Effect of add sodium bicarbonate and niacin in the rate of growth and some Thermoregulatory Responses and blood parameters for Friesian heifers in hot weather

Abstract

15 Friesian heifers were used (average weights 125 kg and the age of 6 months) belonging to the AL-Ishaqi Cattle Station (north Baghdad) for the period from 1/6/2011 to 1/9/2011 ,heifers divided randomly and evenly into three groups represent the first control group and second fed diet containing niacin at 6 g / heifer/ day in the third fed diet containing sodium bicarbonate on the rate of 100 g / heifer/day , For the purpose of the study is that the addition of niacin, sodium bicarbonate has a positive impact in the growth rate weekly and some thermal responses (respiration rate and rectal temperature and Heat tolerance coefficient And some blood parameters (WBC and RBC and glucose, cholesterol, hormones and thyroxine glucagon and cortisol) for the wheels exposed to fall under conditions of heat stress due to high temperature in summer and which is better? ,has been inferred on the occurrence of heat stress during the directory account temperature and humidity (THI) of the rates of air temperature and relative humidity daily, reaching an average of during the months of the study 80.48 , 82.65 and 83.66 units The results showed that the wheels fed on sodium bicarbonate and niacin have registered a growth rate higher than the weekly control group and each month study , also recorded the impact of niacin supplementation highly significant in the rate of respiratory daily and rectal temperature and Heat tolerance coefficient for months of the study as highest rate of respiration and less of the rectal temperature and the highest Heat tolerance coefficient compared with the group that received 100 g of sodium bicarbonate and the control group, also niacin Supplementation showed metabolic changes reflected on the significant increase (P<0.01) in the concentration of glucose and a decrease in concentration of cholesterol as well as the increase in the number of red blood cells and a decrease in white blood cells, and an increase in concentration of thyroxine and Glucagon hormones and significant decrease in the concentration of the hormone cortisol in the blood serum And recorded the group receiving sodium bicarbonate at 100 g / heifer / on the same positive impact on these traits, but to a lesser extent , It is concluded this that the addition of sodium bicarbonate and niacin for Friesian heifers exposed to conditions the summer heat had a positive effect in reducing these conditions and improvement of growth