Evaluation of feeding value of nine unconventional roughages by gas production method in vitro
In order to evaluate the feeding value of nine unconventional roughage(salvia straw,astragalus stems and leaves,pepper stalk,tendril from wild rice shoots,cucumber vine,garlic root,garlic straw,strawberry seedlings,eggplant vine)and develop new feed resources,three 14-month-old healthy castrated Laoshan dairy goat rams with similar body weight([33.33±0.76]kg)were used as rumen fluid donors.The feed grading index(GI)was calculated by measuring the content of conventional nutrients of nine kinds of unconventional roughage.The rumen model was established in vitro,and the gas production,pH value,ammonia nitrogen(NH3-N)and microbial protein(MCP)content of fermentation solution were determined,and kinetic parameters of gas production,organic matter degradation rate(OMD),metabolizable energy(ME)and net energy(NEL)in vitro were calculated.Linear regression was used to analyze the correlation between OMD,ME and NEL and gas production in 24 h,respectively.The results showed that the contents of crude protein(CP),crude ash(Ash)and calcium(Ca)in the tendril from wild rice shoots were the highest,which were 21.80%,29.45%and 1.17%,respectively,and were significantly higher than those of the other eight unconventional roughage(P<0.05),while the contents of crude fiber(CF),neutral detergent fiber(NDF)and acid detergent fiber(ADF)were the lowest,which were 10.26%,31.80%,and 14.61%,respectively,and were significantly lower than those of the other eight unconventional roughage(P<0.05).The crude fat(EE)content(5.94%)of salvia straw was the highest(5.94%),followed by garlic root(5.74%),which were both significantly higher than that of the other seven unconventional roughage(P<0.05).The total phosphorus(TP)content of pepper stalk was the highest(1.10%),which was significantly higher than that of the other eight unconventional roughage(P<0.05).The NDF/CP of astragalus stems and leaves was lower(3.09),and the NDF/CP of pepper stalk was the highest(6.24).The tendril from wild rice shoots and the cucumber vine were special grade in the GI classification of dairy cows and goats.The cumulative gas production in 72 h from high to low was astragalus stems and leaves(26.0 mL)>garlic straw(21.3 mL)>garlic root(13.7 mL)>tendril from wild rice shoots(8.0 mL)>salvia straw(6.7 mL)>cucumber vine(4.7 mL)>strawberry seedlings(4.0 mL)=eggplant vine(4.0 mL)>pepper stalk(3.3 mL).The pH value ranged from 6.42 to 6.95.OMD,ME and NEL were positively correlated with gas production in 24 h,respectively.After in vitro fermentation for 72 h,the NH3-N content of garlic root was the highest(123.17 mg/L),which was significantly higher than that of the other eight unconventional roughage(P<0.05);the content of MCP in the stems and leaves of astragalus was the highest(8.29 mg/mL),followed by strawberry straw(8.00 mg/mL),tendril from wild rice shoots(6.93 mg/mL),and pepper stalk(4.38 mg/mL).The results indicated that all nine unconventional roughage could be used as regional unconventional roughage in Shandong Province,among which the nutritional value and availability of tendril from wild rice shoots,astragalus stems and leaves,garlic straw and garlic root were better.
in vitro gas productionunconventional roughagedairy goatsrumen fluidfeeding value
万方数据
维普
