Effects of gestational plane of nutrition and selenium supplementation on mammary development and colostrum quality in pregnant ewe lambs1

Abstract

To examine effects of nutritional plane and Se supplementation on colostrum quality and mammary development, individually fed, pregnant Rambouillet ewe lambs were allotted randomly to 1 of 6 treatments in a 2 x 3 factorial arrangement. Main effects included dietary Se level, which began at breeding (d = 0) [adequate Se (9.5 mug/kg of BW) vs. high Se (81.8 mug/kg of BW)], and plane of nutrition, which began at d 50 of gestation [60% (RES), 100% (CON), and 140% (HIGH) of requirements]. Upon parturition, lambs were immediately separated from dams and weighed. Three hours after lambing, colostrum yield was determined, and samples were obtained for components and immunoglobulin G (IgG) analysis. Ewes were slaughtered within 24 h of parturition, and mammary tissues were collected for determination of alveolar secretory epithelial cell proliferation index and luminal area. Gestation length was reduced (P < 0.01) in HIGH ewes compared with RES and CON ewes. Although birth weights were reduced (P < 0.01) in RES and HIGH compared with CON ewes, there was little effect of diet on placental size. Mammary gland weight was reduced (P </= 0.05) in RES compared with CON and HIGH, which were similar. However, when expressed as grams per kilogram of BW, mammary gland weight in HIGH ewes was less (P = 0.03) compared with RES and CON. Colostrum weight and volume were reduced (P < 0.01) in RES and HIGH ewes compared with CON. Although colostrum IgG concentration was greater in RES ewes compared with CON and HIGH, total IgG was lower (P </= 0.06) in RES and HIGH compared with CON ewes. The percentage of alveolar cells proliferating was increased (P < 0.04) in HIGH compared with RES ewes, with CON being intermediate. Percentage of alveoli luminal area per unit tissue area was increased (P = 0.04) in RES compared with HIGH and CON ewes, which did not differ. Selenium had no effect (P >/= 0.15) on mammary gland weight, colostrum quantity, or IgG concentration in pregnant ewe lambs. Improper nutrition from mid to late pregnancy in ewe lambs altered colostrum quality and quantity and reduced offspring birth weight, which may have negative implications for lamb health and survival during the early postnatal period.

Supplementation of Merino ewes with cholecalciferol in late pregnancy improves the vitamin D status of ewes and lambs at birth but is not correlated with an improvement in immune function in lambs

“…The colostral IgG concentrations of control and vitamin Dsupplemented ewes at lambing were within the range of 64.2-99.4 mg/mL reported by previous studies (Gilbert et al 1988;al-Sabbagh et al 1995;Loste et al 2008;Swanson et al 2008). The plasma concentrations of IgG in control and vitamin D-supplemented lambs at 1 and 4 weeks of age were slightly lower than those reported in other breeds of sheep (Yılmaz et al 2011;Gokce et al 2014).…”

Neonatal hormone changes and growth in lambs born to dams receiving differing nutritional intakes and selenium supplementation during gestation

“…In the current study, lambs were removed immediately from their dams in order to more closely assess the impacts of the maternal environment during gestation. We have previously reported that maternal diet (both nutritional intake and Se supplementation) can impact colostrum/ milk components as well as colostrum/milk volumes (Swanson et al 2008. Maternal Se supplementation throughout gestation did impact the growth patterns of offspring born from dams fed differing levels of nutrition from mid-to-late gestation.…”

“…When the HSe pellet could not meet the HSe level for RES-or CON-fed ewes without exceeding the desired nutritional intake, a concentrated Se pellet with purified selenomethionine as its Se source was used to augment the Se supply. Nutrient requirements were based on NRC (1985) recommendations as described by Swanson et al (2008), and diets were individually adjusted for BW and BW gain for each 14 day interval of gestation. Feed refusals were collected daily to calculate intake (feed offered minus feed refused), but ewes generally ate the feed offered daily and rarely left refusals.…”

Colostrum production in ewes: a review of regulation mechanisms and of energy supply

“…Therefore, good nutritional management is important for ensuring adequate udder development and the production of sufficient colostrum for the new-born lambs (Treacher, 1970;Wallace et al, 2001;Swanson et al, 2008;Tygesen et al, 2008;Meyer et al, 2011). Poor prepartum nutrition can reduce colostrum and milk production (McCance and Alexander, 1959;Peart, 1967;Treacher, 1970;Mellor and Murray, 1985b;Mellor et al, 1987;McNeill et al, 1988;Swanson et al, 2008;Meyer et al, 2011), delay the onset of lactogenesis, change the viscosity of the colostrum that accumulates before parturition begins (Banchero et al, 2004a and2004b) and reduce the volume of colostrum secreted after lambing (McCance and Alexander, 1959). In twin-bearing Scottish Blackface ewes, restriction of nutrition during the last month of pregnancy reduced by up to 70% the volume of colostrum secreted (Mellor andMurray, 1985a and1985b).…”