| In this experiment,nutritional value of green sweet sorghum stalks was evaluated first,then studied the substitution effect of green sweet sorghum stalks for diet on the growth performance,carcass yields and meat quality in geese to explore the appropriate ratio of substitution and to provide the scientific basis for the better use of green sweet sorghum stalks in geese.Trial 1: Ten 60-week-old healthy male Sichuan White geese with similar body weight were randomly divided into 10 replicates and 1 goose per replicate.The method of provided diet ad libitum was used in this metabolism experiment to evaluate the nutritional value of green sweet sorghum.The results showed as follows: 1)gross energy and the contents of crude protein,ether extract,crude fiber,neutral detergent fiber,acid detergent fiber,total phosphorus,calcium,nitrogen free extract of green sweet sorghum(air-dry basis)were 17.58 MJ·kg-1,11.79%,2.35%,34.13%,63.63%,37.90%,0.31%,0.41%,38.54%,respectively.The content of total amino acids of green sweet sorghum(air-dry basis)was up to 9.81%,and the content of majority amino acids was more than 0.50%,the content of aspartate,glutamic,alanine,leucine,phenylalanine,lysine was 1.41%,1.15%,0.70%,0.85%,0.71%,0.64%,respectively.2)The apparent metabolizable energy of green sweet sorghum was 10.69 MJ·kg-1;the utilization of crude protein was 62.57%;utilization of amino acids of green sweet sorghum was relatively high,utilization of cystine,lysine,aspartic,histidine was 86.11%,80.46%,79.97% and 79.95%,respectively.Trial 2: 360 28-day-old Sichuan White geese(male and female in half)with an initial average body weight of 1.11±0.008 kg were randomly allocated to 6 treatments(control group,experimental groups I-V)containing 6 replicates with 10 birds per pen.The birds in control group were provided the basal diet ad libitum without the green sweet sorghum stalks;the birds in groups I-V were fed 96%,92%,88%,84% and 80% of basal diet in control group,respectively,and green sweet sorghum stalks were provided ad libitum.The experiment last until 70 days of age.The results showed that: 1)The final body weight and average daily gain in control group was not different from those in groups I and II(P>0.05),the average daily gain in control group and group I were higher than those in groups III,IV and V(P<0.05).And the metabolizable energy average daily intake in experimental groups were all higher than those in control group(P<0.05).2)No difference was observed in dressing percentage,breast muscle percentage,and leg muscle percentage across the six treatment groups(P>0.05);compared with control group,abdominal fat yield in groups I-V and skin+subcutaneous fat yield in groups I,IV and V were significantly decreased(P<0.05),the gizzard index in groups I-V was significantly higher than that in control group(P<0.05).3)No difference was observed in the content of crude protein,intramuscular fat and inosine monophosphate in breast muscle across the six treatment groups(P>0.05);the content of total amino acids,essential amino acids,delicious amino acids,saturated fatty acids and unsaturated fatty acids of the breast muscle in groups I-III were not different from those in control group(P>0.05).Collectively,it seems to be feasible to replace partial diet with green sweet sorghum stalks for geese,and 4-8% of diet can be replaced with green sweet sorghum stalks without negative effects on growth performance,carcass yields and meat quality in Sichuan White geese from 4 to 10 weeks of age. |
