Introduction: The Baluchi sheep, one of the most important native fat-tailed breeds in eastern Iran, has always been valued for its high resistance, relatively low nutritional requirements, and stable reproductive capacity. However, the early culling of animals remains a major challenge, reducing herd productivity, increasing replacement costs, and limiting breeding opportunities. In many commercial flocks, a large proportion of culling is due to reproductive inefficiencies, metabolic disorders, and gastrointestinal problems. Despite this, comprehensive, long-term evaluations in Iranian native breeds are still scarce.
Materials & Methods: This study was conducted on a commercial Baluchi sheep flock located in Torbat-e-Jam County, Razavi Khorasan Province. Records of performance, health, and culling of animals between 1996 and 2022 (1375 to 1401 Persian calendar) were included in the analysis. The animals were managed under a consistent management cycle, including grazing on natural rangelands in spring, grazing on crop stubble in summer–autumn, and intensive feeding in winter with a total mixed ration (TMR) consisting of corn silage, alfalfa, and concentrate. Feeding protocols were differentiated for lactating ewes, pregnant ewes, rams, and growing lambs based on physiological needs. Frequencies, temporal trends, and the relative contribution of culling causes were assessed descriptively. The long study duration and management consistency allowed precise monitoring of changes in flock health and culling patterns over time.
Results: Over 26 years, 480 animals were culled, with reproductive disorders being the primary cause of culling, accounting for 52.29% (251 animals) of all cases. Among reproductive disorders, infertility had the highest share (78.53%), followed by abortion (26.70%), dystocia (15.54%), and stillbirth (3.98%).
Conclusion: The predominance of reproductive disorders is consistent with international reports, indicating that reproduction is the most important economic factor determining ewe longevity in both intensive and extensive systems. Infertility, as the main factor, is often multifactorial and can result from poor body condition, mineral imbalances, and other causes. Abortion, the second reproductive factor, aligns with global findings on the role of pathogens, nutritional deficiencies, heat stress, or poisonings. The increasing importance of gastrointestinal disorders in recent years likely reflects changes in rangeland composition, reduced forage quality due to climate change, shifts in parasitic infection patterns, or changes in feeding practices. Although metabolic disorders are less prevalent, they represent critical intervention points due to their rapid progression and high treatment costs. This long-term assessment provides a comprehensive and precise picture of culling factors in Baluchi sheep under semi-intensive production. The findings highlight several key priorities for flock optimization: improving reproductive management, strengthening nutritional programs, improving gastrointestinal health management, and optimizing the environment and infrastructure to reduce injuries. By implementing these measures, early culling rates can be significantly reduced, longevity increased, and more favorable economic and genetic outcomes achieved in Baluchi sheep breeding systems. |
