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1.
AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving.

METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000?cells/mL at the first herd test after calving.

RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000?cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000?cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30).

CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis.  相似文献   
2.
The chemical composition and protein quality of 11 alternative protein sources (chicken products, blood products, enzyme-hydrolyzed fish protein concentrate, soybean meal, and spray-dried pork liver) were determined, and an experiment was conducted to determine palatability and digestibility of processed red blood cell-containing diets. Chicken protein sources differed in concentrations of CP, acid-hydrolyzed fat, and total AA (TAA) by 20, 31, and 24%, respectively, and GE by 1.7 kcal/g. Blood protein sources varied little in acid-hydrolyzed fat and GE concentrations, but concentrations of CP and TAA differed by 11 and 8%, respectively. Protein solubility of chicken and blood protein source categories averaged 57 and 69%, respectively. Protein solubility of enzyme-hydrolyzed fish protein concentrate, soybean meal, and spray-dried pork liver was 53, 67, and 26%, respectively. Based on calculations from immobilized digestive enzyme assay values, lysine digestibility averaged approximately 80.4 and 81.7% for blood and chicken protein sources, respectively. Lysine digestibility values for soybean meal and spray-dried pork liver were 89 and 77%, respectively. A chick protein efficiency ratio (PER) assay showed that chicken protein sources had high protein quality values, as the PER ranged from 2.7 to 5.3, whereas blood protein sources had poor protein quality (PER values less than 1.5). Enzyme-hydrolyzed fish protein concentrate, spray-dried pork liver, and soybean meal had high protein quality (PER values greater than 2.8). In the dog palatability and digestibility experiments, a corn and chicken-based diet supplemented with either 0 or 3% processed red blood cells was tested. The palatability test showed that dogs consumed more of the diet that contained 0% vs. 3% processed red blood cells. The intake ratio for the 3% processed red blood cells diet was 0.34. Nutrient digestibilities did not differ, except for CP, where the digestibility was greater (P = 0.01) for dogs consuming the 0% processed red blood cells diet. These data suggest that chemical composition and quality of alternative protein sources differ greatly among ingredients within the same category. Palatability data suggest that a processed red blood cells-containing diet is not highly palatable but, when this diet was offered as only one food, dogs demonstrated no aversion response but some decrease in protein digestion.  相似文献   
3.
Optical experiments were conducted on a series of organic linear chain conductors with different values of the interchain single-electron transfer integral tb, which quantifies the degree of anisotropy. Electron-electron interactions together with Umklapp scattering resulted in a correlation gap and an insulating state for small tb. An insulator-to-metal transition was observed when tb exceeded a critical value, on the order of the correlation gap Egap. The absence of a plasma edge on the insulator side of the transition for polarization perpendicular to the chains suggests that the electrons are confined to the chains. The optical features of the metallic state, when contrasted with the magnetic properties, are suggestive of spin-charge separation.  相似文献   
4.
An experiment was conducted to analytically define several novel fish substrates and determine the effects of feeding diets containing these substrates on total tract nutrient digestibilities and on immune status of senior dogs. The control diet contained poultry by-product meal while test diets contained 20% milt meal (MM), pink salmon hydrolysate (PSH) and white fish meal (WFM) added at the expense of poultry by-product meal. Concentrations of lymphocytes positive for CD3, CD4, CD8 and CD21 cell-surface markers and immunoglobulin concentrations were measured. Gene expression of cytokines tumour necrosis factor (TNF)-, interleukin (IL)-6, interferon (IFN)-, IL-10 and transforming growth factor (TGF)-β was determined by quantitative real-time polymerase chain reaction. Major compositional differences were noted among fish substrates but apparent nutrient digestibility coefficients and immune indices were not affected by treatment. Fish protein substrates were found to be effective substitutes for poultry by-product meal, providing diets of high nutritive value for senior dogs.  相似文献   
5.
High nitrogen fixing, phosphate solubilizing, phytohormones producing isolates of Azotobacter, Azospirillum, Acetobacter and Pseudomonas were used as inoculants for cotton. Important cultures were selected on the basis of their effect on root/shoot length and chemotactic behaviour. Selected bioinoculants were earlier tested for their beneficial properties like nitrogen fixation (ARA), ammonia excretion, IAA production etc. These bio-inoculants were further tested for phosphate solubilization property. Various chosen strains were tested with Desi (HD 123) and American (H 1098) cotton under field conditions (as for wheat). Plant height and boll weight were determined at the time of harvesting whereas survival rate of inoculated bacteria was determined after 30, 80 and 130 days respectively. In the year 2000–01, on the basis of boll number and boll weight plant?1 AVK 51 (36; 76.2?g plant?1), HT 57 (27; 56.9?g plant?1), AC18 (33; 61.5?g plant?1), Ala 27 (36; 61.4?g plant?1) and Pseudomonas (34; 71.3?g plant?1) were identified as significant both for American and desi cotton varieties. Highest survival rate was observed with Mac 68 (33.4 × 105) followed by HT54 (31.5 × 105) after 30 days of sowing, which decreased after 80 days and remained constant up to 130 days. This trend was observed with all the cultures. Similar results were observed in 2001–02. 25?kg ha?1 N saving was observed with A. chroococcum (AVK51) bioinoculant for cotton crop.  相似文献   
6.
7.
Growing conditions and processing technologies to which soybeans (SB) are exposed have an effect on digestibilities of AA found in the resultant soybean meals (SBM). This study evaluated SBM from five major SB-producing countries (Argentina, Brazil, China, India, and the United States). An industry representative in each country collected samples of unprocessed SB and SBM subjectively determined to be of high, intermediate, or low quality. The SB from each country were processed into SBM under uniform conditions in the United States. Five experiments (each examining the three SBM and the SB processed in the United States from a single country) were conducted to determine true ileal AAd digestibilities. In addition, a standard SBM purchased on the open market in the United States was used in all experiments as a control. Data from pigs fed a low-protein casein diet in each study were used to calculate true AA digestibilities. Pigs were fitted with simple T-cannulas at the terminal ileum and allotted to treatments in Latin square design experiments. Duplicate experiments were conducted at the University of Illinois and at The Ohio State University. Within each country comparison, pigs fed the SBM processed in the U.S. from SB grown in the five countries had lower (P < 0.05) true total amino acid (TAA) digestibilities than did pigs fed any of the SBM prepared within the country of origin, except the United States. This indicates that processing conditions used at the U.S. pilot plant were not ideal when using SB from other countries. True TAA digestibilities of the diets containing the high-, intermediate-, and low-quality SBM did not differ, except for China, where the low-quality SBM (83.5%) had a lower (P < 0.05) digestibility than the intermediate- (89.6%) or high- (89.0%) quality meals. Soybean meal produced in Argentina (average, 87%) and Brazil (average, 82%) had lower (P < 0.05) true TAA digestibilities than did the standard SBM (91%), indicating that the processing plants in those countries may produce a less digestible SBM than that available on the open market in the United States.  相似文献   
8.
To quantify variation in U.S. soybean meals (SBM), samples were collected from 55 U.S. soybean (SB) processing plants located in seven of the geographic SB maturity zones at three time points. These samples were analyzed for crude and acid-hydrolyzed fat, oligosaccharide, and amino acid concentrations. Acid-hydrolyzed fat concentrations were poorly correlated (r = 0.28) to crude fat concentrations and were higher for SBM prepared in the southern zones (V-VII) as compared with the northern zones (I and II). Raffinose and verbascose concentrations were lowest (P < 0.05) for SBM prepared in northern maturity zones, while stachyose concentrations were highest for SBM prepared in central maturity zones (III and IV). Total essential, total nonessential, and total amino acid concentrations were lowest for SBM prepared in northern zones. There was variation in oligosaccharide and amino acid concentrations over time, probably due to variation in composition of SB arriving at the plants within maturity zone.  相似文献   
9.
The purpose of this study was to compare the echocardiographic Doppler blood pressure and heart rate effects of 1:1 thiopental/propofol with thiopental and propofol, when used as anesthesia‐induction agents. Seven healthy dogs (six Beagles and one Pembroke Welsh Corgi), ranging in age from 1 to 9 years and weighing 14.2 ± 2.4 kg (mean ± SD), were used during the study. In a cross‐over study design with a minimum drug interval of 3 days, each dog received propofol, thiopental, or a mixture of propofol–thiopental IV until each dog received all the three anesthetic agents. An initial dose (propofol 4.9 ± 0.8 mg kg?1; thiopental 12.9 ± 2.4 mg kg?1; propofol–thiopental 2.3 ± 0.3 mg kg?1 (P)?5.7 ± 0.8 mg kg?1 (T)) of each anesthetic agent was titrated IV until intubation was accomplished. Echocardiographic Doppler blood pressure and heart rate variables were recorded prior to anesthesia and at 1, 5, and 10 minutes after induction of anesthesia. anova and the Bonferroni's t‐test were used to evaluate the groups for differences. Alpha was <0.05. There was no significant effect of treatment on systolic or diastolic ventricular wall thickness, septal thickness, left atrial diameter, or systolic left ventricular diameter. There was a tendency for diastolic left ventricular diameter to decrease over time. There was a tendency for heart rate to increase with a significant difference at the 10‐minute time period between propofol (109 ± 26 beats minute?1) and thiopental (129 ± 23 beats minute?1). At the 10‐minute recording period, heart rate following the propofol/thiopental mixture (110 ± 34 beats minute?1) was closer to that following propofol than to that following thiopental. With all induction agents, indirect blood pressure tended to decrease over time (p = 0.005); however, there was no difference between the groups. The changes observed were not considered to be of clinical significance. The propofol/thiopental mixture produces similar changes in echocardiographic variables when compared to propofol or thiopental, and could be substituted for propofol for induction of anesthesia in dogs.  相似文献   
10.
An experiment to determine the chemical composition and protein quality of 13 fish substrates (pollock by-products, n = 5; fish protein hydrolysates, n = 5; and fish meals, n = 3) was conducted. Two of these substrates, salmon protein hydrolysate (SPH) and salmon meal with crushed bones (SMB), were used to determine their palatability as components of dog diets. Pollock by-products differed in concentrations of CP, crude fat, and total AA by 71, 79, and 71%, respectively, and GE by 4.1 kcal/g. Fish protein hydrolysates and fish meals were less variable (approximately 18, 14, and 17%, and 1.4 kcal/g, respectively). Biogenic amine concentrations were much higher in fish protein hydrolysates as compared with pollock by-products and fish meals. Pollock liver and viscera had the highest total fatty acid concentrations; however, red salmon hydrolysate and SMB had the highest total PUFA concentrations (49.63 and 48.60 mg/g, respectively). Salmon protein hydrolysate had the highest protein solubility in 0.2% KOH. Based on calculations using immobilized digestive enzyme assay values, lysine digestibility of fish meal substrates was comparable to in vivo cecectomized rooster assay values and averaged approximately 90.3%. Also, pollock milt, pollock viscera, red salmon hydrolysate, and sole hydrolysate had comparable values as assessed by immobilized digestive enzyme assay and rooster assays. A chick protein efficiency ratio (PER) assay compared SMB and SPH to a whole egg meal control and showed that SMB had high protein quality (PER = 3.5), whereas SPH had poor protein quality (PER value less than 1.5). However, using whole egg meal as the reference protein, both fish substrates were found to be good protein sources with an essential AA index of 1.0 and 0.9 for SMB and SPH, respectively. In the dog palatability experiments, a chicken-based control diet and 2 diets containing 10% of either SPH or SMB were tested. Dogs consumed more of the SPH diet compared with the control, and similar amounts of the SMB and control diets. The intake ratios for each were 0.73 and 0.52, respectively. Salmon protein hydrolysate was especially palatable to dogs. These data suggest that chemical composition and nutritional quality of fish substrates differ greatly and are affected by the specific part of the fish used to prepare fish meals and fish protein hydrolysates.  相似文献   
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