Risk factors of lamb mortality in Pakistan

Abstract

-This study was carried out to investigate lamb mortality in 528 Pak-Karakul and 423 Thalli in Pakistan during [1998][1999]. Mortality was 9 and 12% in the lambs of the two breeds, respectively. In Pak-Karakul lambs, pneumonia rendered the highest morbidity and mortality and all mortalities recorded were in the first week, whereas in Thalli lambs diarrhoea was at the peak, with 82 and 18% mortalities in the first and second week of life respectively. Birth weight of neonates that died was lower (P < 0.05) than that of the lambs that had survived. The correlation revealed a positive and significant (P = 0.000) relationship between birth weights of Pak-Karakul lambs and serum Ig, total proteins and globulin concentration. In Thalli lambs such a relationship was found in serum Ig and globulin concentration. Parity of ewes and sex of lambs in both breeds did not affect mortality rates. Lambs with Ig levels less than 20 zinc sulphate turbidity (ZST) units died while those with more than 20 ZST-units survived. Dams that lost their lambs had significantly (P < 0.05) lower values of colostral Ig than those with live neonates. Serum Ig concentration in survived neonates of both breeds had significant (P = 0.000) and positive correlation with colostral Ig of their dams. lamb mortality / Pak-Karakul and Thalli sheep / risk factors / Pakistan Résumé -Facteurs de risque de la mortalité des agneaux au Pakistan. Cette étude a été réalisée pour étudier la mortalité des agneaux de races Pak-Karakul (n = 528) et Thalli (n = 423) au Pakistan au cours des années 1998 et 1999. La mortalité était respectivement de 9 et 12 % pour les deux races. Pour les agneaux Pak-Karakul, la cause de morbidité la plus élevée a été la pneumonie et tous les cas de mortalité ont été enregistrés durant la première semaine de vie. Concernant les agneaux Thalli, la diarrhée a été à l'origine du plus grand nombre de décès, avec des mortalités de 82 et 18 % la première et la deuxième semaine de vie, respectivement. Le poids de naissance des nouveau-nés morts était inférieur (P < 0,05) à celui des agneaux qui ont survécu. La corrélation de Pearson a permis d'établir (P = 0,000) une relation positive et significative entre les poids à la naissance des agneaux Pak-Karakul et les immunoglobulines (Ig) du sérum, les protéines totales et la concentration en globulines. Chez les agneaux Thalli, une telle relation a été trouvée entre les Ig du sérum et la concentration en globulines. La parité des brebis et le sexe des agneaux dans les deux races n'ont Les brebis ayant perdu leurs agneaux ont eu de manière significative (P < 0,05) un colostrum plus pauvre en Ig que celles avec des nouveau-nés vivants. Pour les deux races, il existe une corrélation significative et positive (P = 0,000) entre la concentration sérologique des Ig chez les nouveau-nés qui ont survécu et la teneur en Ig du colostrum de leur mère.agneau / mortalité / Pak-Karakul / Thalli / facteurs de risque / Pakistan

Risk Factors Associated with Passive Immunity, Health, Birth Weight and Growth Performance in Lambs: I. Effect of Parity, Dam’s Health, Birth Weight, Gender, Type of Birth and Lambing Season on Morbidity and Mortality

“…The odds of death or disease during the neonatal and post-neonatal periods did not diff er significantly between the genders in this study. This finding is in line with previous reports obtained for the first three months of life 7,8,16,22,34,35 . As the birth weight of male lambs is expected higher, males are considered to be born physically stronger and to have greater advantage with regards to protection from diseases and the development of passive immunity.…”

“…Parity has a significant effect on neonatal lamb morbidity and mortality and this finding is in agreement with previous literature reports 9,15,16,25,30,34,36 . In the present study, the risk of neonatal mortality and morbidity tended to be higher for the first parity compared to ewes that had given birth before.…”

“…This, in general, is in agreement with previous reports 8,9,18,[22][23][24][25] . It has previously been reported that lambs with a birth weight ≤3 kg have a significantly greater risk of mortality 16,26 . Khan et al 16 , hypothesized that lambs with low birth weight, being physically weak, were unable to suckle sufficient amounts of colostrum as a result the IgG concentration in their serum remained low, which might have led to an increased mortality and hypothermia in these lambs.…”

“…It has previously been reported that lambs with a birth weight ≤3 kg have a significantly greater risk of mortality 16,26 . Khan et al 16 , hypothesized that lambs with low birth weight, being physically weak, were unable to suckle sufficient amounts of colostrum as a result the IgG concentration in their serum remained low, which might have led to an increased mortality and hypothermia in these lambs. Similarly, other researchers also argued that, lamb survival depends on good preferable weight and an adequate colostrum intake 2,27 .…”

“…It has been suggested that lamb mortality could be reduced only if the specific causes of mortality on a given farm are identified and eliminated 2,12,13 . Nevertheless, as the main causes of lamb mortality in diff erent production systems and countries display similarity, it would be more appropriate to identify all underlying factors associated with mortality and adapt farm and lambing management practices accordingly in predefined region or farms 2,[13][14][15][16] . The main problems encountered in sheep production are diseases, malnutrition and poor management, which often result in reduced productivity and increased mortality.…”