This study investigated physiological effects of pistachio by-products silage (PBPS) substituted in Holstein male calves diets and its effects on the growth performance. Twenty-four Holstein male calves (4-5 months of age and 155.6 ± 13.5 kg BW) were randomly assigned to one of four experimental diets (n = 6); contained 0%, 6%, 12% and 18% of PBPS (DM basis) respectively. During a 6-month experiment, dry matter intake (DMI) and weight gain were recorded and blood and urine samples were collected at different times. Results showed that mean DMI was not affected by different levels of PBPS in diets. But the calves fed 6% PBPS had the highest average daily gain (p < 0.05) and the lowest feed conversion ratio (p < 0.05). The calves fed 12% and 18% PBPS had lower albumin, white blood cell, haemoglobin and packed cell volume (p < 0.05) than those fed other diets. However, other serum metabolites, complete blood count (CBC), insulin and liver enzymes were not affected by the experimental diets. The long-term feeding of PBPS at different levels had no significant effect (p > 0.05) on pH, specific gravity, the number of white and red blood cells and epithelial cells count in urine. The animals did not show any symptom of illness or toxicity during the experimental period and all of the blood and urine parameters were in a normal range. It was concluded that substitution of PBPS up to 18% of the total diet that provide up to 18.2 g/kg DM total tannin had no adverse effects for Holstein male calves.

Olive leaf and olive leaf chloroform extract reduced ammonia production and increased the molar proportion of propionate in the rumen and can assist in developing novel feed additives for methane mitigation from the rumen. © 2016 Society of Chemical Industry.

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The objective of this study was to determine the effects of pistachio by-product silage (PBPS) as a partial replacement for corn silage (CS) on chewing activity, nutrients digestibility and ruminal fermentation parameters in Holstein male calves over a 6-month assay. For this purpose, 24 Holstein male calves (4 to 5 months of age and 155.6 ± 13.5 kg BW) were randomly assigned to one of the four dietary treatments (n = 6). In these treatments, CS was substituted with different levels of PBPS (0%, 6%, 12% and 18% of dry matter (DM)). Nutrient digestibility was measured at the end of the experimental period (days 168 to 170). Ruminal fermentation parameters were determined on days 90 and 180 and chewing activity was determined on days 15 of the 3 rd and 6 th month of the experiment. Results showed that calves fed rations containing 6% PBPS spent more time ruminating ( P < 0.05) than the control group on the 3 rd and 6 th months. Feeding PBPS was found to have no effects on DM, organic matter (OM), ether extract or ash digestibility, but apparent digestibility of CP, NDF om and ADF om linearly decreased ( P < 0.01) with increasing substitutions. On days 90 and 180, ruminal concentrations of volatile fatty acids and NH 3 -N linearly decreased ( P < 0.01) with increasing levels of PBPS in the diets; however, ruminal pH and molar proportions of acetate, propionate and butyrate were similar across the treatments. It was concluded that partial substitution of CS with PBPS (6% or 12%) would have no adverse effects on nutrient digestibility, total chewing activity and ruminal fermentation parameters.