| This experiment was codueted to study the effects of Trifolium pratense L. cv.'Minshan'isoflavone on production performance of Roman laying hens, egg quality, bone metabolism, blood serum profiles, internal organs index, and digestion and utilization of nutrients during the late period of laying. Totally 450 Roman layers with 50 weeks in age, close weights and in healthy were divided complete randomly into five groups, each with six replications containing 15 layers. Group 1 was fed with basic diet(BD) which was corn-soy bean -mixed meal. Diets offered to group 2, 3 and 4 were added Trifolium pratense L. cv.'Minshan'isoflavone of 5, 10, 20mg/kg into BD respectively. For comparison, the diet of group 5 was added 20mg/kg soy isflavone into BD. The feeding trial lasted totally 12 weeks including two weeks pretrial. At the end of the trial, one layer of each group was randomly selected for digestive and metabolic trial. The results show that: (1)No significant effects of adding Trifolium pratense L.cv.'Minshan'isoflavone were observed on the performance and eggshell quality for later laying period hens (P>0.05),but there was a tendency that eggshell strenth was lower for group 5(P=0.150). (2) Spleen index for group 4 was higher than that for group 1 , 3 (P<0. 05), and group 5(P=0. 15). (3) Content of tibia ash from group 4 was higher than that from group 1 and 2(P<0.05), the contents for group 3 and 5 trended to be higher than that for group 2(P=0.140,P=0.152). (4)Calcium level in serum was higher for group 5 than for group 1,2,3; the contents for group 4 trended to be higher han that for group1 (P=0.187),there were no significant defferences among all groups on levels of phosphorus(P) , alkaline phosphatase (AKP),superoxide dismutase (SOD) and malondialdehyde (MDA) in serum (P>0.05, but a tendency of increased calcium content in serum for all the groups can be seen(P=0.091). (5) Serum thyroxine (T4) content in group 4 was higher than those for group1(P<0.05) and group 2, 3(P=0.150,P=0.20), the content tended to be higher for group 5 than that from group 1 ( P=0.074 ) too; no deffers among all groups were found on levels of triiodothyronine(T3), estradiol (E2) and progesterone( P4) in serum (P>0.05). (6)there were no deffers among all treatments on total utilizations and retentions for nitregen and calcium (P>0.05), and calcium utilization and retention trended to be higher for group 2, 5(P=0.164,P=0.213,P =0.236, P =0.238); no increasing of phosphorus utilization by adding Trifolium pratense. Minshan isflavone was obseaved compared to group 1, and total utilization of phosphotus for group 5 of adding soy isoflavone was lower than that from group 3(P<0.05) and those for group 1, 4 (P=0.137,P=0.067), phosphorus retention was lower for group 5 than for group 4 and for 1, 3 (P=0.099,P=0.062), the retantion was higher for group 4 than that for 2 (P=0.101). The above indicated that no effects were seen by adding 0～20mg/kg of Trifolium pratense.Minshan isflavone on performance and egg quality, but levels of serum calcium and tibia ash in were raised as adding the isoflavone, calcium utilization was im proved to some extent as adding 5mg/kg of the isoflavone, but phosphorus utilization was no enhgnced by all level of adding the isoflavone, spleen index was increased as adding 20mg/kg of the isoflavone. |
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