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1. The objective of this study was to investigate the effects of cold‐pelleting, the length of the fasting period before feeding of the test diet and the nature of die test diet on apparent ileal nitrogen (N) digestibility in the broiler chicken.
2. Four‐week‐old broiler chickens were given a pelleted or non‐pelleted maize/soyabean meal (basal) diet. The birds were starved for 24 h, given a single test meal (25 g) by intubation and killed 4 h after the start of feeding by administration of a barbiturate, to allow sampling of ileal digesta (terminal 15 cm). Cold‐pelleting did not affect apparent ileal N digestibility.
3. Four‐week‐old broiler chickens were fasted for 12 or 24 h and then received a test meal (1 h free access) of either a pelleted soyabean meal or a pelleted meat‐and‐bone meal diet or were continuously fed on one of the two diets. The imposition of a fast did not affect apparent ileal N digestibility. However, a 24 h fasting procedure was preferred, as the between animal variation for apparent ileal N digestibility was lower than for the 12 h fast or for continuous feeding.
4. Four‐week‐old broiler chickens were given either semi‐synthetic starch‐based diets containing maize, wheat bran, meat‐and‐bone meal or fish meal as the sole sources of protein or each of these diets in combination with the basal diet (50:50 on a dry matter basis). With the exception of the maize diet, the apparent ileal N digestibility values calculated by correcting for the digestibility of the basal dietary component were significantly lower than when digestibility was determined directly using a diet in which the respective proteins were the sole protein source. This implies that interactions between the dietary ingredients influence estimates of apparent ileal N digestibility. 相似文献
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Czuprynski CJ Leite F Sylte M Kuckleburg C Schultz R Inzana T Behling-Kelly E Corbeil L 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2004,5(2):277-282
Progress in producing improved vaccines against bacterial diseases of cattle is limited by an incomplete understanding of the pathogenesis of these agents. Our group has been involved in investigations of two members of the family Pasteurellaceae, Mannheimia haemolytica and Haemophilus somnus, which illustrate some of the complexities that must be confronted. Susceptibility to M. haemolytica is greatly increased during active viral respiratory infection, resulting in rapid onset of a severe and even lethal pleuropneumonia. Despite years of investigation, understanding of the mechanisms underlying this viral-bacterial synergism is incomplete. We have investigated the hypothesis that active viral infection increases the susceptibility of bovine leukocytes to the M. haemolytica leukotoxin by increasing the expression of or activating the beta2 integrin CD11a/CD18 (LFA-1) on the leukocyte surface. In vitro exposure to proinflammatory cytokines (i.e. interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma) increases LFA-1 expression on bovine leukocytes, which in turn correlates with increased binding and responsiveness to the leukotoxin. Alveolar macrophages and peripheral blood leukocytes from cattle with active bovine herpesvirus-1 (BVH-1) infection are more susceptible to the lethal effects of the leukotoxin ex vivo than leukocytes from uninfected cattle. Likewise, in vitro incubation of bovine leukocytes with bovine herpesvirus 1 (BHV-1) potentiates LFA-1 expression and makes the cells more responsive to leukotoxin. A striking characteristic of H. somnus infection is its propensity to cause vasculitis. We have shown that H. somnus and its lipo-oligosaccharide (LOS) trigger caspase activation and apoptosis in bovine endothelial cells in vitro. This effect is associated with the production of reactive oxygen and nitrogen intermediates, and is amplified in the presence of platelets. The adverse effects of H. somnus LOS are mediated in part by activation of endothelial cell purinergic receptors such as P2X7. Further dissection of the pathways that lead to endothelial cell damage in response to H. somnus might help in the development of new preventive or therapeutic regimens. A more thorough understanding of M. haemolytica and H. somnus virulence factors and their interactions with the host might identify new targets for prevention of bovine respiratory disease. 相似文献
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The role of water as an essential nutrient for the animals, their health, performance and welfare is often underestimated. Presently there exists no specific legal regulation which defines the water quality for animal consumption. Some local recommendations make reference to the German regulation for the drinking water of humans. This seems to be useful in respect to food producing animals at a first glance. However, significant practical difficulties can occur. Therefore it is necessary to include in a possible regulation for the drinking water of animals additional animal and management specific aspects such as the type of animal, the keeping system, the water supply system, the distribution systems and the drinkers which are used. It may also be useful to define animal specific thresholds for certain groups of compounds and contaminants. As a first step towards a possible regulation 12 recommendations are given to improve and standardise the water supply of farm and pet animals. 相似文献
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In an experiment, the possible influence of tannic acid (TA) and polyethylene glycol (PEG) on the absorption capacity of intestine for d-xylose and β-carotene in broiler chicken was investigated. Four groups of nine 28-day-old broiler cockerels received d-xylose (500 mg) and β-carotene (52 μg) solutions (Group 1 to 4) with TA (1 g, Group 2 to 4) and PEG (500 mg Group 3 and 1 g Group 4), orally. One blood sample prior to, and four others after the administration of test materials, were collected from wing vein on 40 min basis, for 160 min and the concentration of plasma d-xylose was determined. The concentration of β-carotene was also measured in plasma of blood samples taken prior to and 160 min post-administration of the test materials. Plasma d-xylose concentration of all groups showed quadratic correlations with time (p < 0.001, r(2) = 0.84, 0.60, 0.70 and 0.74 for Group 1 to 4, respectively). Administration of TA reduced the plasma concentration of d-xylose in Group 2. However, feeding PEG after TA raised the concentration of d-xylose in Group 4 to the level that there was no difference in that variable between this group and Group 1. Although the plasma concentration of β-carotene was increased in 160 min post-ingestion of the test material, no difference was found in that variable among the experimental groups. In conclusion, TA and its interaction with PEG have impacts on the absorption capacity of intestine for d-xylose and highly likely other simple sugars, but TA or PEG have no influence on the absorption of β-carotene and most probably other fat soluble vitamins. 相似文献
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Summary The comparative efficacy of a product containing 500 mg benzathine cloxacillin (Orbenin D.C.), another product containing 100 mg nafcillin, 300 mg procaine benzylpenicillin and 100 mg dihydrostreptomycin (Nafpenzal D.C.) and a third product containing 250 mg cephalonium (Cepravin D. C.), in the elimination and prevention of mastitis due to gram‐positive microorganisms during the dry period was investigated in 1253 cows located in 14 herds in Israël. Although more uniform results were observed after treatment with Nafpenzal D.C., differences were not found among the products with respect to the overall efficacy but differences among herds were rather large. The mean cure rate for Staphylococcus aureus quarter infections was 81.4 per cent. New S. aureus infections which occurred between drying off and post calving sampling time were found in 7.0 per cent of the quarters. Dry period therapy reduced infection level with S. aureus from 13.5 per cent of quarters to 8.0 per cent. A similar proportional decrease was found in infection level due to non‐agalactiae Streptococcus quarter infections. 相似文献
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Anna Bassols José Angel Robles-Guirado Laura Arroyo Lourdes Soler Natalia García Raquel Pato Raquel Peña Yolanda Saco Ramon Armengol Fermín Lampreave María A. Alava Francesca Canalias Matilde Piñeiro 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2023,52(Z1):64-74
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Forsberg NE al-Maqbaly R al-Halhali A Ritchie A Srikandakumar A 《Tropical animal health and production》2002,34(3):231-239
The goal of this study was to develop a molasses–urea block (MUB) for purposes of supplementing trace minerals to domestic ruminant livestock in Oman. To accomplish this, the utility of molasses and date syrup as fermentable energy sources, of straw, date flakes and wheat bran as fibre sources, and of cement and lime as binders were evaluated. The proportion of cement needed for adequate hardening of the block was also studied. Molasses- and date syrup-based blocks hardened equally well. However, the higher cost of date syrup precluded its use. Wheat straw yielded a low-density block that hardened slowly. Date fibre retained moisture and hardened extremely slowly. Wheat bran-based blocks hardened quickly and yielded dense blocks. Hence, wheat bran was judged to be the superior source of fibre. Lime did not effectively bind the blocks. A cement content of 15% allowed hardening of the blocks within 2–3 weeks. A level of 10% cement in the block reduced the hardening rate by about 50%. Sheep and goats consumed both the straw- and wheat bran-based blocks but at different rates. Consumption of the straw-based block by sheep ranged from 50 to 179 g/head per day, whereas the denser wheat bran-based block was consumed at a rate of 8–20 g/head per day. Consumption of the straw-based block by goats was low (8 g/head per day) compared to that of wheat bran-based blocks (16–24 g/head per day). On the basis of the intake of the bran-based block by sheep, a block was designed that would provide approximately 50% of an animal's trace mineral requirements per day. This block consisted of 45% molasses, 10% urea, 5% trace minerals, 2.5% NaCl, 22.5% wheat bran and 15% cement. Sheep consuming this block gained more weight than sheep fed a conventional mineral block or sheep receiving no mineral supplementation. MUBs are inexpensive (9.5 US cents/kg). We conclude that MUBs have utility for providing trace elements in ruminant diets. 相似文献
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《Domestic animal endocrinology》1994,11(3):307-314
A study was conducted to characterize steroidogenesis in small ovarian follicles (1–10 mm in diameter) of the hen. The aims of our study were: 1) to determine basal estradiol-17β (E2) production by different sizes of small follicles; 2) to determine the ability of intact small follicles to utilize exogenous substrates for testosterone (T) and E2 production; and 3) to investigate the preferred steroidogenic pathway in small follicles. Small follicles which had not entered the hierarchy were isolated from ovaries obtained 2 hr after oviposition and divided into three groups: small white follicles (SWF; 1–2 mm in diameter), large white follicles (LWF; 2–4 mm in diameter), and small yellow follicles (SYF; 5–10 mm in diameter). Yolk and granulosa cells were removed from LWFs and SYFs and the remaining theca layer was called a follicle shell. Intact follicles or follicle shells (4/4 ml/tube) were incubated in avian Ringer's buffer supplemented with 10 mM HEPES and 0.1% BSA at 37°C for 3 hr with various treatments. Testosterone and E2 were measured in the medium. The SYFs and their corresponding follicle shells produced the greatest amount of E2 when E2 production was expressed per follicle. Addition of 2 mM 8-Br-cAMP to the incubation medium stimulated E2 production by all sizes of follicles and follicle shells. However, follicle shells produced lower basal- and 8-Br-cAMP-stimulated E2 secretion compared to corresponding intact follicles. There was no significant difference in E2 production in response to various concentrations of 25-hydroxycholesterol (25-OH-CHOL; 0–100 μM) by intact follicles and follicle shells. On the contrary, intact follicles and follicle shells produced T and E2 in a dose-dependent manner in response to increasing concentrations (0–100 μM) of pregnenolone (P5). Intact follicles also used progesterone (P4) and dehydroepiandrosterone (DHEA) as substrates for T and E2 production. DHEA was the preferred substrate for steroid production compared to P4. In summary, we found that: 1) steroidogenesis in small follicles is regulated by a cAMP-dependent protein kinase A second messenger system; 2) adequate amounts of endogenous cholesterol are available for steroidogenesis; and 3) both Δ5 and Δ4 pathways are functional in small follicles and the Δ5 pathway may be the preferred steroidogenic pathway. pathway. 相似文献
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D. L. Barnes 《African Journal of Range and Forage Science》2013,30(1):69-76
Uittreksel In hierdie studie is ondersoek ingestel na die invloed van vier belankrike bosveldbome, naamlik, Acacia Senegal, Acacia tortilis, Boscia albitrunca en Combretum apiculatum op die verspreiding en en produktiwiteit van Panicum maximum. Die studie is in twee fases uitgevoer: deur middel van veldproewe in die Laar‐ Krokodilrivier‐vallei, noord‐wes van Thabazimbi, en in die glasbuise van die Potchefstroomse Universiteit. In die veld is opnames deur middel van strookpersele uitgevoer om die verspreiding van Panicum maximum in assosiasie met bogenoemde boomsoorte na te gaan. In die glasbuise is die groeivermoë van Panicum maximum in grondmonsters wat onder die vier boomsoorte versamel is met dié van grondmonsters wat in oop dele versamel is vergelyk. Die invloed van ligte graad van beskaduïng en twee verskillende vogpeile op die groeivermoë van die proef plante is ter‐selfdertyd ondersoek. ‘n Proef is ook uitgevoer om die groeivermoë van Panicum maximum by toedienings van verskillende peile N, P en K by grond wat in oop dele versamel is te ondersoek. 相似文献
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Taşdemir U Ağaoğlu AR Kaymaz M Karakaş K 《Tropical animal health and production》2011,43(5):1035-1038
The aim of this study was to compare ovarian response and embryo yield of Day 0 protocol in Angora goats (AG) and indigenous
Kilis goats (KG) in the non-breeding season. A total of 16 Angora goats (AG group) and 11 Kilis goats (KG group) were used
in this study. In the synchronization process, after controlled internal drug release withdrawal, when estrus signs were observed,
natural mating was performed. Ovarian response was determined by synchronized laparotomy 6 days after natural mating, and
number of corpora lutea (CL) was recorded. Embryos were collected and morphologically evaluated by stereomicroscope. Synchronization
rates did not differ between AG (88%, 14/16) and KG group (91%, 10/11). In AG and KG groups, the proportion of CL on the right
(44% and 53%, respectively) and left (56% and 47%, respectively) ovaries were similar. The CL number per animal did not differ
significantly between the two breeds and was determined as 4.4 ± 0.90 in AG group and 6.4 ± 1.44 in KG group. Transferable
embryo yields were significantly higher in AG group (31/42, 74%) compared to KG group (16/46, 35%) in the non-breeding season
(P < 0.01). In conclusion, it is suggested that the day 0 protocol can be used for goat superovulation in the non-breeding season;
however, transferable embryo yields are affected by the breed. 相似文献
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König M Cedillo Rosales S Becher P Thiel HJ 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(5-6):216-221
Pestiviruses cause economically important diseases of farm animals. Members of the Pestiviruses are bovine viral diarrhea virus 1 (BVDV-1), BVDV-2, classical swine fever virus (CSFV) and border disease virus (BDV). Phylogenetic analyses based on the entire nucleic acid sequence encoding the Npro allow a statistically significant segregation of established species and of subgroups within the species. BVDV-1 strains isolated in Germany can be associated with at least five different subgroups. In contrast all BVDV-2 isolates detected in Germany so far are closely related, belonging to one subgroup. A group of virus isolates from sheep and zoo animals is clearly different from established pestivirus species and can be designated as BDV-2. Antigenetic relatedness of pestiviruses was studied using defined virus isolates and antisera in cross-neutralization assays. Six antigenic groups were distinguished corresponding to the genetic clusters BVDV-1, BVDV-2, CSFV, BDV-1, BDV-2 and Giraffe-1. A significant antigenic difference was also observed between members of subgroups 1a and 1b of BVDV-1. Studies on the genetic and antigenic heterogeneity of pestiviruses are important for the development of new vaccines, diagnostic tests and for eradication programs. 相似文献
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