عنوان مقاله [English]
Background and objective: Based on studies conducted in response to concerns about the use of antibiotics and other growth promoters, the demand for the use of natural growth stimulants in the livestock feed industry has increased in the last 5 to 10 years because, unlike antibiotics There is no tissue residue from the use of natural growth stimulants by livestock and poultry and does not produce microbial resistance. Other additives, including sodium humate, are obtained from organic matter decomposition, were raised. The present study was conducted to investigate the effect of sodium humate on the performance, rumen parameters and Blood parameters included glucose, total protein and cholesterol, and ammonia nitrogen rumors and volatile fatty acids of Holstein calves.
Materials and Methods: Fourtyeight newborn Holstein calves with mean birth weight was 37 ± 2 were studied in four treatments in a completely randomized design for 75 days. Calves received 4 liters of milk replacer (10% of birth weight) from day 4 of birth twice a day at 8 and 16 hours. Treatments were included as1) control (milk replacer supplement without supplementation), 2) milk replacer feeding with addition of 5 grams of sodium humate, 3) milk replacer feeding with addition of 10 grams of sodium humate, and 4) milk replacer feeding by adding 15 grams of sodium humate. In addition to milk replacer, each animal had free access to water and starter. Blood samples were taken at 30, 60 and 75 days of age, as well as rumen fluid sampling in 35 and 75 days of day after 3 to 4 hours after feeding using a vacum pump for sampling from the abdominal fluid Feed intake and calves weight were measured daily and weekly respectively.
Results: Feed intake, Feed conversion, apparent digestibility cofficients of nutrients, volatile fatty acid concentrations, ruminal pH and growth parameters were affected by treatments (p <0.05). In the entire period, there was no significant difference in feed conversion among treatments. The effect of adding sodium humate to milk were different on blood and rumen parameters. Total volatile fatty acids in the group consuming 5 grams of sodium humate daily was significantly higher than other treatments (P<0.05). The amount of ammonia nitrogen concentration was affected by treatments at the end of the period (P = 0.04). In the end of the period, the lowest amount of ammonia nitrogen was related to treatment 2 (5 gr sodium humate). The prevalence of diarrhea was 8.33, 3, 4and 4.66 percentage respectively. General health score for calves consuming 5 grams of sodium humate was significantly higher than other treatments.
Conclusion: In this experiment, calves consuming 5 g of sodium humate of body weight gain, health status, blood and rumen parameters were in more favorable. The consumption of 5 grams of sodium humate had positive effects on blood and rumen parameters.