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1.
试验选用80头体重为40 kg左右的杜×(长×大)三元杂交猪,随机分为5个处理,每处理公、母各半,分别饲喂可消化赖氨酸水平为0.59%、0.67%、0.75%、0.83%、0.91%的等能(14.21 M J/kg)、等氨基酸模式的玉米-豆粕型日粮。通过对生产性能和血液生化指标的研究,来确定生长肥育猪可消化赖氨酸需要量。结果表明,当可消化赖氨酸水平为0.75%时,平均日增重、谷草转氨酶活性最高,差异显著(P<0.05);料重比最低,差异显著(P<0.05);血清尿素氮浓度最低,差异极显著(P<0.01)。可消化赖氨酸的不同水平对血清中甘油三酯、总蛋白、白蛋白浓度以及谷丙转氨酶活性没有影响,差异均不显著(P>0.05)。上述结果提示,40~70 kg生长猪的可消化赖氨酸和总赖氨酸需求参数分别为0.75%、0.84%。  相似文献   

2.
试验旨在研究低蛋白日粮添加不同种类合成氨基酸对培育品种鲁莱猪生长猪氮平衡及氨基酸消化率的影响。采用4×4拉丁方设计,选用平均体重为(35.00±1.05)kg的健康鲁莱阉公猪4头,回肠末端手术安装简单T型瘘管。对照组饲喂高蛋白质水平(粗蛋白为16.50%,可消化赖氨酸为0.78%)日粮,3个试验组分别饲喂添加赖氨酸+苏氨酸+蛋氨酸、赖氨酸+苏氨酸和赖氨酸+蛋氨酸的低蛋白质水平(粗蛋白为13.50%,可消化赖氨酸为0.78%)日粮。结果表明:低蛋白添加3种合成氨基酸组粪氮排出量显著低于其他各组(P0.05),尿氮排出量显著低于高蛋白组(P0.05),与其他低蛋白组相比差异不显著(P0.05),氮表观消化率、氮沉积各组间差异均不显著(P0.05);低蛋白日粮添加3种合成氨基酸组总氨基酸消化率显著高于其他各组(P0.05)。采用低蛋白(粗蛋白为13.50%)并同时添加适量合成氨基酸日粮饲喂鲁莱猪,可以显著降低粪氮和尿氮的排出,对氮利用率和回肠末端总氨基酸消化率影响不显著。  相似文献   

3.
张桂杰  鲁宁  谯仕彦 《动物营养学报》2012,24(12):2326-2334
本文旨在研究低蛋白质平衡氨基酸饲粮对生长猪生长性能、胴体品质、肌肉品质和肠道健康的影响。试验采用单因素完全随机设计,选择初始体重为(17.02±1.40)kg的健康"杜×长×大"三元杂交去势公猪16头,随机分为正常蛋白质组(饲粮粗蛋白质水平为18%,标准回肠可消化赖氨酸含量为0.93%)和低蛋白质组(饲粮粗蛋白质水平为14%,标准回肠可消化赖氨酸含量为1.03%)2个组,每组8个重复,每个重复1头猪。试验期共39 d。在试验结束当天对生长猪进行称重、结料和采血,并屠宰所有生长猪用于测定胴体品质、肌肉品质、肠道形态及消化酶活性。结果表明:与正常蛋白质饲粮相比,低蛋白质平衡氨基酸饲粮显著提高了生长猪背最长肌的亮度值(P<0.01)和黄度值(P<0.05);对小肠各肠段的绒毛形态无显著影响(P>0.05),但有提高空肠绒毛高度和隐窝深度比值的趋势(P=0.09);对生长猪的生长性能、胴体品质和肌肉品质无显著影响(P>0.05)。本试验结果表明,与正常蛋白质饲粮相比,标准回肠可消化赖氨酸含量为1.03%的低蛋白质平衡氨基酸饲粮能够维持生长猪正常生长性能,并有改善肠道健康状况的趋势。  相似文献   

4.
本试验旨在研究低氮日粮条件下20~75 kg生长猪(20~50、50~75 kg 2个阶段)标准回肠可消化异亮氨酸(SID Ile)与标准回肠可消化赖氨酸(SID Lys)的适宜比例。试验一选取108头体重为(21.48±0.50)kg的杜×长×大生长猪,随机分为3个处理组,即对照组(高氮日粮组)、低氮日粮高SID Lys组和低氮日粮低SID Lys组,每个处理6个重复,每个重复6头猪,研究SID Lys的限制性水平。试验二以试验一的限制性SID Lys水平设计日粮,选取180头体重为(21.46±0.48)kg的杜×长×大生长猪,随机分为5个处理组,每个处理6个重复,每个重复6头猪。2个体重阶段日粮SID Ile:SID Lys设为5个不同水平,以研究其适宜比例。结果表明:试验一中低氮日粮低SID Lys组猪的耗料增重比(F:G)显著高于对照组和低氮日粮高SID Lys组(P0.05);在试验二中,当日粮SID Ile∶SID Lys分别为0.48和0.56时,20~50、50~75 kg生长猪获得最大的日增重(ADG)和最佳的F:G。综上所述,20~50、50~75 kg生长猪日粮粗蛋白(CP)水平分别为14%和12.4%时,其适宜的日粮SID Ile:SID Lys别为0.48和0.56。  相似文献   

5.
本试验用70头、体重为15.5kg的长×大×杜三元杂交猪,随机分为7组,研究在不同的赖氨酸水平下添加高浓缩酶制剂对生长猪生产性能的影响,探讨添加酶制剂提高蛋白质、氨基酸消化率基础上能否适当降低赖氨酸水平而不影响生产成绩,从而节约合成赖氨酸添加量。基础日粮配方参照美国NRC生长猪10～20kg和20～50kg两阶段饲养标准,确定介于两阶段间基础日粮的能量、蛋白质水平,赖氨酸水平控制为0.68%,对照组喂给基础日粮。各试验组添加赖氨酸的量依次为(%):0.25、0.20、0.15、0.10、0.05、0.00,相应添加浓缩酶的量依次为(g/100kg):0.00、10.00、10.00、10.00、10.00、10.00。结果表明:30kg前猪的生长速度和日粮的赖氨酸水平呈正相关,随赖氨酸水平提高,生长速度持续提高;适当较低水平的赖氨酸添加和酶结合,比单一添加更高水平的赖氨酸效果更好;在营养需要的基础上,生长猪前期使用浓缩酶制剂可以适当降低赖氨酸的添加量,期望较快日增重(600g/天)时,赖氨酸水平可降低10%,约可节约25%～40%的合成赖氨酸添加量;较低日增重(近500g/天)时,约可节约50%合成赖氨酸添加量。  相似文献   

6.
选取120头22kg左右的杜×长×大三元杂交健康生长猪,随机分成5个处理,每个处理6个重复,每个重复4头,探讨低蛋白不同净能水平(10.54、10.28、9.96、9.63、9.45MJ/kg)日粮对生长猪生长性能和养分消化率的影响。结果表明:日粮蛋白降低4个百分点,不同净能处理间的采食量和饲料转化率没有显著差异(P>0.05),日增重随净能的下降呈线性增加,以9.45MJ/kg组最高(P<0.05);养分消化率中,除钙的消化率外,其余养分的消化率均随净能水平的增加而线性下降(P<0.05)。降低净能水平后,血清赖氨酸含量线性增加(P=0.03),对其余氨基酸影响差异不显著(P>0.05);对血清尿素氮含量的影响不显著(P>0.05)。由此可得出,低蛋白日粮中净能水平的降低并不影响生长猪的生长性能和养分消化率。  相似文献   

7.
本研究旨在探讨饲粮粗蛋白质水平和氨基酸平衡性对肥育猪生长性能、胴体性状和肉品质的影响。选取平均初始体重为(69.3±3.6)kg的杜×长×大去势公猪125头,随机分为5个组,每组5个重复,每个重复5头猪。5个组分别为:高蛋白质饲粮组(粗蛋白质水平约为14%)、低蛋白质(粗蛋白质水平约为10%)-氨基酸平衡饲粮组以及3个低蛋白质(粗蛋白质水平约为10%)-氨基酸不平衡饲粮组(在低蛋白质-氨基酸平衡饲粮组的基础上分别将含硫氨基酸、苏氨酸和色氨酸与赖氨酸的比例降低10%)。所有饲粮的标准回肠可消化赖氨酸水平均设置为0.71%,低蛋白质-氨基酸平衡饲粮组中标准回肠可消化苏氨酸、标准回肠可消化含硫氨基酸和标准回肠可消化色氨酸与标准回肠可消化赖氨酸的比值分别为0.67、0.60和0.20。试验期为28 d。结果显示:与低蛋白质-氨基酸平衡饲粮组相比,高蛋白质饲粮组肥育猪的平均日采食量有下降趋势(P=0.05),低蛋白质-低色氨酸饲粮组肥育猪平均日增重和平均日采食量均显著下降(P0.05),低蛋白质-低苏氨酸饲粮组和低蛋白质-低含硫氨基酸饲粮组肥育猪的生长性能无显著差异(P0.05)。饲粮粗蛋白质水平和氨基酸平衡性对肥育猪的胴体性状和肉品质无显著影响(P0.05)。因此,低蛋白质-氨基酸平衡饲粮不影响育肥猪生长性能、胴体性状和肉品质,分别降低10%标准回肠可消化含硫氨基酸、标准回肠可消化色氨酸和标准回肠可消化苏氨酸对肥育猪胴体性状和肉品质无显著影响,但降低10%标准回肠可消化色氨酸显著降低肥育猪平均日增重和平均日采食量。  相似文献   

8.
35～60kg生长猪可消化氨基酸需要量研究   总被引：6，自引：0，他引：6  
本试验是按照理想蛋白质(IPP)的原理 ,研究35～60kg 生长猪DAA需要量 ,为我国猪饲养标准的修订积累资料。选用大白×长白杂交猪60头 ,试验采用单因子试验设计 ,随机分为5个处理 ,每个处理4个重复 ,每个重复3头猪(饲养于一圈)。5个处理饲粮可消化赖氨酸(DLys)水平( %)分别为0.33、0.46、0.58、0.71和0.83 ,相应的CP( %)分别为8.61、11.33、14.06、16.67、19.29。饲粮等能(13.64MJDE/kg) ,等氨基酸模式 ,其可消化氨基酸模式Lys:SAA:Thr:Trp 为100 :60 :61 :18。试猪始重35.2±3.58kg,末重59.57±6.37kg。试验除考察生产性能外 ,在试验…  相似文献   

9.
本试验旨在研究饲粮消化能水平和可消化赖氨酸与消化能比值对长白×荣昌(长荣)杂交生长猪生长性能及胴体品质的影响。试验选用144头初始体重约为27.05 kg的健康长荣杂交猪,按体重相近、公母各占1/2的原则随机分为6个处理,每个处理6个重复,每个重复4头猪。采用2×3因子设计,即饲粮消化能水平分别为13.00和14.50 MJ/kg,饲粮可消化赖氨酸与消化能比值分别为0.50、0.60和0.70 g/MJ。分别测定生长猪的生长性能、胴体性状、肉品质和血清生化指标。结果表明:饲粮消化能水平升高,显著提高生长猪平均日增重、胴体重、屠宰率和血清尿素氮含量(P<0.05),显著降低平均日采食量、料重比和滴水损失(P<0.05),且有提高血清低密度脂蛋白胆固醇含量(P=0.07)及降低血清甘油三酯含量(P=0.06)的趋势。随着饲粮可消化赖氨酸与消化能比值的增加,生长猪眼肌面积、血清尿素氮和高密度脂蛋白胆固醇含量显著增加(P<0.05),肌内脂肪含量显著降低(P<0.05),且料重比有提高的趋势(P=0.05),平均背膘厚呈降低的趋势(P=0.09)。饲粮消化能水平和可消化赖氨酸与消化能比值对生长猪胴体瘦肉率、血清尿素氮、肌肉pH45 min和pH24 h的影响存在显著交互效应(P<0.05)。以上结果表明,在保持氨基酸模式一致条件下,饲粮消化能和可消化赖氨酸水平对长荣生长猪的生长性能和胴体品质影响显著,综合评定可知,生长阶段的长荣猪最佳生长潜能和最优胴体品质所需的饲粮消化能和可消化赖氨酸水平分别为14.50 MJ/kg和0.73%。  相似文献   

10.
试验选用70头、体重为15kg左右的长×大×杜三元杂交猪,随机分为7组,研究在不同的赖氨酸水平下添加高浓缩酶制剂对生长猪生产性能的影响,探讨添加酶制剂提高蛋白质、氨基酸消化率基础上能否适当降低赖氨酸水平而不影响生产成绩,从而节约合成赖氨酸添加量。基础日粮配方参照美国NRC生长猪10～20kg和20～50kg两阶段饲养标准,确定两阶段基础日粮的能量、蛋白质水平,赖氨酸水平控制为0.68%,对照组喂给基础日粮。各试验组添加赖氨酸的量依次为(%):0.25、0.20、0.15、0.10、0.05、0.00;相应的各试验组添加浓缩酶的量依次为(g/kg):0.00、0.1、0.1、0.1、0.1、0.1。结果表明:猪体重为30kg前的生长速度和日粮的赖氨酸水平呈正相关,随赖氨酸水平提高,生长速度持续提高;适当较低水平的赖氨酸和酶结合添加,比单一添加高水平的赖氨酸效果更好;在营养需要的基础上,生长猪前期使用浓缩酶制剂可以适当降低赖氨酸的添加量,期望较高日增重(600g/d)时,赖氨酸水平可降低10%,约可节约25%～40%的合成赖氨酸添加量;较低日增重(近500g/d)时,约可节约50%合成赖氨酸添加量。  相似文献   

11.
This study was conducted to determine the effect of addition of essential amino acids (EAA) to low-protein diets on N balance in barrows. Thirty barrows (Duroc × Yorkshire) with an initial BW of 36 kg were fed 5 corn- and soybean meal-based diets containing 13.6 to 18.2% crude protein (CP) for 10 d in a randomized complete block design. The 18.2% CP diet was formulated without addition of EAA (Lys, Met or Thr). The other diets contained 13.6 to 16.5% CP and were supplemented with EAA to provide 0.83% true digestible lysine equal to that in the 18.2% CP diet. Fecal, urinary, and total N excretion as well as N retention (g/d) decreased with decreasing dietary CP level (P < 0.01). The apparent digestibility of N was almost the same for the 18.2 and 16.5 CP diets, but the value was 2% higher (P = 0.07) than that for the 13.6% CP diet. These findings indicate that, compared with the 18.2% CP diets, supplementation with three EAA to the lowest-protein diets (13.6 CP) is inadequate for maximum intestinal protein digestion, amino acid absorption, or tissue protein deposition in growing barrows.  相似文献   

12.
This study was conducted to determine the effect of supplementation with Lys, Met, Thr to low-protein diets on growth performance and metabolic responses in growing barrows. Seventy crossbred barrows (Duroc × Yorkshine), with an average initial body weight of 16 kg, were fed diets containing five crude protein (CP) levels (18.2, 16.5, 15.5, 14.5, and 13.6%) and 0.83% true ileal digestible lysine. On d 17 of the trial, all pigs were fitted with an indwelling jugular catheter for blood collection. On d 18 and 53, blood samples were obtained at 4 h post feeding. Reducing dietary CP concentration linearly decreased (P < 0.05) ADG, ADFI, feed efficiency, longissimus muscle area (LMA), and plasma concentrations of urea N and protein, while increasing backfat thickness linearly (P < 0.05). Pigs fed the 13.6% CP diet exhibited the poorest growth performance. On d 53, dietary CP affected plasma IGF-I (quadratic, P < 0.01) and leptin (linear, P < 0.01) concentrations. Plasma leptin levels were correlated positively with backfat thickness (r = 0.76, P < 0.05) and negatively with LMA (r = − 0.64, P < 0.01). There was a positive correlation between ADG and plasma IGF-I concentrations (r = 0.91, P < 0.05). Our results suggest that adequate provision of nonessential AA and all EAA is required for achieving maximum growth performance and reducing fat accretion in growing pigs fed low-CP diets.  相似文献   

13.
The effects of Ile and Val supplementation of a low-CP, corn-wheat-soybean meal-based piglet diet on growth performance, incidence of diarrhea, and N balance were studied using 60 Landrace x Duroc male piglets in a 4-wk experiment. The 60 individually caged piglets were divided into 5 dietary treatments, each consisting of 12 piglets. Diet 1 was a positive control diet (20% CP); diet 2 was a low-CP negative control diet (17% CP); diets 3, 4, and 5 were low-CP diets to which Ile, Val, or the combination of Ile and Val were added, respectively. All diets were supplemented with Lys, Met, Thr, and Trp to provide the required concentrations of these AA according to the 1998 NRC. Average daily gain and ADFI were similar among pigs fed the positive control, Val-added, and the Val plus Ile-added diets. On wk-2 and wk-4, fecal score was greater (softer feces) in piglets fed the 20% CP level compared with the remaining treatments (P < 0.01). Nitrogen intake was decreased (P < 0.0001) in pigs fed diets containing low levels of CP compared with pigs fed the 20% CP diet. Fecal N excretion (g/d) was decreased (P < 0.05) in piglets fed low-CP diets at wk 1 and wk 4 of feeding, and in urine at wk 4 of feeding. Crude protein levels or AA supplementation had no effect on N retention efficiencies. These results indicate that the supplementation of Val alone, or in combination with Ile, to a low-CP piglet diet with adequate levels of Lys, Met, Thr, and Trp is necessary to achieve maximum performance in pigs consuming corn-wheat-soybean meal-based diets.  相似文献   

14.
Energy utilization of low-protein diets in growing pigs   总被引：8，自引：0，他引：8  
Three trials were conducted to measure the effects of reducing the dietary CP content on digestive and metabolic utilization of N and energy in growing pigs. Sixty barrows weighing about 65 kg were used. In Trial 1, four semisynthetic diets with CP content decreasing from 18.9 to 12.3% were formulated. In Trials 2 and 3, two diets with 17.4 and 13.9% CP were formulated using conventional ingredients. In the three trials, diets were supplemented with variable amounts of industrial AA in order to maintain a constant standardized digestible lysine/NE ratio (0.76 g/MJ) and ratios between essential AA relative to lysine of at least 60, 65, 20, 60, and 70% for methionine + cystine, threonine, tryptophan, isoleucine, and valine, respectively. In Trials 1 and 2, feed was given in four meals per day, whereas, in Trial 3, two feeding frequencies (two and seven meals per day) were compared. Five or six N and energy balance (indirect calorimetry) measurements were conducted for each treatment, and components of heat production were estimated. Results of Trial 3 showed no effect of meal frequency on either N or energy utilization. Reduction of dietary CP content had no effect on N retention or animal performance but markedly decreased N excretion (-40% in Trials 2 and 3, and -58% in Trial 1). In the three trials, the lower N excretion with low-CP diets was accompanied by a reduction in urinary energy loss equivalent to 3.5 kJ/g of decrease in protein intake. Data of the three trials indicated that heat production was lower when CP was reduced (-7 kJ/g decrease in protein intake). This lower heat production was attributed to a reduction of the thermic effect of feed, whereas heat production associated with physical activity and maintenance were not affected. Reduction of dietary CP was associated with higher energy gain, mainly as fat. But, this effect was no longer significant when data were adjusted for similar NE intakes. These results confirm the possibility of limiting N excretion, while maintaining a high level of performance, by reducing CP level in the feed with adequate AA supplementation. This study also confirms the superiority of the NE system (in comparison with DE or ME systems) for predicting performance and energy gain of pigs and controlling carcass adiposity, especially in situations of feeds with variable CP contents.  相似文献   

15.
Two studies were conducted to assess the effect of dietary protein reduction on N utilization, N excretion, and AA digestibility in growing pigs. The objective was to determine whether pigs fed diets with a reduced CP concentration could maintain the same N retention as pigs fed an adequate diet. The second objective was to test whether reducing dietary CP concentration decreases AA digestibility. In each study, six barrows were allotted to one of six dietary treatments in a Latin square design. Treatments consisted of four corn-soybean meal-based diets containing 15, 12, 9, and 6% CP, a casein-based diet containing 15% CP, and a protein-free diet. Crystalline AA were included in the 12, 9, and 6% CP diets. The indispensable:dispensable AA ratio was maintained at 45:55 with the addition of L-glutamic acid to the 9 and 6% CP diets. The casein-based and protein-free diets were used to determine endogenous total tract N and ileal AA losses. In the first study, total N losses and N absorbed decreased linearly (P < 0.001) as dietary CP concentration decreased from 15 to 6%. Both a linear (P < 0.001) and a quadratic (P < 0.05) decrease in N retention were found with decreasing dietary CP concentration. Nitrogen retained as a percentage of intake and absorbed increased (P < 0.001) as dietary CP concentration was reduced from 15 to 6%. In the second study, six barrows were surgically fitted with a T-cannula at the terminal ileum to determine ileal AA digestibility. For all dispensable and most indispensable AA, apparent and standardized ileal digestibility increased linearly (P 0.01, and for arginine, P < 0.05) as dietary CP concentration decreased. These results indicate that dietary CP concentration can be decreased from 15 to 12% with crystalline AA supplementation to meet an ideal AA profile without adversely affecting N retention, and that decreasing dietary CP concentration from 15 to 6% increases both dispensable and indispensable AA ileal digestibility.  相似文献   

16.
Two experiments were conducted to determine the lysine requirement of weaned pigs [Duroc × (Yorkshire × Landrace)] with an average initial BW of 7 kg and fed wheat–corn–soybean meal‐based diets. The experiments were conducted for 21 days during which piglets had free access to diets and water. Average daily gain (ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F) were determined on day 7, 14 and 21. Blood samples were collected on day 0 and 14 to determine plasma urea nitrogen (PUN) concentration. In experiment 1, 96 weaned pigs were housed four per pen and allocated to four dietary treatments with six replicates per treatment. The diets contained 0.99%, 1.23%, 1.51% and 1.81% standardized ileal digestible (SID) lysine, respectively, corrected analysed values. The rest of the AA were provided to meet the ideal AA ratio for protein accretion. Increasing dietary lysine content linearly increased (p < 0.05) ADG and G:F. In experiment 2, 90 piglets were housed three per pen and allocated to five dietary treatments with six replicates per treatment. The five diets contained 1.03%, 1.25%, 1.31%, 1.36% and 1.51% SID lysine, respectively, corrected analysed values. Increasing dietary lysine content linearly increased (p < 0.05) G:F, linearly decreased (p < 0.05) day‐14 PUN and quadratically (p < 0.05) increased ADG and ADFI. The ADG data from experiment 2 were subjected to linear and quadratic broken‐lines regression analyses, and the SID lysine requirement was determined to be 1.29% and 1.34% respectively. On average, optimal dietary SID lysine content for optimal growth of 7–16 kg weaned piglets fed wheat–corn–SBM‐based diets was estimated to be 1.32%; at this level, the ADG and ADFI were 444 and 560 g, respectively, thus representing an SID lysine requirement, expressed on daily intake basis as, 7.4 g/day or 16.76 mg/g gain.  相似文献   

17.
Two experiments were conducted to determine the effects of crude protein (CP) level in diets containing coarse wheat bran (CWB) with or without pharmacological levels of Zn (provided by zinc oxide: ZnO) on growth performance and fecal DM of nursery pigs. In experiment 1, 360 barrows (Line 200 × 400, DNA, Columbus, NE, initially 5.6 kg) were allotted to 1 of 6 dietary treatments from d 0 to 21 after weaning with 5 pigs per pen and 12 pens per treatment. Treatments included a positive control diet (21% CP) with 3,000 mg/kg Zn in phase 1 and 2,000 mg/kg in phase 2; negative control (21% CP) with 110 mg/kg added Zn, and 4 diets containing 4% CWB and 110 mg/kg added Zn formulated to contain 21%, 19.5%, 18%, or 16.5% CP. The 2 control diets and 21% CP CWB diet contained 1.40% standardized ileal digestible (SID) Lys in phase 1 and 1.35% SID Lys in phase 2, while the 19.5%, 18%, and 16.5% CP diets contained 1.33, 1.25 and 1.20% Lys, respectively, in both phases. Pigs fed the positive control diet containing pharmacological ZnO had increased (P < 0.05) ADG and G:F compared with the negative control and the 21% CP CWB diet. Reducing CP (concurrently with SID Lys) in diets containing CWB decreased ADG and G:F (linear, P = 0.002); however, fecal DM increased (linear, P = 0.005). In experiment 2, two groups of 300 and 350 pigs, initially 7.0 and 6.2 kg, respectively, were used with 5 pigs per pen and 26 pens per treatment. The objective was to determine if adding back essential AA would improve growth performance of pigs fed the low CP diets. All dietary treatments were fed for 13 days, contained 4% CWB, and consisted of: (1) positive control with 2,000 mg/kg of Zn and 21% CP (1.35% SID Lys); (2) no ZnO and 21% CP; and 3 diets with no ZnO formulated to 18% CP and (3) 1.2% SID Lys; (4) 1.35% SID Lys by the addition of feed grade amino acids (AA), and (5) diet 4 with non-essential amino acids (NEAA; Gly and Glu). Pigs fed 21% CP with ZnO had increased (P = 0.001) ADG compared to those fed 18% CP (1.35% SID Lys) with high levels of feed grade amino acids or those fed the reduced SID Lys (1.2%) diet. Overall, G:F was improved (P < 0.001) for pigs fed 21% CP diets and those fed the 18% CP diet with NEAA compared to pigs fed 1.2% SID Lys and pigs fed high levels of feed grade amino acids. Fecal DM was increased for pigs fed the reduced SID Lys diet. In summary, pharmacological levels of Zn improve pig growth performance, but reducing CP (and subsequently SID Lys) decreased nursery pig growth performance.  相似文献   

18.
Two experiments were conducted to determine the standardized ileal digestible lysine (SID Lys) requirement for weaned pigs fed with low crude protein (CP) diet. In Experiment 1, 144 pigs were fed a normal CP (20%) diet with 12.3 g/kg SID Lys and five low CP (18.5%) diets providing SID Lys levels of 9.8, 11.1, 12.3, 13.5, and 14.8 g/kg, respectively, for 28 days. Reducing dietary CP from 20% to 18.5% enhanced (p < 0.05) the growth performance. The average daily gain (ADG) and gain to feed ratio (G:F) increased (linear and quadratic; p < 0.05), serum urea nitrogen (SUN) decreased (linear and quadratic; p < 0.05) as SID Lys increased. The SID Lys levels required to maximize ADG and optimize G:F were 12.8 and 13.1 g/kg using a curvilinear plateau model, and to minimize SUN was 13.4 g/kg using a two‐slope broken‐line model, which averaged 13.1 g/kg SID Lys. In Experiment 2, 18 pigs were used in a 12‐day N balance trial and received the same diets of Experiment 1. Total N excretion was decreased when dietary CP reduced and further decreased when SID Lys increased. Collectively, 1.5% dietary CP reduction improved the growth performance and decreased the N excretion; the optimal SID Lys requirement was at 13.1 g/kg of 8–20 kg pigs fed with 18.5% CP diet.  相似文献   

19.
Optimal ratio of lysine (Lys) to threonine (Thr) in diets for growing barrows [genotype: Piétrain × (Large White × German Landrace)] was established at 30, 50, 70, 90 and 110 kg body weight (BW). N balance studies were conducted with diets based on constant mixture of wheat, barley, soybean meal and field peas. Supplementation of crystalline amino acids (AA) provided diets with Lys (diet A) and Thr (diet B) in first limiting position. For each BW range, totally 28 individual N balance data were utilized for assessing model parameters (exponential N utilization model) of dietary efficiency of Lys and Thr, respectively. Observed maximal dietary efficiency of Lys and Thr provided the database for conclusion of optimal dietary Lys to Thr ratio. Based on applied experimental conditions, BW dependent Lys to Thr ratio could not be concluded. On average, the dietary ratio Lys to Thr = 1:0.61 ± 0.02 was obtained as optimal for growing pigs.  相似文献   

20.
选用平均体重为(40±2)kg杜长大三元杂交去势公猪3头,按3×3的拉丁方进行试验设计,试验分3期,每期为7 d,采用全收粪法,研究不同蛋白质(CP)水平的氨基酸平衡日粮CP水平分别为14%、16%和18%)对氮、磷及能量代谢的影响。结果表明:不同蛋白质水平日粮处理间的氮表观消化率差异不显(著P>0.05),氮的沉积率以14%CP和16%CP组显著高于18%CP组(P<0.05),而14%CP和16%CP组之间无显著差异(P>0.05)。粪氮排出量14%CP日粮组显著低于16%CP和18%CP日粮组(P<0.05),16%CP日粮组和18%CP日粮组间无显著差异(P>0.05)。随着日粮蛋白质水平下降,生长猪的氮排出量、粪氮和尿氮均减少,总排泄氮中尿氮的比例较大,而粪氮则较少。不同蛋白质水平日粮对磷和能量的消化利用无显著影响(P>0.05)。  相似文献   

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