Effects of Moringa oleifera silage on milk yield, nutrient digestibility and serum biochemical indexes of lactating dairy cows.

This study investigated the effects of Moringa oleifera (MO) as a partial substitute of alfalfa hay on milk yield, nutrient apparent digestibility and serum biochemical indexes of dairy cows. MO was harvested at 120 days post-seeding. Fresh MO was cut, mixed with chopped oat hay (425:575 on a DM basis), ensiled and stored for 60 days. Sixty healthy Holstein dairy cows were allocated to one of three groups: NM (no MO or control), LM (low MO; 25% alfalfa hay and 50% maize silage were replaced by MO silage) or HM (high MO; 50% alfalfa hay and 100% maize silage were replaced by MO silage). The feeding trial lasted 35 days. The LM and HM diets did not affect dry matter (DM) intake, milk yield or milk composition (lactose, milk fat, milk protein and somatic cell count). The apparent digestibility of DM and NDF was lower for HM group than NM group. Additionally, there were no significant differences in serum biochemical indexes between the LM and NM groups. The HM group had lower serum concentrations of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol and higher serum concentrations of urea than the NM group. The partial replacement of alfalfa hay (≤50%) and maize silage with MO silage had no negative effects on milk yield, in vivo nutrient apparent digestibility or serum biochemical indexes of lactating cows.

Critical role of miR-125b in lipogenesis by targeting stearoyl-CoA desaturase-1 (SCD-1).

Alteration of gene expression tightly regulates lipogenesis. Stearoyl-CoA desaturase-1 (SCD-1), a key enzyme in lipogenesis, catalyzes the conversion of SFA to MUFA, and inhibition of its activity impairs lipid synthesis. As posttranscriptional regulators, microRNAs are involved in many pathways of lipid metabolism; however, their effect on SCD-1 has not been reported. In this study, miR-125b was identified as a potential regulator of SCD-1 using bioinformatics analysis. Here, we validated SCD-1 as the target of miR-125b using a dual luciferase assay. During adipogenesis, a synthetic mimic or inhibitor was used to overexpress or reduce the expression of miR-125b in porcine adipocytes. Overexpression of miR-125b reduced the accumulation of lipid droplets and triglycerides concentration and repressed SCD-1 protein expression and MUFA composition. The inhibitor had the reverse effect. Small interfering RNA against tested in adipocytes further proved the direct correlation between miR-125b and SCD-1. Moreover, in vivo experiments in mice showed that injection of miR-125b expression vector decreased the hepatic triglycerides concentration relative to saline. This study indicated that miR-125b regulates lipogenesis by targeting SCD-1; therefore, miR-125b might be applied in therapy of lipid metabolism disorders.

Decorin-induced proliferation of avian myoblasts involves the myostatin/Smad signaling pathway.

Decorin, a small leucine-rich proteoglycan as a component of the extracellular matrix, plays an important role in the skeletal muscle development. It has been reported that decorin promoted proliferation and differentiation of muscle cells by restraining myostatin activity in rodents. However, the effects and mechanisms of decorin on avian myoblast proliferation are not understood clearly. Thus, in our research, decorin overexpressing and knocking-down quail myoblast-7 (QM7) myoblasts were established to explore the effects of decorin on avian myoblast proliferation by flow cytometry. The results showed that overexpression of decorin enhanced the proliferation of QM7 myoblasts, which was accompanied by the upregulation of follistatin and primary muscle regulatory factors (i.e., myogenic factor 5, myogenic factor 1, myogenin), and downregulation of myostatin expression, as well as the decreased phosphorylation level of SMAD family member 3 (Smad3). In line with expectations, decorin RNAi displayed an opposite effect on the proliferation and gene expression pattern of QM7 cells. In conclusion, our in vitro studies suggested the decorin-mediated myostatin/Smad signaling pathway might be involved in the regulation of avian myoblast proliferation.

Sorbic acid improves growth performance and regulates insulin-like growth factor system gene expression in swine.

Sorbic acid (SA) is a PUFA with a conjugated double bond. The conjugated fatty acids, including CLA, are multifunctional bioactive fatty acids with the ability to improve growth performance. The effect of SA on pig growth performance was examined to determine its mechanism of action. The ADG, ADFI, and serum IGF-I concentration were examined, as were IGF-I secretion and IGF system gene expression in hepatocytes. Two hundred forty 21-d-old Duroc × Landrace × Yorkshire weaned piglets (6.86 ± 0.02 kg) were randomly divided into 4 groups, each consisting of 3 pens of 20 piglets (10 female and 10 male). The 4 groups of piglets were kept in a temperature-controlled room (26 to 28 °C), and feed and water were provided to the pigs ad libitum. Weanling piglets were fed diets that included 0, 0.5, 2, or 4 g of SA/kg for 42 d. The diet supplemented with 0.5 g/kg of SA improved (P < 0.05) ADG, BW, and G:F, whereas supplementation with all 3 SA doses increased (P < 0.05) ADG and G:F at 21 to 42 d of age. The greatest concentration of plasma triglycerides was observed (P < 0.05) in the 4 g/kg of SA group. The SA increased (0.5 g of SA/kg, P > 0.05; 1 g of SA/kg, P < 0.05; and 2 g of SA/kg, P < 0.05, respectively) plasma total serum protein and globulin concentrations in a dose-dependent manner. It was noted that the smallest SA treatment dose (0.5 g/kg) dramatically increased (P < 0.05) serum IGF-I concentration but decreased (P < 0.05) the concentrations of blood urea N and cortisol. The SA increased (P < 0.05) IGF-I, IGF-II, IGF-I receptor (IGF-IR), and PPARα gene mRNA expression and IGF-I secretion, but not (P > 0.05) IGFBP or PPARγ mRNA expression, in pig primary hepatocytes. These results indicate that SA improves growth performance by regulating IGF system gene expression and hormone secretion.

[Molecular analysis of polymorphisms for B-LII beta(beta 1 exon) locus in some Chinese native chicken].

Molecular genetic polymorphisms were studied for MHC-B-LII beta(beta 1 exon) locus in ten breeds of chicken by PCR-RFLPs. Thirty-seven genotypes were detected in these chicken. In the 305 bp fragment derived from MHC-B-LII beta(beta 1 exon) locus digested with Hha I, EcoRV, HaeIII, Xba I, there were significant difference with the frequencies of genotype and combined genotype among individuals or breeds. Statistical results showed Hardy-Weinberg equilibrium in polymorphic sites were inconsistent among various breeds. Sequencing results suggested there are more polymorphism at the level of amino acid than at that of nucleotide. Furthermore, as antigen binding site, the highly polymorphisms of beta 1 exon sequence was a reflection to the antigen diversity of immune systems. Moreover, it was implied that there was highly association between genetic polymorphisms of beta 1 exon and reproduction performance in chicken.