Effects of plane of nutrition of ewes in early and mid-pregnancy on performance of the offspring: female reproduction and male carcass characteristics

Effects of Maternal Undernutrition during Mid-Gestation on the Yield, Quality and Composition of Kid Meat Under an Extensive Management System

Simple Summary

Nutrition status during pregnancy affects the meat production of offspring. In ruminants, the nutrient supply during the first and third periods of gestation is generally stressed, whereas the nutrition level during the second period of gestation is given less attention, in particular under the extensive husbandry system. This study focused on the effects of a 40% maternal undernutrition during mid-gestation, on the yield, quality, and composition of kid meat under an extensive system. The meat yield of the kids was decreased, while the meat quality and chemical composition, including the amino acid and fatty acid profiles, were unaffected. In meat production under an extensive husbandry system, the importance of the nutrient supply during mid-gestation in ruminants should be stressed.

Abstract

Nutritional status during mid-gestation is often ignored under extensive husbandry. This study aimed to examine the effect of maternal undernutrition during mid-gestation on kid meat production under an extensive system. Twenty-seven goats (45 ± 3 d of gestation) were randomly assigned to an unrestricted group (100% of nutrient requirements), or a restricted group (60% of nutrient requirements from 45 to 100 d of gestation, and then re-alimented to 100%). Among the offspring, 16 eligible kids (eight per treatment) were selected, based on birth type and survival, and were harvested to evaluate the meat yield, quality, and composition at 90 d after birth. Maternal undernutrition reduced the body weight and size, average daily gain and hot carcass weight of the kids (p < 0.05). The lightness of the meat at 45 min postmortem was increased (p = 0.029) in the restricted kids. Apart from an increase in tyrosine concentration (p = 0.046), the proximate composition and the amino acid and fatty acid profiles were unaffected in the restricted kids (p > 0.05). Overall, maternal undernutrition during mid-gestation decreased the yield of kid meat, but did not significantly modify the quality and composition. These results highlight the importance of nutrient status during mid-gestation in the meat production of small ruminants under an extensive regime.

Offspring subcutaneous adipose markers are sensitive to the timing of maternal gestational weight gain

BACKGROUND

Excessive maternal weight gain during pregnancy impacts on offspring health. This study focused on the timing of maternal gestational weight gain, using a porcine model with mothers of normal pre-pregnancy weight.

METHODS

Trial design ensured the trajectory of maternal gestational weight gain differed across treatments in early, mid and late gestation. Diet composition did not differ. On day 25 gestation, sows were assigned to one of five treatments: Control sows received a standard gestation diet of 2.3 kg/day (30 MJ DE/day) from early to late gestation (day 25-110 gestation). E sows received 4.6 kg food/day in early gestation (day 25-50 gestation). M sows doubled their food intake in mid gestation (day 50-80 gestation). EM sows doubled their food intake during both early and mid gestation (day 25-80 gestation). L sows consumed 3.5 kg food/day in late gestation (day 80-110 gestation). Offspring body weight and food intake levels were measured from birth to adolescence. Markers of lipid metabolism, hypertrophy and inflammation were investigated in subcutaneous adipose tissue of adolescent offspring.

RESULTS

The trajectory of gestational weight gain differed across treatments. However total gestational weight gain did not differ except for EM sows who were the heaviest and fattest mothers at parturition. Offspring birth weight did not differ across treatments. Subcutaneous adipose tissue from EM offspring differed significantly from controls, with elevated mRNA levels of lipogenic (CD36, ACACB and LPL), nutrient transporters (FABP4 and GLUT4), lipolysis (HSL and ATGL), adipocyte size (MEST) and inflammation (PAI-1) indicators. The subcutaneous adipose depot from L offspring exhibited elevated levels of CD36, ACACB, LPL, GLUT4 and FABP4 mRNA transcripts compared to control offspring.

CONCLUSIONS

Increasing gestational weight gain in early gestation had the greatest impact on offspring postnatal growth rate. Increasing maternal food allowance in late gestation appeared to shift the offspring adipocyte focus towards accumulation of fat. Mothers who gained the most weight during gestation (EM mothers) gave birth to offspring whose subcutaneous adipose tissue, at adolescence, appeared hyperactive compared to controls. This study concluded that mothers, who gained more than the recommended weight gain in mid and late gestation, put their offspring adipose tissue at risk of dysfunction.

Leptin in farm animals: where are we and where can we go?

Fat affects meat quality, value and production efficiency as well as providing energy reserves for pregnancy and lactation in farm livestock. Leptin, the adipocyte product of the obese (ob) gene, was quickly seen as a predictor of body fat content in animals approaching slaughter and an aid to assessing reproductive readiness in females. Its participation in inflammation and immune responses that help animals survive infection and trauma has clear additional relevance to meat and milk production. Furthermore, almost a decade of discoveries of nucleotide polymorphisms in the leptin and leptin receptor genes has suggested useful applications relating to feed intake regulation, the efficiency of feed use, the composition of growth, the timing of puberty, mammogenesis and mammary gland function and fertility in cattle, pigs and poultry. The current review attempts to summarise where research has taken us in each of these aspects and speculates on where future research might lead.

Maternal periconceptional undernutrition in Merinos d'Arles sheep: 1. Effects on pregnancy and reproduction results of dams and offspring growth performances

Maternal undernutrition during gestation can condition offspring adult health, with the periconceptional period pointed out as a key period. The aim of this study was to evaluate the effects of maternal periconceptional undernutrition on pregnancy and offspring growth performance in sheep. 52 Merinos d'Arles ewes were fed to requirements (control group, C), whereas 64 ewes received 50% of their dietary needs from -15 to +30 days post-conception (restricted group, R). Thereafter, both groups were fed according to needs. Maternal body weight (BW), body condition score (BCS) and Non Esterified Fatty Acids (NEFA), progesterone, leptin and cortisol plasma concentrations were monitored weekly during the restriction period and the following month, then monthly until weaning. Lambs were weighed weekly until weaning at 22 kg BW, then monthly. Plasma leptin was monitored monthly in lambs. The BW, BCS, and leptin concentrations were significantly decreased, whereas NEFA and cortisol concentrations were increased in R dams. Maximum progesterone concentration was higher in R ewes that had a high (10-25%) vs. low (0-10%) BW loss during restriction (27.9 ± 2.59 vs. 20.8 ± 2.00 ng/mL, P < 0.05). Overall, gestation was significantly longer in the R group (151.0 ± 0.3 vs. 149.4 ± 0.4 days, P < 0.001). There was no difference between groups for pregnancy rates, prolificacy, birth weight and lamb mortality, but the proportion of male lambs was significantly higher in the R group, only for singletons (16/26 vs. 9/26, P < 0.05). Lamb growth was not significantly modified by treatment. Leptin concentrations at birth were significantly lower in R vs. C males (6.15 ± 0.13 ng/mL vs. 7.42 ± 0.36 ng/mL, P < 0.05), whereas in females, leptin concentrations were significantly higher in R vs. C lambs at 4 mo of age (7.31 ± 0.27 ng/mL vs. 6.41 ± 0.29 ng/mL, P < 0.05). These results indicate that maternal periconceptional undernutrition in a hardy breed does not significantly affect lamb birth weight and growth rates, in contrast to previous reports in other breeds, suggesting that caution must be taken when extrapolating programming data between breeds and breeding conditions.

Fetal muscle development, mesenchymal multipotent cell differentiation, and associated signaling pathways

Enhancing muscle growth while reducing fat accumulation improves the efficiency of animal production. The fetal stage is crucial for skeletal muscle development. Fetal muscle development involves myogenesis, adipogenesis, and fibrogenesis from mesenchymal multipotent cells (MC), which are negatively affected by maternal nutrient deficiencies. Enhancing myogenesis increases the lean-to-fat ratio of animals, enhancing intramuscular adipogenesis increases intramuscular fat that is indispensible for the superior eating properties of meat because fat is the major contributor to meat flavor. The promotion of fibrogenesis leads to the accumulation of connective tissue, which contributes to the background toughness of meat and is undesirable. Thus, it is essential to regulate MC differentiation to enhance lean growth and improve meat quality. To date, our understanding of mechanisms regulating the lineage commitment of MC is limited. In this review, we first discuss the impact of maternal nutrient deficiency on fetal development, offspring body composition, and meat quality. Because maternal nutrition affects fetal muscle through altering MC differentiation, we then review several important extracellular morphogens regulating MC differentiation, including hedgehog, Wingless and Int (Wnt), and bone morphogenic proteins. Possible involvement of epigenetic modifications associated with histone deacetylases class IIa and histone acetyltransferase, p300, in MC differentiation is also discussed.