Pre-Weaning Growth Rate and Thermoregulatory Parameters of Friesian X Bunaji Calves as Influenced by Different Ratios of Soy: Cow Milk

Résumé

The study was carried out to evaluate the effect of feeding different ratios of soybean (Glycine max (L.) Merril) milk and Friesian x Bunaji cow milk on pre-weaning growth rate, weaning weight and thermoregulatory parameters of Friesian x Bunaji calves. Sixteen (16) calves with average body weight of 34.8±0.7 kg were randomly assigned to four dietary treatments with 4 calves per treatment in a Completely Randomized Design. Results showed that calves had significantly (p<0.05) different weights at birth. There was also significant (p<0.05) difference in pre-weaning growth rate (PWGR), pre-weaning average daily weight gain (PWADWG) and weaning weights (WW) of calves across the treatments. Calves fed diet containing 25:75 ratio of soy:cow milk had higher PWGR (108.75 g), PWADWG (109.41 g) and WW (109.75 kg) followed by those on treatment containing 50:50 ratio of soy:cow milk (105.00 g, 105.73 g and 106.00 kg), respectively. There was no significant (p>0.05) difference in rectal temperature (RT) of calves across the treatments, but heart rate (HR) and respiratory rate (RR) differed significantly (p<0.05) as the level of soymilk increased in the diet. The highest and lowest HR (97.43 bpm) and (90.00 bpm) were observed in calves fed diets containing 75:25 and 25:75 ratios of soy:cow milk, respectively. While the highest (43.43 brpm) and lowest (40.86 brpm) respiratory rates were recorded in calves fed diets containing 75:25 and 50:50 ratios of soy:cow milk, respectively. All the thermoregulatory parameters measured were within the normal range for healthy calves. Therefore, feeding calves with 25:75 ratio of soy:cow milk is recommended for better weaning weight than feeding cow milk alone.