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...

Staphylococcus aureus is the most common contagious mastitis pathogen of dairy cattle. Antimicrobial treatment of infected cattle results in variable cure rates. Epidermal growth factor (EGF) plays an important role in the modulation of host innate immune responses and the regulation of mammary epithelial regeneration, indicating that EGF may be useful as a treatment for mastitis. A pilot study...

Mature pregnant crossbred ewes (n = 90) were used in a randomized complete block design and assigned to 1 of 3 winter-feeding systems differing in primary feed source: haylage (HL), limit-fed corn (CN), or limit-fed dried distillers grains (DDGS). Effects of these winter-feeding strategies on ewe and lamb performance were determined. Diets were formulated to meet or exceed NRC (1985) nutrient r...

The effects of contrasting photoperiods (16L:8D vs 8L:16D) and ambient temperatures (5 C vs 18 C vs 31 C) on performance traits of ewe lambs have been evaluated. Seventy-two lambs were paired and allotted to one of six treatment groups in a 2 x 3 factorial experiment. The lambs were fed a pelleted diet ad libitum. throughout the 14-wk study (i.e., as lambs progressed from 12 to 26 wk of age). A...

Causes of reproductive loss in ewes synchronized and mated during the anestrous season and during the normal breeding season were compared with those for natural cyclic ewes mated in season. Synchronization of ewes in season and out of season with progestogen: pregnant mare serum gonadotropin (PMSG) increased ovulation rate, but the percentage of ewes ovulating did not differ from that noted fo...

Three experiments were conducted, using 1,488 ewes during seasonal anestrous and during the normal estrous period, to evaluate the influence of breed on response to exogenous hormones. Treatment was intravaginal, progestogen pessaries Days 1 to 16, 10 mg crystalline progesterone on Day 16, followed by 750 IU PMS on Day 17. In the anestrous ewes a second PMS injection was given on Day 32 in one ...

Multiparous Suffolk and Suffolk-cross ewes were randomly allotted to treatments within breed and year to measure effects of ram exposure, during transition from anestrus to breeding activity, on reproductive performance. Treatments were: 1) ewes joined with two mature vasectomized Rambouillet rams for 15 d before breeding (DC), 2) ewes maintained across a net wire fence from two vasectomized ra...

Seventy-two Rambouillet ewes were fed one of two different levels of energy and protein during gestation to determine the effects of maternal undernutrition on growth and development in their offspring. Levels of energy and protein for the two groups of ewes were: 70% of National Research Council (NRC) requirements 30 d prior to breeding and the first 100 d of gestation and then alfalfa hay fed...

Osteoporosis is a chronic systemic disease characterised by bone loss and microarchitectural deterioration. Since the underlying regulatory mechanisms are still not fully understood and treatment options are not satisfactorily resolved, massive efforts are underway to further investigate this critical illness. Large animal models are stipulated, e.g. by the Food and Drug Administration, for pre...