نتایج جستجو برای: cows and bull populations
تعداد نتایج: 16856168 فیلتر نتایج به سال:
background: suicide is one of the most important health problems in communities and knowledge of rates and epidemiology of it in any region could help in control and preventing programs .longitudinal registration of annual death data has been employed in this study. methods: in an analytical and cross sectional study pre conducted forms of suicide was engaged to register data , crude and specif...
BACKGROUND The physiological mechanism by which bulls stimulate resumption of ovarian cycling activity in postpartum, anovular, suckled cows after calving may involve the concurrent activation of the hypothalamic-hypophyseal-ovarian (HPO) axis and hypothalamic-hypophyseal-adrenal (HPA) axis. Thus, the objectives of this experiment were to determine if characteristics of temporal patterns of cor...
The aim of this study was to determine possible differences in the faecal microbiota of dairy cows infected with Mycobacterium avium subsp. paratuberculosis (Johne's disease) in comparison with noninfected cows from the same herds. Faecal samples from cows in 4 herds were tested for M. avium subsp. paratuberculosis by real-time PCR, and faecal bacterial populations were analysed by 454 pyrosequ...
To establish the basis for implementation of a producer education program, a social assessment of the willingness and barriers to adoption of a measure of feed efficiency in beef cattle [residual feed intake (RFI)] was conducted. A 35-question mailed survey was sent to 1,888 producers acquired from the stratified random sample of the Idaho Cattle Association member list (n = 488), Red Angus Ass...
The influence of pH dynamics on ruminal bacterial community composition was studied in 8 ruminally cannulated Holstein cows fitted with indwelling electrodes that recorded pH at 10-min intervals over a 54-h period. Cows were fed a silage-based total mixed ration supplemented with monensin. Ruminal samples were collected each day just before feeding and at 3 and 6h after feeding. Solid and liqui...
—Identification of the factors limiting inland salmonid populations, such as those of the threatened bull trout Salvelinus confluentus in the Pacific Northwest, can be particularly challenging due to substantial gaps in our understanding of population demographics, population structure in the presence of multiple life history forms, and vital rates. We implemented a large-scale mark–recapture p...
Vinkler A., E. Kudlac, A. J ii'icek: Some Factors Influencing the Results of Conception in Cows and Heifers in Estrus Synchronized by the Synthetic Analogue of PGF2<x Cloprostenol. Acta vet. Brno, 51, 1982: 81-89. A study of the contribution of the breeding bull, the work of the operator and the influence of the size of the synchronized group on the conception rate in breeding cows after a firs...
—We evaluated the association of local-habitat features, large-scale watershed factors, the presence of nonnative brook trout Salvelinus fontinalis, and connectivity to neighboring populations with patterns of occurrence of threatened bull trout S. confluentus in 112 first-order to fourthorder streams in the Bitterroot River drainage in western Montana. Species presence or absence was estimated...
The effect of early gestation maternal undernutrition followed by realimentation on placentomal vascular growth and angiogenic factor expression was determined in multiparous beef cows bred to the same bull. Cows gestating only female fetuses (n = 30) were fed in equal numbers to meet the NRC requirements (control) or were fed below the NRC requirements to lose BW (nutrient restricted; NR) from...
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