WITHDRAWN: Impact of climatic variability of the temperature-humidity index during winter, spring and summer seasons in Egypt on the growth of the native bovine calves

Abstract

This research aims to check the impact of climatic variability of the THI index during the three main seasons of the year in Egypt on growth traits and biochemical blood components in native bovine calves. Eighteen Egyptian bovine calves after weaning were used in this study. The experimental design included three experimental groups according to the year's seasons. In the 1st group, sex calves were rearing under winter conditions. In the 2nd group, sex calves were kept during the spring season. In the 3rd group, sex calves were maintained during the summer season. Weekly and monthly Temperature-humidity index (THI) was calculated for the three seasons. The daily body gain (DBG) the feed intake (DMI), and water consumption (WC) were measured weekly for each calf. The highest THI value (85.5) during summer resulted in a significant (P<0.01) decrease in DBG, daily DMI, thyroid hormonal levels, total proteins, and glucose and a significant (P<0.01) increase in daily WC and levels of cortisol and urea. The rate of decline increases with increasing THI values from low THI in winter (68.1) to moderate THI during spring (74.9) and high THI (85.5) during the summer season. With increasing THI, the depression in DBG was more than the decline in daily DMI; therefore, food conversion increases when the value of THI increases. THI has highly (P<0.01) significant negative correlations with DBG, DMI, thyroxin (T4), triiodothyronine (T3), total proteins, and glucose and has highly significant (P<0.01) positive correlations with water intake as well as cortisol and urea concentrations.

The detrimental impact of high environmental temperature on physiological response, growth, milk production, and reproductive efficiency of ruminants

“…DMI was decreased daily by 36.0 g and 85 g during the spring and summer seasons, respectively, compared to winter. These results designate that the extreme deteriorating effect of heat stress on both DBG and daily DMI was detected in the summer season (Habeeb et al 2022 ).…”

“…In the hot summer months, if this water is unavailable, the animal may quickly get dehydrated. Water consumption (L/day) significantly increased by 28.8% at THI 74.9 during the spring season and by 63.4% at greater THI (85.5) during the summer season compared to those at low THI 68.1 in winter (Habeeb et al 2022 ). High ambient temperatures affect the peripheral thermal sensors to transmit nerve signals to the hypothalamus and then to thirst center that increases the water consumption as presented in Fig.…”

“…The effectiveness of conversion of DMI to DBG ratio was improved significantly by 13.1% at THI 74.9 during the spring season and by 33.6% at THI 85.5 during the summer season compared to those in winter 68.1. With increasing THI, the depression in DBG was more than the decline in daily DMI; therefore, food conversion (DMI/DBG) increases when the value of THI increases (Habeeb et al 2022 ).…”