Document Type : Research Paper

Authors

• Amirhosein Mehranforooz ¹
• Hassan Aliarabi ²
• Daryoush Alipour ³
• Abbas Farahavar ⁴

¹ Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran. E-mail: a.mehranforooz@agr.basu.ac.ir

² Corresponding Author, Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran. E-mail: aliarabi@basu.ac.ir

³ Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran. E-mail: alipourd@basu.ac.ir

⁴ Department of Animal Science, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran. E-mail: a.farahavar@basu.ac.ir

Abstract

Objective: The physical characteristics and nutrient balance of feed are among the most critical factors influencing animal health, performance, and feeding behavior of livestock. These factors not only have a direct impact on meeting the nutritional requirements of livestock but also play a key role in enhancing production efficiency, improving product quality, and mitigating nutrition-related diseases. This study aimed to evaluate the effects of feed physical form during late gestation and early lactation in ewes on blood metabolites, antioxidant status, and lamb performance after birth.
Materials and methods: This study was conducted using 36 Mehraban breed ewes with an average body weight of 50.17±2.09 kg and an average age of three to four years in a completely randomized experimental design. The experimental treatments included: 1- mash concentrate, 2- pelleted concentrate, and 3- pelleted total mixed ration (TMR). Experimental treatments were provided to ewes during the last two months of pregnancy and the first month of lactation. To evaluate blood biochemical parameters and antioxidant status, blood samples were collected from the ewes at three times (30 days before lambing, day of lambing, and 30 days after lambing) before the morning feeding. Milk yield and milk fat content were also assessed on day 21 postpartum. Also, the performance of the lambs was evaluated by weighing them on the day of birth and weekly until the end of the trial.
Results: The results indicated that feed intake during in the pre- and post-partum periods, as well as milk production, was higher in ewes fed with pelleted TMR and pelleted concentrate compared to those fed with mash concentrate (P<0.05), while the milk fat percentage was not affected by the experimental treatments. Feeding pelleted TMR and pelleted concentrate significantly increased serum glucose and urea concentrations (P<0.05), while other blood parameters, such as cholesterol, triglycerides, total protein, and liver enzymes, were not influenced by the experimental treatments. Also, feeding ewes with pelleted feed led to a significant reduction in malondialdehyde concentration and an increase in total antioxidant capacity at certain time points (P < 0.05), indicating a reduction in oxidative stress in animals fed this type of feed. In addition, body weight and daily weight gain of lambs were affected by the physical form of the feed consumed by the ewes at certain time points. Lambs born to ewes fed with pelleted TMR and pelleted concentrate had higher weight and daily weight gain between days seven and 30 of age than those born to ewes fed with mash concentrate (P<0.05). However, no significant difference was observed in lamb birth weight between different treatments.
Conclusions: Overall, the results of this study indicated that feeding ewes with pelleted TMR and pelleted concentrate during late pregnancy and early lactation can improve ewe performance, improve lamb performance, increase certain biochemical parameters, and enhance the antioxidant status of the ewes' blood. These findings emphasize the effective role of the physical form of feed as an effective tool in optimizing animal health, production performance, and welfare.

Keywords

• Antioxidant capacity
• Ewe
• Pellet
• Performance
• Physical form of feed