary zinc source on performance and mammary epithelial integrity of lactating dairy cows

2018 ◽  
Vol 101 (3) ◽  
pp. 2617-2630 ◽  
Author(s):  
X. Weng ◽  
A.P.A. Monteiro ◽  
J. Guo ◽  
C. Li ◽  
R.M. Orellana ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Mammary Epithelial ◽  
Dietary Zinc ◽  
Epithelial Integrity ◽  
Zinc Source ◽  
Lactating Dairy Cows

Fertility and hormonal responses to temporary relief of heat stress in lactating dairy cows

1988 ◽  
Vol 29 (5) ◽  
pp. 1027-1035 ◽  
Author(s):  
M.E. Wise ◽  
R.E. Rodriguez ◽  
D.V. Armstrong ◽  
J.T. Huber ◽  
F. Wiersma ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Hormonal Responses ◽  
Temporary Relief ◽  
Lactating Dairy Cows

The role of the mammary gland during heat stress

2019 ◽  
Author(s):  
◽  
Ricardo Oliveira Rodrigues
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Prolonged Exposure ◽  
Transcriptional Profiling ◽  
Mammary Tissue ◽  
Secretory Cells ◽  
University Of Missouri ◽  
Lactating Dairy Cows

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Disruptive effects of climate change, such as increasing environmental temperature, have direct impacts on economic viability and efficiency of food production. In lactating dairy cows, heat stress reduces milk production and alters function of mammary secretory cells, at least partly by disturbing local protein metabolism. We hypothesized that hyperthermia would not only reduce mammary blood flow but would also reduce mammary extraction of nutrients from blood. In addition, we hypothesized that transcriptional profiling of mammary tissue would reveal disruption of cellular homeostasis. Our objective was to determine the effects of hyperthermia on mammary function. More specifically, we aimed to profile mammary blood flow and the changes in mammary transcriptome of heat-stressed lactating dairy cows. We investigated the effects of early and prolonged exposure of lactating dairy cows to hyperthermia by exposing cows to programmed constantly elevated temperature and humidity to induce and maintain body temperature approximately 1[degree]C above normal. Experiments were conducted to evaluate the production responses of hyperthermic lactating dairy cows, to characterize total and nutritive mammary blood flow, and to elucidate the regulation of mammary function during early and prolonged exposure to hyperthermia. Results from these studies established that 1) hyperthermia reduces total and nutritive mammary blood flow, limiting nutrient disappearance across the mammary gland; 2) hyperthermia does not induce shunting of blood away from the gland; 3) hyperthermia affects mammary tissue transcriptome, mainly altering processes associated with ECM and cell adhesion; 4) the effects of exposure to prolonged heat stress on mammary gene expression are distinct from the effects of feed restriction, in lactating dairy cows; and 5) mammary function is reestablished within 8 days after cessation of heat stress.

Daily rumination time of lactating dairy cows under heat stress conditions

2020 ◽  
Vol 88 ◽  
pp. 102484 ◽  
Author(s):  
Theresa Müschner-Siemens ◽  
Gundula Hoffmann ◽  
Christian Ammon ◽  
Thomas Amon
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Stress Conditions ◽  
Lactating Dairy Cows

scholarly journals Effect of Heat Stress on Bacterial Composition and Metabolism in the Rumen of Lactating Dairy Cows

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 925
Author(s):  
Zhao ◽  
Min ◽  
Zheng ◽  
Wang
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Production ◽  
Dry Matter ◽  
16S Rrna Genes ◽  
Dry Matter Intake ◽  
Rrna Genes ◽  
Bacterial Composition ◽  
Rumen Ph ◽  
Lactating Dairy Cows

Heat stress negatively impacts the health and milk production of dairy cows, and ruminal microbial populations play an important role in dairy cattle’s milk production. Currently there are no available studies that investigate heat stress-associated changes in the rumen microbiome of lactating dairy cattle. Improved understanding of the link between heat stress and the ruminal microbiome may be beneficial in developing strategies for relieving the influence of heat stress on ruminants by manipulating ruminal microbial composition. In this study, we investigated the ruminal bacterial composition and metabolites in heat stressed and non-heat stressed dairy cows. Eighteen lactating dairy cows were divided into two treatment groups, one with heat stress and one without heat stress. Dry matter intake was measured and rumen fluid from all cows in both groups was collected. The bacterial 16S rRNA genes in the ruminal fluid were sequenced, and the rumen pH and the lactate and acetate of the bacterial metabolites were quantified. Heat stress was associated with significantly decreased dry matter intake and milk production. Rumen pH and rumen acetate concentrations were significantly decreased in the heat stressed group, while ruminal lactate concentration increased. The influence of heat stress on the microbial bacterial community structure was minor. However, heat stress was associated with an increase in lactate producing bacteria (e.g., Streptococcus and unclassified Enterobacteriaceae), and with an increase in Ruminobacter, Treponema, and unclassified Bacteroidaceae, all of which utilize soluble carbohydrates as an energy source. The relative abundance of acetate-producing bacterium Acetobacter decreased during heat stress. We concluded that heat stress is associated with changes in ruminal bacterial composition and metabolites, with more lactate and less acetate-producing species in the population, which potentially negatively affects milk production.

Heat stress in lactating dairy cows: a review

2002 ◽  
Vol 77 (1) ◽  
pp. 59-91 ◽  
Author(s):  
C.T Kadzere ◽  
M.R Murphy ◽  
N Silanikove ◽  
E Maltz
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Lactating Dairy Cows

Natural tree shade increases milk stability of lactating dairy cows during the summer in the subtropics

2020 ◽  
pp. 1-4
Author(s):  
Alexandre S. Abreu ◽  
Vivian Fischer ◽  
Marcelo T. Stumpf ◽  
Concepta M. McManus ◽  
Felix H. D. González ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Functional Characteristics ◽  
Coagulation Time ◽  
Research Communication ◽  
Lactating Cows ◽  
Acceptable Range ◽  
Lactating Dairy Cows ◽  
Time Test ◽  
Post Stress

Abstract This research communication addresses the hypothesis that, during the summer in the subtropics, natural tree shade helps to improve milk functional characteristics such as stability and acidity. Sixteen Holstein lactating cows were enrolled. The study consisted of three periods (pre-stress, heat stress and post-stress) based on allocating grazing cows into two treatments (with and without access to shade during the Heat Stress period). Overall THI during the trial was (mean ± se) 76.0 ± 3.4. Access to shade prevented the heat stress-related decrease in milk stability both in the ethanol and in the coagulation time test, as well as maintained milk acidity within an acceptable range (14 to 18°D).

Sign in / Sign up

Export Citation Format

Share Document