Silencing acetyl-CoA carboxylase A and sterol regulatory element-binding protein 1 genes through RNAi reduce serum and egg cholesterol in chicken.

Cholesterol is synthesized in chicken through de novo lipid biosynthetic pathway where two most important genes viz. SREBP1 and ACACA play immense role. To minimize cholesterol synthesis, RNAi approach was adopted and accordingly, we developed transgenic chicken possessing ACACA and SREBP1 shRNA constructs, which showed lower level of ACACA and SREBP1 in serum. The serum total cholesterol, triglycerides, HDL and LDL cholesterol was significantly lower by 23.8, 35.6, 26.6 and 20.9%, respectively in SREBP1 transgenic birds compared to the control. The egg total cholesterol and LDL cholesterol content was numerically lower in both ACACA and SREBP1 transgenic birds by 14.3 and 13.2%, and 10.4 and 13.7%, respectively compared to the control. It is concluded that the protocol was perfected to develop transgenic chicken through RNAi for knocking down the expression of ACACA and SREBP1 proteins, which minimized the cholesterol and triglycerides contents in serum and eggs.

A comparative study on the antioxidant status, meat quality, and mineral deposition in broiler chicken fed dietary nano zinc viz-a-viz inorganic zinc.

Use of nano minerals in farm animal nutrition offers considerable advantages over inorganic or organic mineral sources. But, the conventional chemical synthesis of nano minerals suffers from disadvantage of possible environmental accumulation and pollution due to the non-biodegradable materials and chemicals. This study investigated the effects of green nano-zinc (GNZ) and market nano-zinc (MNZ) with respect to the inorganic zinc (IZ) on meat quality, antioxidant status, mineral deposition, and bone development in broiler chicken. Following a 3 × 3 factorial design, nine dietary treatments were formulated by employing three levels (40, 60, and 80 ppm) and three sources (inorganic, green nano, and market nano) of zinc viz. IZ-40, GNZ-40, MNZ-40, IZ-60, GNZ-60, MNZ-60, IZ-80, GNZ-80, MNZ-80. Six replicates of broiler chicken were assigned to each treatment with eight birds in each. The birds fed 80 ppm Zinc of either GNZ or MNZ source resulted in significantly higher serum SOD, glutathione peroxidase, catalase, zinc, calcium, and phosphorus levels; increased bone dimensions, weight, total ash, phosphorus, and zinc content along with higher liver and muscle zinc concentration. The meat of chicken fed 80 ppm zinc of MNZ source followed by GNZ source has shown significantly better antioxidant (DPPH and ABTS values) status and lower lipid peroxidation (free fatty acid and TBARS values). The 80 ppm zinc of either MNZ or GNZ source resulted in significantly lower fat and cholesterol content of chicken meat compared to lower Zn levels and IZ source. This study indicated that 80 ppm dietary zinc of either MNZ or GNZ source improved the antioxidant status, and reduced the meat cholesterol, fat content, and lipid peroxidation of chicken meat along with increased bone dimensions and mineralization.

Polymorphisms in GnRHI and GnRHII genes and their association with egg production and egg quality traits in chicken.

1. Two candidate genes, namely, Gonadotropin releasing hormone I (GnRHI) and Gonadotropin releasing hormone II (GnRHII) play pivotal roles in ovulation and egg production in chicken. The objective of this study was to explore polymorphism in these genes and to estimate the effects of polymorphism of these two genes on egg production and egg quality traits in White Leghorn laying hens. 2. Single strand conformation polymorphism followed by sequencing was performed to detect polymorphism in these genes. 3. The coding regions of the GnRHI and GnRHII genes were found to be polymorphic. In the GnRH1 gene, 12 haplotypes were determined, of which the h1 haplotype was predominant and the h5, h9 and h11 haplotypes were the least frequent ones. In the GnRHII gene, eight haplotypes were found, of which the h1 haplotype was the most frequent and the h6 was the least frequent haplotype in the White Leghorn population. 4. The haplogroups of GnRHI had a significant effect on body weight and egg production up to 64 weeks of age, yolk content, Haugh units and egg shell parameters. The h1h2 haplogroup of the GnRHI gene showed the highest egg production, with 211.0 ± 24.3 eggs up to 64 weeks of age, while the highest yolk content and Haugh unit was found in h3h10 haplogrouped birds. The haplogroups of GnRHII had a significant effect on age at sexual maturity (ASM) where the shortest ASM was found in the h1h4 birds (147.3 ± 5.9 d) and the longest ASM was observed in the h1h3 birds (160.6 ± 23.4 d). 5. It was concluded that GnRHI and GnRHII genes are polymorphic and have a significant effect on body weight, egg production and egg quality traits in White Leghorn laying hens.

In ovo carbohydrate supplementation modulates growth and immunity-related genes in broiler chickens.

A study was undertaken to investigate the role of in ovo administrated carbohydrates on the expression pattern of growth and immune-related genes. In ovo injections (n = 400) were carried out on the 14th day of incubation into the yolk sac/amnion of the broiler chicken embryos. Expression of growth-related genes: chicken growth hormone (cGH), insulin-like growth factor-I & II (IGF-I & II) and mucin were studied in hepatic and jejunum tissues of late-term embryo and early post-hatch chicks. Expression of candidate immune genes: Interleukin-2, 6, 10 and 12 (IL-2, IL-6, IL-10 and IL-12), Tumour necrosis factor-alpha (TNF-α) and Interferon gamma (IFN-γ) were studied in peripheral blood monocyte cells of in ovo-injected and control birds following antigenic stimulation with sheep RBC (SRBC) or mitogen concanavalin A (Con-A). Glucose injection significantly increased the expression of IGF-II gene during embryonic period and both cGH and IGF-II in early post-hatch period, while ribose-injected chicks had higher expression of IGF-II gene during embryonic stage. Enhanced mucin gene expression was also observed in fructose-injected chicks during embryonic age. Glucose-injected chicks had higher expression of IL-6 or IL-10, while those injected with fructose or ribose had higher expression of IL-2, IL-12 and IFN gamma. It is concluded that in ovo supplementation of carbohydrates might help in improving the growth of late-term embryos and chicks. In ovo glucose could modulate humoral-related immunity, while fructose or ribose might help in improving the cellular immunity in broiler chickens.