Tackling the future challenges of Organic Animal Husbandry - vTI

RAHMANN G & GODINHO D (Ed.) (2012): Tackling the Future Challenges of Organic Animal Husbandry.
Proceedings of the 2 nd OAHC, Hamburg/Trenthorst, Germany, Sep 12-14, 2012
reared under conventional 3- tier cages (standard cages of 48 x 42 x 45 cm with stocking rate of 4
birds per cage with density of 504 cm 2 ). All birds were housed in a closed computerized control
system. Similar feed composition (14.6 % CP, 2800 kcal ME / kg feed, 3.95 % Ca and 0.37 %
available P) and 16L:8D photoperiod were provided for hens in both systems. Feed and water were
supplied ad. libitum. However, birds on organic system fed ration with all ingredients of organically
produced (the ingredients and their percentages were corn 36.653, soybean meal 20.035, oat 10,
milo 10, soybean meal by products 8, alfalfa meal 3.509, biotine 0.5, choline chloride 0.045, DL
methionine 0.123, probiotics 0.0075, limestone 9.9885, mono-ca-p 0.726, salt 0.207, oyster meal,
0.131and clover mixture feed 0.01). On the other hand, birds on the conventional system were fed
commercial diet with the following ingredients and their percentages corn 53.073, soybean meal
12.141, DDGS 12.0, wheat middling 9.442, canola oil 1.85, biotine 0.5, limestone 9.948, mono-ca-p
0.599, salt 0.163, oyster meal 0.081, rhodinmet (ca) 0.072, Rouch mix feed 0.010 and L-lysine
0.121). A total of 240 eggs were randomly obtained on August 9, 2011from hens of 48-wk old . The
120 eggs of each system were randomly assigned to 2 storage treatments (one day vs. 7 days) before
chemical analysis, which were analyzed at Biological Lab., Michigan State University. Fatty acid
profiles were measured for the 120 eggs/system (15 samples, each was taken from a pooled of 8
eggs yolk). Lipid extraction of egg yolk and preparation of fatty acids methyl esters (FAME) was
performed using a direct 2-step transesterification procedure (Jenkins, 2010). FAME was quantified
using a GC-2010 plus gas chromatography (Shimmadzu, Kyoto, Japan). Whereas, eggs proximate
and amino acids analysis were done on 15 samples/system, each was taken from a pooled of 8 whole
eggs, at Agricultural Experiment Station Chemical Lab., Missouri University, according to
AOAC (2006a and 2006b, respectively). Hen-day egg production was 165 and 175 at 48 wk for
organic and cages system, respectively. Feed consumption was 108.7 gm/day for both systems.
Feed efficiency was 141.6 and 116.3 gm feed/egg for organic and cages system, respectively. As
the purpose of this investigation was to examine if production system (organic or conventional
cages) affects the quality of eggs, several traits were studies (weights and percentages of egg albumin,
yolk and shell) as well as percentages of dry matter (DM) of whole egg, albumin and yolk,
also albumin, yolk and whole egg solids. Furthermore, egg quality traits (specific gravity, Haugh
unit, yolk index, yolk color, shell thickness and egg shape index) were studied. Statistical analyses
were performed using GLM of SAS (2001). The model used for data included the effects of rearing
system, storage period and the interaction between them. Duncan's multiple range tests was used to
separate group means.
Results
Hen-day egg production, were measured at 48 being 165 and 175 for organic and cages system,
respectively. Feed consumption was 108.7 gm/day for both systems. Feed efficiency was 141.6
and 116.3 gm feed/egg for organic and cages system, respectively. Result of statistical analysis
showed that storage treatments as well as the interaction between rearing system and storage treatments
had significant effects on some traits studied. Generally, storage at 5-7 °C for a week caused
unfavorable effects on egg quality and chemical analysis. Result of proximate analysis revealed that
eggs produced under organic system had significantly (P < 0.05) more ash (1.93 vs. 1.74%) and less
fat (13.88 vs. 11.95 %). Storing eggs for 7 days decreased crude protein significantly (P < 0.05)
from 31.18 to 28.95 %, but did not influence crude fat and ash percentages. Moreover, eggs produced
under organic system had significantly (P < 0.05) lower egg weight (59.60 vs. 61.00 gm),
yolk weight (17.45 vs. 19.13 gm). Shell weight (6.65 vs. 6.27), yolk solid (7.40 vs. 8.27 %), egg
solid (22.69 vs. 23.22 %), yolk percent (29.36 vs. 31.41 %), but more shell weight (11.16 vs. 10.30
%), albumin percent (59.48 vs. 58.29 %), egg shape index (76.63 vs. 75.40 %), yolk color (8.15 vs.
6.98), shell thickness(0.45 vs. 0.39 mm), Haugh unit (81.87 vs. 77.79 %), and yolk index (0.47 vs.
0.45). Results also showed that eggs produced under organic system had significantly (P < 0.05)
lower amino acids Proline (1.17 vs. 1.28 %), Hydroxylysine (0.010 vs. 0.005%) and Ornithine
165