Effects Of Different Housing Systems On The Feather Score,Production Performance, Meat Quality And Egg Quality Of The Rejected Layers

In this experiment we studied the effect of different housing systems on the feather score,production performance, meat quality and egg quality of Luhua rejected layers. We did primarily analysis and discussion of the results and mechanism to make sure which feeding pattens can effectively improve the integrated value of the layers.This experiment includes two trails, the first one:45-week-old of the Luhua layers were chosen as the control group (group A). We randomly selected 72 layers and 60 eggs from group A for the determining feather score and egg quality and collected the related laying performance datas. The second one:there are 180 aged 45 weeks layers, which were randomly divided into four treatment groups,45 layers in each group,3 repeats in each group,15 layers in each repeat, the periods of the experiment were 5 weeks and 10 weeks. We designed four experimental groups (group B:greenhouses fermentation rearing five weeks; Group C:ladder cages indoor rearing five weeks; D Group:greenhouses fermentation rearing 10 weeks; E Group:ladder cages indoor rearing 10 weeks).The following conclusion can be drawn preliminarily under the conditions of this experiment:The feather score:under the same conditions of feeding, environmental factors, etc., The results were as following:the saddle feathers’ score> the tail feathers’s core> the abdominal feathers’ score> the neck feathers’ score. The total score of caged layers was significantly (P< 0.05) lower than the layers which were raised on ground.Egg performance and egg quality:The laying rate of caged layers was significantly (P < 0.05) higher than that raising on ground. The result showed there were no significant effect in egg quality on egg weight,egg yolk weight, egg yolk color,eggshell color, eggshell thickness, egg shape index and eggshell strength. For the egg quality, only the Haugh unit and albumen height presented remarkable difference(P< 0.05) between the two feeding manners. layers which were raised on ground significantly improved in the haugh unit and albumen height. This experiment shows that feeding on ground can improve eggs quality, but its laying performance is worse than caged group.Production performance and slaughter performance:the effect of different feeding pattens and different weeks on weight of the Luhua rejected layer was not remarkable(P> 0.05). The result showed that different feeding methods and age have little impact on the weight of rejected layers.The effects of different feeding manners on breast muscle weight of the rejected layer was remarkable(P<0.05). In 55 week, the semi-eviscerated weight, eviscerated weight,breast meat weight, thigh meat weight of caged layers were significantly (P< 0.05) lower than the layers which were raised on ground.Slughter rate, half eviscerated rate and full eviscerated rate of caged layers were significantly (P< 0.05) higher than the rate of layers which were raised on ground.Meat quality and flavor:the value of pH1 and pHu in leg muscle were higher than those in breast muscle. The result indicated that leg meat quality is better than that of breast muscle. Layers which were fed in cage had higher pH value than that were fed on ground. Muscle moisture and intramuscular fat content were not significantly difference (P > 0.05) in each experimental and control group. Breast muscle fiber diameter and muscle fiber density of the Rejected layer were not remarkable(P>0.05) in different feeding pattens. At 55 week,result showed that the drip loss rate of breast meat and the value of L* in caged were both higher than those raised on ground(P<0.05).The effects of different feeding manners on the essential amino acids, total amino acids and flavor amino acids of the rejected layer were not remarkable(P>0.05).Comprehensive economic benefits:the economic benefits of caged layers was lower than the layers which were raised on ground.In conclusion, the appearance of layers which were raised on ground were greatly improved and some egg and meat quality indicators also had been improved. However, the performance of laying and slaughter were worse than the layers which were raised in caged. The economic benefits of caged layers was lower than the layers which were raised on ground.