A study on the effects of different ruminally degradable to ruminallyundegradable protein ratio on performance and nutrient digestibility in fattening male lambs

Authors
M.A. Ramezani
Y. Chashnidel
A TeimoriYansari
S.A Moftakharzadeh
H NabipourAfrouzi
10.22077/jlr.2015.344
Abstract
This study was conducted toevaluate the effects of different ruminally degradable to ruminallyundegradable protein ratio on performance and nutrients digestibility in fattening male lambs. In the first experiment, degradability of dry matter and crude protein of fish meal, soybean meal and concentrate in diets was estimated in different incubation times (0, 4, 8, 12 and 24 h) with two fistulatedsheep of Zel breed which were fed to their maintenance requirement. The effective degradability of dry matter and crude protein in fish meal was significantly lower than in soybean meal (P<0.05). The effect of three levels of varying ruminally degradable to ruminallyundegradable protein ratio 60:40 (A), 65:35 (B) and 70:30(C) on performance and nutrientdigestibility in Zel-Sangssari male lambs was investigated. For these, Twenty four lambs aged 6-7 months with an initial live weight of 29±2.5 kg were used. The animals were fed for a period of 95 days. The level of metabolizable energy was similar in all the rations, 10.5 MJ/KgDM. Apparent nutrients digestibility was notaffected by the treatments.Urine pHsignificantly decreased byreduction of RUP to RDP ratio (P<0.05).The pH of rumen fluid and fecal were not affected by experimental treatments.The results showed that the ration which contained 1.86(B) RDP to RUP ratio was economically viable.
Keywords
RUP:RDP
Performance
Nutrients digestibility
Male lamb