نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Introduction: However, since milk is widely consumed early in life, it is considered an ideal food for increasing vitamin D intake. Therefore, vitamin D3 emulsion can be mixed into the milk consumed by suckling calves, and in the emulsification method, fats become viscous and improve digestive absorption. On the other hand, the use of vitamin D3 emulsion does not require skilled workers and does not cause stress in calves. Therefore, based on the above, it can be said that the use of vitamin D3 emulsion is preferable to the injection and oral methods.The aim of this study was to investigate the effects of different sources of vitamin D3 on growth performance, blood metabolites and liver enzymes of suckling Holstein calves.
Materials and Methods: Forty Holstein calves with a mean age of 30±2 days and a weight of 59±1 kg were selected in a completely randomized design with 5 treatments and 8 replications. Treatments included: 1) Control group (basal diet): receiving commercial basal diet without additional vitamin D3, 2) Commercial basal diet + daily intake of 1000 IU of vitamin D3 supplement orally, 3) Commercial basal diet + daily intake of 1000 IU of vitamin D3 supplement in injectable form, 4) Commercial basal diet + daily intake of 1000 IU of vitamin D3 supplement in emulsion type I, 5) Commercial basal diet + daily intake of 1000 IU of vitamin D3 supplement in emulsion type II, mixed with milk per day. For in vitro production of fat-soluble vitamin D3 (cholecalciferol) emulsion, a method described by Asghari et al. (Asghari et al., 2021) with minor modifications was used. High-dose ampoules (300,000 IU/mL; manufactured by Darupakhsh Pharmaceutical Factory, Iran) were used as the source of vitamin D3. After data collection, statistical analysis was performed using software (SAS, 2003). Repeated data including calf growth performance were analyzed using Mixed procedure and blood parameters data were analyzed using GLM. LSMEANS method was used to compare means and 5% probability level was considered as significant level.
Results and discussion: The results obtained regarding growth performance indicate that the weight of calves, daily weight gain, feed intake and feed conversion ratio of suckling calves were affected by the addition of different sources of vitamin D3. Thus, the daily weight gain and feed conversion ratio were significantly improved by adding 1000 IU of vitamin D3 emulsion type II source in suckling calves in the first, second, third and entire research period (0-7, 7-14, 14-21 and 0-21 days of the experiment) and also by injecting 1000 IU of vitamin D3 per day in the second, third and entire period (7-14, 14-21 and 0-21 days of the experiment), in a linear and quadratic manner compared to the other experimental treatments. The weight of calves also showed a significant increase in a linear manner in the second week (7-14 days of the experiment) and also in a linear and quadratic manner compared to the other treatments by using 1000 IU of vitamin D3 in the form of injection and type II emulsion in the second week (7-14 days of the experiment) and in the third week (14-21 days of the experiment). The results related to feed intake also showed that in the first week of the experiment (0-7 days of age), adding 1000 international units of vitamin D3 emulsion type I and II per day, and in the second, third and entire period (7-14, 14-21 and 0-21 days of age), using 1000 international units of vitamin D3 per day by injection and emulsion type I and II showed a significant increase compared to the other treatments. Of course, this significance was linear in the first and second weeks and linear and quadratic in the third week and the entire period. The results obtained from blood metabolites and liver enzymes also indicate that the use of different sources of vitamin D3 could not have a significant effect on the plasma concentrations of glucose, cholesterol, triglycerides, albumin and protein. In contrast, the blood concentration of aspartate aminotransferase using 1000 IU of vitamin D3 in the form of injection and emulsion type I and II per day and the serum concentration of alanine aminotransferase also showed a significant linear decrease compared to other experimental groups with the addition of 1000 IU of vitamin D3 emulsion type II per day (P<0.05). Also, treatments 3, 4 and 5 (treatments receiving 1000 IU of vitamin D3 in the form of injection, emulsion type I and II per day) increased the plasma concentration of vitamin D3, calcium and phosphate in a linear and quadratic manner significantly compared to the other treatments.
Conclusion: In general, adding excess vitamin D3 to commercial diets, depending on the form of consumption and the calf's growth stage, can be effective in improving the metabolic status and general health of suckling calves by improving growth performance, increasing vitamin D status, improving calcium and phosphorus status, and adjusting some biochemical indicators.
کلیدواژهها English
