Effects Of Adding Different Level Of Copper, Iron, Zinc And Manganese On Hens

The study adopted one-factor completely random distract design. It studied the effects of copper, iron, zinc and manganese preparations on performance of growth, metabolism of nutrients and trace elements, performance on laying and egg quality for the brooding, breeding and the laying hens (altogether 33 weeks). 525 Lomman chickens of day-old were equally divided into 5 groups, and the trace elements of 5 levels were added into the same dietary dividually. The study comprised four phases. Each phase had five dietary treatments, consisting of the basal diet (Treatment A), basal diet plus 50%NRC (Treatment B), basal diet plus 200%NRC plus contents of trace elements in basal diet (Treatment C), basal diet plus 300%NRC plus contents of trace elements in basal diet (Treatment D) and Treatment E which is calculated by the proportion of contents of trace elements in basal diet and NRC, other trace elements replenish the most high multiple(because the contents of iron and copper in the basal diet are very high from 19 to 33 weeks, the treatment C,D,E of this phase are basal diet plus 300%,400%,500%NRC minus content of trace elements in basal diet separately). Parameters comprised ADG, FI and FE and apparent metabolism of crude protein, energy and trace elements. The main results are showed as follows: 1. The performance on growing: â‘ The experiment showed average daily gain that Treatment A was significantly higher than Treatment B, C, E (P<0.05); ratio of feed to weight of Treatment A was significantly lower than Treatment D (P<0.05) during the 1-6 weeks old. â‘¡The next phase all these observation datum were not significant. â‘¢During the 13-18weeks old, terminal weight of Treatment A were increased by 3.13% than Treatment B, weight yield were increased by 6.74% than Treatment C, ratio of feed to weight were reduced by 7.24% relative to Treatment C. â‘£The next phase, ratio of laying of Treatment A was significantly lower than other Treatments (P<0.01). Daily egg yield of Treatment C was significantly higher than Treatment A (P<0.05). Ratio of feed to egg of Treatment A was increased by 4.18% than Treatment C. The content of cholesterol in the yolk of Treatment C was lower than others and the color of yolk was higher than others. Remnant of trace elements in the eggs: the content of copper in the eggs was increased while it was increased in the diet. However it is inclined to reduce to some extent. With the increasing of manganese in the diet, the content of manganese in the eggs were increased. It is inversely proportional for the content of zinc in the diet and in eggs. 2. Metabolism of nutrient:â‘ The younger hens'apparent metabolism of crude protein of the Treatment E and C were significantly higher than Treatment A (P<0.05). The content of trace elements didn't affect the apparent metabolism of energy of this phase (P>0.05). â‘¡The laying hens'apparent metabolism of energy of the Treatment B,C and D were increased by 9.5%,9.2%,9.3% than Treatment E (P<0.01), but weren't significant than Treatment A (P>0.05). The content of trace elements didn't affect the apparent metabolism of crude protein (P>0.05). 3. Utilization of trace elements: â‘ The contents of copper, zinc and manganese in the hens'excreta were significantly correlative. â‘¡Apparent metabolism of trace elements: copper>iron>zinc>manganese is for the younger hens; and the laying hens is iron>zinc>copper>manganese. Considering all parameters, the diets of 1-12-weeks old in Shannxi have enough copper, iron, zinc and manganese for growing hens, so it isn't necessarily to add them. The suggested adding project was basal diet plus 300% NRC minus contents of trace elements in basal diet after 13 weeks old.