| Titles |
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English :
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An approach to develop a biometeorological thermal discomfort index for sheep and goats under Egyptian conditions
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Arabic :
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دراسة تقدمية لمعرفة المدى الحرارى للاغنام و الماعز تحت ظروف البيئة المصرية
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| Abstract |
Sheep and Goats are thought to be less susceptible to environmental stress than other domesticated ruminant species. They are widely distributed in regions with diverse climatic conditions and possess unique characteristics such as water conservation capability, higher sweating rate, lower basal heat metabolism, higher respiration rate, higher skin temperature, and constant heart rate and constant cardiac output (Heisey et al., 1971; Borut et al., 1979; D'miel et al., 1979; Rai et al., 1979; Shkolnik et al., 1980 and Feistkorn et al., 1981). Silanikove (2000) stated that the ability of goats to live in harsh environments may be due to low body mass and low metabolic requirements of goats which can be regarded as important assets in minimizing their maintenance and water requirements in areas where water sources are widely distributed and food sources are limited by their quantity and quality. Also, a skilful grazing behavior and efficient digestive system enable goats to attain maximal food intake and maximal food utilization in a given condition. Efforts to develop thermal indices for domestic animals have been made by many authors as a basis for environmental management of animals (Mitchell et al., 2001; Gaughan et al., 2002 and Eigenberg et al., 2002). Hahn et al (2003) stated that any improved animal index will ideally be useful as a basis for continued development of biologic response functions, and representative of consequences resulting from primary factors influencing energy exchange between the animal and its surrounding. Temperature humidity index (THI) is commonly used as an indicator of the degree of climatic stress on animals where a THI of 72 and below is considered as no heat stress (cool), 73-77 as mild heat stress, 78-89 as moderate and above 90 as severe (Fuquay, 1981). Meanwhile, according to Davis et al. (2003) periods were deemed thermoneutral when average THI < 70, mild heat stress when 70 < THI < 74, heat stress when 74 < THI < 77, and severe heat stress when THI > 77. On the other hand, the Livestock Weather Safety Index (LCI, 1970) categories associated with THI are normal (THI < 74), Alert (75-78 THI), danger (79-83 THI) and emergency (THI > 84). Seasonal high temperatures in subtropical, tropical, and arid areas are known to reduce fertility in the bovine (Stott and William, 1962; Stott and Wiersma, 1974; EI-Fouley et al., 1976; Ingraham et al., 1976 and Nienaber et aI., 1999). Srikandakumar et al., (2003) compared the effect of 72 and 93 THI on RR and Tr of Omani and Merino sheep. The aim of the present study is fo develop an animal thermal discomfort index for sheep and goats based on changes in their rectal temperature, respiration rate and metabolic rate with climatic changes under natural conditions.
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| Publication year |
2005
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| Pages |
118-122
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| Availability location |
معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى - الجيزة
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| Availability number |
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| Organization Name |
Animal Production Research Institute (APRI)
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| serial title |
17th International Congress of Biometerorology ICB
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| Author(s) from ARC |
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| External authors (outside ARC) |
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| Agris Categories |
Animal physiology - Nutrition
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AGROVOC
TERMS |
Goats.
Respiration rate.
Sheep.
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| Proposed Agrovoc |
Egyptian conditions;metabolic rate;
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| Publication Type |
Conference/Workshop
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