Relationships among ewe milk production and ewe and lamb forage intake in Targhee ewes nursing single or twin lambs

Abstract

Targhee ewes with single or twin lambs were used in four trials during early lactation through weaning to evaluate ewe milk production (MP), kilograms of lamb weaned, and forage intake by ewes and lambs. During Trial 1, ewes with lambs were individually penned, fed .45 kg of barley-ewe-1.d-1 and allowed ad libitum access to chopped alfalfa hay. Trials 2, 3, and 4 were conducted on three different types of Western range environments. Forage intake of ewes in Trials 2, 3, and 4 and of lambs in Trials 3 and 4 was estimated using chromic oxide. Estimates of milk production were obtained by hand-milking. Average lamb age was 4, 50, 78, and 106 d at the beginning of Trials 1, 2, 3, and 4, respectively. Milk production was greater (P = .01) for ewes nursing twins than for those nursing singles at d 4 and 14 in Trial 1. In Trials 2, 3, and 4, all ewes had similar (P > .18) milk production. Ewe DMI during Trials 1 and 2 was greater (P < .05) for ewes nursing twin lambs than for those nursing singles. There was no difference (P > .88) in DMI between ewes with single and those with twin lambs in Trials 3 and 4. Forage DMI by twin lambs, expressed as either kilograms.ewe-1.day-1 or percentage of lamb BW, was higher (P = .01) than intake by single lambs in Trials 3 and 4.(ABSTRACT TRUNCATED AT 250 WORDS)