نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکده کشاورزی، دانشگاه یاسوج، یاسوج، ایران
2 گروه علوم دامی دانشگاه یاسوج
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: Livestock farming is the most important source of income for tribes and nomads. Unfortunately, this source of income in the nomadic breeding system has been significantly affected by weather conditions and has seriously destabilized the productivity of animals. In tropical regions, heat stress is the main obstacle to livestock production, which endangers the general well-being of livestock, growth, protein metabolism, energy, mineral balance, reproduction, and livestock production, and can cause significant economic losses to follow. However, the intensity of the effects of heat stress on the animal can be different depending on the animal species, breed, and rearing conditions. So, it is necessary to conduct more research on the effect of the region's climate on livestock performance, especially in pasture-based systems. Therefore, this research aimed to investigate nutritional behaviors and changes in vital signs and blood parameters in Turki-Qashqai ewes in two climates, Yilaq and Qeshlaq.
Materials and Methods: This experiment was conducted in a completely randomized design with two treatments (Qeshlaq and Yilaq climates) and the same number of repetitions in each treatment (n = 8) in two areas of Qeshlaq (Afzer, Qir-o-karzin city, Fars province as Qeshlaq) and Yilaq (Kamaneh, Semiram city, Isfahan province as Yilaq) for 21 days; including 14 days of habituation period and 7 days of sampling and it was done with the same ration. For this purpose, out of 16 Turki-Qashqai lactating ewes with an average calving belly of 2.81±0.21 (mean ± standard error), live weight 44.81±0.84 Kg, milk production 306.06±5.65g hot and the physical score was 3.23±0.07. At the end of the experimental period, the time spent on eating and rumination activities for 24 hours and every 5 minutes was recorded visually for all the animals. Rectal temperature, skin surface temperature, discharge, heart rate, and pulse of the studied animals were measured during the sampling hours at 7:00 and 14:00. Blood sampling and measurement of plasma parameters were done on days 1, 3, and 7 of the sampling period from all ewes. The statistical analysis of the results obtained by the Mixed Model method of SAS statistical software (9.1) was used and the comparison of means was done using Tukey Kramer test at a significance level of 0.05.
Results: In this study, it was found that the type of climate had an effect on the nutritional behavior of ewes, so that the duration of eating, ruminating, and chewing time of ewes in Qeshlaq was significantly less than in Yilaq (P≤0.05). Also, the results showed that skin temperature, rectal temperature, respiration rate, and heart rate of ewes changed due to sampling time and climate (P≥0.05); So that with the increase of thermal-humidity index (THI) the values of these parameters increased. The levels of non-esterified fatty acids and thyroid hormones (T3 and T4) in ewes kept in Qeshlaq were significantly lower than sheep located in Yilaq climate (P<0.05). Also, the activity of alanine aminotransferase and gamma-glutamyl-transferase enzymes in the serum of ewes located in Yilaq was significantly (P<0.05) higher than the levels of these variables in ewes located in Qeshlaq.
Conclusion: The results of this study showed that the hot and humid conditions of Qeshlaq climate had adverse effects on the nutritional behaviors and welfare parameters of ewes, and these effects were accompanied by changes in some blood parameters.
کلیدواژهها [English]
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