The potential roles of 2 reproductive hormones, prolactin and prostaglandin, in the regulation of nematode growth, fecundity, and survival in lambs were examined in 2 experiments. In the first experiment, prolactin (25 ILJ/lamb) was administered to 3 groups of lambs at 1-wk intervals during each of the first 3 wk of patency of Haemonchus contortus infections, respectively. Fecundity (eggs/femal...

Group living facilitates pathogen transmission among social hosts, yet temporally stable host social organizations can actually limit transmission of some pathogens. When there are few between-subpopulation contacts for the duration of a disease event, transmission becomes localized to subpopulations. The number of per capita infectious contacts approaches the subpopulation size as pathogen inf...

The present study evaluated the effect of controlled ryegrass-white clover herbage availability from day 128 until day 142 of pregnancy in comparison to unrestricted availability, on the performance of twin-bearing ewes of varying body condition score (BCS; 2.0, 2.5, or 3.0) and their lambs. It was hypothesised that under conditions of controlled herbage availability, the performance of lambs b...

New-born lambs have limited energy reserves and need a rapid access to colostrum to maintain homeothermy and survive. In addition to energy, colostrum provides immunoglobulins which ensure passive systemic immunity. Therefore, getting early access to the udder is essential for the neonate. The results from the literature reviewed here highlight the importance of the birth site as the location w...

Records of mortality during the first year of life of 8,642 lambs from a composite population at the U.S. Meat Animal Research Center were studied using survival and logistic analyses. The traditional logistic approach analyzes the binary response of whether or not a lamb survived until a particular time point, thus disregarding information on the actual age at death. Survival analysis offers a...

Context Australian sheep breeding values (ASBVs) for lambing ease (LE) are estimated by Sheep Genetics, using a threshold animal model at the lamb level, in tri-variate analysis that includes data on birth weight, gestation length and score. The implications of these traits survival, or use other indirect to improve accuracy ASBVs LE, not currently being considered. Ultimately, it is desirable ...

Lifetime (5 yr) lamb production and wool production from 207 straightbred Targhee (T) and 474 1/4 Finn-1/4 Dorset-1/2 Targhee (FDT) crossbred ewes managed in a range or farm flock system were evaluated for ewe fertility, prolificacy, ewe fleece weight, and total lamb weight weaned per ewe exposed. Data included 2,620 ewe exposures, 2,384 parturitions, 4,638 lambs born, and 3,498 lambs weaned. E...

Abstract. The predator/prey (capture) problem is a prototype of many networkrelated applications. We study the capture process on complex networks by considering multiple predators from multiple sources. In our model, some lions start from multiple sources simultaneously to capture the lamb by biased random walks, which are controlled with a free parameter α. We derive the distribution of the l...