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961.
Swanson KC Kelly N Salim H Wang YJ Holligan S Fan MZ McBride BW 《Journal of animal science》2008,86(4):909-915
Twenty-four yearling beef steers (initial BW = 510 +/- 4.9 kg) predominantly of Angus breeding were used in a randomized complete block design to determine the effect of dietary CP concentration on pancreatic cellularity, mass, and alpha-amylase and trypsin activities. Treatment diets were formulated to contain 8.8, 11.0, 13.2, and 15.4% CP. Soybean meal and Top Soy (ruminal bypass soybean meal) were used as supplemental protein sources to ensure that MP intake was increased with increasing dietary CP concentrations. Steers were penned in groups of 4 (1 steer per treatment) and individually fed at 2.5x the NE(m) requirement by using Calan gates for 28 d before tissue collection. Four steers (1 pen) were slaughtered per week. Pancreases were weighed, subsampled, frozen in liquid N(2), and stored at -80 degrees C until analyses for DNA, RNA, and protein concentrations, and alpha-amylase and trypsin activities. Pancreatic weight (g and g/kg of BW) did not differ among treatment groups. Pancreatic DNA concentration (mg/g) decreased linearly (P = 0.06) with increasing CP concentration. Pancreatic protein (g/pancreas) increased linearly (P = 0.08) with increasing dietary CP concentration. Pancreatic alpha-amylase activity (U/g, U/mg of DNA, U/g of protein, U/pancreas, and U/kg of BW) increased linearly (P < or = 0.04) with increasing dietary CP concentration. Pancreatic trypsin activity (U/g, U/g of DNA, U/g of protein, U/pancreas, and U/kg of BW) increased linearly (P < or = 0.09) with increasing dietary CP concentration. Pancreatic alpha-amylase and trypsin activities (U/mg of RNA) responded quadratically (P < or = 0.09), with the greatest alpha-amylase activity observed in the 13.2% CP treatment. These data indicate that increasing dietary CP concentration decreases pancreatic cell numbers and also increases the concentration and content of pancreatic alpha-amylase and trypsin activities. Changes in cell number and size may be important factors regulating digestive enzyme production in the pancreas of cattle. 相似文献
962.
Shi LH Ai JS Ouyang YC Huang JC Lei ZL Wang Q Yin S Han ZM Sun QY Chen DY 《Journal of animal science》2008,86(5):1106-1113
To investigate the influence of histone deacetylases on nuclear reprogramming after nuclear transfer, we treated the cloned embryos with a histone deacetylase inhibitor, Trichostatin A (TSA). In the present study, global changes in acetylation of histone H3-lysine 14, histone H4-lysine 12, and histone H4-lysine 5 were studied in rabbit in vivo fertilized embryos, somatic cell nuclear transfer (SCNT) embryos, and TSA-treated SCNT embryos. From the pronuclear to the morula stage, the deacetylation-reacetylation changes in acetylation of histone H3-lysine 14 and histone H4-lysine 12 occurred in both fertilized embryos and TSA-treated cloned embryos; however, the distribution pattern in untreated cloned embryos failed to display such changes. More interesting, the signal of acetylation of histone H4-lysine 12 in cloned embryos was detected in both the inner cell mass and the trophectoderm, whereas TSA-treated cloned embryos showed the same staining pattern as fertilized embryos and the staining was limited to the inner cell mass. The histone acetylation pattern of TSA-treated SCNT embryos appeared to be more similar to that of normal embryos, indicating that TSA could improve nuclear reprogramming after nuclear transfer. 相似文献
963.
Variation at the insulin-like growth factor 1 gene and its association with body weight traits in the chicken 总被引:1,自引:0,他引:1
L H Bian S Z Wang Q G Wang S Zhang Y X Wang H Li 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2008,125(4):265-270
The insulin-like growth factor 1 (IGF1) is essential for normal embryonic and postnatal growth in mammals. In this study, a total of 342 F(2) individuals, derived from Broiler crossing to Baier layer (Northeast Agricultural University Resource Population, NEAURP), were used to investigate the associations of haplotypes in the chicken IGF1 (cIGF1) gene with body weight traits. Primers for the 5'-flanking, exon 3 and 3'-flanking regions of cIGF1 were designed according to chicken genome database. Single nucleotide polymorphisms (SNPs) between parental lines were detected by sequencing, and PCR restriction fragment length polymorphism (PCR-RFLP) and PCR single-stranded-conformation polymorphism (PCR-SSCP) methods were used to genotype the SNPs in the population. Haplotypes were constructed with the three SNPs detected. The association analysis showed that haplotypes based on three cIGF1 polymorphisms (c.-366A>C, c.528G>A and c.*1024C>T) were associated with body weight traits, suggesting that cIGF1 or a tightly linked gene had effects on body weight in the chicken. 相似文献
964.
965.
X. B. LI W. X. WU D. SU Z. J. WANG H. Y. JIANG J. Z. SHEN 《Journal of veterinary pharmacology and therapeutics》2008,31(6):523-527
A study on bioavailability and pharmacokinetics of cefquinome in piglets was conducted after intravenous (i.v.) and intramuscular (i.m.) administrations of 2.0 mg/kg of body weight, respectively. Plasma concentrations were measured by high‐performance liquid chromatography assay with UV detector at 268‐nm wavelength. Plasma concentration–time data after i.v. administration were best fit by a two‐compartment model. The pharmacokinetic values were distribution half‐life 0.27 ± 0.21 h, elimination half‐life 1.85 ± 1.11 h, total body clearance 0.26 ± 0.08 L/kg·h, area under curve 8.07 ± 1.91 μg·h/mL and volume of distribution at steady state 0.46 ± 0.10 L/kg. Plasma concentration–time data after i.m. administration were also best fit by a two‐compartment model. The pharmacokinetic parameters were distribution half‐life 0.88 ± 0.42 h, elimination half‐life 4.36 ± 2.35 h, peak concentration 4.01 ± 0.57 μg/mL and bioavailability 95.13 ± 9.93%. 相似文献
966.
Population pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin in ill cows 总被引:1,自引:1,他引:0
Fu LX Jiang ZG Ding HZ Liu YH 《Journal of veterinary pharmacology and therapeutics》2008,31(3):240-245
This study was performed in 105 ill cows to determine the best practical individualized dose of enrofloxacin after i.m. (2.5 mg/kg) single-dose administration. Samples were collected from each cow at random time to ensure the percentage of samples distributed equally in the absorption phase, distribution phase, and elimination phase of the drug. Drug concentrations were determined by high-performance liquid chromatography with fluorometric detector, analyzed by population pharmacokinetic (PPK) modeling with NONMEM. The concentration–time data for enrofloxacin in plasma and ciprofloxacin were fitted to the one-compartment model with first-order absorption and elimination. The final covariate model indicated that body weight and daily milk productions have significant influence on clearance (CL) of enrofloxacin and ciprofloxacin, and the volume ( V ) of distribution of enrofloxacin. The typical PPK parameters were K a = 3.33 h−1 , CL = 1.25 L/h/kg, and V = 2.98 L/kg of enrofloxacin, and the interindividual variability for CL and V were 20.2% and 24.3%, respectively, the population mean estimates of K a , CL, and V for ciprofloxacin were 1.12 h−1 , 2.36 L/h/kg, 8.20 L/kg, respectively, and their interindividual variability was 36.9%, 15.8% and 14.1%, respectively. 相似文献
967.
968.
969.
Amory JR Barker ZE Wright JL Mason SA Blowey RW Green LE 《Preventive veterinary medicine》2008,83(3-4):381-391
The milk yields of 1824 cows were used to investigate the effect of lesion-specific causes of lameness, based on farmer treatment and diagnosis of lame cows, on milk yield. A three-level hierarchical model of repeated test day yields within cows within herds was used to investigate the impact of lesion-specific causes of lameness (sole ulcer, white line disease, digital dermatitis and other causes) on milk yield before and after treatment compared with unaffected cows. Cattle which developed sole ulcer (SU) and white line disease (WLD) were higher yielding cattle before they were diagnosed. Their milk production fell to below that of the mean of unaffected cows before diagnosis and remained low after diagnosis. In cattle which developed digital dermatitis (DD) there was no significant difference in milk yield before treatment and a slightly raised milk yield immediately after treatment. The estimated milk loss attributable to SU and WLD was approximately 570 and 370 kg, respectively. These results highlight that specific types of lameness vary by herds and within herds they are associated with higher yielding cattle. Consequently lesion-specific lameness reduction programmes targeting the cow and farm specific causes of lameness might be more effective than generic recommendations. They also highlight the importance of milk loss when estimating the economic impact of SU and WLD on the farms profitability. 相似文献
970.
Baktiar O Karim Syed Z Ali Jennifer A Landolfi Jill F Mann Guosheng Liu Archie Christian John F Dicello Dorothy L Rosenthal David L Huso 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2008,37(2):229-236
BACKGROUND: Fine needle aspiration (FNA) offers a rapid and minimally invasive means to distinguish malignant from benign neoplasms. However, few studies have been published regarding the cytopathology of mammary tumors in rats despite widespread use of the rat model for breast cancer formation and inhibition. OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of FNA cytology and to develop distinguishing cytologic criteria for the diagnosis of radiation-induced benign and malignant mammary tumors in rats. METHODS: In a study of radiation-induced mammary carcinogenesis, 100 Sprague-Dawley rats with cutaneous masses were randomly chosen for FNA. The aspirates were smeared, fixed, and stained with a modified Papanicolaou procedure for diagnostic evaluation. Cytologic and histologic diagnoses (benign vs malignant) were compared, and diagnostic accuracy was calculated using the histologic diagnosis as the criterion standard. FNA smears were scored semiquantitatively on a scale of 1-4 for cellularity, atypia, nuclear size, chromatin pattern, nuclear membrane thickness, nucleoli, and mitoses. The background was evaluated for necrosis, hemorrhage, inflammation, and mucosecretory material. Cytomorphologic features were compared statistically between benign and malignant tumors, based on the histologic diagnosis. RESULTS: The sensitivity of FNA was 92.3% and specificity was 89.4% for the detection of malignancy. However, 14% of specimens, all fibroadenomas by histology, had insufficient cells for cytologic evaluation, for an overall accuracy rate of 78.0%. Malignant tumors had significantly higher scores for all cytomorphologic features, and were significantly more likely to contain cell clusters and necrotic debris. CONCLUSIONS: FNA is an accurate method for differentiating benign and malignant rat mammary tumors. 相似文献