QUALITY INDICATORS OF EGGS OF LOHMANN BROWN AND LOHMANN SANDY CROSSBREEDS

Abstract

The paper presents the results of researches of the chemical and morphological composition of eggs of chicken crossbreeds Lohmann Brown and Lohmann Sandy. It was established that the chemical composition of egg yolks depended on the specific crossbreed and age of chickens. The chemical composition of the egg yolk of Lohmann Brown crossbreed mainly prevailed over the chemical composition of the egg yolk of Lohmann Sandy chickens of the same age, however this difference was mostly doubtful. The most relevant difference in the age of 21 weeks was in the content of the fat (0,16 % when Р<0,005), in the age of 49 weeks – in the content of the dry matter and ash (0,69% and 0,06 % respectively when Р<0,001 in both cases), in the age of 71 weeks – in the content of the protein and ach (0.18% (Р<0,01) and 0,24 % (Р<0,001) respectively).
 With aging of chickens, the most of the researched indicators of eggs of Lohmann Brown crossbreed underwent fluctuant changes, and only the content of the raw fat in the yolk decreased. At the same time, the eggs of Lohmann Sandy chickens of the same age demonstrated a lowering content of raw protein, raw fat and raw ash, while changes of the content of the dry matter had a fluctuant character. At the same time, with aging of both crossbreeds we observed the highly probable increase in the weight, length and width of eggs, the weight of the yolk, white and shell, while the thickness of the shell on the blunt end decreased with every next age period. The majority of morphological indicators of eggs of Lohmann Brown crossbreed exceeded the similar indicators of eggs of Lohmann Sandy chickens of the same age.
 This prevalence in the egg weight depending on the age period ranged from 6,81 to 7,95 grams, in the egg length – from 1,1 to 3,0 mm, in the egg width – from 1,6 to 1,8 mm, in the yolk weight – from 2,2 to 2,55 grams, in the egg white weight – from 3,83 to 4,44 grams. The concentration of hydrogen ions (pH) of the egg yolk and white depending on the age period and crossbreed of chicken ranged within 6,28-6,43 and 8,11-8,21 respectively, that corresponds to the permissible levels. The difference of the first indicator for birds of different crossbreeds was statistically reliable (P<0,001) and constituted 0,02-0,05 depending on the age period, while the difference in indicators related to the egg white was doubtful and comprised 0,02-0,13. The energy value of eggs of both controllable crossbreeds was almost equal, with the highly probable difference in the age of 21 weeks and 77 weeks.