不同浓度活菌酶蛋白血粉饲养育肥猪的对比试验

在测定活菌酶蛋白血粉养分及氨基酸组成的基础上，以玉米）豆粕型日粮为对照组，将活菌酶蛋白血粉按2．5％、5％、10％的配比分为3个试验组进行了试验。选用40头仔猪进行饲养对比试验。根据各组的增重情况进行统计分析，试验结果表明饲料中添加2．5％～5％活菌酶蛋白血粉有利于育肥猪的生长。     

鱼溶浆蛋白在母猪上的应用效果

本试验主要研究哺乳母猪日粮中添加4kg/t鱼溶浆蛋白对哺乳母猪生产性能和繁殖性能的影响。试验选择49头"长×大"二元杂母猪,随机分为2个组。对照组饲喂基础日粮,试验组每吨日粮中用4kg鱼溶浆蛋白代替鱼粉。试验结果表明,试验组的头均日采食量比对照组提高3.70%;母猪断奶后背膘厚损失试验组比对照组降低34.35%;断奶仔猪在哺乳期间增重试验组比对照组提高5.90%。     

日粮蛋白来源与蛋白水平对断奶仔猪生产性能的影响

试验将体重约10kg的35日龄断奶仔猪135头随机分成9组，通过添加豆粕、鱼粉、血浆蛋白粉3种不同蛋白源分别配制18％、20％、22％三个不同蛋白水平的日粮，研究蛋白源与蛋白水平对断奶仔猪生产性能与腹泻率的影响。结果表明：日粮蛋白含量超过20％时，仔猪腹泻率超过10％，其中蛋白含量20％和22％的豆粕组日粮腹泻率最高；但蛋白含量相同时，血浆蛋白粉组日粮腹泻率要低于鱼粉组日粮，鱼粉组日粮腹泻率低于豆粕组日粮。9个试验组中蛋白含量22％的豆粕组平均日增重最低；蛋白含量18％和20％的豆粕组、18％的鱼粉组日增重次之；血浆蛋白粉组及蛋白含量20％和22％的鱼粉组日增重最高，但18％、20％和22％血浆蛋白粉组之间日增重差异不显著（P〉0．05）。蛋白含量22％的豆粕组饲料转化率最高；血浆蛋白粉组、蛋白含量20％和22％的鱼粉组饲料转化率最低，但与血浆蛋白粉组的饲料转化率差异不显著（P〉0．05）。     

马铃薯蛋白作为一种新型的抗菌剂对断奶仔猪生产性能、营养物质消化率、肠道中微生物和免疫力的影响

选择23±3日龄、初重基本一致的杜×长×大断奶仔猪（6．42±0．74kg）280头．随机分为5个处理．每个处理4个重复．每个重复14头猪．自由饮水和采食。试验主要探讨饲喂不同水平的马铃薯蛋白对断奶仔猪生产性能、营养物质消化率、免疫、小肠形态、大肠和粪便中的细菌菌落数的影响。对照组（PC）为基础日粮＋150mg／kg的安普霉素和10mg／kg的硫酸黏杆菌素．试验组（PP）为基础日粮中添加0、0．25％、0．50％和0．75％的马铃薯蛋白。经过28d试验，对照组与试验组相比．提高了断奶仔猪全期的平均日增重ADG（P〈0．05）和G：F（P=0．09）。试验组中断奶仔猪的ADG（P〈0．05）、平均日采食量ADFI（P=0．052）和G：F（P=0．098）随着日粮中马铃薯蛋白添加量的增加呈线性增加。对照组与试验组相比．干物质和粗蛋白质的消化率较高。除了14d和28d．对照组比试验组的断奶仔猪粪便中的细菌总数和大肠杆菌数少．随着日粮中马铃薯蛋白添加量的增加．断奶仔猪粪便、盲肠、结肠和直肠中的微生物数量呈线性减少。试验组可以提高植物血凝素的水平．21d时血凝素效价在PC组中的断奶仔猪最高。在28d血凝素的效价随着PP日粮中的马铃薯蛋白粉的添加量呈二次增加（P=0．07）。PC日粮与PP日粮相比．能降低断奶仔猪的隐窝深度（P=0．06），提高绒毛高度：隐窝深度（P＝0．082）的趋势。这些结果可以表明．马铃薯蛋白可以替代抗生素在饲料中的使用。因为它具有抗菌活性．能有效减少大肠杆菌的数量．也可以提高断奶仔猪生产性能。     

蜘蛛酶替代保育料中血浆蛋白粉的影响初探

蜘蛛酶是由专门从事昆虫源微生物制品研发的韩国Insect Biotech公司,利用现代生物技术研制开发的新型饲料添加剂,其有效成分为来源于韩国的巫婆蜘蛛,具有抗菌消炎作用的高效蛋白酶—蜘蛛酶(Arazyme)。本试验旨在验证蜘蛛酶加鱼粉替代血浆蛋白后,在降低饲料配方成本的同时,是否对断奶仔猪日增重、采食量、料肉比和预防仔猪腹泻等方面产生影响。对照组为原有基础日粮,试验组日粮采用基础日粮去掉血浆蛋白粉的添加,而相应添加4%的鱼粉和0.1%的蜘蛛酶。试验结果表明:对照组仔猪的日增重为0.348kg,而试验组为0.333kg,经统计分析,两者差异不显著(P0.05)。日粮中添加0.1%蜘蛛酶对仔猪的日耗料量无明显影响(P0.05)。对照组和试验组料肉比分别为1.870和1.830,两者比较,差异也不显著(P0.05)。另外,对照组和试验组仔猪腹泻率分别为1.79%和1.43%,用0.1%蜘蛛酶替代血浆蛋白粉后仔猪腹泻率有所下降,但两者比较差异并不显著(P0.05)。但是通过试验数据和经济效益分析可以看到,用0.1%蜘蛛酶结合鱼粉替代基础日粮中3%的血浆蛋白粉对断奶仔猪的生长性能无影响,但可节省每吨饲料的成本从而增加养殖者的经济效益。     

生长猪日粮中添加虫肽蛋白对肉质和风味的影响

本试验选用保育出栏的杜×长×大三元杂交小猪96头,随机分成两个组,试验组日粮中添加5％虫肽蛋白．对照组饲喂常规日粮（玉米豆粕型）。经过105d的饲喂试验．结果表明：试验组日增重比对照组提高2．24％;饲料转化率比对照组提高0．75％。通过屠宰猪对肉质和风味进行观察和品尝．试验组猪肉比较鲜红、肉味口感爽滑、肥肉肥而不腻、清煮肥肉汤中油腻甚少、肉质细嫩、甘香可口：对照组猪肉色泽暗红、口感有渣、含酸味、有肉膻味。     

酶蛋白饲喂鲤鱼的效果

鲤鱼试验日粮中添加１５％的酶蛋白，与对照组添加１０％鱼粉＋５％菜粕比较，其增重，成活率和相对增长率变化基本一致。试验表明，鱼料中以酶蛋白替大部分进口鱼粉安全可行，效果显著。     

小肽替代血浆蛋白粉对断奶仔猪生产性能的影响

为对比小肽与血浆蛋白粉对断奶仔猪生产性能的影响,选取240头24日龄的杜长大断奶仔猪,随机分为对照组和试验组,对照组添加3％血浆蛋白粉,试验组添加5％小肽制品,进行为期14d的试验,结果表明小肽组的仔猪日采食量、日增重、料重比、单位增重饲料成本等均好于血浆蛋白粉组,可见,在断奶仔猪日粮中采用小肽制品替代血浆蛋白粉应是可行的。     

日粮中添加不同水平的血浆蛋白粉对7～35日龄哺乳仔猪生产性能和腹泻率的影响

选用第5～4胎、产期基本一致的哺乳仔猪（长X大）12窝,随机分为6组,每组2窝。对照组饲喂基础日粮,试验Ⅰ组为基础日粮＋2％血浆蛋白粉（SDPP）,试验Ⅱ组为基础日粮＋4％血浆蛋白粉,试验Ⅲ组为基础日粮＋6％血浆蛋白粉,试验Ⅳ组为基础日粮＋8％血浆蛋白粉,试验Ⅴ组为基础日粮＋10％血浆蛋白粉。5日开始龄诱饲,35日龄断奶。结果表明：各试验组的仔猪21日龄重分别比对照组提高了8．7％、13．8％、9．1％、15．6％和20％（P〉0．05）,差异不显著;各试验组的35日龄断奶重分别比对照组提高了4．8％、5．4％、7．6％、8．30％和12．38％,差异不显著（P〉0．05）;各试验组的7日龄至断奶采食量比对照组分别降低了17．28％、25．87％、32．95％、P．4．05％和18．44％,差异不显著（P〉0．05）;腹泻率各组差异比较大但试验组之间以及试验组与对照组之间无显著差异（P〉0．05）。结论：在仔猪日粮中添加血浆蛋白粉有效提高了仔猪的生长性能,并且随着日粮中血浆蛋白粉添加量（2％、4％、6％、8％、10％）的提高,仔猪的生长性能也逐步提高,但对改善仔猪腹泻效果不明显。     

活菌酶蛋白血粉对育成猪饲养效果

在测定活菌酶蛋白血粉养分的基础上，以玉米豆粕型日粮为对照线，将猪活菌酶蛋白血粉按2．5％，5．0％，10．0％的配比分为三个试验组。选用40头仔猪进行了饲养对比试验。根据各级的增量情况进行统计分析，总结出在猪日粮中添加适量活菌酶蛋白血粉的可行性。     

Ruminal protein degradation and protein value of feeds

The relationship between dry matter (DM) degradation and crude protein (CP) degradation in the dairy cow's rumen was determined with a view to defining the protein value of feeds for ruminants. The nylon bag technique was applied for these studies. For all the feeds investigate (green fodder and preserves from cocks-foot, ryegrass, alfalfa/grass and meadow grass, as well as alfalfa, extracted soybean meal) a significantly positive relationship was found to exist between the levels of DM and CP degradation (r = 0.73 to 1.0). The regression coefficient b1 (CP degradation as regressor) was found to average 0.87. The positive relationship between DM degradation and CP degradation implies that microbial protein amount and unfermented feed protein at the duodenum are negatively correlated. Model calculations show that, on account of the compensation between microbial protein and feed protein at the duodenum, in feeds with a CP concentration below 200 g/kg DM, the extent of ruminal protein degradation does not exert a marked influence on duodenal protein passage. The partial calculation of the duodenal protein supply on the basis of undegraded feed protein and microbial protein, as practiced in the new models of protein evaluation, leads to systematic errors unless the relationship between DM degradation and CP degradation is considered.     

Hypolipidaemic effects of potato protein and fish protein in pigs

This study was performed to assess the effects of potato protein and fish protein on concentrations of lipids in plasma and lipoproteins and the expression of genes involved in lipid metabolism in pigs used as an animal model. Therefore, 27 young male pigs with an average body weight of 22 kg were fed diets supplemented with protein extracted from potatoes (containing 849 g protein/kg dry matter), Alaska Pollack fillet as a source of fish protein (containing 926 g crude protein/kg dry matter) or casein which was used as control, for 3 weeks. Diets were formulated to supply identical amounts of each protein to the pigs by the three protein sources, namely 116 g/day in first week and 150 g/day in the second and third week. Pigs fed potato protein had lower concentrations of cholesterol in plasma and LDL than pigs fed casein (p < 0.05); no effect was observed on concentrations of HDL cholesterol and triglycerides. Pigs fed fish protein had lower cholesterol concentrations in plasma, LDL and HDL, and lower triglyceride concentrations in triglyceride-rich lipoproteins than pigs fed casein (p < 0.05). mRNA concentrations of genes involved in bile acid synthesis and cholesterol uptake were higher in pigs fed fish protein than in pigs fed casein (p < 0.05); no effect on these genes was observed in pigs fed potato protein. Expression of genes involved in lipogenesis and fatty acid oxidation was not altered by fish protein. In conclusion, this study shows that fish protein and potato protein lower plasma cholesterol concentrations in pigs. The hypocholesterolaemic effect of fish protein might be in part caused by a stimulation of bile acid synthesis; the reason for the hypocholesterolaemic effect of potato protein requires further elucidation.     

Influence of dietary protein intake on whole-body protein turnover in chicks

1. Experiments were conducted to investigate whether or not varying dietary protein intake affects whole-body protein turnover rates in young chicks. 2. Seven-d-old single comb White Leghorn male chicks were fed on diets with protein concentrations of 0, 100, 200 or 400 g/kg diet under conditions of ad libitum or equalised feeding. At the end of the experiments, the rate of protein synthesis and protein degradation in the whole body were measured in vivo. 3. The results showed that both fractional and absolute rates of protein synthesis increased with increasing dietary protein up to 200 g/kg; above this concentration they remained almost constant when feeding was ad libitum. 4. Similar responses were found with equalized feeding except that a significant reduction in protein synthesis was found when dietary protein was increased from 200 to 400 g/kg diet. 5. Less sensitive and almost parallel changes in protein degradation rates were found. 6. It was concluded that adaptation to varied dietary protein intake occurred primarily through changes in protein synthesis, accompanied by parallel alterations in protein degradation in the whole body.     

Adaptation of protein oxidation to protein intake in the domestic cat

It is well-accepted that cats require more dietary protein than omnivores and herbivores. Work on hepatic enzyme activities showed that cats lack the ability to regulate the urea cycle enzymes in response to the dietary supply of protein. It was thus hypothesized that the high protein requirement of cats is due to an inability to regulate these enzymes, limiting adaptation to a low protein diet. We used indirect respiration calorimetry to assess the in vivo ability of cats to adapt substrate oxidation to different levels of dietary protein, including one below their protein requirement. In random order, eight cats consumed each of four semi-purified diets containing 7.7% (LP), 14.6% (AP), 27.3% (MP) and 51.1% (HP) of ME from protein. Cats consumed each diet for at least 14 days and then completed a 5-day nitrogen balance trial and at least 2, 12-hour indirect calorimetry measurements. The data were analyzed by anova using the Mixed procedure of SAS and are expressed as mean ± SEM. There was a significant effect of diet on protein oxidation (p < 0.0001), measuring 9.8 ± 0.5%, 13.4 ± 0.9%, 23.5 ± 0.8% and 49.0 ± 1.8% of total energy expenditure on the LP, AP, MP and HP diets, respectively. The ratio of protein oxidation/protein intake was significantly higher with the LP diet (1.27 ± 0.07) than the other three diets (AP, 0.92 ± 0.06; MP, 0.86 ± 0.03; HP, 0.96 ± 0.04; p < 0.0001), indicating a net loss of protein on the LP diet. Thus, cats adapted to a wide range of dietary protein concentrations, but were unable to fully adapt to the LP diet.     

Level of supplemental protein does not influence the ruminally undegradable protein value

Two experiments were conducted to determine whether elevating the percentage of ruminally undegradable protein (RUP) in the diet would influence the RUP value of the protein feedstuff. A single-effluent, continuous-culture study was designed to test the effect of RUP inclusion rate in the diet on ruminal degradability of the protein. Treatments consisted (DM basis) of a control diet with no supplemental protein, control + 2.5% bloodmeal (BM-L), control + 5% bloodmeal (BM-H), control + 4.45% soybean meal (SBM-L), and control + 8.89% soybean meal (SBM-H). Proteolytic activity and total VFA concentration were not affected (P = 0.73 and P = 0.13) by treatment. Within protein source, dietary RUP value was not affected (P = 0.94) by level of inclusion. When corrected for control diet RUP flow, the RUP value of the blood meal (BM) protein was higher (P = 0.01) than soybean meal (SBM); however, level of supplementation did not affect (P = 0.07) the RUP value of BM or SBM. In Exp. 2, 32 British x Continental crossbred steers (276 +/- 26.3 kg) were fed for 72 d to examine the effects of balancing the AA:energy ratio, using BM as a RUP source, on ADG, G:F, and lean tissue deposition. Diets were formulated to provide increasing levels of arginine, while ruminally degradable protein and energy were held constant. Four dietary treatments provided 0.5, 1, 1.5, and 2x the required amount of arginine, whereas the control diet had no BM included. Daily DMI averaged 7.6 kg/steer and did not differ (P = 0.71) among treatments. Steers gained an average of 1.9 kg/d and average G:F was 0.260, with no differences (P = 0.60 and P = 0.97, respectively) among treatments. There was no difference (P = 0.48) in the change in 12th-rib fat depth during the study; however, change in LM area was affected quadratically as the level of BM increased in the diet, with the greatest increase in LM area occurring in steers fed the 1x and 1.5x required arginine treatments. Balancing the AA:energy ratio did not affect G:F, DMI, or ADG; however, it increased deposition of lean in the LM quadratically. Level of dietary inclusion of BM as an RUP source does not affect its RUP value or efficacy of providing postruminal AA in growing steers.