Context Reproduction is an economically important trait in both males and females; however, the relationships between fertility body composition traits are little researched, but essential to breeding programs, as they will help inform selection decisions allow greatest opportunity for genetic gain. Aims Estimate phenotypic correlations male female yearling investigate their relationship with t...

This study evaluated the plasma membrane integrity, acrosomal membrane integrity, and mitochondrial membrane potential of Nelore bull sperm from early puberty to early sexual maturity and their associations with sperm motility and vigor, the mass motility of the spermatozoa (wave motion), scrotal circumference, and testosterone. Sixty Nelore bulls aged 18 to 19 months were divided into four lot...

The aim of this investigation was to assess the effect of improved diet above maintenance requirement on reproductive parameters, including testicular size, semen volume, sperm concentration and viability. Twelve Bakhtiary rams were allocated to two groups of six animals and were fed during a 12-week experiment period with different diets which were designed to supply maintenance and above main...

A cross-sectional study was conducted in communal and small-scale Nguni cattle enterprises to determine preferential traits for improvement under low-input cattle breeding programs. Forty-one farmers participated in ranking six specific traits of breeding bulls and cows. Kruskal-Wallis test and ordinal logistic regression were used to determine mean ranks of traits and odds ratios of predictors...

A total of 51,161 records of scrotal circumference measurements at 18 mo of age (SC18) and 17,648 records of sperm defects and breeding soundness of Nellore bulls (mean age of 22.5 mo), raised under extensive conditions, were analyzed to estimate coefficients of heritability and genetic correlations of morphological semen traits by Bayesian inference. The observed semen traits were classified a...

Six apparently healthy Borno white bucks weighing 15± 1.6 kg and aged 1.3± 0.3 years were used for this study. Two and half (2.5) ml Purit® (chlorhexidine gluconate 0.3% B.P W/V and cetrimide 3.0% B.P W/V CAPL Lagos) were injected bilaterally into the caudae of each epididymis following sedation with xylazine hydrochloride. The prestudy scrotal circumference was 20.1±1.5cm; Significant decrease...

Net feed intake (NFI) is a moderately heritable feed efficiency trait that has been shown to be genetically independent of ADG and BW in beef cattle. Objectives of this study were to characterize NFI in growing bulls, and to examine phenotypic correlations between NFI and performance, body composition, and fertility traits. Net feed intake was positively correlated phenotypically with feed conv...

Sequence polymorphisms in the growth hormone (GH) gene and its transcriptional regulators, Pit-1 and Prop-1, were evaluated for associations with growth and carcass traits in two populations of Brangus bulls Chihuahuan Desert Rangeland Research Center (CDRRC, N = 248 from 14 sires) and a cooperating breeding program (COOP, N = 186 from 34 sires). Polymorphisms were SNP mutations in intron 4 (C/...

Bull calves (n = 143) were obtained from two strains of Angus and two strains of Hereford cattle for which replacements were selected on the basis of superior feedlot growth performance on either high- or medium-energy diets. From weaning to slaughter at 15 mo of age, bulls were fed either the high-energy (80% grain + 20% forage) or medium-energy diet (100% forage) corresponding to their strain...

The present study was carried out to estimate both (co)variance components and genetic parameters for frame scores obtained using two methods (FRAME_GMA and FRAME_BIF) as well as phenotypic and genetic correlations with traits such as weaning weight, weight gain from weaning to yearling, scrotal circumference, muscle score, and an empiric index for animal classification for the Special Certific...