Journal of Animal Health and Behavioural Science

Effects of Different Carbohydrate Sources on the Performance, Ruminal and Blood Metabolites and Nutrients Digestibility of Fattening Male-Lambs Fed Corn Steep Liquor

Abstract

Parmis Zahedi Moghadam, Arash Azarfar and Ayoub Azizi*

The current experiment was conducted to evaluate the effects replacing dietary corn/barley mixture with molasses at levels of 0, 50 and 100 g/kg dietary Dry Matter (DM) as a ruminal fermentable carbohydrate source, in the ration containing Corn Steep Liquor (CSL, 130 g/kg DM), as a ruminal degradable protein source. Twenty four male Lori lambs were randomly assigned into three groups of eight lambs each in a balanced completely randomised design. Nutrients digestibility, ruminal parameters, blood metabolites, feed intake and growth performance were determined. Results indicated that supplementing dietary CSL with increasing levels of molasses up to 100 g/kg of DM linearly increased organic matter (L, p=0.05) and ash-free neutral detergent fibre (L, p<0.05) digestibility, while DM, crude protein and ash-free acid detergent fibre digestibility remained unchanged (p>0.05). Increasing the level of molasses in the CSL containing diets had no effect on ruminal pH (p>0.05), but linearly decreased rumen concentration of NH3-N (L, p<0.05). Except for total Volatile Fatty Acids (VFAs) and molar proportion of butyrate which were increased linearly (L, p<0.05) with increasing dietary molasses level, other individual VFAs were similar (p>0.05) among the experimental rations. Increasing the level of molasses in the diet up to 100 g/kg of DM linearly increased (L, p=0.05) plasma total protein concentration, while linearly reduced blood urea nitrogen concentration (L, p<0.05). Total weight gain and average daily gain were improved (L, p<0.05), while feed conversion ratio was decreased linearly (L, p<0.05) with increasing dietary level of molasses. However, final body weight and feed intake remained unchanged (p>0.05) by feeding the experimental diets. In conclusion, results of present study indicated that supplementing CSL with molasses at levels of 100 g/kg dietary DM increased nutrients digestibility and production performance of fattening lambs.