The water intake of ewes.

Abstract

1. Two experiments were carried out with non-pregnant ewes in which individual drymatter intake (DMI) and total water intake (TWI) were measured. TWI was closely correlated with DMI; TWI/unit DMI was higher for silage than for cubed dried grass and with both foods water intakes were higher than with long hay.2. Twelve ewes were fed on silage and twelve on hay from the 9th to the 19th week of pregnancy. TWI/unit DMI of each feed doubled during this period. Another twenty-four ewes were fed on silage from the 14th to the 20th week of pregnancy. TWI/unit DMI was positively related to litter size.3. Fifteen ewes were fed on hay from the 4th week of pregnancy until the 7th week of lactation. Milk yield was estimated weekly. Six non-pregnant ewes were controls. TWI/unit DMI for the seven twin-bearing and the nine single-bearing ewes in the last 4 and 3 weeks of pregnancy respectively was significantly higher than that of the six non-pregnant ewes. In the control group TWI/unit DMI was closely related to environmental temperature. In the first 4 weeks of lactation TWI/unit DMI was greater than the sum of TWI/unit DMI of the non-pregnant ewes plus the water in the milk.4. The results supplement those used by the Agricultural Research Council (1965) to assess the water requirements of sheep.