Tracking the development of serum biochemical parameters in two laying hen strains – a comparative study

Abstract

A follow-up, comparative study was designed for the description of differences between two divergent laying hen strains, a Leghorn type and a medium heavy body (MHB) genotype (Hy-Line Brown), in chemical body composition and serum biochemical parameters determined at 3, 4, 6, 8, 10, 12, 14, 18, 20, 25, 30, 52 and 72 weeks of age; each time 5 birds of both genotypes were analysed and exterminated for body composition analysis.Resulting from the genotype-associated differences, the bodyweight of the populations differed from week 20 on. In the chemical body composition dry matter content was similar, while crude protein was higher on weeks 3, 8, 10, and after 18 weeks in the Leghorns. Crude fat content was higher in the brown birds (weeks 8, 10, 25, 30). Total serum protein and albumin showed slightly increasing trends, while serum creatinine concentration showed a downward trend in both genotypes, the MHB birds having higher values. Triglyceride concentration showed a drastic step-up at 17 weeks by changing to the pre-layer diet, coupled with marked between-genotype differences. This quick increase was matched by concentration drops in total and HDL cholesterol, the serum HDL cholesterol of Leghorns being always lower. Sodium concentration showed an increasing tendency with body DM content (R 2 =0.914, P<0.001, n=115). The Leghorns tended to show minimally higher Ca concentrations. The γ-GT activity was always higher in MHB birds, indicating a less effective hepatic adaptation to the peak production. Applying discriminant analysis to classify the genotypes, 94.4% of the original grouped cases was correctly classified, using all variables.

Blood Plasma Mineral Profile and Qualitative Indicators of the Eggshell in Laying Hens in Different Housing Systems

“…On the other hand, Koelkebeck and Odom (1995) reported no significant changes in plasma potassium levels under ambient temperature. Mean values similar to those received in this study were reported by Suchy et al (1989;, Gezen et al (2005), and Gyenis et al (2006). Lower mean plasma potassium levels were reported by Koelkebeck and Odom (1995).…”

“…A considerable increase in plasma Ca levels at the beginning of laying period and subsequent gradual increase was also observed by Cerolini et al (1990), Gyenis et al (2006), Filizciler et al (2002), and Strakova et al (1994). On the contrary, Burnham et al (2003) described an increase in calcium levels before the laying period and a decrease in calcium levels during the laying.…”

“…Traces of magnesium, potassium, copper and zinc were also found in the egg cuticle. Plasma mineral concentrations during the laying period can be influenced by many factors; such as laying rate and energy requirements (Suchý et al 2001), partial quantitative feed restriction (Sahin and Kucuk 2001), mineral supplements (Eren et al 2004), ambient temperature (Siegel 1995;Donoghue et al 1990;Ching 1992;Belay and Teeter 1993;Večerek et al 2002), production type (Suchý et al 2004), age of hens (Cerolini et al 1990; Gyenis et al 2006), stress (Beisel 1982;Combs and Combs 1984;Tufft and Nockles 1991;Klasing 1998), exposure to heavy metals (Zralý et al 2008), etc.…”

Effect of humic-plant feed preparations on biochemical blood parameters of laying hens in deep litter housing system

“…Increase of TAG concentration in subsequent samplings attracts an attention, because laying rate and deposition in egg yolks is subject to a decrease. Similar tendencies were noted by Gyenis et al (2006) in the study on Hy-Line Brown line hens. In turn, in Hy-line laying hens between 28 th and 30 th wk of life, the values in the range of 10.87-12.08 mmol/l were observed (Kralik et al 2006).…”

Effect of hen age, environmental temperature, and oviposition time on egg shell quality and egg shell and serum mineral contents in laying and broiler breeder hens

“…Similarly, Gunaratne and Boorman (1996) could measure no significant trends in plasma Ca during the day. The serum Ca content was the same at both ages which is in contrast with Brackpool et al (1996), Suchy et al (2004), Gyenis et al (2006), and Pavlik et al (2009) who demonstrated a gradual decrease in plasma Ca with age. However, differences in serum Ca between laying hens and broiler breeders were the same as reported by Suchy et al (2004) who described highly significantly lower plasma Ca levels in broiler breeders than in egg type hens.…”