Effect of nutrition from mid to late pregnancy on the performance of twin- and triplet-bearing ewes and their lambs

Abstract

This experiment was conducted to determine the effect of two different feeding levels on ewes during mid and late pregnancy on lamb birthweight and growth to weaning. Twin- and triplet-bearing Romney ewes (n = 80 and 56, respectively) were allocated to one of two feeding regimes and provided pastures with an average sward height of less than 2 cm (~700 kg dry matter/ha) or greater than 4 cm (~1300 kg dry matter/ha). Ewes were allocated to these feeding regimes during mid pregnancy (day 70–107 of pregnancy; P70–P107) and were reallocated in late pregnancy (P108–P147). This resulted in four sward height treatments: 2–2, 2–4, 4–2 and 4–4. During mid pregnancy, ewes provided with >4-cm-high swards had liveweight gains of 262–290 g/day compared with 12–31 g/day for ewes provided with <2-cm-high swards. In late pregnancy, ewe liveweight gains were influenced by the ewes’ previous nutritional treatment. Ewes in the 2–4 treatment had higher daily gains (538 g/day) than 4–4 ewes (343 g/day). In addition, 4–2 ewes gained 90 g/day compared with 247 g/day for 2–2 ewes. Throughout pregnancy, triplet-bearing ewes were heavier (P < 0.05) than twin-bearing ewes, but during lactation ewe weights were similar. On P130, ewes provided with <2-cm-high swards (4–2 and 2–2) had greater β-hydroxybutyrate (P < 0.05) and lower glucose (P < 0.05) plasma concentrations than ewes provided with >4-cm-high swards (2–4 and 4–4). On P139, however, ewes provided with 4–4 swards had higher plasma non-esterified fatty acid and β-hydroxybutyrate concentrations than ewes in all other treatments. Lambs born to ewes in the 4–4 treatment had the greatest birthweights (P < 0.05), whereas lambs born to 2–2 ewes had the lowest birthweights. The birthweight of lambs born to 2–4 ewes was similar to that of lambs born to ewes provided with 4–2 and 4–4 swards. At weaning, ewe weights were similar between ewe nutritional treatments and ewes bearing twin or triplet fetuses. These findings suggest that when pasture growth is inadequate to provide pasture sward heights of 4 cm throughout pregnancy, restricted intake in mid-pregnancy may be partially compensated by providing additional pasture in late pregnancy.

Altering ewe nutrition in late gestation: I. The impact on pre- and postpartum ewe performance1

“…The mobilization of body fat reserves is indicated by elevated plasma concentrations of NEFA and βHB (Robinson et al, 2002b). In previous studies (Corner et al, 2008;Tygesen et al, 2008;Álvarez-Rodríguez et al, 2012) where ewes received a restricted plane of nutrition during late gestation, increasing plasma NEFA concentrations were observed in conjunction with a decline in BCS. Therefore, in the present study, the lack of difference in ewe plasma NEFA concentrations was unexpected.…”

Effect of nutrition from mid-pregnancy to parturition on the live weight of twin-bearing hoggets and the live weight and survival of their lambs

“…Previous hogget pastoral studies Kenyon et al 2008b;Mulvaney et al 2008Mulvaney et al , 2010 have shown that under similar herbage levels, the live weight of the lamb was not affected by herbage intake. Also, pastoral studies by and Corner et al (2008) involving twin lambs born to mature multiparous ewes reported that similar nutritional levels did not affect the lamb weaning live weights. This suggests that nutrition during pregnancy does not affect lamb live weight during lactation of twin lambs born to hoggets.…”

“…In twin-bearing mature multiparous ewes, increasing the level of pastoral nutrition from mid-pregnancy to parturition increased lamb birth weight under New Zealand pastoral conditions Corner et al 2008). This supports the results obtained in the present study from hoggets.…”

“…Twin lambs born to mature multiparous ewes offered ad libitum herbage from midpregnancy until parturition were heavier at birth Corner et al 2008), but the weaning weights of these lambs were similar Everett-Hincks et al 2005) or heavier (Corner et al 2008) compared with twin lambs born to mature ewes offered a restricted level of herbage from mid-pregnancy until parturition. In addition, the live weight of *Corresponding author.…”

“…In addition, the live weight of *Corresponding author. Email: fraser.mulvaney@dpi.nsw.gov.au the mature multiparous ewes offered ad libitum or a restricted level of herbage from midpregnancy until parturition did not differ at weaning Corner et al 2008).…”