Ewes were injected intramuscularly with 1 ml iodised oil at mating or during the first two months of pregnancy to determine if marginal iodine deficiency contributed to the high mortality of newborn lambs in Victoria. Iodine treatment markedly increased milk iodine concentration of ewes. In nine of ten trials conducted in 1979 and 1980 at Ararat, Hamilton, Langi Kal Kal, Ruffy, Rutherglen and T...

This study assessed the effectiveness of a mutant strain of Toxoplasma gondii (RH strain) lacking the mic1 and mic3 genes (Mic1-3KO) against Toxoplasma abortion in sheep. Ewes were inoculated subcutaneously with 10(5) Mic1-3KO tachyzoïtes in three independent experiments. Following vaccination, Mic1-3KO induced a mild febrile response and serum IgG antibodies, which persisted throughout the exp...

In Exp. 1, 45 fine-wool ewes received (sc) either 0, 50 or 100 mg epostane (3-beta-hydroxysteroid dehydrogenase inhibitor) to examine effects on return to estrus and conception rates. Treatments were imposed on d 10 of an estrous cycle (estrus = d 0) and jugular blood samples were collected once daily on d 8 and 9, twice daily on d 10 through 13 and once daily from d 14 until first post-treatme...

A cohort study was conducted in order to measure the effect of the chronic indurative lymphocytic mastitis caused by the South African strain of maedi visna virus (MVV) on the pre-weaning growth of lambs born either of naturally infected or uninfected ewes kept under similar conditions. Fifty naturally infected ewes as well as another 40 from a maedi-visna-free source to be used as control anim...

Experiments were designed to localize the central sites of action of melatonin involved in the control of seasonal reproduction. Ewes were exposed to long days and received microimplants of melatonin in the preoptic area (n = 9), anterior hypothalamus (n = 4), dorsolateral hypothalamus (n = 4), or mediobasal hypothalamus (n = 12). The effects of implants were determined by comparison with contr...

Newborn lambs depend on their dams for passive transfer of immunoglobulins, primarily IgG, for protection from harmful pathogens until their own immunological defenses have developed. Previous studies have suggested that supplementation with Se results in a modest increase in IgG concentration in serum of newborn calves and lambs. To evaluate the effect of the Se source and supplementation rate...

Milk production and lamb growth were characterized in 118 multiparous, 3- to 7-yr-old Rambouillet, Columbia, Polypay, and Suffolk ewes under spring sage range and high mountain meadow grazing from 28 to 98 d postpartum. Daily milk yield as measured by the lamb suckling weight differential technique did not differ (P greater than .05) among breeds, although milk production of Suffolk ewes tended...

The aim of this trial was to evaluate the effectiveness (fertility and lambing) of priming with a single injection of progesterone plus PMSG in anovulatory lactating Sarda ewes subjected to the ram effect (RE) in spring. Thirty ewes (P4 group) were i.m. injected with 30 mg progesterone and 500 IU PMSG 36 h before ram introduction (d 0). This treatment was compared to a 12-day treatment with flu...

Our objective for this study was to determine the pattern of nutrient flux across the portal-drained viscera (PDV) and liver in ewes with varying numbers of fetuses. Catheters were placed in the hepatic portal vein, a branch of the hepatic vein, a mesenteric vein, and the abdominal aorta of ewes. Blood flow and net nutrient release across the PDV and liver were determined before exposure to ram...

The studies were conducted on thirty ewes of two genotypes. For each genotype the ewes were divided into two groups: stabling and pasture. The objective of the investigation was to determine the influence of maintenance system on chosen morphological and biochemical blood indicators as well as the parameters of reproduction traits of sheep. In the first year of the studies the ewes of both grou...