TAIMOUR TANHA1, EHSAN EHSAN MAHJOBI2, ALI ALI3
1University of Paiamnoor Tehran, Animal Science, Iran
2University of Zanjan, Animal Science, Iran
3University of Paiamnoor Tehran, Agronomy, Iran
This study was conducted to test the simplicity of treating wheat straw with urea. Wheat straw was prepared in two physical forms including chopped straw (ChS) and baled form (BS). then it was sprayed with urea mixed water in amount of 5% urea and 100 liters of water per 100kg of straw (DM basis). After 4 weeks the treated straw as well as initial straw (IS) were sampled for in vitro measurements. The in vitro digestibility was determined for DM and OM. In sacco degradability was measured, using of 3 fistulated male cows. Results indicated that treatment significantly (p < 0.05) increased the DM and OM digestibility of the straw. The degradability of DM in 8, 16, 24 and 72 h post incubation was significantly (p < 0.05) higher in treated straw than the IS. The gas test method was used to measure the gas production of the samples. The treated straw showed significantly (p < 0.05) higher amount of gas production after 2, 4, 6, 8, 12 and 24 h of incubation as the other samples.
In a feeding trial, 3 diets containing 40% of IS, ChS or BS, respectively, were fed to Holstein male calves (6 head per diet) for 4 months. During this trial DM intake and daily gain were recorded and in vivo DM digestibility of the diets was measured. Results showed that the DM intake and average daily gain were significant (p < 0.05) different among the diets, but no significantly differences was observed for the DM digestibility of the diets. Economic estimation showed that the feed cost per kg of live weight gain was 13104 Rial for the normal straw diet while these costs for the baled treated straw diet amount 12194 Rial.
Keywords: Baled straw, chopped straw, degradability, Wheat straw