Quantitative Associations between Season, Month, and Temperature-Humidity Index with Milk Yield, Composition, Somatic Cell Counts, and Microbial Load: A Comprehensive Study across Ten Dairy Farms over an Annual Cycle

被引：10

作者：

Bokharaeian, Mostafa ^{[1
]}

Toghdory, Abdolhakim ^{[1
]}

Ghoorchi, Taghi ^{[1
]}

Nejad, Jalil Ghassemi ^{[2
]}

Esfahani, Iman Janghorban ^{[3
]}

机构：

[1] Gorgan Univ Agr Sci & Nat Resources, Anim Sci Fac, Dept Anim & Poultry Nutr, Gorgan 4918943464, Iran

[2] Konkuk Univ, Sanghuh Coll Life Sci, Dept Anim Sci & Technol, Seoul 05029, South Korea

[3] Glopex Co Ltd, R&D Ctr, GeumGang Penterium IX Tower A2801,Dongtancheomdans, Hwaseong Si 18469, Gyeonggi Do, South Korea

来源：

ANIMALS | 2023年 / 13卷 / 20期

关键词：

heat stress; milk production; temperature-humidity index; somatic cell count; microbial load; HEAT-STRESS; HOLSTEIN COWS; LACTATION PERIOD; PERFORMANCE; INDICATORS; TRAITS; HEALTH; PARITY;

D O I：

10.3390/ani13203205

中图分类号：

S8 [畜牧、动物医学、狩猎、蚕、蜂];

学科分类号：

0905 ;

摘要：

This current study addresses the knowledge gap regarding the influence of seasons, months, and THI on milk yield, composition, somatic cell counts (SCC), and total bacterial counts (TBC) of dairy farms in northeastern regions of Iran. For this purpose, ten dairy herds were randomly chosen, and daily milk production records were obtained. Milk samples were systematically collected from individual herds upon delivery to the dairy processing facility for subsequent analysis, including fat, protein, solids-not-fat (SNF), pH, SCC, and TBC. The effects of seasons, months, and THI on milk yield, composition, SCC, and TBC were assessed using an analysis of variance. To account for these effects, a mixed-effects model was utilized with a restricted maximum likelihood approach, treating month and THI as fixed factors. Our investigation revealed noteworthy correlations between key milk parameters and seasonal, monthly, and THI variations. Winter showed the highest milk yield, fat, protein, SNF, and pH (p < 0.01), whereas both SCC and TBC reached their lowest values in winter (p < 0.01). The highest values for milk yield, fat, and pH were recorded in January (p < 0.01), while the highest protein and SNF levels were observed in March (p < 0.01). December marked the lowest SCC and TBC values (p < 0.01). Across the THI spectrum, spanning from -3.6 to 37.7, distinct trends were evident. Quadratic regression models accounted for 34.59%, 21.33%, 4.78%, 20.22%, 1.34%, 15.42%, and 13.16% of the variance in milk yield, fat, protein, SNF, pH, SCC, and TBC, respectively. In conclusion, our findings underscore the significant impact of THI on milk production, composition, SCC, and TBC, offering valuable insights for dairy management strategies. In the face of persistent challenges posed by climate change, these results provide crucial guidance for enhancing production efficiency and upholding milk quality standards.

引用

页数：15