| The purpose of this research was to assess the nutritive and feeding value of the dehulled double-low rapeseed meal (DLRM) for ruminants. Chemical analysis and determination for rumen degradability of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) were undertaken. Additionally, a feeding trail was carried out to assess the feeding value of dehulled DLRM for Macheng black goats. To evaluate the safety of dehulled DLRM and the degradability of glucosinolates (GL) in ruminant, oxazolidine (OZT) and isothiocyanate (ITC)were measured in rumen liquid and blood. The results were as follows.The CP of dehulled DLRM reached to 41.42%, up 11.00 % from that of DLRM. Its NDF decreased by 43.31% to 21.68%. Nitrogen in NDF decreased by 69.52% to 0.96%. The value of protein solubility, GL and the proportion of amino acids in dehulled DLRM and DLRM were little influenced by dehulling treatment. Dehulling treatment for DLRM increased the percentage of CP and decreased the NDF.The degradability of DM, CP, and NDF were measured with nylon bag technique. The results showed that the treatment of dehulling increased the rumen degradability of DM and NDF significantly. The DM of dehulled DLRM and DLRM degradability were 64. 35 ±0. 6% Vs 58. 02 ± 2. 8% (P<0. 05) and the degradability of NDF were 52. 33 ±1. 8% Vs 47. 28 ± 1. 0% (P<0. 05 ). The degradability of CP of dehulled DLRM and DLRM had no significant difference (P>0.05). These results indicated that more organic matter were degraded, and organizisms in rumen obtained more energy to meet the requiments of the high-level microbe to synthesize microbial protein. Then the energy and nitrogen of the synthesized protein were balanced in rumen during lactating or growing-finishing periods. Meanwhile, CP degradability did not increase significantly, so protein wasn't degraded overfull in rumen, and didn't decrease the amount of absorbable protein in intestine.A 40-day feeding trial was conducted to assess the feeding value of dehulled DLRM for Macheng black goats (3 months old).Two replications with five goats at each group. Three diets which dehulled DLRM replaced diets protein (20%, 40%, and 60%) and the control diets which main protein contributor was soybean meal were fed to goats. Goats fed control diet had greater (P<0.05) average food intake than three trail groups, and it had no significant difference between in trail groups (P>0.05). Average daily gains was decreased (P<0.05) in goats fed 60% replaced group, and it had no significant difference between in control group and other two trail groups. The 40% replaced group had the greaest in feed conversion. It was greater (P<0.05) than the 20% replaced group, and was much greater (P<0.01) than the 60% replaced group. These results indicated that 18.2% was proper ratio for dehulled DLRM add into the diets to Macheng black goat (4months old), and the dehulled DLRM could replace the soybean in ruminant diets and obtained the good performance as a good protein resource.Four goats fitted with ruminal cannulas were used in this experiment. Rumen liquid and blood in 0.5h, lh, 2h, and 4h were collected after 200g, 300g, 400g rapeseed meal were put into rumen through the ruminal cannulas respectively, then the OZT and ITC in rumen liquid and blood were analyzed. The results indicated that GL, OZT, and ITC could be degraded in rumen. Moreover degradation of OZT and ITC became quickly as the concentration of GL increased. A comparison between the concentration of OZT and ITC in blood showed that OZT and ITC could be absorbed in intestine but at a low speed and amount. Eventually 400g dehulled DLRM was put into rumen through the ruminal cannulas, and OZT and ITC weren't detected in rumen liquid and blood. It proved thatdehulled DLRM was safe for feeding to ruminants. |
PDF Full Text Request