Production responses in selenium supplemented sheep in northern New South Wales. 2. Liveweight gain, wool production and reproductive performance in young Merino ewes given selenium and copper supplements

Abstract

Young Merino ewes on five commercial properties in northern New South Wales were supplemented with selenium and their production was compared with untreated flock mates. They were studied from weaning till first lambing at about two years of age. Treatments of 5 mg selenium were given orally every six weeks for approximately 12 months. Copper treatments were also included to test for a possible concurrent deficiency or interaction with selenium. There were significant responses to selenium in liveweight in four of the five flocks and in wool production in two of the flocks at both shearings. Reproductive performance at first mating was also significantly better in two flocks. There were no beneficial effects of copper treatment nor were there any significant interactions with selenium treatment in any aspect of production measured.

Effect of dietary selenium and vitamin E supplementation on productive and reproductive performance in rams

“…Table 2, showed that Body weight gains and feed efficiency between animals of group 1 and 2 correspond to the results of Mahan and Parrett, 1996, who did not find any influence that adding Se to rations for rams but in contrast with the findings of Gabbedy 1971., Wilkins et al, 1982, who found an increase in body weight of rams supplemented with selenium Rams of group 2 exhibited by 26.83±0.31 cm larger testes circumference compared with those of the group 1, 25.54± 0.25cm. The differences found between the groups were, however, statistically non-significant that agrees with.…”

Rapid morphological change in an insular population of feral sheep

“…These tests are conservative because weights reported in the literature are for shorn sheep, whereas weights for all feral SCI ewes and many farmed rams include fleece. Estimates of fleece weights for feral sheep range 3–7 kg (Wilson & Orwin, 1964), and fleece weights for unshorn farmed sheep are similar (Wilkins et al , 1982). Masses of sheep on SCI in the 1800s are unknown, aside from a report of a 6‐month‐old ram in 1858 that weighed an estimated 46 kg (Fig.…”

Dietary Selenium Changes and Its Relation With Adaptability in Small Ruminants

“…Average fiber diameter and staple length showed similar trend to that of the wool production where they did not differ significantly between the experimental groups. Fry et al (1996) and Wilkins et al (1982) reported that the increase in wool length and fiber diameter which occurred in response to Se supplementation.…”

“…When marginal selenium deficiency is underestimated because of the absence of clinical symptoms; the deficiency may only be detected by careful measurement of body weight or wool production (Hill et al, 1969, Whelan et al, 1994. Wool production is more susceptible to selenium deficiency in growing ewes than in matures (Wilkins et al, 1982). Fry et al (1996) stated an increase in wool length and fibre diameter in response to selenium supplementation.…”