液态饲料在早期隔离断奶仔猪中的应用

本文就液态饲料的营养生理作用、对断奶仔猪生产性能、肠道健康以及液态饲料开发与利用方面存在的问题进行阐述,以期为液态饲料的科学配制提供理论依据。     

Free versus microencapsulated organic acids in medicated or not medicated diet for piglets

Aim of the study was to investigate the growth performance of weaned piglets fed either a medicated or not medicated diet supplemented with either a blend of formic and lactic (64/36) acids (FL, 11 kg/ton) or a microencapsulated blend of organic acids and flavors (T) (1 kg/ton, Tetracid®S, EU patent 1391155B1,Vetagro srl, Italy). 480 three-week old SCAAPAG × Goland piglets were fed four diets (4 pens of 30 piglets per diet): FL or T with or without the medication (M) comprising colistin 180 ppm + amoxicillin 600 ppm for the 1st phase and chlortetracycline 1000 ppm + sulphadiazine 1250 ppm + trimetoprim 250 ppm for the 2nd phase. The piglets received a two-phase diet (I:18% CP, 1.3% Lys, 7.5% CF and 2600 kcal/kg NE; II:18% CP, 1.2% Lys, 5.6% CF and 2400 kcal/kg NE). All data were analysed by ANOVA. After 49 days, animals fed the medicated diets had higher feed intake (+ 24.5% for group FL + M vs FL − M and + 22.3% for group T + M vs T − M; P < 0.01) and lower mortality (overall 1.2% for the medicated diets fed animals vs 9.2% for the non-medicated ones). Final weights were: 26.8 ± 1.0 kg, 25.7 ± 0.8 kg for FL + M, T + M, 20.9 ± 0.7 kg, 21.6 ± 0.8 kg for FL − M and T − M, respectively (P < 0.05). The medication resulted in maintaining animals in good health status. The microencapsulation technique allowed to lower the acids dose to be included in the feed by ten fold at least maintaining the same effects that a high dose can give without medication.     

Physiological aspects and ileal gene expression profile of early-weaned piglets fed a low threonine diet

High dietary threonine extraction by the digestive tract suggests that threonine contributes to maintain gut physiology. The aims of this study were to investigate both the physiological disturbances and the molecular events caused by an inadequate dietary threonine supply to the ileum of piglets. We compared paracellular permeability and gene expression, using porcine cDNA microarrays, of the ileum of piglets weaned at 7 days of age fed either a low (LT; n = 7) or a control (C; n = 7) well balanced threonine diet for 2 weeks. At slaughter, the ileal paracellular permeability, measured by FD4 flux in Ussing chambers, increased in piglets fed a LT diet compared with C piglets (P = 0.017). Furthermore, 170 genes had their expression significantly modified in the ileum of the LT piglets: 64 were down regulated and 106 were up regulated. These genes are involved in immune response, apoptosis, energy metabolism, cell migration, epithelial permeability, RNA processing or protein translation. In conclusion, dietary threonine deficiency induced alteration of the ileal barrier and the ileum seems to respond by increasing its metabolic activity.     

Small intestinal morphology and disaccharidase activities in early-weaned piglets fed a diet containing spray-dried porcine plasma

The purpose of this study was to test whether dietary spray-dried porcine plasma (SDPP) in early-weaned piglets prevents small intestinal villus atrophy by trophic or protective activity. Fifty-four weaned, 18-day-old piglets were used to determine the effect of dietary SDPP on small intestinal villus length, crypt depth, enterocyt mitotic activity and brush border enzyme activities during the first week after weaning. The piglets were offered a diet containing either 8% SDPP or 8% casein. At 2 and 7 days after weaning, piglets were anaesthetized to provide samples of the small intestinal wall and killed immediately afterwards. There were no differences in daily gain and daily feed intake between the two dietary treatments. At day 2 after weaning, all piglets showed a marked reduction in villus height when compared with baseline values. In all piglets, small intestinal enterocyte mitotic activity had decreased by day 2 and was increased again on day 7. There were no significant effects of dietary SDPP on small intestinal villus length, crypt depth and enterocyt mitotic activity. This indicates that SDPP has no trophic effect on the small intestinal mucosa and that it does not protect against the damaging effect on the small intestinal villi that is associated with the process of weaning. There was no effect of SDPP on lactase-, sucrase- or maltase-specific activities that are a measure of the digestive function of the small intestine. It can be concluded that SDPP versus casein has no effect on small intestinal morphology and disaccharidase activities in early weaned piglets kept under low infection pressure.     

营养对早期断奶仔猪免疫功能及健康的影响

本文阐述了饲料中主要营养物质(蛋白质、氨基酸、糖类、脂肪、矿物质和维生素)对早期断奶仔猪免疫功能和健康的影响。     

提高早期断奶仔猪免疫功能及健康水平的营养措施

早期断奶使仔猪出现断奶后腹泻、生长滞缓等“早期断奶综合症”,严重影响仔猪生产效益。大量研究表明,合理的营养措施能够提高早期断奶仔猪的免疫功能和健康水平,从而有效地防止或减少早期断奶仔猪腹泻和其它许多疾病的发生。主要阐述了提高早期断奶仔猪免疫功能和健康水平的营养措施,为在实际生产中更好地控制断奶仔猪腹泻和提高断奶仔猪健康水平与生产性能提供参考。     

Ornithine metabolism, but not arginine synthesis, is affected by the addition of ornithine to an arginine-deficient diet in enterally-fed piglets

In a previous study, ornithine addition to an arginine-deficient diet did not improve whole-body arginine status in enterally-fed piglets; however, the metabolic fates of the supplemental ornithine were not studied. This experiment determined the metabolic fates of the supplemental ornithine and whether ornithine metabolism was affected by the addition of -ketoglutarate. Male piglets (n = 20, 1.8 kg), fitted with gastric catheters for diet and isotope infusion, portal vein catheters for isotope infusion and femoral vein catheters for blood sampling (d 0), received 2 d of a complete diet, followed by 5 d of 1 of 4 test diets: the arginine-deficient diet (basal), or the basal diet with either -ketoglutarate [ +  - KG; 4.6 mmol/(kg d)], ornithine [ + Orn; 9.2 mmol/(kg d)] or both [ +  - KG/ + Orn; 4.6 mmol/(kg d)  - ketoglutarate + 9.2 mmol/(kg d) ornithine]. Piglets received primed, constant infusions of [1-¹⁴C]ornithine infused intragastrically (either d 5 and d 7) to determine ornithine kinetics, and [guanido-¹⁴C]arginine intragastrically to measure arginine flux (d 6). Piglets receiving the ornithine-containing diets had a higher intragastric ornithine flux (P < 0.0001) and ornithine oxidation (P < 0.05). Ornithine supplementation did not increase arginine synthesis, although the ornithine supplemented piglets had a greater conversion of ornithine to proline (P < 0.0001). The fates of supplemental ornithine in piglets fed an arginine-deficient diet appear to be oxidation and proline synthesis; this was not affected by the presence of -ketoglutarate.     

复合酶制剂对早期断奶仔猪消化机能的影响研究

试验主要研究不同水平的复合酶制剂(0%,0.1%,0.5%,1.0%)对断奶仔猪消化机能的影响。结果表明,饲料中添加复合酶制剂提高了营养物质消化率,其中干物质、粗蛋白质和粗脂肪均达显著水平(P<0.05);且随酶制剂水平的增加,腹泻频率、粪便总菌数、大肠杆菌数表现出不同程度的降低,而乳酸杆菌表现出上升趋势,但差异均不显著(P>0.05)。大肠杆菌数较对照组分别降低2.51%、9.18%、9.56%。     

Susceptibility of Pacific herring to viral hemorrhagic septicemia is influenced by diet

Groups of specific-pathogen-free Pacific herring Clupea pallasii were highly susceptible to infection by viral hemorrhagic septicemia virus (VHSV); however, the level of mortality was influenced by diet during the 40-71 d before, during, and after the first exposure to the virus. Cumulative mortality was highest among the herring maintained on an experimental soy-based pellet, intermediate among those maintained on a commercially available fish-meal-based pellet, and lowest among those maintained on a second commercially available fish-meal-based pellet containing beta-glucans. Additionally, the herring maintained on the experimental soy-based feed demonstrated less growth than those on the commercially available feeds. The results indicate the importance of standardizing diet during empirical determinations of disease susceptibility and provide insights into the risk factors affecting VHS susceptibility in wild populations.     

二次制粒加工断奶过渡料对早期断奶仔猪生长性能的影响

选用360头21日龄早期断奶仔猪平均分为4组,按制粒工艺、原料膨化预处理不同设计2因素2水平试验,研究二次制粒加工断奶过渡料对早期断奶仔猪生长性能的影响。结果显示:采用二次制粒工艺及膨化玉米、膨化豆粕原料的处理4仔猪,断奶后第一周,有最大的采食量(P<0.05);试验全期断奶14 d中,处理组4仔猪平均日增重最大,生长性能最好。血清尿素氮测定结果显示:断奶后第7天,处理组4仔猪血清尿素氮显著低于其他三组。断奶后第14天,处理组4仔猪血清皮质醇显著低于处理1组。此外,试验全期四个处理组仔猪血清总血糖无显著差异(P>0.05)。表明,在选择膨化玉米与膨化豆粕优质饲料原料的基础上,采用二次制粒工艺,尤其是先将鱼粉与膨化玉米、膨化豆粕进行第一次高温制粒,对降低仔猪断奶应激,改善生长性能有良好的效果。     

三种生长促进剂组合使用对断奶仔猪生产性能的影晌

试验研究了复制3种生长促进剂组合使用对断奶仔猪生产性能的影响.试验选择128头28±1日龄、平均断奶体重(7.78±0.74)kq的健康三元(杜×长×大)杂交仔猪,按体重和性别分成4个处理组,每个处理4个重复,每个重复8头仔猪.第1组为对照组,饲喂玉米-豆粕型基础日粮;第2组添加喹乙醇(50mg/kg)、阿散酸(150mg/kg);第3组添加喹乙醇(50mg/kg)、吉他霉素(60mg/kg);第4组添加喹乙醇(50mg/kg)、阿散酸(150mg/kg)、吉他霉素(60mg/kg).研究结果表明,各试验组日增重、料肉比得到显著改善(p＜0.05),腹泻率显著下降(p＜0.01).     

金泰素预混剂对早期断奶仔猪腹泻病的预防

用金泰素预混剂拌料可有效防治早期断奶仔猪腹泻的发生，在100kg日粮中添加金泰素预混剂200g组的发病率为3．13％，有效率为100％；日粮中不添加任何药物的对照组的发病率为42．86％。     

Neutrophil extracellular trap formation by bovine neutrophils is not inhibited by milk

Neutrophils are the first line of defense in a mammary gland infection. However, the process of neutrophil transmigration across a membrane and ingestion of fat and/or casein when incubated in milk have been shown to inhibit bacterial phagocytosis and oxidative burst functions. Recently, a killing mechanism has been described whereby stimulated neutrophils release nuclear and granule material in fibrous webs that physically trap and kill bacteria. We demonstrate that these neutrophil extracellular traps are also produced by bovine blood neutrophils stimulated with PMA/ionomycin. Importantly, neutrophil extracellular traps can be formed when neutrophils have been incubated for up to 6h in milk prior to stimulation. This contrasts milk's rapid inhibition of bacterial phagocytosis and oxidative burst functions in the neutrophil. Furthermore, stimulation of neutrophils with bacteria common to mammary gland infections leads to neutrophil extracellular traps being formed in milk. Some bacteria tested stimulated enhanced formation of neutrophil extracellular traps in milk compared to culture media. Therefore, being unaffected by incubation in milk may indicate an important role for neutrophil extracellular traps in defense against mastitis.     

In vitro growth and starch digestion by Entodinium exiguum as influenced by the presence or absence of live bacteria

In a preliminary study, the addition of antibiotics was shown to reduce bacterial concentrations in Entodinium exiguum cultures by more than 99% in 4 h, whereas the protozoal population was apparently unaffected. Using this procedure, the growth and amylolytic capability of Entodinium exiguum, in the presence or absence of live bacteria, was studied in vitro. Treatments for Trial 1 were protozoa plus antibiotics (PA), PA plus autoclaved bacteria (PAB), protozoa plus living bacteria (PLB), and only bacteria (BAC). Autoclaved or non-autoclaved cornstarch was used as an energy source. Treatment main effects were as follows: higher concentration of E. exiguum in PLB than in PA or PAB at 24 and 48 h (P < 0.01); PA and PAB were not different (P > 0.05); concentrations of E. exiguum higher in autoclaved cornstarch at 12 h (P < 0.05) but lower than in non-autoclaved cornstarch at 24 and 48 h (P < 0.01); and starch digestion in PLB was higher than in PA and PAB at all time periods, but only greater than BAC up to 24 h (P < 0.01). In Trial 2, only treatments PA, PLB, and BAC were tested. Rice starch and cornstarch were used as substrates. With rice starch, growth was higher in PLB than in PA at 24 and 48 h (P < 0.05). Starch digestion started earlier in PLB with rice starch (P < 0.05) but was complete for both substrates after 24 h. Up to 12 h (autoclaved cornstarch and rice starch) and 24 h (non-autoclaved cornstarch and cornstarch), the sum of digestion by bacteria and protozoa did not equal the extent of digestion in PLB, suggesting some kind of synergism. Total extent of digestion with protozoa was similar between the two sources; however, bacteria digested rice starch faster and to a greater extent than cornstarch. Approximate lag times with rice starch, autoclaved cornstarch, and non-autoclaved cornstarch were 6, 3, and 12 h for bacteria and < 6, 3, and 9 h for protozoa, respectively. Rate of digestion for non-autoclaved cornstarch was similar for bacteria and protozoa, whereas the rate of bacterial digestion was much faster with the other two substrates (autoclaved cornstarch and rice starch).     

低蛋白氨基酸平衡日粮对断奶仔猪生产性能的影响

试验选取38头35日龄±1日龄断奶、体重在5.9kg左右的杂交仔猪为试验动物。随机分为 3组，研究 3种不同蛋白质水平（17％、18％和20％）的玉米—膨化大豆型基础日粮对断奶仔猪生产性能的影响，试验期为28d。试验结果表明：①蛋白含量为 18％的试验组仔猪的腹泻率为最低（ 9.18％），与17％的试验组的差异不显著（ P>0.05），与20％的试验组差异极显著（ P<0.01）；②蛋白质含量为18％的试验组仔猪的料肉比为1.79，而蛋白为17％和20％的试验组则分别为1.97、1.94。说明低蛋白氨基酸平衡日粮对仔猪生产性能无影响，但可明显影响减少仔猪的腹泻率。     

不同代乳料对海南黑山羊早期断奶的影响

选取体重接近的海南黑山羊36头,随机分为3个处理组,每组12头,其中一组为对照组,正常断奶,不补充精料,另外两组分别饲喂代乳料Ⅰ和代乳料Ⅱ,试验期为50 d。结果表明：早期断奶补饲会明显增加海南黑山羊的体重,但与正常断奶羔羊比较,体重和日增重均差异不显著（P〉0.05）。表明在海南对黑山羊实施早期断奶是可行的。