Prestorage heat treatment reduces pathogenicity of Penicillium expansum in apple fruit

Penicillium expansum is one of the main postharvest pathogens of apples in Israel. Heating apple fruit inoculated with P. expansum for 96 h at 38°C completely inhibited decay development. Fruit held for 24 h at 42°C or 12 h at 46°C had significantly reduced decay after an additional 14 days incubation at 20°C, compared with unheated inoculated control fruit. Mycelial growth and percentage spore germination in vitro were inversely proportional to length of time of exposure to various temperatures. The ET₅₀ for spore germination was 42, 34 and 20 h at 38, 42 and 46°C, respectively, while the ET₅₀ for mycelial growth was 48, 44 and 36 h at those temperatures. When Penicillium spores were incubated on crude extract prepared from the peel of apple fruits held 4 days at 38°C, germ tube elongation was significantly reduced, while the walls of the tubes were thicker, compared with germ tubes from spores incubated on crude extract prepared from peel of non-heated fruit. The evidence presented here supports the hypothesis that the effect of heating on the decay of apples caused by P. expansum is not only the result of direct inhibition of fungal germination and growth by high temperature, but is also partly due to the formation of an inhibitory substance in the heated peel.     

Procollagen type-III aminoterminal peptide in serum and synovial fluid of dogs with hip dysplasia and coxarthrosis

Hip dysplasia is an affection of the coxofemoral joint that progresses until stabilization is caused by fibrosis and osteoarthritic changes. This stabilization process can be examined by clinical and radiographic methods. The capability of evaluating the procollagen concentrations in liquids, such as serum and synovial fluid, has further offered the basis for an objective biochemical evaluation of the stabilization process. Our study was performed to evaluate whether determination of procollagen concentrations was suitable for the use in practice. The procollagen type-III aminoterminal peptide (P-III-NP) concentration was measured in serum and in synovial fluid from coxofemoral joints in 20 dogs. Dogs were grouped on the basis of evidence of dysplasia and osteoarthritic changes of the hip: (1) a control group of 6 dogs without clinical or radiographic signs of hip dysplasia, and (2) dysplastic group of 14 dogs, which was further grouped with respect to the coxofemoral joint laxity, as determined by the Ortolani test. Synovial fluid concentration of P-III-NP was significantly (P less than 0.05) higher in fluid from dysplastic joints than in fluid from normal joints. Serum concentrations of P-III-NP were significantly (P less than 0.05) higher in dogs in which results of the Ortolani test were positive.     

Genetic parameters for body weight, reproduction, and parasite resistance traits in the Creole goat

We estimated the genetic parameters for BW, reproduction, and parasite resistance traits to implement a breeding program for the Creole goat. The traits were preweaning BW at 70 d of age (BW70d), BW at 11 mo of age (BW11), fecal egg count at 11 mo of age (FEC11) for all animals, packed cell volumes of lactating does (PCV), and their fertility (FER) and litter size (LS). We analyzed about 30 yr of data, which included 18,450 records on 11,970 animals from the INRA experimental flock in Guadeloupe (French West Indies). Heritability estimates were low for reproduction traits (0.11 ± 0.02 for LS and FER) to moderate for production traits (0.32 ± 0.03 for BW11; 0.20 ± 0.03 and 0.08 ± 0.02 for the direct and maternal heritability estimates of BW70d, respectively). Heritability estimates for gastrointestinal nematode resistance traits were situated in an intermediate range (0.13 ± 0.05 for PCV and 0.18 ± 0.04 for FEC11). Genetic correlations between FER, PCV, BW11, and the maternal effect of BW70d were altogether positive, whereas LS and FEC11 were almost uncorrelated phenotypically and genetically. These correlations are very favorable for setting up a breeding program, making it possible to improve BW, reproduction, and parasite resistance traits simultaneously.     

Production of polyclonal antisera against feline immunoglobulin E and its use in an ELISA in cats with experimentally induced asthma

Serum samples from six cats with experimentally induced asthma were used to purify feline IgE using gel filtration and affinity chromatography. The resultant IgE, evaluated for purity by immunoelectrophoresis (IEP) and reactivity by Prausnitz-Kustner (PK) testing, was used to develop polyclonal rabbit anti-feline IgE antisera. Using reverse cutaneous anaphylaxis (RCA), the antisera were determined to be specific for feline IgE. The polyclonal rabbit anti-feline IgE antiserum was then validated in an allergen-specific ELISA. Serum samples from an additional five asthmatic cats sensitized with Bermuda grass allergen (BGA) were evaluated prior to sensitization, after parenteral sensitization, and after aerosol sensitization and challenge. A significant increase in serum BGA-specific IgE was noted over time.     

Dynamics of the change in free blood serum amino acids of broiler chicks under the effect of lithium salts

The effect of lithium glycinate on the adaptive compensatory reaction in poultry during vaccinal stress is studied and its use as a stress protector is suggested.     

Effects of aluminium on the mineralization of dissolved organic carbon derived from forest floors

Aluminium (Al) is abundant in soils, but the influence of Al on the mineralization of dissolved organic carbon and thus on carbon sequestration in soil is only poorly understood. We investigated the extent and rate of mineralization of dissolved organic carbon at various Al/C ratios. Dissolved organic carbon extracted from Oi and Oa layers under coniferous and deciduous forest was incubated with initial molar Al/C ratios from < 0.004 to 0.44 for 130 days. Mineralization was quantified by measurement of CO₂. Rapidly and slowly mineralizable pools of dissolved organic C and their decomposition rate constants and half‐lives (as a measure of labile and stable C) were modelled with a double exponential equation. Increasing initial Al/C ratios up to 0.1 led to a considerable decrease in mineralization (up to 50% compared with control samples). The half‐life of the stable C pool increased up to 4‐fold, whereas the half‐life of the labile C pool was unaffected. Ratios of Al/C > 0.1 did not further decrease the mineralization, but led to increasing concentrations of free Al³⁺ in solution, and to increasing Al/C ratios in the precipitate, indicating that the Al complexation capacity of dissolved organic C was exceeded. Decrease in mineralization as well as formation of particulate organic matter (up to 56% of initial dissolved organic C) affected mainly the stable pool. Mineralization of dissolved organic C can be predicted from UV absorption by use of exponential regressions, but adding an Al variable did not improve the prediction significantly. We conclude that Al influences substantially the biodegradability of dissolved organic C percolating into the mineral soil, which may have consequences for the carbon sequestration in the soil. Declining Al concentrations would increase the mineralization of dissolved organic C only if the Al/C ratio becomes less than the ‘threshold value’ in the range of the Al complexation capacity of the dissolved organic C.     

Impact of macronutrient composition and palatability in wet diets on food selection in cats

Cats are obligate carnivores adapted to high‐protein diets, but are commonly fed diets rich in carbohydrate. The aim of this study was to examine the food intake choices of cats when diets with different protein and carbohydrate contents were offered. Thirty‐nine cats participated in voluntary dietary intake studies. Four foods were formulated to provide between 24% and 53% of metabolizable energy as protein, between 43% and 11% as carbohydrate and holding dietary fat constant with a contribution of approximately 36%. Foods were offered either singly to evaluate voluntary food intake or in pairs to compare food intake between pairs of diets. Cats regulated their macronutrient intake to attain an overall diet composition that provided 53% of metabolizable energy as protein, 11% as carbohydrate and 36% as fat. The protein contribution corresponded to approximately 6 g of protein/kg body weight/day. High‐protein/low‐carbohydrate diets were always eaten preferentially over low‐protein/high‐carbohydrate foods. When low‐protein/high‐carbohydrate diets were offered, cats limited their food intake to limit daily carbohydrate intake to less than 3 g of carbohydrate/kg body weight. This carbohydrate ceiling may limit protein and even energy intake when only low‐protein/high‐carbohydrate diets were offered. The inclusion of palatability enhancer in the diets increased food intake but did not change protein or carbohydrate intake patterns, indicating that macronutrient intake can be regulated regardless of the use of palatability enhancers in cats. We conclude that cats can discriminate between diets based on macronutrient composition and regulate their intake to maintain maximal protein intake but limit carbohydrate intake.