| Titles |
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English :
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Thermoregultory mechanisms in new born kids and lambs
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Arabic :
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ميكانيكية التنظيم الحرارى في الجداء و الحملان حديثة الميلاد
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| Abstract |
The present study was carried out at Sakha Animal Production Experimental Station belonging to Animal Production Institute. Ten lambs (3/8 Finish:5/8 Ossimi) and ten kids (3/4 Damascuss: 1/4 Baladi) were selected at random from new born animals during winter season at I, 2, 3 and 4 weeks of age. Thermoregulatory mechanisms (rectal temperature, skin temperature, ear temperature, oxygen consumption. heat production. respiration rate, tidal volume and gas volume) were measured at maximum (12:00 to 14:00) and minimum (05:00 to 07:00) ambient temperatures at each age during January - March 2002.
Meteorological data revealed that at 12:00 - 14:00 (maximum temperature), ambient temperature (14.8 to 22.8 °c) and THI (58.4 - 69.5) were within the thermoneutral zone, while at 05:00 - 07:00 (minimum temperature) the corresponding values were 9.6 - 15°C and 52.5 - 58.6 which lie in the cold stress range for newborn lambs and kids. Results indicated that under cold stress rectal temperature was significantly lower in kids than in lamb due to a significant reduction in rectal temperature of kids at minimum Ta during night, while no significant changes occurred in lambs. Similar trend was found in ST. The lower RT and ST of kids at minimum Ta than at maximum Ta, while no significant changes occurred in lambs indicates that kids are less cold tolerance than lambs. In both breeds, the occurrence of vasoconstriction was observed from the significant decrease in ear temperature at nigh: in both kids and lambs. In kids, gas volume (GV) tended to increase due to a significant increase in tidal volume (TV) while respiration rate (RR) increased insignificantly at night revealing more hot loss by evaporative cooling in kids than in lambs under cold stress at night. Heat production (HP) was significantly lower in kids than in lambs during at maximum and minimum temperatures although the reduction in heat production in lambs at night.
It could be concluded that the main cause of higher mortality rate in new born kids than lambs is due to lower metabolic rate and higher heat loss in kids than in lambs so that kids cannot tolerate the effect of cold stress at night in winter.
Keywords: New born, Lambs, Kids, Thermoregulation, Metabolic rate
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| Publication year |
2004
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| Pages |
391-402
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| Availability location |
معهد بحوث الانتاج الحيوانى -7 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 |
Egyptian Journal Animal Production
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| Author(s) from ARC |
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| External authors (outside ARC) |
هشام محمد خليفة
جامعة الازهر
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| Agris Categories |
Animal physiology - Nutrition
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AGROVOC
TERMS |
Body temperature.
Cold stress.
Kids.
Lambs.
Oxygen consumption.
Respiration rate.
Thermoregulation.
Winter.
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| Proposed Agrovoc |
Metabolic rate;
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| Publication Type |
Journal
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