甜菜碱对热应激肉鸡生长性能、十二指肠消化酶活性及盲肠微生物区系的影响

本试验通过在饲粮中添加不同剂量的甜菜碱研究其对热应激肉鸡生长性能、十二指肠消化酶活性及盲肠微生物区系的影响。选取270只14日龄爱拔益加(AA)肉鸡随机分成6组:常温组、热应激组,常温+0.1%甜菜碱组、热应激+0.1%甜菜碱组、热应激+0.2%甜菜碱、热应激+0.4%甜菜碱组。热应激肉鸡饲养在(32±1)℃的高温环境中。每组3个重复,每个重复15只。预试期7 d,正试期21 d。结果表明:1)饲粮添加甜菜碱可极显著增加28~42日龄热应激肉鸡的体重(P<0.01),极显著降低22~35日龄肉鸡料重比(P<0.01);2)除添加0.1%和0.2%甜菜碱饲粮对28日龄热应激肉鸡胰蛋白酶活性无显著影响(P>0.05)和添加0.1%甜菜碱对35日龄热应激肉鸡淀粉酶活性无显著影响(P>0.05)外,不同浓度的甜菜碱均能显著或极显著增加28、35、42日龄热应激肉鸡十二指肠胰蛋白酶、淀粉酶和胰脂肪酶活性(P<0.05或P<0.01);3)饲粮添加甜菜碱极显著提高了28、35、42日龄热应激肉鸡盲肠内乳酸杆菌的数量(P<0.01),极显著降低了产气荚膜梭菌的数量(P<0.01)。由此可见,热应激状态下,在基础饲粮中添加甜菜碱可改善AA肉鸡生长性能,提高十二指肠消化酶的活性,维持盲肠内微生物区系平衡,从而减轻热应激对肉鸡的危害。     

盘江黄牛及其杂交牛育肥中干物质、粗蛋白、综合净能需要研究

将３６ 头盘江黄牛及其杂交牛分成１２ 组,采用不同的日粮,进行两期育肥试验,得到不同的增重水平和实际营养物质摄入量。用各组实际采食的干物质（ ＤＭ） 、粗蛋白（ＣＰ） 、综合净能（ＮＥｍｆ） 与我国试行的《肉牛饲养标准》进行比较。结果表明,除干物质与标准相差较多（ － ６ ．３ ％ ） 外,粗蛋白和综合净能与标准相当接近（ 仅相差－ １ ．５ ％ 和２ ．８ ％ ） ,说明盘江黄牛及其杂交牛在育肥中的营养需要基本与标准相符,在配制日粮时,可以参考我国的《肉牛饲养标准》。     

The use of polymerase chain reaction for determination of virulence factors of Escherichia coli strains isolated from pigs in Poland.

E. coli strains isolated from pigs with postweaning diarrhea or edema disease were tested by phenotypic and genotypic methods for the presence of virulence antigens and genes, respectively. The slide agglutination and ELISA analyses were used for determination of F4, F5, F6, F17, and F41 fimbriae whereas the prevalence of fimbrial fedA and toxin eltI, estI, estII, stx1, stx2 and stx2e genes were recorded by the means of PCR. Only F4 antigen (ac variant) was found in strains of the serogroup O149:K91 isolated from pigs with diarrhea. PCR analyses showed that the fedA gene encoding F18 fimbriae was present in 61.9% of strains isolated from pigs with diarrhea and in 84.2% of strains isolated from pigs with edema disease. The eltI genes encoding heat-labile toxin I (LTI) were present only in 9 out of 21 strains recovered from pigs with diarrhea. Shiga toxin 2 variant (stx2e) genes were found in six isolates from edema disease and also in one strain from diarrhea. The PCR test used in the study was a sensitive and valuable method for determination of virulence factors of E. coli strains.     

Alternative low doses and routes of administering a prostaglandin F2�� analogue to induce luteolysis in Nelore cows

The present study was conducted in order to verify the efficacy of lower doses and alternative routes of a prostaglandin F2α analogue, luprostiol (PGF), for the induction of luteolysis and the precipitation of estrus in nonlactating Nelore cows (Bos taurus indicus). A conventional dose (15 mg) of PGF was compared to doses lower than the conventional dose, which ranges from 10 to 50%, that were administered intramuscularly (IM), intravulvosubmucosally (IVSM), or in the Bai-hui acupuncture site located within the lumbosacral area. The cows were administered PGF 8 day after estrus in the presence of a corpus luteum, and randomly assigned to the following groups: G1 (positive control), 15 mg, IM (n = 23); G2, 7.5 mg, IM (n = 23); G3, 3.75 mg, IM (n = 24); G4, 7.5 mg, IVSM (n = 25); G5, 3.75 mg, Bai-hui acupoint (n = 24); and G6, 1.5 mg, Bai-hui acupoint (n = 25). The results indicated that 50% of a conventional dose of PGF (7.5 mg) resulted in a complete luteal regression (plasma progesterone <1 ng/ml) at Hour 48, and hastened estrus, regardless of whether or not PGF was administered IM or IVSM. Comparatively, 10 or 25% of the conventional dose, even when administered to the Bai-hui acupoint, resulted in an initial reduction in the concentration of progesterone at Hour 24, followed by an increase observed at Hour 48. In conclusion, 25% of a conventional PGF dose administered via the Bai-hui acupoint proved inadequate to induce a complete luteal regression, whereas 50% of a conventional dose administered IM or IVSM was found to be the minimal dose required to induce effectively a complete luteal regression, and to precipitate the onset of estrus in nonlactating Nelore cows.     

Endogenous N-losses in piglets estimated by a [15N]-isotope dilution technique: effect of xylanase addition to a wheat and rye based diet.

The nitrogen pool of piglets weighing 19.4 +/- 1.4 kg at the beginning of the experiment was labeled with an oral application of ([15N]H4)2SO4 (1.26 [15N]-atom percent excess of dietary N) over a period of 7 d. The labeling period was followed by an equilibration period of 7 d without feeding the labeling compound. The two experimental diets were based on wheat (53%) and rye (25%) and were fed either with or without a xylanase containing enzyme preparation over both experimental periods. Additionally, diets were supplemented with an indigestible marker during the 2nd period of the experiment to allow the calculation of endogenous N-losses in subsequent segments of the digestive tract of the pigs. These endogenous N-losses were estimated at the end of the experiment by analyzing feces, ingesta and urine for [15N]-enrichment assuming that [15N]-enrichment of urine represents the [15N]-enrichment of the precursor pool. Endogenous N-losses were not significantly affected by xylanase addition at any measurement site (stomach, 3 sections of the small intestine, total digestive tract). Endogenous N-proportions of total nitrogen amounted on average for the six pigs to 42 +/- 11% and 56 +/- 5% at the last section of the small intestine and over the whole digestive tract, respectively, which corresponded to endogenous N-losses of 2.8 +/- 1.3 g N/kg DM and 2.0 +/- 0.3 g N/kg DM, respectively.     

Impact of diets varying in dietary fibre characteristics on gastric emptying in pregnant sows.

The effects of feeding two fibre-rich diets with contrasting solubility and a concentrated low dietary fibre on the rate of gastric emptying were examined in six gastric cannulated pregnant sows. Additionally, it was examined whether any effect could be related to the physico-chemical properties of digesta, i.e. viscosity and/or water binding capacity. The sows were fed each diet for one week in a 3 x 3 Latin Square design and the samples were taken in a randomised order 0.5, 1, 2, 3, 5 and 15.5 h after the morning meal. The stomach contents were evacuated through the gastric cannula once daily. The evacuated gastric digesta was quantified and a representative sample was taken to determine its viscosity, water binding capacity and its content of dry matter, dietary components and solid (Cr2O3) and liquid (polyethylene glycol) phase markers. The flow of liquid digesta was calculated as the difference between digesta and dry matter. Increasing the content of dietary fibre in the diet led to higher recovery of liquid digesta but did not have any significant effect on the gastric emptying of dry matter and dietary components. The effect of dietary fibre could not be attributed to the viscosity of the liquid phase of digesta but might be related to the ability of the increased gastric dietary fibre content to hold water. The stomach selectively retained the insoluble dietary fibre components most noticeably seen with the bran-supplemented diet where the concentration of insoluble NSP in digesta increased significantly from 2 hours and onward.     

Several surgical treatments in rhinoceroses in the Berlin Zoo

It is reported of the treatment of a lower jaw fracture, a toe fracture, dislodging of the horn, and fissures in the plantar surface of the foot in three Indian and one Black rhinoceros in Berlin Zoo. Discussed are cause and course of the diseases, and surgical measures taken.     

Managerial and environmental determinants of clinical mastitis in Danish dairy herds

Background

Several management and environmental factors are known as contributory causes of clinical mastitis in dairy herd. The study objectives were to describe the structure of herd-specific mastitis management and environmental factors and to assess the relevance of these herd-specific indicators to mastitis incidence rate.

Methods

Disease reports from the Danish Cattle Data Base and a management questionnaire from 2,146 herds in three Danish regions were analyzed to identify and characterize risk factors of clinical mastitis. A total of 94 (18 continuous and 76 discrete) management and production variables were screened in separate bivariate regression models. Variables associated with mastitis incidence rate at a p-value < 0.10 were examined with a factor analysis to assess the construct of data. Separately, a multivariable regression model was used to estimate the association of management variables with herd mastitis rate.

Results

Three latent factors (quality of labor, region of Denmark and claw trimming, and quality of outdoor holding area) were identified from 14 variables. Daily milk production per cow, claw disease, quality of labor and region of Denmark were found to be significantly associated with mastitis incidence rate. A common multiple regression analysis with backward and forward selection procedures indicated there were 9 herd-specific risk factors.

Conclusion

Though risk factors ascertained by farmer-completed surveys explained a small percentage of the among-herd variability in crude herd-specific mastitis rates, the study suggested that farmer attitudes toward mastitis and lameness treatment were important determinants for mastitis incidence rate. Our factor analysis identified one significant latent factor, which was related to labor quality on the farm.     

Metabolic profiles in five high-producing Swedish dairy herds with a history of abomasal displacement and ketosis

Background

Body condition score and blood profiles have been used to monitor management and herd health in dairy cows. The aim of this study was to examine BCS and extended metabolic profiles, reflecting both energy metabolism and liver status around calving in high-producing herds with a high incidence of abomasal displacement and ketosis and to evaluate if such profiles can be used at herd level to pinpoint specific herd problems.

Methods

Body condition score and metabolic profiles around calving in five high-producing herds with high incidences of abomasal displacement and ketosis were assessed using linear mixed models (94 cows, 326 examinations). Cows were examined and blood sampled every three weeks from four weeks ante partum (ap) to nine weeks postpartum (pp). Blood parameters studied were glucose, fructosamine, non-esterified fatty acids (NEFA), insulin, β-hydroxybutyrate, aspartate aminotransferase, glutamate dehydrogenase, haptoglobin and cholesterol.

Results

All herds had overconditioned dry cows that lost body condition substantially the first 4–6 weeks pp. Two herds had elevated levels of NEFA ap and three herds had elevated levels pp. One herd had low levels of insulin ap and low levels of cholesterol pp. Haptoglobin was detected pp in all herds and its usefulness is discussed.

Conclusion

NEFA was the parameter that most closely reflected the body condition losses while these losses were not seen in glucose and fructosamine levels. Insulin and cholesterol were potentially useful in herd profiles but need further investigation. Increased glutamate dehydrogenase suggested liver cell damage in all herds.