Calving ease is of economic importance in dairy cattle and should be considered in breeding programs. Economic values of direct and maternal calving ease were derived based on cost-benefit analysis and gene flow methodology. Marginal returns from dystocia reduction in primiparous dams were -$43 per phenotypic standard deviation compared with $300 for production. For an average mate, numbers of ...

This study was designed to determine the effects of semen type and calf gender on milk yield parameters, electrical conductivity flow values postpartum maternal body weight. A total 265 Holstein cows in first lactation were used study. The effect sperm weight levels after calving significant (P0.05). Heifers inseminated with sexed had higher 100-days yield, peak lactation. Milk duration heifers...

Gestation length, birth weight calving difficulty, calf mortality rate at birth, calf mortality rate from birth to weaning, preweaning calf growth rate and calf 200-d weight were evaluated in a biological type study in which four sire breeds were bred by AI to Hereford dams. Angus and Red Poll sires represented breeds of medium size, and Pinzgauer and Simmental sires represented large breeds. A...

A total of 1385 lactation records of Tharparkar cattle collected from LRS Chandan, Jaisalmer spreading over a period of 33 years were utilized to assess the effects of period and season of birth/calving on age at first calving, calving interval and service period and also studied effect of parity on calving interval and service period. The least-squares means were 1821.86 ± 37.022 days, 414.16 ...

At 50 d prior to predicted calving, 37 multiparous Angus cows were grouped by sire of mating, age and weight of cow and placed on either a high energy (HE, n = 19) diet or a moderate energy (ME, n = 18) diet. Objectives were to determine the effect of prepartum nutrition on: prepartum serum concentrations of estrone (E1), estrone sulfate (E1SO4) and progesterone (P4); pre- and postpartum cow bo...

Milk production is a primary factor controlling weaning weight of beef calves. The purpose of this experiment was to develop a practical and reliable on-farm method of estimating milk production and to relate estimates of milk production and milk composition to preweaning weight gain of calves. A second objective was to relate milk production to postpartum ovarian activity. Milk production of s...

Effects of inbreeding of animal and dam on estimates of genetic parameters and predictions of breeding values for five productive and reproductive traits of Piedmontese cattle were studied. Traits were (a) age at first insemination, (b) age at first calving, (c) 120-day weight, (d) yearling weight of males, and (e) yearling weight of females. Data for animals born from 1970 to 1995 were used. I...

This study examines the impact of body mass index (BMI) at calving on development and postpartum efficiency cows Zebu origin. The involved 87 their calves [pure Nellore (N) or predominant composition in a cross with Charolais (C) (3/4N1/4C 5/8N3/8C)]. mothers were grouped into classes according to BMI calving, namely, ‘small’, ‘moderate’ ‘large’. Body was determined by dividing weight length hi...

Bone accumulations faithfully record historical ecological data on animal communities, and owing to millennial-scale bone survival on high-latitude landscapes, have exceptional potential for extending records on arctic ecosystems. For the Porcupine Caribou Herd, maintaining access to calving grounds on the Arctic National Wildlife Refuge (ANWR, Alaska) is a central management concern. However, ...