Effects of potassium sorbate and sodium benzoate at two application rates on fermentation and aerobic stability of maize silage

This study evaluated two potassium sorbate (PS) and sodium benzoate (SB) application rates in improving the aerobic stability of maize silage. Treatments included no additive, the addition of PS at 1 and 2 g kg^?1 fresh matter (FM) and the addition of SB at 1 and 2 g kg^?1 FM. Four replicates of each treatment were ensiled in 15‐L plastic jars. The silages were analysed for their fermentative characteristics and were subjected to an aerobic stability test with pH and yeast and mould count measurements. Considering fermentation quality and aerobic stability, both additives were effective. The PS was more active against yeasts during aerobic exposure. When the additives were applied at 2 g kg^?1, the silages were more stable (256 h, on average) than those with 1 g kg^?1 (119 h, on average) and control (61 h). Aerobic deterioration was more pronounced in the controls than in the treated silages. Silages treated at 2 g kg^?1 had consistent effects on pH values and yeast counts over 288 h of aerobiosis. Overall, PS and SB applied at 2 g kg^?1 were more effective in improving aerobic stability.     

Simulating tropical forage growth and biomass accumulation: an overview of model development and application

Crop models can aid the synthesis and application of knowledge, planning of experiments and forecasting in agricultural systems. Few studies have reviewed the uses and applications of these models for tropical forages. The purpose of this study was to review the information available in this scientific area, highlighting the main models, their applications and limitations. Several empirical models have been developed to predict the growth and biomass accumulation of tropical forages, especially for the genera Cynodon, Paspalum, Panicum and Brachiaria. Their application, however, is often location or region specific. The adaptation of mechanistic models to accurately predict biomass accumulation in tropical grasses is still limited. Recent advances have been made on the plot‐scale and farm‐scale process‐based models ALMANAC, CROPGRO Perennial Forage and agricultural production systems simulator (APSIM), with promising results. In addition, global‐scale process‐based models, such as the Century Agroecosystem Model and the Orchidee Grassland Management Model, have been tested for tropical grassland areas. A greater number of region‐specific calibrations of empirical models can enhance their use, and improved databases and model parameterizations for a wide range of tropical grasses will enable the continuous improvement of mechanistic models.     

Characterization of progressive keratitis in Otariids

Objective To characterize a form of progressive keratitis that occurs commonly in otariids. Materials and methods One hundred and thirteen captive otariids were evaluated by ophthalmologic examination and digital photography. Results Forty‐six females and 67 males were in the reference population, average age of 14 years. California sea lions predominated (n = 100); there were also six Steller sea lions, five brown fur seals, one Guadalupe fur seal and one northern fur seal. Three stages of progressive keratitis are described. Overall, 64.6% animals and 142 eyes from 113 animals (62.8%) were affected with one of three stages. The mildest form, Stage 1 keratitis, occurred in 78 of 226 eyes (34.5%); the intermediate Stage 2 keratitis occurred in 30 of 226 eyes (13.3%); and the most severe, Stage 3 keratitis, occurred in 34 of 226 eyes (15%). All but six animals had bilateral disease. Animals with Stage 1 keratitis were significantly younger than those in more advanced stages. Discussion ‘Otariid Keratitis’ occurs in all populations of eared seals evaluated. A large‐scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs. Age may be important since exposure accumulates with aging. Progression of the disease is also associated with secondary opportunistic bacterial and fungal infections. The surface immune system may be imbalanced contributing to these infections and progression.     

Relationships between puppy management practices and reported measures of success in guide dog training

This study surveyed international guide dog organizations to compare their success rates with management practices. A questionnaire designed to identify the factors associated with international guide dog success was piloted with the cooperation of Guide Dogs NSW/ACT. The International Guide Dog Federation endorsed the study before the questionnaire was sent to 76 of its member organizations from 27 countries. There were 38 responses (of which 36 were usable) from guide dog organizations in 15 countries (50% response rate). Guide dog success rates were defined by the dogs' graduating success (the proportion of dogs commencing the program that successfully graduated as guide dogs) as well as working success (the proportion of dogs commencing the program that were working 1 year later). Working success and graduating success were found to be significantly different. Working success was considered the more informative estimate of true success, as it incorporated more variables than did graduating success.Quotas were used by many organizations to ensure that dogs graduated in sufficient numbers to meet the demand from visually impaired clientele. Despite our hypothesis that quotas would artificially inflate graduating success rates, logistic regression found that they were not associated with differences in graduating success rates, but that they were associated with greater working success. This finding indicates that quotas are not set at unrealistic levels and may help improve long-term success rates. Logistic regression also showed that dog breeds, the application of different temperament tests, the use of external breeders (as opposed to the organization breeding their own dogs), and the methods used to acquire information about the dogs during the puppy-raising period were significantly associated with these outcomes.     

Control of Salmonella enteritidis phage type 4 experimental infection by fosfomycin in newly hatched chicks

One hundred and twenty 1-day-old broiler chickens were divided into four groups: group I unmedicated and orally challenged with 1.5×10⁸ cfu of Salmonella enteritidis phage type 4; group F infected and treated with 300 ppm of fosfomycin in their drinking water; group CF uninfected and treated, and group C maintained as a control group. Their performance, clinical signs, S. enteritidis PT4 reisolation and biochemistry variables were compared. Group F showed fewer symptoms and gross lesions than those from group I. Fosfomycin treatment at 300 ppm improved body weight at 7 days of age by 42.3%. S. enteritidis PT4 reisolation in group I was higher than in the treated group, but total decontamination of challenged birds was not achieved. There was an increase in the levels of total protein and globulins in group I but not in the treated group. Fosfomycin caused no adverse effects on chickens from group CF, assessed by performance and biochemical variables. The results indicate that fosfomycin could be used in the treatment of S. enteritidis PT4 experimental infection.     

Comparison of agar gel immunodiffusion test, rapid slide agglutination test, microbiological culture and PCR for the diagnosis of canine brucellosis

The performance of the rapid slide agglutination test, with and without 2-mercaptoethanol (RSAT and 2ME-RSAT) and agar gel immunodiffusion test (AGID) was evaluated for the diagnosis of brucellosis in naturally infected dogs. The microbiological culture, PCR and clinical parameters were used as reference. A total of 167 dogs were clinically examined and tested by blood culture, culture of semen/vaginal swab and PCR in blood and semen/vaginal swab. According to the results observed the 167 dogs were divided into three groups: Brucella canis infected dogs (Group 1), B. canis non-infected dogs (Group 2) and dogs with suspected brucellosis (Group 3). The dogs were then tested by RSAT, 2ME-RSAT and AGID. Groups 1 and 2 were used to calculate the diagnostic sensitivity and specificity of the serological tests and the results observed in Group 3 were also discussed. The diagnostic sensitivity of RSAT, 2ME-RSAT and AGID was respectively 70.58%, 31.76%, and 52.94%. The diagnostic specificity of RSAT, 2ME-RSAT and AGID was respectively 83.34%, 100%, and 100%. In dogs with suspected brucellosis 15% were RSAT positive, none was 2ME-RSAT positive and 5% were AGID positive. Although the serological tests are the most commonly used methods for brucellosis diagnosis, a significant proportion of false-negative results were observed highlighting the importance of the direct methods of diagnosis, like blood culture and PCR to improve the diagnosis of canine brucellosis.     

Immunohistochemical expression of estrogen receptor beta in normal and tumoral canine mammary glands

To date, two isoforms of estrogen receptors (ER) have been identified, cloned, and characterized from several species, estrogen receptor-alpha (ERalpha) and estrogen receptor-beta (ERbeta). Although the presence of ERalpha has been demonstrated in normal and tumoral canine mammary tissues, the issue of ERbeta expression has not been addressed in the dog. In this study, we have analyzed the expression of ERbeta in formalin-fixed, paraffin-embedded tissue samples of nonaltered mammary gland, 30 malignant (six complex carcinoma, 12 simple carcinoma, three carcinosarcoma, and nine carcinoma or sarcoma in benign tumor), and five benign (one fibroadenoma, one complex papilloma, one complex adenoma, and two benign mixed tumors) mammary tumors of the dog by using a polyclonal ERbeta antibody and the avidin-biotin-peroxidase complex immunohistochemical technique. Our results show that high numbers of normal ductal and acinar epithelium and approximately one third of canine mammary tumors express ERbeta. This expression was higher in benign than in malignant tumors. Furthermore, expression was higher in complex and mixed histologic subtypes of malignant tumors when compared with simple subtypes.