It is known that breeding success in birds declines with an advance in the laying date. In this paper, breeding success diminished with laying date in a house sparrow (Passer domesticus) population breeding in captivity. The principal cause of the cline in breeding success with date was a decrease in the female feeding rate. The parental effort in females decreased with the advance of the layin...

Arabian babblers (Turdoides squamiceps; mean adult body mass=72.5 g) inhabit extreme deserts of Israel. Previous studies have shown that their daily field metabolic rates are similar in winter and summer and that there is an increase during the breeding season. We hypothesized that the difference in seasonal daily field metabolic rate would be a consequence of differences in daytime metabolic r...

The Texas horned lizard (Phrynosoma cornutum) is protected in several states due to its apparently declining numbers; information on its physiology is therefore of interest from both comparative endocrine and applied perspectives. We collected blood samples from free-ranging P. cornutum in Oklahoma from April to September 2005, spanning their complete active period. We determined plasma concent...

Results: Average ovulation rate for all sows in the study was 14.58 +/0.32 ova and for the parity-two sows was 14.0 +/0.23 ova. The mean weaning-to-breeding interval for the parity-two sows was 5.87 +/0.14 days. Ovulation rate in the parity-two sows increased by 0.25 +/0.09 ova as the number of piglets weaned in the sow’s previous parity increased by one piglet (P <.05). The parity-two sow’s po...

no published information are available on the reproductive indices of local abadeh does reared innorthern fars province, southern iran. this study was conducted to determine the duration of the breedingseason, and the length and duration of the oestrous cycle. twenty single parity 2-year-old does from abadeh(weighing 19–26 kg) were purchased and transferred to the school of veterinary medicine ...

Two studies were conducted to evaluate the effects of postweaning management of British crossbred heifers on growth and reproduction. In Exp. 1, 239 spring-born, crossbred heifers were stratified by weaning BW (234 ± 1 kg) and allotted randomly to 1 of 2 treatments. Treatments were fed at a rate equivalent to 1.14 kg/d while grazing dormant forage (6.5% CP and 80% NDF, DM basis) and were 1) 36%...

Fifty one dairy buffaloes in their last two months of gestation were selected at seven peri-urban commercial farms located within a radius of 70km around Peshawar. These animals were monitored from parturition until 150 days post-partum. After parturition, rectal examination of reproductive organs was carried out. Estrus detection was made through visual signs and use of intact bulls. Milk samp...

Effects of ovulation rate and of fetal number and distribution within the uterus on pregnancy rate and fetal survival were evaluated in nulliparous (n = 1,331) and parous (n = 3,517) cattle selected for twinning. Cattle were divided into a spring (70 d) and fall (60 d) breeding season and bred by a combination of AI and natural service. Ovulation rate, pregnancy status, and fetal number and dis...

The conservation status and taxonomy of the three gadfly petrels that breed in Macaronesia is still discussed partly due to the scarce information on their spatial ecology. Using geolocator and capture-mark-recapture data, we examined phenology, natal philopatry and breeding-site fidelity, year-round distribution, habitat usage and at-sea activity of the three closely-related gadfly petrels tha...

Achieving a consistently successful A.I.-breeding program in a cow-calf operation requires attention to those heifers and cows not having normal estrous cycles (cycling) at the beginning of the breeding season. Because so many factors contribute to whether breeding females are cycling, including weather patterns, nutrition (availability of native forages or stored feeds), age or days since calv...