Document Type : Research Paper

Authors

• Hadi MORADI ¹
• Abolfazl Zali ²
• Mehdi Ganjkhanlou ³

¹ Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. E-Mail: moradi.hadi@ut.ac.ir

² Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Email: a.zali@ut.ac.ir

³ Corresponding Author, Department of Animal Science, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran. Email: ganjkhanlou@ut.ac.ir

Abstract

Objective: Body Condition Score (BCS) of ewes has a significant impact on the occurrence and severity of metabolic disorders in late pregnancy and early lactation. Body Condition Score refers to the amount of body fat in ewes and can affect their energy reserves, feed intake, and metabolic performance. Providing trace minerals during pregnancy not only affects the performance and health of ewes but also affects growth and health of lambs both before and after birth. Feed formulations traditionally use inorganic mineral salts that are poorly absorbed and retained by the body. Compared to inorganic forms, the organic trace minerals could be used more effectively, which boosts health and body performance. Therefore, the objective of this study was to evaluate the effect of dietary supplementation of organic and inorganic trace minerals on the productive performance of Ghezel ewes with different BCSs in late pregnancy and early lactation, and their newborn lambs.
Material and method: In this study, 72 Ghezel ewes in third parity and an estimated lambing date of 30±5 days were used in a 2 × 3 factorial design, including three levels of BCS (low, moderate and high) and two types of trace mineral supplements (organic and inorganic) .Treatments were as follows: 1) low BCS (<3) and diet containing chelated minerals 2) low BCS (<3) and diet containing inorganic trace minerals, 3) Moderate BCS (3-4) and diet containing chelated minerals, 4) moderate BCS (3-4) and diet containing inorganic trace minerals 5) high BCS (>4) and diet containing chelated minerals, and 6) high BCS (>4) and diet containing inorganic trace minerals.
Results: The results showed that the sources of mineral supplements did not affect feed intake, milk yield and composition, but feed intake and milk yield increased with the enhancement in BCS (P<0.05). Fat and milk total solids were significantly higher in high BCS ewes compared to low BCS ewes (P<0.05). Ewes with low BCS had lower MUN in comparison with other BSC levels (P<0.05). Body weight and BCS loss during all periods were lower in low BCS ewes rather than other BCS levels (P<0.05). The weight of lambs at 30 days of age tended to increase in high BCS compared to those with low BCS (P < 0.1). Additionally, chelated minerals supplements increased average daily gain and weaning weight (P<0.05).
Conclusion: An appropriate BCS during late gestation has positive effects on productive performance in the postpartum period. Furthermore, supplementing trace elements in chelated form during the transition period, positively, affects the weight gain of newborn lambs.

Keywords

• BCS
• Ghezel ewe
• Organic mineral
• Transition period
• Trace mineral