The present study was conducted to investigate the attributes of ram sexual behaviour under different social conditions. Six intact rams and eight overiectomized ewes were used in this experiment. Ewes were artificially brought into oestrus. All mating traits were recorded every 10 sec during a 1 h mating session under five social conditions viz., ram exposed to single oestrus ewe, ram exposed ...

Data from the Montana State University Targhee flock were used to estimate genetic and environmental relationships between lamb BW and adult ewe BW, condition score, and prolificacy. The flock was managed under commercial western range conditions typical of the area. Data included records from 12,154 lambs born to 2,930 dams and 200 rams between 1960 and 2005. Lamb traits included BW at birth a...

To determine if a circadian rhythm known to be functionally related to the reproductive axis varies on a circannual basis, we monitored the circadian secretion of melatonin at monthly intervals for 2 years in four ovariectomized, estradiol-implanted ewes held in a constant short-day photoperiod. Prior to the study, ewes had been housed in a short-day (8L:16D) photoperiod for 4 years and were ex...

The ability to maintain weight during adverse seasons is an important characteristic in mature ewes. Ewes that lose less weight will be in better condition at mating and throughout pregnancy resulting in higher fertility, fecundity and lamb survival, and lower ewe mortality. Liveweight data (corrected for greasy fleece and conceptus weights) from mature Merino ewes was analysed to determine fac...

Scrapie is one of several transmissible spongiform encephalopathies of livestock. Disease susceptibility is linked to polymorphisms in the normal prion protein gene that encodes the mammalian prion precursor. Codon 171 of this gene is a major determinant of scrapie susceptibility. Selection for arginine (R) at codon 171 is encouraged by the USDA to decrease the incidence of scrapie. Objectives ...

in this study records of 15723, 12108 and 5236 zel sheep for birth weight (bw), weaning weight (ww) and 6-month weight (6mw) traits were used. data has been collected by the jahad-e-keshavarzi organization of province of mazandaran during 1994-2009. the heritability of direct and maternal of growth traits was estimated using the univariate analysis with restricted maximum likelihood (reml). in ...

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...

twenty eight lactating buffaloes were used in a completely randomized design with 2×2 factorial arrangement of four experimental diets including low protein–low energy (lp-le), low protein–high energy (lp-he), high protein–low energy (hp-le) and high protein–high energy (hp-he). results showed that the hp-he diet recorded the highest digestibility coefficients of cp, ee, nfe, nutritive values, ...

The reproductive success of sibling cocklebur plants (Compositae: Xunthium strumarium) was monitored after growth at different levels of availability of water and nutrient resources. Variation in reproductive success among individual plants was related to physiological, structural, and phenological characteristics. Reproductive success increased with increased availability of resources, but the...