Effect of plane of nutrition of 1- and 2-year-old ewes in early and mid-pregnancy on ewe reproduction and offspring performance up to weaning

Abstract

The objective of the present study was to determine the effect of plane of nutrition in early pregnancy (EP) and mid-pregnancy (MP), on the productive performance of 1-and 2-year-old ewes and their offspring. Over 2 successive years, between days 0 and 39 after synchronized mating (EP), 1-(n 5 117) and 2-(n 5 52) year-old ewes were allowed 60% (low, L-EP), 100% (medium, M-EP) or 200% (high, H-EP) of requirements for maintenance (M). Between days 40 and 90 (MP), 1-year-old ewes were allowed 140% (M-MP) or 200% (H-MP), while 2-year-old ewes were allowed 80% (M-MP) or 140% (H-MP) of their M requirement. After day 90, all ewes were fed to meet requirements for late pregnancy. Increasing the plane of nutrition between days 0 and 39 resulted in increases in live weight (LW) ( P , 0.001) and body condition score (BCS) ( P , 0.001) during the EP period (H-EP . M-EP . L-EP), differences that in 1-year-old ewes were sustained to lambing ( P , 0.05). On day 42 of gestation H-EP ewes had lower plasma progesterone concentrations than L-EP or M-EP ewes in 1-( P , 0.01) and 2-( P , 0.001) year olds. This was concomitant with diet H-EP tending to reduce the number of lambs born per ewe in both age groups ( P 5 0.06 and 0.07, respectively). Foetuses from 1-year-old L-EP ewes had smaller cranial ( P , 0.01) and abdominal ( P , 0.05) diameters at day 53 of gestation, with H-EP lambs tending to be heaviest at birth ( P 5 0.07). Similar findings were recorded for 2-year-old ewes. One-year-old ewes offered diet L-EP presented negative maternal behaviours more frequently ( P , 0.05), while the incidence of lamb mortality at 6 weeks tended to be greater for L-EP lambs ( P 5 0.07). In MP, 1-year-old ewes offered diet M-MP were associated with foetuses with bigger abdominal diameters at day 78 ( P , 0.05). However, there were no differences in lamb weight or size at term ( P . 0.05). These ewes exhibited more positive maternal behaviours (e.g. increased grooming frequency and duration; P , 0.05) than ewes offered diet H-MP, and their offspring were more successful in suckling ( P , 0.05). Results suggest that in young ewes, a temporary nutrient restriction in EP resulted in increased prolificacy. However, ewes and their offspring were lighter at birth and ewe maternal behaviour was poorer, resulting in increased lamb mortality. In MP, a medium plane of nutrition offered to 1-year-old ewes led to improved maternal and offspring behaviour.

Reproductive Performances of Indigenous Ewes in Bangladesh

“…A longer pregnancy in response to maternal under nutrition has been observed in some [47], [48], [49] but not all [50] studies and may be a response that results in increases in physiological maturity of the lamb at birth.…”

Epigenetics and developmental programming of welfare and production traits in farm animals

“…Excess intakes of minerals during pregnancy do not alter colostrum IgG content, but impair immunoglobulin absorption in lambs, and this appears to be largely attributable to the iodine component of the mineral mix (Boland et al 2005). Generally, undernutrition during early (Muñoz et al 2009) or late (Hammer et al 2011) pregnancy increased lamb plasma IgG concentrations at birth and 24 h of age respectively. The study of Hammer et al (2011) is of particular interest because lambs were removed from their mothers before suckling and fed colostrum replacer, and so the differences in lamb IgG absorption were independent of maternal colostrum production.…”

Differential effects of maternal undernutrition between days 1 and 90 of pregnancy on ewe and lamb performance and lamb parasitism in hill or lowland breeds1

“…Pregnancy length was longer in RES than CON ewes, and the difference was more marked for BF ewes (1.2 d) than SUF ewes (0.3 d). A longer pregnancy in response to maternal undernutrition has been observed in some (Holst et al, 1986;Wallace et al, 2005;Munoz et al, 2008) but not all (Munoz et al, 2009) studies and may be a response that results in increases in physiological maturity of the lamb at birth. Dwyer and Morgan (2006) have previously reported that over the first 3 d of life, BF lambs maintained greater body temperatures and concentrations of plasma T3 and T4 and decreased cortisol concentrations than SUF lambs.…”

“…Therefore, the lighter birth weight in SUF-RES lambs observed in the present experiment as a result of undernutrition indicates that these lambs are less likely to survive than lambs well-fed in gestation. Although reduced fetal BW when maternal nutrition is reduced before d 90 of gestation is a frequent (Reed et al, 2007), but not consistent (Rae et al, 2001;Nishina et al, 2003;Lutz et al, 2006), response, most reports have found no reduction in birth weight as a result of undernutrition during this period (Gopalakrishnan et al, 2005;Annett and Carson, 2006;Ford et al, 2007;Gardner et al, 2007;Poore et al, 2007;Munoz et al, 2008Munoz et al, , 2009. The absence of an effect on birth weight appears to be due to compensatory growth during the later stages of pregnancy after undernutrition has been removed (Luther et al, 2007).…”

“…The phenotype varied between studies, likely because of differences in extent and timing of undernutrition, maternal body reserves, and genotype. Lambs from ewes which had experienced restricted global nutrition exhibited increased fat deposition (Daniel et al, 2007;Ford et al, 2007) and reduced ovarian follicular development or testicular Sertoli cell numbers (Rae et al, 2001;Kotsampasi et al, 2009a,b;Munoz et al, 2009).…”