Effects of smooth and rough Pasteurella haemolytica lipopolysaccharides on plasma cyclic-nucleotides and free fatty acids in calves

The present study examined the potency of smooth or rough Pasteurella haemolytica lipopolysaccharide infusion (LPS, 24 ng kg-1 min-1 for 500 min) on plasma cyclic-nucleotides and several free fatty acids (FFA) in calves. Both smooth or rough LPS increased plasma cAMP immediately to its maximum at 1 h of infusion, whereas plasma cGMP levels rose slowly and peaked 12 h later. The increases in cAMP levels were more prolonged for smooth LPS than rough LPS. The maximum plasma cAMP rise coincided with increases of several plasma FFA. Rough LPS increased plasma oleic greater than palmitic greater than stearic greater than linoleic acids in the second hour and reached their steady state levels between 2 h of infusion and 5 h post-infusion. Thereafter, oleic acid remained maximally elevated, while stearic acid decreased and other FFA returned to baseline. Smooth LPS had no effects on palmitic and stearic acids, but elevated oleic acid in an essentially similar manner to rough LPS and increased linoleic acid initially at 5 h, followed by decreases throughout post-infusion. These results demonstrate that endotoxemia produces early marked elevations in plasma cAMP, a gradual rise in plasma cGMP and disproportionate increases in several plasma FFA. The data also demonstrate that smooth and rough LPS differ in their abilities to increase plasma cAMP and FFA and these may be attributed to differences in their in vivo mechanisms of action. The study suggests that cAMP and cGMP may mediate actions of endotoxin at the cellular level and that differences exist in release and/or utilization of each FFA at different stages of endotoxemia.     

A multicentric retrospective study of serum/plasma urea and creatinine concentrations in dogs using univariate and multivariate decision rules to evaluate diagnostic efficiency

BACKGROUND: Urea and creatinine are the most frequently used indirect markers in plasma and serum of glomerular filtration rate in dogs. Both have been shown to lack sensitivity but their diagnostic efficiency for the diagnosis of kidney disease has been minimally investigated. OBJECTIVE: The purpose of this retrospective study was to investigate the influence of possible factors of variation on both analytes and to determine whether specific decision rules should be drawn up for subpopulations of dogs. METHODS: The results of urea and creatinine measurements, breed, sex, age, and health status (healthy, renal disease, or nonrenal disease) of 3822 dogs were collected from the archives of 5 veterinary clinics. Data were analyzed with univariate and multivariate decision rules with and without adjustment. RESULTS: There were significant effects and interactions of almost all of the sources of variation. Slight improvements in diagnostic efficiency were obtained by adjusting the decision rules to these sources of variations. Univariate decision rules gave approximately the same diagnostic efficiency for urea and creatinine concentrations, with sensitivity and specificity in the range of 70% and 90%, respectively, using the upper limit of the reference interval as the threshold value. Multivariate decision rules provided only minor improvements in diagnostic efficiency. CONCLUSION: Simultaneous measurement of both urea and creatinine is of limited diagnostic value over the analysis of a single variable. Creatinine is the preferred analyte as it is affected by fewer extrarenal factors of variation.     

Multicenter case-control study of risk factors associated with development of vaccine-associated sarcomas in cats

OBJECTIVE: To determine whether particular vaccine brands, other injectable medications, customary vaccination practices, or various host factors were associated with the formation of vaccine-associated sarcomas in cats. DESIGN: Prospective multicenter case-control study. ANIMALS: Cats in the United States and Canada with soft tissue sarcomas or basal cell tumors. PROCEDURE: Veterinarians submitting biopsy specimens from cats with a confirmed diagnosis of soft tissue sarcoma or basal cell tumor were contacted for patient medical history. Time window statistical analyses were used in conjunction with various assumptions about case definitions. RESULTS: No single vaccine brand or manufacturer within antigen class was found to be associated with sarcoma formation. Factors related to vaccine administration were also not associated with sarcoma development, with the possible exception of vaccine temperature prior to injection. Two injectable medications (long-acting penicillin and methyl prednisolone acetate) were administered to case cats more frequently than to control cats. CONCLUSIONS AND CLINICAL RELEVANCE: Findings do not support the hypotheses that specific brands or types of vaccine within antigen class, vaccine practices such as reuse of syringes, concomitant viral infection, history of trauma, or residence either increase or decrease the risk of vaccine-associated sarcoma formation in cats. There was evidence to suggest that certain long-acting injectable medications may also be associated with sarcoma formation.     

Experimental reproduction of severe disease in CD/CD pigs concurrently infected with type 2 porcine circovirus and porcine reproductive and respiratory syndrome virus

Three-week-old cesarean-derived colostrum-deprived (CD/CD) pigs were inoculated with porcine circovirus type 2 (PCV2, n = 19), porcine reproductive and respiratory syndrome virus (PRRSV, n = 13), concurrent PCV2 and PRRSV (PCV2/PRRSV, n = 17), or a sham inoculum (n = 12) to compare the independent and combined effects of these agents. Necropsies were performed at 7, 10, 14, 21, 35, and 49 days postinoculation (dpi) or when pigs became moribund. By 10 dpi, PCV2/PRRSV-inoculated pigs had severe dyspnea, lethargy, and occasional icterus; after 10 dpi, mortality in this group was 10/11 (91%), and all PCV2/ PRRSV-inoculated pigs were dead by 20 dpi. PCV2-inoculated pigs developed lethargy and sporadic icterus, and 8/19 (42%) developed exudative epidermitis; mortality was 5/19 (26%). PRRSV-inoculated pigs developed dyspnea and mild lethargy that resolved by 28 dpi. Microscopic lesions consistent with postweaning multisystemic wasting syndrome (PMWS) were present in both PCV2- and PCV2/PRRSV-inoculated pigs and included lymphoid depletion, necrotizing hepatitis, mild necrotizing bronchiolitis, and infiltrates of macrophages that occasionally contained basophilic intracytoplasmic inclusion bodies in lymphoid and other tissues. PCV2/ PRRSV-inoculated pigs also had severe proliferative interstitial pneumonia and more consistent hepatic lesions. The most severe lesions contained the greatest number of PCV2 antigen-containing cells. PRRSV-inoculated pigs had moderate proliferative interstitial pneumonia but did not develop bronchiolar or hepatic lesions or lymphoid depletion. All groups remained seronegative to porcine parvovirus. The results indicate that 1) PCV2 coinfection increases the severity of PRRSV-induced interstitial pneumonia in CD/CD pigs and 2) PCV2 but not PRRSV induces the lymphoid depletion, granulomatous inflammation, and necrotizing hepatitis characteristic of PMWS.     

Estimated Breeding Value in Iranian Buffaloes

This study was conducted from 1992-2002 on 65,534 individual milk records and fat percentage in 473 herds, in six provinces of Khuzestan, Mazndaran, W. Azerbaijan, E. Azerbaijan, Ardabil and Gilan. The data was analyzed by SAS sotfware using GLM procedure. The heritability and breeding value of 1,195 animals were calculated by DFRML procedure. The average milk yield per lactation, days of lactation, fat percentage and LSM of fat percentage were 1,513 kg, 202 days, 5.04 and 6.77, respectively. The estimated heritability of milk was 0.16. The LSM of average milk production in the provinces of Gilan, Mazandaran, E. Azerbaijan, W. Azerbaijan, Khuzestan and Ardabil were： 1,452, 1,586, 1,382, 1,183, 2,135 and 1,189 kg, respectively. These results indicated that Khuzestan province has the highest potential in the field of milk production. The top five highest breeding value bulls have been introduced to artificial insemination＇s station in the city of Uremia.     

Black carbon estimation in French calcareous soils using chemo‐thermal oxidation method

We studied the black carbon (BC) content of ca. 405 samples from French topsoil and artificial soil and carbonate mixtures. Our protocol involved three main steps: (i) decarbonation by HCl, (ii) elimination of non‐pyrogenic organic carbon in a furnace at 375 °C, and (iii) quantification of residual carbon by CHN analysis. BC content increased for calcareous soils according to their carbonates content. Subsequent analyses confirmed the existence of a methodological artefact for BC determination only in calcareous soils. Decarbonation changes the thermal properties of organic matter, creating more recalcitrant carbon than in the initial sample. Higher CaCO₃ and organic carbon content results in a more pronounced artefact. The reversal of the first two steps of the chemo‐thermal oxidation method (i.e. thermal oxidation before soil decarbonation) eliminates this artefact. Overall, our results suggest that BC content may have been overestimated in a large number of studies on calcareous soils.     

Can soil moisture deficit be used to forecast when soils are at high risk of damage owing to grazing animals?

A potentially significant cause of damage to grassland soils is compaction of unsaturated soil and poaching of saturated or nearly saturated soil by animal hooves. Damage is caused when an applied stress is in excess of the bearing strength of the soil and results in a loss of soil structure, macroporosity and air or water conductivity. Severely damaged soils can cause reduced grassland productivity and make grazing management very difficult for the farmer. The actual amount of soil damage that can occur during grazing is dependent on the grass cover which acts as a protecting layer, the soil water content and the characteristics of the grazing animal (weight and hoof size). Assuming that the farmer is knowledgeable about the characteristics of the grazing animal and grass cover, it would be very useful for short‐term operational farm planning to be able to predict when soil water contents were likely to be in a critical range with respect to potential hoof damage. In this study soil moisture deficits (SMDs) which can be derived from meteorological forecasts are evaluated for predicting when soil water conditions are likely to lead to hoof damage. Two contrasting Irish grassland soils were analysed using a Hounsfield servo‐mechanical vertical testing machine to simulate static (285.4 N) and dynamic (571 N) hoof loads on the soil over a range of estimated SMDs (0, 5, 10 and 20 mm). The deficits were analysed with respect to the soil volumetric water content, compression (displacement) and change in dry bulk density. The SMDs imposed in the laboratory were similar to those under field conditions and thus the methods used in this study are applicable elsewhere. The change in dry bulk density following loading (0.2–0.7 g/cm³) was linearly related to SMD (R² ranged from 0.90 to 0.99), leading to the conclusion that a forecast of SMD can be used to predict when grassland soils are likely to be at risk of damage from grazing.     

Development of multiple cutaneous and follicular neoplasms associated with canine papillomavirus type 3 in a dog

A 12‐year‐old spayed English pointer dog developed multiple skin lesions including pigmented viral plaques, basal cell carcinomas, squamous cell carcinomas and trichoblastomas. Canine papillomavirus type 3 was detected in multiple lesions suggesting common aetiology.

     

Xylanase and xylo- oligosaccharide prebiotic improve the growth performance and concentration of potentially prebiotic oligosaccharides in the ileum of broiler chickens

ABSTRACT

1. The objective of this study was to investigate the effect of supplementing broiler diets with xylanase or xylo- oligosaccharide (XOS) on growth performance, the concentration of non-starch polysaccharide (NSP) hydrolysis products in the ileum and concentration of short chain fatty acids (SCFA) in the caeca of broiler chickens.

2. In total, 500 male Ross 308 broilers were used in this 29-day (d) study. The treatments were organised into a 2 × 2 plus 1 factorial arrangement consisting of two additives (xylanase or XOS) at two levels (low or high) plus a control treatment with no additives. This gave five treatments with 100 birds in each treatment group. The diets were slightly deficient in protein by 20 g/kg and energy by 1 MJ/kg.

3. On d 14 and 28, two birds per pen were euthanised, the caeca content collected and analysed for short chain fatty acid (SCFA) concentration. On d 29, six birds per pen were euthanised and ileal digesta were collected and analysed for the concentration of NSP fractions.

4. On d 14, caecal acetic acid, iso-butyric acid, iso-valeric acid, n-valeric acid and total SCFA concentrations were significantly greater (P ≤ 0.05) when diets were supplemented with XOS compared with xylanase.

5. Ileal concentration of arabinose, galactose and glucuronic acid (GlucA2) were significantly greater (P ≤ 0.05) in the insoluble NSP fraction when diets were supplemented with a high level of xylanase, compared with the control treatment. Ileal concentration of fructose was significantly greater (P ≤ 0.05) in the water soluble NSP when a high level of xylanase or low level of XOS were included in the diet compared with the control.

6. It was concluded that xylanase and XOS had similar effects on NSP concentration and SCFA in the caeca, although there was little effect on performance. This observation demonstrated further benefits of xylanase supplementation in wheat-based broiler diets beyond digesta viscosity reduction and the release of extra nutrients.     

Are dual-purpose and male layer chickens more resilient against a low-protein-low-soybean diet than slow-growing broilers?

ABSTRACT

1. Although fattening dual-purpose types or male layer hybrid chickens appears more ethical than the common practice of culling day-old male layer chicks, the lower feed efficiency of these birds raises concerns. Replacing feed ingredients that compete with food production by those of lower value for human nutrition would be beneficial.

2. Lohmann Dual (LD), a modern dual-purpose type, Lohmann Brown (LB), a male layer hybrid, and Hubbard JA 957 (HU), a slow-growing broiler type, were fattened for nine weeks on two diets (control or ?20% crude protein; n = 6 × 12 birds). Growth, carcass and meat quality were analysed.

3. Growth performance of HU exceeded that of LD and especially of LB. The growth depression caused by the low-protein diet fed to LD (?7%) was only half of that found in HU (?13%). The LD fed the control diet had the same feed efficiency as the HU fed the low-protein diet. Even the LB had a lower performance and feed efficiency with the low-protein diet in growth. There was a gradient in carcass properties (weight, dressing percentage, breast meat yield, breast proportion and breast angle) from HU to LD to LB, with some additional adverse effects of the low-protein diet especially in HU. There were some breed differences in fatty acid profile in the intramuscular fat.

4. In conclusion, the dual-purpose type used complied with regulations for Swiss organic poultry systems in terms of growth rate and was found to respond less when fed a low-protein diet than the slow-growing broiler type. The LB males were inferior in all growth and carcass quality traits. Future studies need to determine the exact protein and amino acid requirements of dual-purpose and layer hybrid chickens and the economic feasibility of the systems, especially for organic farming.