Comparison of external and internal pelvic measurements of Belgian Blue cattle from sample herds in Belgium and the United kingdom

Fetal metacarpal/metatarsal bone thickness as possible predictor of dystocia in Holstein cows

Dystocia and perinatal calf mortality cause significant economic losses in the dairy cattle industry. Despite advanced ultrasound examination procedures, there is no reliable method to estimate the birth weight of calves in order to predict, prepartum, the risk of dystocia. The aim of this study was to predict calf birth weight and dystocia based on transrectal ultrasonographic (TRUS) examinations in late-term Holstein heifers and cows. Therefore, TRUS examination was performed on 128 animals that were between 265 and 282 d of gestation to measure the bone thickness of the fetal metacarpus (MC) or metatarsus (MT). Fetal TRUS measurements were successful in 104 cases. Excluding twin deliveries, 97 fetal MC/MT bone thicknesses were measured and the mean (±SD) MC/MT thickness was 2.54 ± 0.37 cm. A novel index, the metacarpal/metatarsal index [MCTI = maternal body weight (kg)/fetal MC or MT thickness (cm)], was also calculated to study its association with calving ease. The average MCTI was 257.3 kg/cm in the studied population. A lower MCTI was associated with the risk of dystocia with an odds ratio of 2.074 that was not significantly different from 1 (95% confidence interval: 0.002-11.104). Fetal presentation, fetal age, fetal sex, body condition score of the dam, age of dam, and intercoxal and interischiadic distances were not related to dystocia. A fair phenotypic correlation (0.226) was found between MC/MT thickness and calf birth weight. The genetic correlation between MC/MT thickness and calf birth weight was 0.235. Our results indicate that late-term measurement of the fetal MC/MT bone thickness by means of TRUS examination augmented with the MCTI may have clinical significance in the prediction of dystocia in Holstein cattle. Because the odds ratio for dystocia based on MCTI determination was not significant, the applied technique should be improved based on further studies on prepartum TRUS examinations combined with dam pelvic measurements.

Determinants of meat quality: tenderness

Meat quality is a term used to describe a range of attributes of meat. Consumer research suggests that tenderness is a very important element of eating quality and that variations in tenderness affect the decision to repurchase. The present paper highlights recent information on the factors that affect tenderness. While the precise aetiology is not fully understood, a number of factors have been shown to affect tenderness. Of these factors, postmortem factors, particularly temperature, sarcomere length and proteolysis, which affect the conversion of muscle to meat, appear most important. However, it is now becoming clear that variation in other factors such as the muscle fibre type composition and the buffering capacity of the muscle together with the breed and nutritional status of the animals may also contribute to the observed variation in meat tenderness.