Intravenous maternal L-arginine administration to twin-bearing ewes, during late pregnancy, is associated with increased fetal muscle mTOR abundance and postnatal growth in twin female lambs1

Abstract

The aims of this study were to determine whether parenteral Arg administered to well-fed twin-bearing ewes from 100 to 140 d of pregnancy influences fetal skeletal muscle growth, the abundance and activation of mechanistic target of rapamycin (mTOR) protein, and postnatal muscle growth of the offspring. Ewes fed 100% of NRC-recommended nutrient requirements for twin-bearing ewes were administered an intravenous bolus of either 345 μmol Arg HCl/kg BW or saline solution (Control) 3 times per day. At 140 d of pregnancy (P140), a group of 11 Control and 9 Arg-treated ewes were euthanized and hind leg muscles and longissimus dorsi (LD) were excised and weighed. A sample of LD was snap frozen in liquid nitrogen for later analysis of free AA (FAA) concentration, mTOR abundance and phosphorylation, and biochemical indices (DNA, RNA, and protein content). For the remaining 25 ewes (Arg, = 13, and Control, = 12), Arg administration was continued until the initiation of parturition and ewes were allowed to lamb. Lambs were weaned at postnatal Day 82 and grazed on pasture until postnatal day 153 (PN153), when a subset of 20 lambs ( = 10 per group) was euthanized. At P140, only the psoas major was heavier in the Arg-administered group compared with the Control group. Female lambs from ewes supplemented with Arg (Arg-F) had increased abundance of total mTOR, RNA concentration, and RNA:DNA ratio in LD compared with female lambs from Control ewes (Con-F), whereas males did not differ. At PN153, Arg-F were heavier than Con-F and had heavier LD and plantaris and a trend for heavier psoas major muscles compared with Con-F. In contrast, BW and individual muscle weights did not differ in male lambs. Lambs from Arg-treated ewes had heavier semimembranosus and tended to have heavier biceps femoris compared with Control lambs. The RNA concentration in LD was greater in Arg-F compared with Con-F, and DNA concentration was greater in the Arg group compared with the Control group. In conclusion, Arg administration to the ewe during gestation increases female lamb weight and muscle weight after birth and these changes are associated with altered mTOR protein abundance and have potential implications for sheep production.

Effects of maternal nutrition and rumen-protected arginine supplementation on ewe performance and postnatal lamb growth and internal organ mass1

“…Because lambs were euthanized at day 54 of age, we were not able to follow offspring growth long term. Sales et al (2016) found that female lambs from dams given intravenous boluses of arginine (345-µmol Arg HCl/kg BW 3 times daily) from days 100 to 140 of pregnancy were heavier at day 153 of age and tended to have heavier psoas major muscles than female lambs from dams not administered arginine boluses. Although we saw offspring from all treatments equal by day 40, future studies could follow growth more long term to evaluate the effects of oral administration of arginine at market weight.…”

Effect Of Arginine On The Some Blood And Biochemical Parameters For Local Goat Females.

“…Sterndale et al (19) noted that there was no significant difference between selenium vitamin E and control in glucose level in ewes during pregnancy (33). Yunta et al (31) noted that giving arginine during pregnancy did not significantly affect glucose (12,16,21,26). While the results of the current study with Jarad and Al-Kaisei (34) showed that the Arginine had an effective effect in reducing the blood glucose level .…”

“…Recent studies have shown that arginine plays a role in stimulating the growth and development of the placenta (9), Prolactin and IGF Insulin like Growth Factor 1, IFN-t, Glycogen (10). Treatment of pregnant ewes with arginine or selenium plus vitamin E increases fetal growth by increasing The arrival of food to the fetus and the maintenance of pregnancy (11), nitrogen uptake and reduction of ammonia toxicity in tissues (12). However the previous studies did not showed significantly the use of arginine with selenium and vitamin E during pregnancy and its impact on the state of health of the dam and fetus and may considered as an indicators of the values of lambs and chemists in addition to measuring concentrations of sex hormones.…”

The effect of a fodder beet versus rye-grass grazing regime during mid-to-late gestation twin-bearing ewes on dam and progeny performance and lamb survival

“…Pacheco et al (2016) reported that proportions of arginine, citrulline and ornithine in plasma of lactating cows fed fodder beet were lower than those from cows fed ryegrass, suggesting the possibility of insufficient AA supply/synthesis. Arginine, in particular, has been found to have a key role in foetal growth and development (McCoard et al 2016), where parenteral supplementation to twin-bearing pregnant sheep in the last trimester increased foetal brown-fat reserves and core body temperature at birth (McCoard et al 2014), increased female lamb birth weight (McCoard et al 2013), placental development and function (van der Linden et al 2015) and improved offspring postnatal growth rate and muscle mass (Sales et al 2016). The potential for changes in specific AA to mediate, at least in part, the differences in ewe and lamb performance observed in this study warrant further investigation.…”