Author:
El-Tarabany Mahmoud S.,Roushdy Elshimaa M.,El-Tarabany Akram A.
Abstract
The thermal environment is a major factor that can negatively affect milk production and health traits of dairy cows. The objective of this study was to assess the production and health traits of the pure Holstein (HO), Brown Swiss (BS), first generation crossbred (BH) and the backcross (BC) cows under subtropical Egyptian conditions, in addition to investigating the impact of temperature–humidity index (THI) on milk production traits. Pure HO, BH crossbred and BC backcross cows had significantly higher 305-milk yield (MY) (9145, 8914 and 9021 kg, respectively), and total-MY (10 694, 9845 and 10 118 kg, respectively), than pure BS. However, the BS and BH crossbred cows had significantly shorter days open (121 and 131 days, respectively), than pure HO and BC backcross cows (160 and 154 days, respectively). Furthermore, pure HO cows at greater THI had decreased daily-MY and peak-MY in a rate of 23.8% and 12.9%, respectively, compared with lesser THI conditions. In contrast, production traits of pure BS and BH cows were more adapted with conditions of heat stress, even though slight deterioration of peak-MY was recorded in BH cows, ultimately at the greater THI level. The BH crossbred had significantly lower incidence of feet problems, clinical mastitis and metritis (crude odds ratio = 0.45, 0.54 and 0.47; P = 0.027, 0.046 and 0.041, respectively), suggesting an overall amelioration in their reproductive and general health parameters in comparison with their pure HO contemporaries. Our results indicate that the first generation crossbred (BH) has a more stable production performance and adaptability than pure HO under subtropical conditions.
Subject
Animal Science and Zoology,Food Science