Productive and physiological performance of lactating Friesian cows as affected by heat stress under Egyptian condition
Abstract: The experimental work was carried out in Animal Production Station, Salhiya Company for Agricultural Investment, Ismailia Governorate. Twenty Holstein Friesian Cows of five years of age in third lactation with an average live body weight of 500-550 kg were used during summer and winter seasons. The present study aimed to investigate the effect of heat-stress on feed intake, thermal response, blood serum components, milk yield, milk components, udder measurements and conception rate of lactating Friesian cows under Egyptian environmental conditions. The obtained results showed that, rectal temperature, skin temperature, respiration rate, pulse rate and sodium concentration increased significantly (P<0.05) during summer (20.84-34.30°C) as compared to winter (8.86-9.l5°C) season. Total protein, albumin, globulin, albumin/globulin ratio, aspartate-aminotransferase and alanine-aminotransferse enzyme concentrations in blood serum were insignificantly increased during summer as compared to winter season. Whereas, calcium, potassium concentrations in blood serum and conception rate were significantly (P<0.05) lower during summer than that winter season. Animals during winter had higher (P<0.05) levels of melatonin, progesterone and oesteradiol-17β hormones in blood serum as compared to summer season. Feed intake, efficiency of feed utilization, daily milk(kg), total milk yield(kg), protein yield(kg), fat(%) and fat yield(kg)in milk during winter were significantly (P<0.05) higher than summer season. While, protein (%) was insignificantly higher during winter season than summer one. Udder measurements (long front teats, front teats circumstance (FTC), rear teats circumstance (RTC), distance between behind teats and udder depth had higher (P<0.05) values during winter season than summer. While, distance between front teats (DFT), udder width and udder length significantly (P<0.05) increased during summer than winter. Whereas, long behind teats insignificantly decreased, while distance between front and behind teats increased insignificantly during summer than that winter season. The feed costs/kg milk produced showed insignificantly higher, while input of milk (LE) and output of feeds (LE) showed insignificantly lower during winter than that summer season.
Keywords: Friesian cows, heat stress, milk, blood, conception rate
Publication year 2014
Pages 463-480
Availability location معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
Availability number
Organization Name
serial title Jouranl of the Egyptian Veterinary Medical Association
Author(s) from ARC
External authors (outside ARC)
    محمد مصطفى باز جامعة الازهر
    احمد حمدى عتمان جامعة الازهر
Agris Categories Animal husbandry
AGROVOC
TERMS		 Blood. Feed intake. Heat stress. Milk. Milk yield. Reproductive performance. Summer. Winter.
Proposed Agrovoc Friesian cows;thermal response;
Publication Type Journal
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