Nutritional effects of ground cannula and soybean as a fat supplement on performance of Ghezel ewes during the transition period

Background and objectives: The last month of pregnancy is one of the critical stages for cattle. Providing the nutrients and energy needed at this time is vital, as In sufficient energy supply at this time increases the risk of metabolic diseases in livestock, which can be greatly prevented by increasing the energy density of the diet using oilseeds. Therefore, this experiment was performed to investigate Nutritional effects of cannula and soybean as a fat supplement on performance of Ghezel ewes during the transition period
Materials and Methods: This experiment was carried in a completely randomized design using 16 ghezel ewes with an average age of three years and an average weight of ±59.8 kg in a 74-day period (14 days of adapting and 60 days of experiment). Treatments included: 1. Control (diet without fat supplementation) 2. Base diet containing 5% milled cannula as a source fat supplementation, 3. Base diet it contained 5% of milled soybean source fat supplementation and 4. Base diet containing 5% mixture of cannula and soybean at 50:50. The rations were given to the cattle in a completely mixed manner at 6:00 and 18:00. The weight gain of lambs in the postpartum period was measured daily using a digital scale. In order to determine the milk produced and the composition of ewes' milk, milk samples were collected on two consecutive days and analyzed using a Milco-scanner. Rumen fluid sample was taken to evaluate the parameters of ruminal fermentation on the twentieth day after delivery using esophageal catheter. Intravenous blood samples were taken from the venous vein on the twentieth day after delivery to measure blood counts.
Results: The results showed that the birth weight of lambs, the amount of feed intake and daily changes in the weight of ewes before and after calving were not affected by experimental treatments (p < 0.05). Weight gain of lambs did not show a significant difference between treatments. Milk production was significantly higher in the diet of cannula (p < 0.05). There was no significant difference in the amount of milk compounds (P <0.05). There was no significant difference in blood triglyceride, cholesterol and beta-hydroxybutyrate levels between different experimental treatments. The amount of glucose and total blood protein in the postpartum period showed a significant difference between treatments (p < 0.05). However, the amount of blood urea nitrogen in the postpartum period was higher in soybean treatment than other treatments (P <0.05). There was no significant difference in pH and the amount of major volatile fatty acids in the rumen including acetic acid, propionic acid, butyric acid and iso valeric acid (P <0.05). The control treatment had the lowest digestibility of protein and the highest digestibility of insoluble fibers in neutral detergent among the treatments (p < 0.05).
Conclusion: According to the results of this study, the use of oilseed cannula as a fat source at the level of 5% can improve milk production without changing the composition of milk and feed intake. However, more studies are needed in this area.