Effects of Nutrient Restriction During Midgestation to Late Gestation on Maternal and Fetal Postruminal Carbohydrase Activities in Sheep

Abstract

To examine the effects of nutrient restriction during midgestation to late gestation on maternal and fetal digestive enzyme activities, 41 singleton ewes (48.3 ± 0.6 kg of BW) were randomly assigned to dietary treatments: 100% (control; CON; n = 20) or 60% of nutrient requirements (restricted; RES; n = 21) from day 50 until day 90 (midgestation). At day 90, 14 ewes (CON, n = 7; RES, n = 7) were euthanized. The remaining ewes were subjected to treatments of nutrient restriction or remained on a control diet from day 90 until day 130 (late gestation): CON-CON (n = 6), CON-RES (n = 7), RES-CON (n = 7), and RES-RES (n = 7) and were euthanized on day 130. The fetal and maternal pancreas and small intestines were weighed, subsampled, and assayed for digestive enzyme activity. One unit (U) of enzyme activity is equal to 1 µmol of product produced per minute for amylase, glucoamylase, lactase, and trypsin and 0.5 µmol of product produced per minute for maltase and isomaltase. Nutrient restriction during midgestation and late gestation decreased (P < 0.05) maternal pancreatic and small intestinal mass but did not affect fetal pancreatic or small intestinal mass. Maternal nutrient restriction during late gestation decreased (P = 0.03) fetal pancreatic trypsin content (U/pancreas) and tended to decrease (P < 0.08) fetal pancreatic trypsin concentration (U/g), specific activity (U/g protein), and content relative to BW (U/kg of BW). Nutrient restriction of gestating ewes decreased the total content of α-amylase (P = 0.04) and tended to decrease total content of trypsin (P = 0.06) and protein (P = 0.06) in the maternal pancreas on day 90. Nutrient restriction during midgestation on day 90 and during late gestation on day 130 decreased (P = 0.04) maternal pancreatic α-amylase-specific activity. Sucrase activity was undetected in the fetal and maternal small intestine. Nutrient restriction during late gestation increased (P = 0.01) maternal small intestinal maltase and lactase concentration and tended to increase (P = 0.06) isomaltase concentration. Realimentation during late gestation after nutrient restriction during midgestation increased lactase concentration (P = 0.04) and specific activity (P = 0.05) in the fetal small intestine. Fetal small intestinal maltase, isomaltase, and glucoamylase did not respond to maternal nutrient restriction. These data indicate that some maternal and fetal digestive enzyme activities may change in response to maternal nutrient restriction.

Influence of dietary fructose supplementation on visceral organ mass, carbohydrase activity, and mRNA expression of genes involved in small intestinal carbohydrate assimilation in neonatal calves

“…Additionally, dietary fructose supplementation can induce sucrase activity in patients with congenital SI deficiency (Greene et al, 1972). However, several authors have failed to detect sucrase activity in the small intestine of cattle (Dollar and Porter, 1957;Huber et al, 1961;Siddons, 1968;Trotta et al, 2020a) and sheep (Walker, 1959;Shirazi-Beechey et al, 1989;Trotta et al, 2020b). Moreover, abomasal infusion of sucrose does not induce sucrase activity in lambs (Swanson and Harmon, 1997).…”

Prenatal and Postnatal Nutrition Influence Pancreatic and Intestinal Carbohydrase Activities of Ruminants

“…For example, when fetal small intestinal maltase concentration was found to be decreased with maternal dietary intake restriction, fetal BW and small intestinal mass were also decreased (13.8% and 21.2%, respectively) [7,49]. Whereas when Trotta et al [38] found no differences in fetal small intestinal carbohydrase activities, fetal BW and small intestinal mass also did not differ compared to fetuses from ewes fed to meet NRC [50] recommendations. The fetal small intestine is relatively short in length compared to their maternal counterpart and therefore, differences in fetal intestinal sampling sites could be a potential explanation for variation in carbohydrase activities.…”

“…Furthermore, fetal pancreatic α-amylase per gram of protein was not influenced when cows were restricted during either early or early-to-mid-gestation. In sheep, maternal dietary restriction during mid-, late-, or mid-to-late-gestation did not influence fetal pancreatic α-amylase activity [ 37 , 38 ]. Therefore, there could be species-specific responses to maternal nutrient restriction when comparing cattle and sheep.…”

“…Maternal dietary restriction (40% restriction) from mid-to-late-gestation (day 50 to day 130) did not influence fetal small intestinal maltase, isomaltase, or glucoamylase activities in sheep [ 38 ]. In another study, 40% maternal dietary restriction from mid-to-late-gestation (day 50 to day 130) decreased fetal maltase activity per gram of intestine in sheep [ 48 ].…”

“…However, the practical implications of programming for enhanced small intestinal lactase activity are not clear, as small intestinal lactase activity decreases with age in lambs, irrespective of diet [ 52 ]. Trotta et al [ 38 ] found that maternal dietary restriction during mid-gestation followed by realimentation to 100% of NRC [ 50 ] recommendations during late-gestation increased fetal lactase activity per gram of intestine and per gram of protein. This may indicate that nutrient restriction during mid-gestation potentially could be used as a programming strategy to increase fetal lactase activity.…”