No abstract

Ninety-seven Awassi ewes were included in three experiments. The ewes were milked twice daily, and also suckled lambs. Three different suckling regimes (12 hours per day, 4hr. and residual milk only) and three weaning times after lambing were compared.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.

1. The rectal temperatures of shorn and unshorn Awassi sheep were measured at various hours of the day and during various seasons of the year in two different locations in Israel.2. An increase in body temperature accompanied an increase in environmental temperature. A steeper temperature increase was noted in shorn sheep kept in the shade. When ambient temperatures were below 30° C. the body temperature of shorn sheep was lower than that of the unshorn sheep by an average of 0·16° C.3. When ambient temperatures were above 30° C. the body temperature of shorn sheep was equal to or higher than that of unshorn ones.4. Upon exposure to direct sunlight, the body temperature of shorn sheep exceeded that of unshorn animals. However, when the animals were transferred to the shade, or after sunset, the shorn sheep cooled at a faster rate. Their body temperature fell below that of the unshorn sheep during the cool hours of the day.5. Wind velocity, both in the shade and in the sun, had a greater effect on shorn than on unshorn sheep.6. A rise in the relative humidity of ambient temperatures above 25° C. caused body temperature to rise, particularly in unshorn animals. The body temperature of shorn sheep exceeded that of unshorn ones when the animals were maintained in a hot and dry environment.7. While the body of the shorn sheep was entirely affected by the macroclimate, the unshorn sheep were greatly influenced by the microclimate existing in the fleece. Fleece temperatures always lagged behind and were rarely equal to environmental temperatures. Since it was postulated that heat tolerance of certain animals was related to their ability to exploit cool hours of the day, it is suggested that in certain ‘tolerance tests’ records should be taken not only during exposure to heat but also during cool hours of the day.

SUMMARYSixty-six Awassi ewes were divided into two equal groups. The sheep were milked twice daily from lambing for 22 weeks. In one group (weaned) the lambs were separated from their dams within 6 h of parturition. In the second group (suckling) the lambs sucked the residual milk after milking for 15 weeks, after which they were weaned. Milking yields, fat tests, lactational persistency and udder health were not affected by the early weaning. The suckling ewes had greater amounts of residual milk and consumed more concentrates. Further data are presented that suggest that there may be a critical period of attachment of at least 10 days following lambing, during which weaning may effect subsequent milk production. The practical implications of these results are discussed in terms of flock management and the intensification of breeding programmes.