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Eliminace výskytu vajec s poškozenou skořápkou u nosných hybridů na konci snášky
Horník, Radek
The deterioration of eggshell quality depending on the age of the laying hens causes significant economic losses for table egg producers. The aim of the experiment was to determine whether feeding vitamin D3 in the form of 25-hydroxyvitamin D3 would improve eggshell quality after 46 weeks of flock age. Two houses with flocks of Lohmann Brown-Classic laying hens housed in enriched cage technology were included in the observation. Both houses were fed the same feed mixture from the same supplier. From 38 weeks of age onwards, eggs were collected at regular two-week intervals in a number of 60 eggs from each house for each observation. Egg weight and eggshell strength, weight and thickness were determined for these eggs. From the 46th week onwards, 25 hydroxyvitamin D3, its hydroxy analogue, was started in the feed mixture in addition to vitamin D3 at one house. Monitoring of the above parameters was continued until the 67th week of age. It was found that the eggs were lighter on the shed where 25 hydroxyvitamin D3 was fed (P < 0,001), which was due to the fact that the eggs were conclusively lighter on this shed before the experimental intervention (P < 0,05). The egg weight was closely related to the eggshell weight, which was also conclusively lower on the experimental shed (P < 0,05). There was no conclusive difference in eggshell strength and thickness between the sheds. Egg and eggshell weight and shell thickness were significantly influenced by flock age (P < 0,001). There was no positive effect of 25 hydroxyvitamin D3 on eggshell quality.
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