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61.
Meat composition and palatability of Holstein and beef steers as influenced by forage type and protein source. 总被引:1,自引:0,他引:1
E W Mills J W Comerford R Hollender H W Harpster B House W R Henning 《Journal of animal science》1992,70(8):2446-2451
This experiment determined meat composition and palatability changes resulting from feeding Holstein (HOL) and crossbred beef (XB) steers diets containing corn silage (CS) or alfalfa haylage (AH) (forage type) and soybean meal (SM) or fish meal (FM) (protein source). Fifty-nine steers (30 HOL and 29 XB) were randomly assigned to diet combinations for a 2 x 2 x 2 (breed x forage x protein) factorial arrangement. Steers were fed to a fat-constant end point (fat depth over the longissimus muscle measured by ultrasound: 1.0 cm XB, .6 cm HOL). Proximate and fatty acid analysis and sensory evaluation were conducted on a rib eye roast and steaks, respectively, removed from the left side of each carcass at ribs 9 to 12. Proximate analysis of the longissimus muscle showed no significant difference (P greater than .05) in moisture, protein, or fat content due to breed, forage, or protein treatment. Forage type had no significant effect (P greater than .05) on amount of individual fatty acids found in longissimus muscle. However, total polyunsaturated fatty acids were higher (P greater than .05) for AH than for CS-fed animals. Longissimus muscle from steers fed FM had higher palmitoleic and lower stearic acid contents (both P less than .05) than longissimus muscle from animals fed SM. Muscle from HOL had higher palmitoleic and lower stearic acid contents than that from XB steers (both P less than .05). There was no significant interaction (P greater than .05) of breed with either diet treatment for individual fatty acid contents.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
62.
Dhanoa MS France J Crompton LA Mauricio RM Kebreab E Mills JA Sanderson R Dijkstra J López S 《Journal of animal science》2004,82(3):733-746
A method is proposed to determine the extent of degradation in the rumen involving a two-stage mathematical modeling process. In the first stage, a statistical model shifts (or maps) the gas accumulation profile obtained using a fecal inoculum to a ruminal gas profile. Then, a kinetic model determines the extent of degradation in the rumen from the shifted profile. The kinetic model is presented as a generalized mathematical function, allowing any one of a number of alternative equation forms to be selected. This method might allow the gas production technique to become an approach for determining extent of degradation in the rumen, decreasing the need for surgically modified animals while still maintaining the link with the animal. Further research is needed before the proposed methodology can be used as a standard method across a range of feeds. 相似文献
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64.
The use of topical pharmaceutical formulations is increasingly popular in veterinary medicine. A potential concern is that not all formulations are registered for the intended species, yet current knowledge strongly suggests that simple extrapolation of transdermal drug pharmacokinetics and pharmacodynamics between species, including humans, cannot be done. In this review, an overview is provided of the underlying basic principles determining the movement of topically applied molecules into and through the skin. Various factors that may affect transdermal drug penetration between species, between individuals of a particular species and regional differences in an individual are also discussed. A good understanding of the basic principles of transdermal drug delivery is critical to avoid adverse effects or lack of efficacy when applying topical formulations in veterinary medicine. 相似文献
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66.
OBJECTIVE: To investigate the effects of short-chain fatty acids (SCFAs) and pH on neutrophil oxidative burst, phagocytosis, and morphology after exposure to acetate, propionate, butyrate, or succinate at pH 5.5 and 6.7. SAMPLE POPULATION: Neutrophils isolated from bovine blood samples and Porphyromonas levii, Prevotella spp, and Bacteroides fragilis isolated from lesions of cattle with acute interdigital phlegmon (foot rot). PROCEDURES: Bacteria were cultured in strictly anaerobic conditions. Bacterial SCFA production was measured with high-performance liquid chromatography. Neutrophils were isolated, stimulated with phorbol 12-myristate 13-acetate (PMA) or opsonized zymosan (OZ), and incubated with dihydroethidium or dichlorofluorescein diacetate to measure production of O(2)and H(2)O(2), respectively. Phagocytosis was assessed after exposure to serum-opsonized bacteria. Cellular morphology was assessed with differential staining. RESULTS: All bacteria produced at least 3 of the 4 SCFAs. Production of both O(2) and H(2)O(2) was markedly curtailed in PMA-stimulated neutrophils exposed to SCFA at pH 5.5, compared with production at pH 6.7. Succinate caused a significant dose-dependent decrease in O(2) production at pH 6.7 in OZ-stimulated neutrophils. Monoprotic SCFAs elicited a significant increase in H(2)O(2) production in OZ-stimulated neutrophils at pH 6.7 but a significant decrease at pH 5.5. Monoprotic SCFAs significantly increased phagocytosis at pH 6.7 but decreased phagocytic activity at pH 5.5. Cellular necrosis was observed in cells exposed to SCFAs at pH 5.5. CONCLUSIONS AND CLINICAL RELEVANCE: Establishment and persistence of anaerobic bacteria in cattle with foot rot infection may result in part from neutrophil dysfunction secondary to the effects of bacterially secreted SCFA in acidotic microenvironments. 相似文献
67.
De Graef J Sarre C Mills BJ Mahabir S Casaert S De Wilde N Van Weyenberg M Geldhof P Marchiondo A Vercruysse J Meeus P Claerebout E 《Veterinary parasitology》2012,189(2-4):378-382
The main objective of the present study was to evaluate the accuracy of the faecal egg count reduction test (FECRT) to assess the resistance status of ivermectin (IVM)-resistant isolates of the cattle nematodes Ostertagia ostertagi and Cooperia oncophora, using the controlled efficacy test (worm counts) as a reference. The second objective was to investigate whether both IVM-resistant isolates showed side-resistance against moxidectin (MOX) under controlled conditions. Thirty male Holstein calves were experimentally infected with 25,000 L3 of an IVM-resistant O. ostertagi isolate and 25,000 L3 of an IVM-resistant C. oncophora isolate. Twenty-eight days later the calves were randomly divided into 2 treatment groups and 1 untreated control group. Animals in groups 1 and 2 received MOX (Cydectin(?) 1%, Pfizer) and IVM (Ivomec(?) 1%, Merial) respectively, by subcutaneous injection at a dose rate of 0.2mg/kg bodyweight. Faecal samples were collected 7 and 14days after treatment and animals were necropsied 14/15days post-treatment. Both the FECRT and the controlled efficacy test demonstrated that the O. ostertagi and C. oncophora isolates were resistant against IVM, with efficacies below 90%. The IVM-resistant O. ostertagia isolate was still susceptible to MOX treatment, as shown by over 99% reduction in egg counts and worm burden. The FECRT suggested borderline resistance against MOX in the IVM-resistant C. oncophora isolate, with egg count reductions between 97% (95% CI: 76; 100) at day 7 and 86% (95% CI: 49; 96) at day 14. However, the controlled efficacy test clearly showed MOX-resistance, with a decrease of only 31% (95% CI: -12; 57) in C. oncophora worm numbers. After MOX treatment, a significantly lower number of eggs per female C. oncophora worms was counted compared to the control group (43% reduction). Due to this reduced fecundity, the FECRT may fail to detect MOX-resistance. 相似文献
68.
The area restriction model for harvest scheduling problems can be formulated using mixed integer programs. The three different formulation types are cluster packing, cell aggregation, and the assignment formulation. Within the cell aggregation subgroup there is an exact formulation, the cover constraint (CC) approach; and an inexact formulation, the stand-centered approach. The cover constraint formulation has significantly more constraints than the stand-centered formulation. A computational comparison between these two methods is completed using cutting planes and constraint combinations using the CPLEX solver package. The CC approach as cutting planes was superior based on solution time. If formulation time were included with solution time, then the CC approach remains superior. The maximum harvest area is a significant factor of solution time. In addition, the percentage of total cutting planes used to solve the problem was examined. 相似文献
69.
AIM: To develop a technique to estimate the volume of epithelial lining fluid (ELF) obtained during bronchoalveolar lavage (BAL) and pleural lavage (PL) in the dog, using the urea dilution method. METHODS: BAL and PL fluids were obtained by saline lavage of pulmonary and pleural cavities of nine clinically healthy mixed-breed dogs immediately after euthanasia. Cell counts in the BAL and PL fluids were measured using standard techniques. The concentration of ELF in each lavage fluid was calculated from the relative concentration of urea in plasma and in each type of lavage fluid. Cell counts in ELF were then calculated. RESULTS: There were substantially higher cell counts in ELF compared to BAL or PF fluid. However, nucleated cell counts in ELF could not be predicted from cell counts in BAL or PL fluid. CONCLUSIONS AND CLINICAL RELEVANCE: These results suggest that accurate assessment of cellular or non-cellular components in lavage fluids should include a calculation of the proportion of ELF recovered, using a method such as urea dilution. 相似文献
70.