Comparison between wheat, triticale, rye, soyabean oil and strain of laying bird on the production, and cholesterol and fatty acid contents of eggs

The effect of different dietary levels of hybrid rye and xylanase addition on the performance and egg quality in laying hens

1. In this study, 240 ISA Brown hens were fed diets containing different levels of hybrid rye, and the influence of xylanase addition on laying performance and egg quality was evaluated. 2. Birds were allocated to 10 treatment groups with 12 replicates (cages) of two hens and were fed, from week 26 to 50, isocaloric and isonitrogenous experimental diets. A 5 × 2 experimental arrangement was applied, using diets with increasing level of rye (0%, 10%, 15%, 20% or 25%) with or without xylanase supplementation (200 mg/kg of feed; Ronozyme WX (CT) with minimum xylanase activity of 1,000 FXU/g). 3. Increasing dietary level of rye did not affect daily mass of eggs, mean egg weight or feed conversion ratio (P > 0.05). Laying rate decreased in all groups fed with rye. Egg and eggshell quality indices were unaffected by dietary rye grain (P > 0.05); however, rye inclusion significantly decreased yolk colour on the DSM scale (P < 0.05). In comparison with the control group, high dietary levels of rye (25%) significantly increased viscosity of small intestine content (P < 0.05). Diet supplementation with xylanase had no significant effect on egg production indices and egg quality (except for yolk colour) but decreased the viscosity of intestinal content in laying hens fed high levels of rye (P < 0.05). 4. The results of this experiment suggest that rye may be incorporated to a level of 25% in the diet of laying hens without any strong negative effect on egg performance, while xylanase added to high-rye grain reduced the viscosity of intestinal content; however, it did not positively affect the laying performance or egg quality.

Effect of omega-3 and omega-6 fatty acid inclusion in broiler breeder's diet on laying performance, egg quality, and yolk fatty acids composition

The present study was conducted to evaluate the effect of different dietary oil sources (omega-3 and omega-6 fatty acid) in female broiler breeders’ diets on laying performance, egg quality and yolk fatty acids composition. Ross-308 breeders (220; 25 weeks old) were used in this experiment for 6 weeks. Birds were placed in a complete randomized design with 4 dietary treatments (containing 2% soybean oil, 2% sunflower oil, 2% flaxseed oil, and 2% fish oil) and 5 replications containing 1 male + 10 females in each pen having a similar body weight (3,424 g) and egg production (86%). Results indicated that different sources of dietary oil had no significant effect on body weight gain, feed conversion ratio, and egg production but had a significant effect on egg weight. Also feeding the diets containing 2% of different fatty acids had a significant effect on some egg quality parameters and egg yolk fatty acids composition. It was concluded that inclusion of 2% flaxseed oil can improve laying performance, egg quality, and egg yolk fatty acids composition parameters in broiler breeders.

Maternal diet influences offspring feeding behavior and fearfulness in the precocial chicken

Background

In chicken, oils in the maternal diet confer a specific scent to the yolk. Embryos are known to perceive and memorize chemosensory signals of the surrounding environment; however, the potential impact of the maternal diet has not previously been investigated. In the present study, we hypothesized that chicken embryos memorize the chemical signals of the maternal diet and that this perceptual learning may orient subsequent feeding behavior of the hatchlings.

Methodology/Principal Findings

Laying hens were fed standard food enriched with 2% menhaden oil (MH group) or 2% soybean oil (controls). The scent of menhaden was significantly more detected in MH egg yolks than in control yolks by a human panel. We analyzed the development and behavior of offspring towards different types of food, bearing or not bearing the menhaden scent. When chicks were exposed to a 3-min choice test between the familiar food bearing the menhaden scent and the familiar food without menhaden, no effect of treatment was observed. In a 3-min choice test with unfamiliar food (mashed cereals) MH chicks showed a clear positive orientation toward the unfamiliar food bearing the menhaden scent. By contrast, control chicks showed a preference for the non-odorized unfamiliar food. MH chicks expressed higher emotional reactivity level than control chicks as expressed by food neophobia and longer immobility in a restraint test.

Conclusion/Significance

Chicks exposed in ovo to menhaden oil via the maternal diet preferentially oriented their feeding behavior towards food containing menhaden oil, but only when the food was unfamiliar. We propose that oil in the maternal diet engenders maternal effects and contributes to the development of behavioral phenotype in the offspring. In ovo chemosensory learning may have evolved to prepare precocial offspring for their environment. This suggests a common principle of embryonic chemosensory learning across vertebrate taxa.

Effects of glucagon and insulin on plasma glucose, triglyceride, and triglyceride-rich lipoprotein concentrations in laying hens fed diets containing different types of fats

The influence of dietary fat supplementations differing in the ratio of n-6 to n-3 polyunsaturated fatty acids (PUFA) on the effects of glucagon and insulin on plasma glucose, triglyceride (TG), and TG-rich lipoprotein concentrations was investigated in laying hens. Birds were fed either a low-fat control diet (LF) or diets supplemented with 4% pumpkin seed oil (PO; rich in n-6 PUFA) or 4% cod liver oil (CO; rich in n-3 PUFA). After 4 wk feeding of the experimental diets, hens were implanted with wing vein catheters and injected with porcine glucagon (20 microg/kg BW) and porcine insulin (0.5 IU/kg BW), 2 to 5 h after oviposition. Plasma glucose, TG, and TG-rich lipoprotein concentrations were determined from 10 min pre-injection to 60 min post-injection. PO diet resulted in a prolonged plasma glucose response to glucagon administration and altered hypoglycemic response to insulin. However, CO diet did not influence plasma glucose response to either glucagon or insulin administration compared to LF diet. The effects of glucagon and insulin on plasma TG and TG-rich lipoproteins were similar for all diets regardless of the amount or type of fat. The results suggest that feeding dietary fats with high n-6 to n-3 PUFA ratio alters the glucagon and insulin sensitivity of plasma glucose in laying hens. Fats rich in n-3 PUFA seem to have no influence on the plasma glucose response to glucagon and insulin.