Document Type : Research Articles
Department of Animal Sciences, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
Introduction: One of the most important factors in the profitability of dairy farms is effective management methods in keeping and feeding infant calves. Several factors such as underdeveloped immune system and environmental stress can increase the survival power of the animal. Researchers suggest different factors can to improve the immune system of neonatal calves, including the use of fat-soluble vitamins and unsaturated fatty acids. While these vitamins play a major role in the immune system of animals, the supply of fat-soluble vitamins in the calf's diet is essential for promotion the normal growth of muscles and the skeleton of the body. Common symptoms of a deficiency in fat-soluble vitamins in neonatal calves include retardation of growth, and susceptibility to infectious diseases.
Materials and Methods: This experiment was performed in the farm of Ferdowsi University of Mashhad. Twenty-eight Holstein female calves with an average bodyweight of 37.74 kg (± 4.76) were used from birth to 56 days of age. On the fourth day, the calves were randomly assigned to one of four treatments. All calves received colostrum for the first 3 d and then whole milk at 8% of bodyweight in the two-equal part in the morning (4.00 A.M) and evening (16 P.M) until weaning. The experimental treatments included: 1) whole milk with starter (Control), 2) control diet supplemented with flax seed oil (0.3 ml per kilogram of body weight), 3) control diet and weekly injection of 7 cc of fat-soluble vitamins (A, D3, E), 4) control diet which supplemented with flaxseed oil (0.3 ml per kilogram of body weight) plus weekly injection of 7 cc of fat-soluble vitamins (A, D3, E). Flax seed oil was mixed into milk (morning feeding) until weaning. During the experiment period, calves had ad libitum access to starter diet and water. Blood sample were harvested from jugular vein for collection of full blood for Complete Blood Count (CBC) test and blood serum metabolites. Serum was stored in -20 centigrade until further analysis. Complete blood count (CBC) test was performed to determine the number of blood cells white blood cells, red blood cells, lymphocytes, monocytes, eosinophils, granulocytes, hemoglobin and hematocrit. Serum blood metabolites, total protein, creatinine, beta-hydroxybutyric acid, albumin, liver enzymes (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase), antioxidant capacity (malondialdehyde and total antioxidant capacity) were analyzed using Alpha Classic autoanalyzer. Data were analyzed using SAS version 9.4 as a completely randomized design experiment. For all results, significant differences between treatments were declared at P≤ 0.05 and tendencies were declared at 0.05 < P≤ 0.10. Least square means for each treatment are reported in the tables and were separated using Tukey-kramer test.
Results and Discussion: The results of this study showed that the use of flaxseed oil and injection of fat-soluble vitamins during preweaning had no significant effect on the Serum concentrations of total protein, creatinine, beta-hydroxybutyric acid, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, malondialdehyde, total antioxidant capacity and had no significant effect on the starter feed intake, daily weight gain, rectal temperature of calves. Calves received flax seed oil and fat-soluble vitamins injection had the highest Red blood cells, White blood cells, Hematocrit, Lymphocytes, Monocytes, Eosinophils and hemoglobin concentration. Claves received flaxseed oil and fat-soluble vitamins injection have the highest serum cholesterol concentration (P<0.00).
Conclusion: The results of this study indicated that inclusion of flaxseed oil and injection of fat-soluble vitamins (A, D, E) had no significant effect on blood serum parameters such as total protein, creatinine, albumin, beta-hydroxybutyric acid, malondialdehyde and total antioxidant capacity, but partially improved the immune system (white blood cells, monocytes, eosinophils) and reduces liver enzymes such as aspartate aminotransferase and alanine aminotransferase, which indicates an increase in animal health.