Interpretive Summary: Negative dietary cation and anion difference supplementation of twin-bearing Merino ewes grazing pasture in late gestation did not affect lamb growth or survival
By: Amy Laurel Munn, William H E J van Wettere, Alyce Marie Swinbourne, Ian John Lean, Alice Caroline Weaver
In Australia, 53% of lamb deaths annually are caused by birthing difficulties, otherwise known as dystocia. Calcium and magnesium deficiencies in ewes during late gestation are suspected to be causing cases of dystocia. We evaluated a supplement that provided a negative dietary cation and anion difference (DCAD) which can influence calcium metabolism, and in turn, may reduce lamb death rates. Grazing twin-bearing Merino ewes were provided either a positive DCAD supplement (n = 58) or a negative DCAD supplement (n = 57) at day 130 of gestation until 2.3 ± 0.2 d postpartum. Negative DCAD supplementation did not improve ewe calcium and magnesium concentrations or lamb survival, weight, or viability. The DCAD of the pastures was too high for the negative DCAD supplement to induce a metabolic acidosis as indicated by the urinary pH, which may explain the lack of improvement in mineral status.
Read the full article in the Journal of Animal Science.
