Influence of Source and Percentage of Fat Added to Diet on Performance and Fatty Acid Composition of Egg Yolks of Two Strains of Laying Hens

Abstract

We conducted a trial to study the influence of strain of hen (white vs. brown) and source and percentage of added fat to diet on productive performance and fatty acid (FA) profile of the egg yolk. There were nine dietary treatments: a control diet without added fat and eight diets arranged as a 2 x 4 factorial (5 vs. 10% added tallow, olive, soy, or linseed oil). Each treatment was replicated five times, and the trial lasted 12 wk. White hens produced yolks with more saturated FA (P < 0.001) and less monounsaturated FA (P < 0.001) and polyunsaturated FA (P < 0.05) than brown hens. Fat supplementation improved egg mass output (P < 0.05) and feed efficiency of hens (P < 0.001). Linseed and soy oil diets produced greater egg mass than diets based on tallow or olive oil (59.6, 59.4, 57.9, and 57.1%, respectively; P < 0.001). The proportion of saturated FA in the yolk decreased as the percentage of added fat increased (36.5, 32.3, and 31.0% for diets containing 0, 5, and 10% added fat, respectively; P < 0.001). When the alpha-linolenic acid content of the diets increased from 0 to 0.8%, the arachidonic, docosapentanoic, and docosahexanoic acids in the egg yolk increased. Increases in the alpha-linolenic acid content of the diet over 2.3% did not further augment the concentration of docosapentanoic or docosahexanoic acid of the yolk and, in fact, decreased that of arachidonic acid. Only diets supplemented with linseed oil produced eggs with measurable amounts of eicosapentanoic acid. Diets supplemented with soy oil, with moderate levels of alpha-linolenic acid and high levels of linoleic acid, increased arachidonic and docosahexanoic acids in the egg yolk but not eicosapentanoic acid.

Influence of feed form and energy concentration of the rearing phase diets on productivity, digestive tract development and body measurements of brown-egg laying hens fed diets varying in energy concentration from 17 to 46 wk of age

“…Probably, the low LNA intake was limiting egg mass production in hens fed the low energy diet, penalizing feed efficiency. In contrast, in the current research LNA intake was 2.94 and 2.15 g/d for the high and low energy diets, respectively, values that were above requirements for both groups of hens (Grobas et al, 2001;Bouvarel et al, 2010). Also, in the research of Pérez-Bonilla et al (2012a), in which egg production increased with increases in the energy content of the diet, an increase in energy concentration of 7.5% (11.10-11.94 MJ AME n /kg) decreased Table 5.…”

“…From 17-46 wk of age, hens fed the high energy diet consumed 3.7% less feed and had 3.1% better FCR than hens fed the low energy diet but egg production was not affected, consistent with data of Grobas et al (2001) and Safaa et al (2009). The decrease in ADFI observed in hens fed the high energy diet was expected because poultry eat to satisfy their energy requirements, provided that the capacity of the GIT is not compromised (Hill et al, 1956;Leeson et al, 1997).…”

The impact of incorporation of n-3 fatty acids into eggs on ovarian follicular development, immune response, antioxidative status and tibial bone characteristics in aged laying hens

“…Similar results were documented by Cachaldora et al (2008) who revealed that yolk color increased in the diets supplemented with n-3 oils with respect to the control diets. Also, Grobas et al (2001) noted that yolk color benefited from n-3 oils. The oxycarotenoids contained in the diet are lipid soluble, and therefore their absorption from the intestine are likely to be improved when fed in parallel with the lipids (Grobas et al, 2001).…”

“…Also, Grobas et al (2001) noted that yolk color benefited from n-3 oils. The oxycarotenoids contained in the diet are lipid soluble, and therefore their absorption from the intestine are likely to be improved when fed in parallel with the lipids (Grobas et al, 2001). Virtually, commercial table eggs contain a high proportion of n-6 PUFA but are a poor source of n-3 PUFA.…”

<b>Intestinal carbohydrase activity and sodium-glucose transporter expression in layers fed diets containing wheat and rice brans supplemented with phytase

“…The eggs were individually weighed and the external and internal quality was determined. The shell was separated from the yolk and albumen weighed after drying overnight at 60℃ as indicated by Grobas, Mendez, Lazaro, De Blas, and Mateo (2001). Shell thickness was measured using a digital micrometer (Echometer 1061, Robotmation Company, Tokyo, Japan).…”