Effects of Replacing Corn Silage with Varying Levels of Ammonia Gassed Wheat Straw on Performance, Fermentation Parameters and Blood Metabolites in Holstein heifers

The replacement of corn silage with varying levels of ammonia gassed wheat straw on performance, digestibility, fermentation parameters, chewing activities, blood metabolites and profitability of Holstein heifers have been evaluated. Fifteen Holstein heifer with 9-10 months of age were assigned in a completely randomized design with 3 treatment as 1) 36% corn silage, 2) 18% corn silage and 18% wheat straw and 3) 36% treated wheat straw and 5 replicates for 2 months. Straw presses treated with 4% ammonia gas for 30 days. The results showed that the difference in dry matter intake and average daily weight gain and wither sheight among treatments is not significant. Digestibility of DM, CP, ADF and NDF in treatment 1 was significantly higher than other treatments. Ruminal pH and ammonia nitrogen in treatment 3 as were significantly higher than other treatments. Eating time, rumination time and total chewing time in treatment 3 was significantly higher than the other two treatments. Blood urea nitrogen in treatment 3 than the other two treatments and blood albumin in treatment2 were significantly higher than the other two treatments. Glucose, cholesterol, TG and AST and ALT had no significant difference among treatments. In general, for every kilogram of weight gain, in treatment 3 and treatment 2 as compared to treatment 1, 3860 and 3935 Rials were saved respectively The results showed that the treated straw with 4% ammonia gas can be completely replaced corn silage in the diet of Holstein heifers without negative impact on their performance

Effect of Supplementation of Fish and Canola Oil in the Diet on Milk Fatty Acid Composition in Early Lactating Holstein Cows

This study examined the effects of supplementation of fish oil and canola oil in the diet on milk yield, milk components and fatty acid composition of Holstein dairy cows in early lactation. Eight multiparous early lactation Holstein cows (42±12 DIM, 40±6 kg daily milk yield) were fed a total mixed ration supplemented with either 0% oil (Control), 2% fish oil (FO), 1% canola oil +1% fish oil (FOCO), or 2% canola oil (CO) according to a double 4×4 Latin square design. Each period lasted 3 wk; experimental analyses were restricted to the last week of each period. Supplemental oils were added to a basal diet which was formulated according to NRC (2001) and consisted of 20% alfalfa, 20% corn silage and 60% concentrate. Milk yield was similar between diets (p>0.05), but dry matter intake (DMI) was lower (p0.05). The proportion (g/100 g fatty acids) of short chain fatty acids (SCFA) decreased and polyunsaturated fatty acids (PUFA) increased (p0.05). The proportion of trans(t)-18:1 increased (p<0.01) in milk fat of cows fed FO and FOCO diets, but CO diet had the highest proportion of cis(c)-11 18:1 (p<0.01). The concentration of t-10, c-12 18:2, c-9 t-11 18:2, 18:3, eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) increased (p<0.05) in FO and FOCO diets in comparison with the other two diets. These data indicate that including fish oil in combination with canola oil significantly modifies the fatty acid composition of milk

Effects of Processing of Starter Diets on Performance, Nutrient Digestibility, Rumen Biochemical Parameters and Body Measurements of Brown Swiss Dairy Calves

In order to investigate the effect of physical forms of starter diets on performance, weaning age, nutrient digestibility and rumen biochemical factors, 24 female of neonatal Brown Swiss calves (average body weight of 39.5±1.2 kg) were randomly assigned to three treatments. Dietary treatments were mashed (MS), pelleted (PS), and texturized (TS) starter using 8 calves from birth till 90 days of age in each treatment. Diets were formulated to be iso-nitrogenous with 21% crude protein. Based on the experimental results, calves that received PS and TS diets, had significant higher average daily gain (ADG) than those receiving MS (p0.05). Ruminal pH was higher (p<0.01) in MS than the other groups, but ruminal ammonia (g/dl) concentration was not different among the treatments. Body measurements such as body length, pin width, hip width, pin to hip length, size of metacarpus and metatarsus bones, hip height, wither height, stomach size and heart girth were not significantly different among the treatments. Overall, it is concluded that starter diets in the form of pellet and texture can improve performance in neonatal Brown Swiss calves compared to the mashed form