Department of Animal Genetics and Breeding, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India, 125001.
Trop Anim Health Prod. 2022 Aug 10;54(5):256. doi: 10.1007/s11250-022-03255-y.
Lamb mortality is an important aspect in sheep production system which affects farm profitability worldwide. The aim of the present study was to investigate the causes of pre-weaning mortality (PWM) in Harnali lambs with respect to various associated factors. The data records of 173 lambs which died before 90 days of age (weaning age) out of 2057 lambs born during 2001-2020 year were collected from various registers, and the respective causes of mortality were taken from the post-mortem reports. The association of various factors such as age, sex, period of birth, birth weight of lamb and causes of death with PWM was assessed using chi-square test and log-linear modelling. The results showed that respiratory and digestive diseases were major causes of PWM. The log-linear modelling showed significant (P < 0.05) association of age, sex and period of birth with PWM. In the first month of age, digestive disease was the predominant cause of death; however, with age of lamb advances, respiratory disease was more prevalent. It was also revealed that male lambs (odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.24, 0.97) had lesser deaths due to respiratory diseases as compared to digestive disease. The reverse scenario was observed in female lambs. The findings of the present study might be helpful for understanding the risks and common causes of PWM in lambs to implement appropriate management practices in order to reduce economic losses to sheep farmers.
羔羊死亡率是绵羊生产系统中的一个重要方面，它影响着全球农场的盈利能力。本研究旨在调查哈纳利羔羊（Harnali lambs）在断奶前死亡（PWM）的原因，并分析各种相关因素。从 2001 年至 2020 年出生的 2057 只羔羊中，选取了 173 只在 90 日龄（断奶年龄）前死亡的羔羊的数据记录，从各种登记册中收集了各自的死亡原因，并从尸检报告中获取了死亡率的相关信息。采用卡方检验和对数线性模型评估了年龄、性别、出生时期、羔羊出生体重和死亡原因等因素与 PWM 的关联。结果表明，呼吸和消化系统疾病是 PWM 的主要原因。对数线性模型显示，年龄、性别和出生时期与 PWM 显著相关。在出生后的第一个月，消化系统疾病是主要的死亡原因；然而，随着羔羊年龄的增长，呼吸系统疾病更为普遍。研究还发现，雄性羔羊（比值比（OR）=0.48，95%置信区间（CI）=0.24, 0.97）因呼吸系统疾病导致的死亡比因消化系统疾病导致的死亡少；而雌性羔羊的情况则相反。本研究的结果可能有助于了解羔羊 PWM 的风险和常见原因，以便实施适当的管理措施，从而减少绵羊养殖户的经济损失。
