Effect of maternal feed restriction in dairy goats at different stages of gestation on skeletal muscle development and energy metabolism of kids at the time of births

Dairy goats' management and performance under smallholder farming systems in Eastern Africa: the systematic review and meta-analysis

The systematic review and meta-analysis study was conducted to describe dairy goat management practices among smallholder farmers in Kenya and Tanzania. The study also evaluated the effects of breed and upgrade level (50%, 75% and > 75%) on growth and lactation performances. Google Scholar was used to search for dairy goats' studies followed by an eligibility check. Eligible studies were assessed for risk of bias using RoB 2.0 (Cochrane risk-of-bias in randomised trial) and ROBINS-I (Risk of Bias Assessment in Non-Randomised Studies of Interventions). Smallholder farmers were mainly stall-feeding natural pasture and crop residues to goats with supplementation limited by the high costs of concentrate feeds. Forage cultivation and conservation were limited by the scarcity of land and improved forage planting materials, low technical know-how and high labour demand. Similarly, farmers had limited access to formal market, veterinary and extension services. Prevalence of infectious diseases, antibiotic resistance and pre-weaning kid mortality were high. Nevertheless, there were breed effects (p < 0.05) on pre-weaning growth and weaning weight but not lactation parameters. However, Saanen goats had relatively higher lactation length (252 days) and yield (637 l) than other goat breeds. Daily milk and lactation yields, pre-weaning growth and growth rate (post-weaning) varied significantly among upgrade levels (p < 0.05) and were highest in > 75% level. It was concluded that Saanen goats and > 75% were the best breed and upgrade level for goat milk production in smallholder farms due to high lactation performance. Improving the different managerial aspects of smallholder dairy goat farming is of paramount importance if the dairy goats' performance, farm income, food safety and security are to be improved in Eastern Africa.

Identification of eQTLs and differential gene expression associated with fetal programming in beef cattle

This study assessed differential gene expression and identified expression quantitative trait loci (eQTLs) from samples of Longissimus lumborum muscle from bulls at 15 months of age submitted to different prenatal nutrition. Upon confirmation of pregnancy, 126 dams were separated into three diet treatments varying the period of inclusion of energy protein supplementation (NP, PP, and FP). At calving, 63 males were genotyped with GGP LD BeadChip. The skeletal muscle of 15 bulls was sequenced (RNA-seq) at 15 months of age. The EdgeR package was used for differential gene expression and principal component analysis (PCA), and the Matrix eQTL package was used for the eQTLs analysis (R statistical). The functional enrichment analysis was performed using the MetaCore® software. No genes differentially expressed were found between treatments (FDR > 0.05); nevertheless, we found 179 cis-tag-eQTLs and 20,762 trans-tag-eQTLs (FDR < 0.05) after linkage disequilibrium analysis. The functional enrichment analysis identified terms from gene ontology related to genes associated to trans-eQTLs (FDR < 0.05) as well as metabolic pathways (> gScore). Most biological pathways and genes found had been previously associated to fetal programming. The different prenatal supplementation strategies did not impact on muscle transcriptome of bulls. Additionally, there is a link between genotype and gene expression levels related to developmental traits in Nellore cattle.

Impact of Maternal Feed Restriction at Different Stages of Gestation on the Proteomic Profile of the Newborn Skeletal Muscle

We aimed to investigate the effects of the maternal plane of nutrition during gestation on the proteome profile of the skeletal muscle of the newborn. Pregnant goats were assigned to the following experimental treatments: restriction maintenance (RM) where pregnant dams were fed at 50% of their maintenance requirements from 8−84 days of gestation, and then feed of 100% of the maintenance requirements was supplied from 85—parturition (n = 6); maintenance restriction (MR) where pregnant dams were fed at 100% of their maintenance requirements from 8−84 days of gestation, and then experienced feed restriction of 50% of the maintenance requirements from 85—parturition (n = 8). At birth, newborns were euthanized and samples of the Longissimus dorsi muscle were collected and used to perform HPLC-MS/MS analysis. The network analyses were performed to identify the biological processes and KEGG pathways of the proteins identified as differentially abundant protein and were deemed significant when the adjusted p-value (FDR) < 0.05. Our results suggest that treatment RM affects the energy metabolism of newborns’ skeletal muscle by changing the energy-investment phase of glycolysis, in addition to utilizing glycogen as a carbon source. Moreover, the RM plane of nutrition may contribute to fatty acid oxidation and increases in the cytosolic α-KG and mitochondrial NADH levels in the skeletal muscle of the newborn. On the other hand, treatment MR likely affects the energy-generation phase of glycolysis, contributing to the accumulation of mitochondrial α-KG and the biosynthesis of glutamine.

Skeletal Muscle Development in Postnatal Beef Cattle Resulting from Maternal Protein Restriction during Mid-Gestation

We aimed to investigate the effects of maternal protein restriction during mid-gestation on the skeletal muscle composition of the offspring. In the restriction treatment (RES, n = 9), cows were fed a basal diet, while in the control (CON, n = 9) group cows received the same RES diet plus the protein supplement during mid-gestation (100-200d). Samples of Longissimus dorsi muscle were collected from the offspring at 30d and 450d postnatal. Muscle fiber number was found to be decreased as a result of maternal protein restriction and persisted throughout the offspring's life (p < 0.01). The collagen content was enhanced (p < 0.05) due to maternal protein restriction at 30d. MHC2X mRNA expression tended to be higher (p = 0.08) in RES 30d offspring, however, no difference (p > 0.05) was found among treatments at 450d. Taken together, our results suggest that maternal protein restriction during mid-gestation has major and persistent effects by reducing muscle fiber formation and may slightly increase collagen accumulation in the skeletal muscle of the offspring. Although maternal protein restriction may alter the muscle fiber metabolism by favoring the establishment of a predominant glycolytic metabolism, the postnatal environment may be a determinant factor that establishes the different proportion of muscle fiber types.

Differential protein input in the maternal diet alters the skeletal muscle transcriptome in fetal sheep

Maternal nutrition during pregnancy is one of the major intrauterine environmental factors that influence fetal development by significantly altering the expression of genes that might have a consequence on the physiological, morphological, and metabolic performance of the offspring in the postnatal period. The impact of maternal dietary protein on the expression of genes in sheep fetal skeletal muscle development is not well understood. The current study aims to investigate the impact of high and low maternal dietary protein on the holistic mRNA expression in the sheep fetal skeletal muscle. Dams were exposed to an isoenergetic high-protein diet (HP, 160-270 g/day), low-protein diet (LP, 73-112 g/day), and standard protein (SP, 119-198 g/day) diets during pregnancy. Fetal skeletal muscles were obtained at the 105th day of pregnancy and mRNA expression profiles were evaluated using Affymetrix GeneChip™ Ovine Gene 1.0 ST Array. The transcriptional analysis revealed a total of 323, 354, and 14 genes were differentially regulated (fold change > 2 and false discovery rate ≤ 0.05) in HP vs. SP, LP vs. HP, and SP vs. LP, respectively. Several myogenic genes, including MYOD1, MYH2, MYH1, are significantly upregulated, while genes related to the immune system, such as CXCL11, HLA-E, CXCL10, CXCL9, TLRs, are significantly downregulated in the fetal muscle of the HP group compared to those of SP and LP group. Bioinformatic analysis revealed that the majority of these genes are involved in pathways related to the immune system and diseases. The results of our study demonstrate that both augmented and restricted dietary proteins in maternal diet during pregnancy alter the expression of genes as well as the offspring's genetic marks.