Effects of Extra Nutritional Vitamin D۳ Levels on Physiological Response of Broiler Chicks Exposed to Repeated Lactic Acidosis

A number of ۱۴۴ male Ross-۳۰۸ broiler chicks (۱۸-day old) were used to investigate the effects of extra nutritional vitamin D۳ levels on the physiological response of broiler chicks exposed to lactic acidosis stress. Effects of the six experimental treatment consisting subcutaneous (SC) injection of ۰ (control- and control+), ۲۰۰۰۰, ۳۰۰۰۰, ۴۰۰۰۰, and ۵۰۰۰۰ IU of vitamin D۳ were examined in four replicates of six birds in a complete randomized block design during days ۲۱ to ۲۹ of age. Lactic acidosis is a form of metabolic acidosis that begins when a bird overproduces or underutilizes lactic acid, and their body is not able to adjust to these changes. Liver fat percentage decreased in the birds receiving ۵۰۰۰۰ IU of vitamin D۳ compared with the control birds (P < ۰.۰۳۶). Administration of ۳۰۰۰۰ IU vitamin D۳ enhanced serum concentration of creatinine by ۱۸.۵۲ percent compared with the control+ birds (P < ۰.۰۰۰۱). Injection of ۵۰۰۰۰ and ۴۰۰۰۰ IU vitamin D۳ decreased serum concentration of lactate dehydrogenase by ۲۴.۹۹ and ۱۹.۸۱ percent, respectively, compared with the control+ birds (P < ۰.۰۰۰۳). The mean serum activity of alanine aminotransferase in the birds receiving ۲۰۰۰۰ IU vitamin D۳ was greater by ۲۸.۵۷, ۱۸.۸۴, and ۱۷.۳۲ percent, compared with the control+ birds and those received ۴۰۰۰۰ and ۵۰۰۰۰ IU, respectively (P < ۰.۰۰۸). It was concluded that administration of extra nutritional vitamin D۳ up to ۵۰۰۰۰ IU per bird resulted in broad but inconsistent changes in the blood biochemical and enzymatic parameters in birds exposed to lactic acid. No firm evidence was found to suggest a protective effect vitamin D۳ on the incidence of sudden death syndrome in broilers during lactic acidosis.

Keywords:

Vitamin D۳ , Lactic acidosis , Broiler chicken , Sudden death syndrome