Effects of formic and propionic acid as silage additive on haematology and biochemical attributes in growing cattle

This study aimed to evaluate the effect of formic and propionic acid, alone or in combination as silage additive on haematological and biochemical attributes in growing Sahiwal cattle. A total of 24 growing Sahiwal heifers were randomly allocated into four groups (n=6) on body weight (117±5.0 kg) and age (10±2.0 months) basis. The experimental heifers either received a basal total mixed ration (TMR) having ensiled sorghum fodder without organic acids (S_C) or were fed on TMR having silage preserved with 0.5% formic acid (S_0.5%FA), 0.5% propionic acid (S_0.5%PA) or 0.25% formic acid and 0.25% propionic (S_{0.25%FA+0.25%PA}). Feeding of silage treated with formic and propionic acids did not exert any effect on dry matter intake (DMI) while average daily gain (ADG) and feed efficiency were better (P<0.05) in S_0.5%FA group. Treatments, days of feeding and their interaction did not affect red blood cells (RBCs) count, granulocyte count, lymphocytes count, mean corpuscular volume (MCV), mean cell haemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC). However, white blood cells (WBCs) and platelet (PLT) count were significantly lower (P<0.05) in S_0.5%FA group and haemoglobin (Hb) concentration and packed cell volume (PVC) value in 0.5% S_0.5%PA group. No significant differences in the alanine transaminase (ALT), aspartate aminotransferase (AST) and creatinine were observed among four different groups, however; mean plasma alkaline phosphatase (ALP) concentration was higher in S_0.5%PA group. Treatments did not affect plasma Ca and P levels. In conclusion, feeding of silage preserved with formic and propionic acid, alone or in combination had no adverse effect on performance, haematological attributes and liver and kidney function test.