【作者】 杨峰；

【导师】 印遇龙；

【作者基本信息】 华中农业大学 ， 动物营养与饲料科学， 2008， 硕士

【摘要】 目前,氨基酸营养研究大多数关注于理想氨基酸模式本身,而在保证理想氨基酸模式的情况下,确定适宜赖氨酸水平的研究尚不多见。本论文通过单因子试验设计,以酶解酪蛋白法测定的饲料原料可消化氨基酸含量为基础,研究生长猪（40～70kg）和肥育猪（70～100kg）适宜的可消化赖氨酸（Digestible lysine,DLys）水平。试验一:研究40～70kg生长猪DLys需要量。选用80头体重为40 kg左右的杜×（长×大）三元杂交猪,随机分为5个组,每组4个重复,每重复4头猪（公母各半）。各组分别饲喂DLys水平为0.59%、0.67%、0.75%、0.83%和0.91%的等能（14.21MJ/kg）、等氨基酸模式的玉米-豆粕型日粮,日粮粗蛋白水平分别为11.8%、13.4%、15.0%、16.6%和18.2%。结果表明,生长猪的平均日增重,料重比均随饲粮DLys水平的增加呈显著的二次曲线变化。当DLys水平分别为0.78%和0.80%时,平均日增重和料重比分别达到极大值（791.42g/d）和极小值（2.92）。当DLys水平为0.75%时,谷草转氨酶活性最高（P＜0.05）;料重比最低（P＜0.05）;血清尿素氮浓度最低（P＜0.01）;T₃、胰岛素、生长素和类胰岛素生长因子浓度最高（P＜0.05）。屠宰率（P＜0.05）、瘦肉率（P＞0.05）、眼肌面积（P＜0.01）、平均背膘厚（P＜0.01）和第10肋膘厚（P＜0.01）随DLys水平的升高,先升后降。不同DLys水平影响不同肌肉部位（除股二头肌外）的化学组成（除水分和灰分含量）。上述结果提示,40～70kg生长猪,适宜DLys水平为0.78%。试验二:研究70～100kg肥育猪DLys需要量。选用60头体重70 kg左右的杜×（长×大）三元杂交猪,随机分为5组,每组3个重复,每重复4头猪（公母各半）。各组分别饲喂DLys水平为0.47%、0.53%、0.59%、0.64%和0.71%的等能（13.60MJ/kg）、等氨基酸模式的玉米-豆粕-麦麸型日粮,日粮CP水平分别为10.46%、11.78%、13.12%、14.40%和15.78%。结果表明,肥育猪的平均日增重,料重比均随饲粮DLys水平的增加呈显著的二次曲线变化。当DLys水平为0.61%时,平均日增重和料肉比分别达到极大值（778.37g/d）和极小值（3.24）。无脂瘦肉生长指数随DLys水平的升高,先升后降。血清尿素氮浓度随DLys水平的升高而显著上升（P＜0.05）;胰岛素（P＞0.05）、生长激素（P＜0.05）、类胰岛素生长因子（P＜0.05）浓度随DLys水平升高,先升后降,当DLys水平为0.59%时,达到最大值。随DLys水平升高,眼肌面积增大（P＜0.05）,第10肋膘厚（P＞0.05）和平均背膘厚变?P＞0.05)。不同DLys水平影响不同肌肉部位（除股二头肌和股四头肌外）的化学组成（除水分和灰分含量）。上述结果提示,70～100 kg肥育猪,适宜DLys水平为0.61%。更多还原

【Abstract】 Currently, most of amino acid nutrition research focused on the ideal amino acid pattern, while the study on the appropriate dietary lysine level under ideal amino acid pattern was very limited. This single factorial designed experiment was conducted to establish the appropriate dietary digestible lysine levels of growing pigs (40～70kg) and finishing pigs (70～100kg). The true digestibility of lysine in feedstuff was estimated by enzyme-hydrolyzed casein.The first experiment was conducted to establish the proper digestible lysine levels for 40～70kg growing pigs. A total of eighty Duroc×(Landrace×Yorkshire) growing pigs with 40 kg of body weight were randomly allocated into five groups(4 replications per group,4 pigs per replication, half male and half female) .The digestible lysine concentrations in five diets were 0.59%, 0.67%, 0.75%, 0.83%, 0.91%. The experimental diets were based on corn-soybean meal with isoenergy (14.21MJ/kg) and same amino acids pattern. The crude protein concentrations in the diets were 11.80%、13.40%、15.00%、16.60%、18.20%. The results showed that average daily gain and feed/gain changed with the elevated digestible lysine levels quadratically. The established digestible lysine requirement of growing pigs was not the same when using different evaluation index. The optimal digestible lysine level was 0.78% for highest average daily gain (791.42g/d), but the optimal digestible lysine level was 0.80% for lowest feed/gain (2.92). The glutamic oxaloacetic transaminase activity were maximized (P<0.05), the feed/gain was minimal (P<0.05), the serum urea nitrogen concentration was minimal (P<0.01) at 0.75% of digestible lysine levels compared with the other groups. The concentrations of T3, insulin, growth hormone and insulin-like growth factor-I at 0.75% of digestible lysine levels were higher (P< 0.05) compared with the other groups. The dressing percentage (P<0.05), lean meat percentage (P>0.05), longissimus muscle area (P<0.01), average backfat thickness (P<0.01), tenth rib fat depth (P<0.01) of barrows first increased and then decreased (P<0.05) with dietary digestible lysine levels, and reached the maximum value in 0.75% digestible lysine treatment group. The carcass components (except for water and lipid content) of the muscle samples (except for the quadriceps muscle) were influenced (P<0.05) by the digestible lysine level. These findings suggest that the optimal digestible lysine levels in growing pigs with 40～70 kg of body weight were 0.78%The second experiment was conducted to establish the proper digestible lysine levels for 70～100kg finishing pigs. A total of sixty Duroc×(Landrace×Yorkshire) finishing pigs with 70 kg of body weight were randomly allocated into five groups (3 replications per group, 4 pigs per replication, half male and half female) .The digestible lysine concentrations in five diets were 0.47%, 0.53%, 0.59%, 0.64%, 0.71%. The experimental diets were based on corn-soybean-wheat bran meal with isoenergy (13.60MJ/kg) and same amino acids pattern. The crude protein concentrations in the diets were 10.46%, 11.78%, 13.12%, 14.40% and 15.78%. The results showed that average daily gain and feed/gain changed with the elevated digestible lysine levels quadratically. The established digestible lysine requirement of fishing pigs was not the same when using different evaluation index. The optimal digestible lysine level was 0.61% for hightest average daily gain (778.37g/d) and lowest feed/gain (3.24). Fat free lean index was highest at 0.59% digestible lysine group (P<0.01). The concentration of serum urea nitrogen increased with increasing digestible lysine levels(P<0.05); The concentrations of grow hormone (P<0.05) and insulin-like growth factor-I (P<0.05) first increased and then decreased with dietary digestible lysine levels, and reached the maximum value in 0.59% digestible lysine level. The longissimus muscle area (P<0.05) increased with increasing digestible lysine levels, while tenth rib fat depth (P>0.05) and average backfat thickness (P>0.05) decreased. The carcass components (except for water and lipid content) of the muscle samples (except for the biceps femoris and quadriceps muscle) were influenced (P< 0.05) by the digestible lysine levels. These findings suggest that the optimal digestible lysine levels in finishing pigs with 70～100 kg of body weight were 0.61%.更多还原