نوع مقاله : مقاله پژوهشی
نویسندگان
1 پژوهشگر، مجتمع شیر و گوشت مهدشت، شرکت دشت ناز، ساری، مازندران
2 پژوهشگر، شرکت گسترش (هلدینگ) کشاورزی و دامپروری فردوس پارس، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Comparison of heat stressed purebred Holstein vs. crossbred Holstein × Montbeliarde and Holstein × Simmental cows : Production, reproduction, metabolism and health
Abstract
Background and objectives : Crossbred lactating cows were hypothesized to outperform Holsteins under environmental stresses . The objective of this study was , therefore, to compare production, reproduction, metabolism and health of purebred Holstein cows vs . crossbred Holstein × Montbeliarde and Holstein×Simmental cows under hot and humid conditions of north of Iran ( Sari , Mazandaran ) .
Material and methods : Dairy crosses were produced by crossing Holstein ( H ) cows with Montbeliarde ( M ) and Simmental ( S ) bulls’ semen . The performance and health of 70 primiparous cows from each breed ( 210 cows in total) were compared during their first lactation . Blood samples were taken from 15 primiparous cows from each breed at stages of close-up , calving , 21 days after calving. Samples were analyzed for glucose , BHBA, NEFA, calcium and mangium . Statistical analyses were performed using SAS programs ( GLM and MIXED procedures ).
Results: Results showed that Montbeliarde × Holstein and Simmental×Holstein crossbred cows were not different (P> 0.05) from pure Holsteins in rectal temperature , fertility and other reproductive indices , 305-d milk yield, milk fat and protein yield, stillbirth, mastitis, and laminitis rates and close-up blood metabolites. However , Montbeliarde × Holstein cows had greater calving difficulty than did Simmental×Holstein cows (P < 0.05 ) . Also , both crossbred groups had higher incidence of metritis compared to purebred Holstein cows ( P < 0.05 ) . The purebred Holsteins exhibited more desirable udder traits than did crossbred cows (P < 0.05). The crossbred cows had more body condition score ( BCS ) during the transition period than did the pure Holsteins (p < 0.05 ). However, stature of Simmental × Holstein crossbred cows was shorter than pure Holstein . Foot angle was steeper for Holstein×Simmental and Holstein × Montbeliarde crossbred cows , but Holstein × Montbeliarde crossbred cows were similar to pure Holstein cows for hoof measurements .
Conclusions: findings of this study suggest that Holstein×Simmental and Holstein × Montbeliarde crossbred cows did not outperform first - lactation purebred Holstein cows, and that they experienced higher rates of dystocia and metritis under stressful hot and humid conditions .
Key words : Crossbreeding , Heat stress , Holstein , Mahdasht, Montbeliarde , Simmental
کلیدواژهها [English]
Bretschneider, G., Arias, D.R. and Cuatrin, A. 2015. Comparative evaluation of udder and body conformation traits of first lactation ¾ Holstein x ¼ Jersey versus Holstein cows= Comparación de las características de conformación de la ubre y el cuerpo de vacas de primera lactancia ¾ Holstein x ¼ Jersey versus Holstein. Facultad de Ciencias Veterinarias, Universidad Austral de Chile.
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