Abstract:

This study aimed to determine the effects of DL-malic acid supplementation in beef cattle rations containing high concentrated feed and dry forage (alfalfa hay and wheat straw) on fattening performance, carcass traits and ru- men parameters. In present study, 47 male beef cattle (19 Simmental, 28 Limousine) at the age of 14-16 months were used. Cattle breeds were divided into two groups (0 and 30 g/day of DL-malic acid). In the present study, the differ- ences in live weights, daily live weight gains and carcass weights of the control and DL-malic acid groups were found to be significant in Simmental breed (P<0.05), but insignificant in Limousine breed. The beef cattle body measurements (withers height, chest girth, rump height, body length) did not change with malic acid supplementation (P>0.05).The malic acid addition increased the molarities of acetic, butyric, propionic and total volatile fatty acids (TVFA) and acetic acid/ propionic acid ratio in the rumen fluid (P<0.05).The addition of malic acid had no significant effect on the number of ciliated protozoa (Entodinium, Diplodinium, Isotricha and Dasytricha) and total bacteria count in the rumen fluid (P>0.05). As a result, DL-malic acid supplementation to beef cattle ration varied with cattle breeds in terms of fattening performance, while such supplementations had positive effect on fattening in Simmental breed. Besides, the increase in TVFA and acetic, propionic and butyric acids, which are indicators of fiber and carbohydrate fermentation efficiency in the rumen, shows that malic acid has a positive effect on feed digestion in the rumen.

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