Including magnesium sulphate in the diet of twin-bearing ewes in the last week of gestation improves the adaptation of lambs to extra-uterine life.

Mauro Minteguiaga; Carlos Lopez-Mazz; Sergio Fierro; Georgget Banchero

Just Accepted

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Including magnesium sulphate in the diet of twin-bearing ewes in the last week of gestation improves the adaptation of lambs to extra-uterine life.

Mauro Minteguiaga , Carlos Lopez-Mazz, Sergio Fierro, Georgget Banchero

Abstract

Context: Most deaths of lambs in the first days of life are due to failure to adapt to extra-uterine life. Aims: His study aimed to test the hypothesis that adding Magnesium sulphate (MgSO4) to the diet of twin-bearing ewes in the last week of gestation improves the adaptation to the extra-uterine life of the lambs. Methods: Eighty-three multiparous Finnish x Polwarth ewes carrying twins in the last week of gestation were MgSO4 supplemented (M; n=40) or control (C; n=43). The duration of gestation (DG), the duration of expulsion (DII), duration of lambing (LT), inter-lambing interval (IL), lamb birthweight, litter birthweight, meconium score, rectal temperature of the lambs (at birth -RT0 and three h after birth -RT3), and assistance (yes or not), time from lamb expulsion to stand (ES) or suck (SS) was recorded (n=148). A jugular blood sample of the lambs was analyzed for pH, pCO2, pO2; HCO3st and act, BE (ecf and b), saO2, ct CO2. Glucose was analyzed with a portable device. Key results: The DG was longer in M lambs (147.7 ± 2.0 vs. 146.7 ± 1.7 days, M and C respectively, P<0.05). Birthweight and litter birthweight of M lambs were higher than C lambs (3.74 ± 0.6 and 7.47 ± 0.9 Kg vs. 3.51 ± 0.5 and 7.02 ± 0.9 kg; M and C respectively, P<0.05). The assistance, meconium score, DII, LT, ES, and SS were not different between treatments (P> 0.05). The IL was shorter in the M ewes (6.7 ± 2.7 m vs. 10.4 ± 2.6, M and C respectively, P<0.05). The RT3 was not different between treatments, but RT0 was lower in M lambs than in control lambs (P<0.05). The pH, pCO2, HCO3st, and act, BE (ecf and b), ct CO2, and blood glucose were not different between treatments. The M lambs had higher pO2 and saO2 than the C lambs (P<0.05). Conclusions: The MgSO4 supplementation improves the adaptation to extra-uterine life in pen conditions. Implications: It should be tested whether maternal supplementation with MgSO4 reduces the mortality of twin lambs.

AN24022 Accepted 14 July 2024