Nutrient restriction and realimentation in beef cows during early and mid-gestation and maternal and fetal hepatic and small intestinal in vitro oxygen consumption

Abstract

Objectives were to determine the effects of advancing gestation, maternal nutrient restriction during early and mid-gestation, and realimentation on fetal liver and jejunal mass and energy use in both dams and fetuses. On day 30 of pregnancy, multiparous, non-lactating beef cows (initial BW = 621 ± 11.3 kg and body condition score = 5.1 ± 0.1) were assigned to one of the two dietary treatments: control (CON; 100% requirements; n = 18) and restricted (R; 60% requirements; n = 28). On day 85, cows were slaughtered (CON, n = 6; R, n = 6), and remaining cows continued on control (CC; n = 12) and restricted (RR; n = 12) diets, or were realimented to the control diet (RC; n = 11). On day 140, cows were slaughtered (CC, n = 6; RR, n = 6; RC, n = 5), remaining cows continued on the control diet (CCC, n = 6; RCC, n = 5), or were realimented to the control diet (RRC, n = 6). On day 254, all remaining cows were slaughtered. Maternal liver O 2 consumption linearly increased ( P ⩽ 0.04) and jejunal weight (g/kg) linearly decreased (P = 0.04) as gestation advanced in CON groups. Fetal BW, and hepatic and small intestinal absolute mass, protein content and O 2 consumption linearly increased ( P ⩽ 0.04) as pregnancy advanced in CON groups. However, mass and O 2 consumption relative to BW linearly decreased ( P ⩽ 0.001) in the fetal liver in CON groups. When analyzing the effects of dietary treatment, at day 85, fetal jejunal O 2 consumption (mol/min per kg BW) was lower ( P = 0.02) in the R group when compared with the CON group. At day 140, maternal hepatic weight (g) was lower ( P = 0.02) in RC and RR cows when compared with CC, and fetal jejunual O 2 consumption (mmol/min per mg tissue and mmol/min per g protein) was greater ( P ⩽ 0.02) in RC when compared with RR. At day 254, maternal hepatic O 2 consumption (absolute and relative to BW) was lower ( P ⩽ 0.04) in the RCC cows when compared with RRC. Fetal hepatic weight was lower ( P = 0.05) in the CCC group when compared with RCC and RRC. The changes in response to nutrient restriction and realimentation in both the dam and fetus may indicate an adaptation to a lower amount of available nutrients by altering tissue mass and metabolism.Keywords: bovine, energy use, fetal, maternal, viscera ImplicationsPoor nutrition during pregnancy can result in long-lasting negative effects on the cow and offspring. Our data suggest that cows and fetuses have the ability to adapt to restriction and realimentation by altering mass or energy use in an attempt to increase the digestion and utilization of feed or to alter maintenance requirements to maintain fetal growth and development. Maternal realimentation and length of realimentation has the potential to change the effects observed in cows and fetuses by mid or late gestation. These effects may influence whole animal energetic efficiency and future productivity of the cow and offspring. IntroductionPregnancy results in a 20% to 50% increase in maternal metabolic rate, measured via O 2 consumption, in most mammals (Stock and Metcalfe, 199...

Does maternal size, nutrition and metabolic status affect offspring production traits in domestic species?

“…The birthweight of calves born to Angus cross-bred cows fed 60% of their requirements between 30 and 85 days or between 30 and 140 days of gestation was the same as offspring born to cows fed 100% of requirements but their liver was heavier (Prezotto et al, 2016). Moreover, nutritional supplementation of restricted beef heifers during pregnancy did not increase offspring birthweight nor subsequent performance (Summers et al, 2015) but increased feedlot efficiency and altered carcass characteristics with a tendency for high fat concentrations in the meat of animal born to restricted, non-supplemented heifers (Summers et al, 2015).…”

“…Effects of excess maternal nutrition have been mainly studied in sheep (Table 1) with little observed effects on lamb birthweight and postnatal growth (Hoffman et al, 2014;Khanal et al, 2014;Kleemann et al, 2015;Sen et al, 2016). Nevertheless, expression of Insulin Growth Factor 1 (IGF1) is increased in the lamb liver (Hoffman et al, 2014) resulting in increased plasma IGF1 concentrations (Hoffman et al, 2016) and lipid accumulation is also observed in the lambs' muscle (Hoffman et al, 2014;Reed et al, 2014), together with increased insulin resistance (Hoffman et al, 2016), increased adiposity (Khanal et al, 2014), hyperglycemia and alteration of hepatic signaling pathways (Philp et al, 2008).…”

“…Nevertheless, expression of Insulin Growth Factor 1 (IGF1) is increased in the lamb liver (Hoffman et al, 2014) resulting in increased plasma IGF1 concentrations (Hoffman et al, 2016) and lipid accumulation is also observed in the lambs' muscle (Hoffman et al, 2014;Reed et al, 2014), together with increased insulin resistance (Hoffman et al, 2016), increased adiposity (Khanal et al, 2014), hyperglycemia and alteration of hepatic signaling pathways (Philp et al, 2008). Finally, increased ovarian size and reduced ovarian follicular numbers have also been observed (Da Silva et al, 2003;Kleemann et al, 2015).…”

“…Only severe maternal undernutrition reduces birthweight whereas moderate undernutrition appears un-noticed in terms of offspring birthweight (Bispham et al, 2003;Gardner et al, 2005;Ford et al, 2007;Hoffman et al, 2014Hoffman et al, , 2016Field et al, 2015;Kleemann et al, 2015;Sen et al, 2016;Whorwood et al, 2016). Nevertheless, lambs born to undernourished ewes have reduced plasma IGF1 and T3 (triiodothyronin) concentrations (Hoffman et al, 2014;Field et al, 2015) and physiological pathways involving corticosteroid hormones are disturbed (Whorwood et al, 2016). Maternal undernutrition has also been associated with alterations in glucose metabolism, including hyperglycemia or hyperinsulinemia, increased insulin secretion by β-cells and reduced glucose tolerance (Gardner et al, 2005;Ford et al, 2007;Hoffman et al, 2016).…”

“…Nevertheless, lambs born to undernourished ewes have reduced plasma IGF1 and T3 (triiodothyronin) concentrations (Hoffman et al, 2014;Field et al, 2015) and physiological pathways involving corticosteroid hormones are disturbed (Whorwood et al, 2016). Maternal undernutrition has also been associated with alterations in glucose metabolism, including hyperglycemia or hyperinsulinemia, increased insulin secretion by β-cells and reduced glucose tolerance (Gardner et al, 2005;Ford et al, 2007;Hoffman et al, 2016). Intra-muscular lipid depositions are also increased in these lambs together with modifications in muscular fiber development (Ford et al, 2007;Reed et al, 2014) and increased perirenal fat mass was observed with or without reduction of subcutaneous fat (Gardner et al, 2005;Ford et al, 2007;Hoffman et al, 2014Hoffman et al, , 2016.…”