PRODUCTION BY EWES REARING SINGLE OR TWIN LAMBS - EFFECTS OF DIETARY CRUDE PROTEIN PERCENTAGE AND SUPPLEMENTAL ZINC METHIONINE

Eighty Targhee ewes with single or twin lambs were used to investigate the effects of chelated zinc methionine and level of dietary CP on mi lk and wool production, DMI, and ewe and lamb BW change. Treatments we re arranged as a 2 x 2 x 2 factorial. Dietary treatments started 30 d prepartum and continued until 42 d postpartum. Milk production was est imated at 4, 10, 18, and 28 d postpartum During gestation, DMI by ewes receiving zinc methionine and the 14.9% CP diet was greater (P <.10) than DMI by ewes not supplemented with zinc methionine and ewes fed th e 11.3% CP diet. Ewes fed the 14.9% CP diet tended (P <.14) to gain mo re BW from 30 d prepartum to 4 d postpartum and lose more BW from 4 to 42 d postpartum than ewes fed the 11.3% CP diet. Ewes fed zinc methio nine and the 14.9% CP diet produced more (P <.10) milk on d 28 than th eir counterparts. Ewes rearing twins produced more (P <.05) milk on d 4, 10, and 18 than ewes rearing single lambs. However, milk production on d 28 was not affected by number of lambs reared (P = .68). Lamb AD G at 28, 42, and 59 d postpartum was greater (P <.05) for both the zin c methionine treatment and the 14.9% CP diet. Zinc methionine (P = .11 ) and the 14.9% CP diet (P = .02) increased weaning weights by 6 and 9 %, respectively. We conclude that both the zinc methionine supplement and the 14.9% CP diet resulted in more persistent milk production. In addition, when ewes and lambs were fed for an average of 42 d during e arly lactation, a 14.9% CP diet, and to a lesser degree, a chelated zi nc methionine supplement, lamb weaning weights were improved.