Low occurrence of pathogenic Yersinia enterocolitica in pig tonsils at slaughter in Southern Brazil

Tropical Animal Health and Production - Yersinia enterocolitica is a foodborne pathogen and pigs are the main reservoir of it in their tonsils. As Brazil is a large producer and exporter of pork...     

Non-phytate phosphorus requirement for broilers from 8 to 21 days of age under heat stress conditions

Two trials were conducted to determine the non-phytate phosphorus (nPP) requirement for broiler under heat stress. In both trials, birds were distributed in a completely randomized 4 × 2 factorial design with four nPP concentrations: 0.25, 0.35, 0.45, and 0.55%, and two Ca supply techniques: Ca fixed at 0.899% (CaF) or varying along with nPP aiming a 2:1 Ca to nPP ratio (CaV). Both trials had eight pens/treatment, with nine and five birds/pen for exp. 1 and exp. 2, respectively. nPP concentration had no effect on feed intake (FI), body weight gain (BWG), feed conversion ratio (FCR), nor fat deposition ratio (FDR). nPP levels showed a linear effect on protein deposition ratio (PDR) only for CaF diets. The nPP levels had a significant effect, regardless the technique adopted, on tibia phosphorus (TibP), which varied quadratically, on tibia calcium (TibCa) that increased quadratically and linearly, respectively, on CaF and CaV diets, and on tibia ash (TibAsh) that showed a quadratic effect for both. No effect was observed on Ca to P ratio in the tibia (TibCa:TibP). The nPP levels showed a linear increase effect over phosphorus intake (PI), phosphorus excreted (PE), and phosphorus retained (PR), and a linear decrease effect on phosphorus retention coefficient (PRC). Therefore, the nPP requirement for broilers from 8 to 21 days of age that provided better performance and bone variables were 0.250 and 0.484%, respectively, for CaF diets and 0.250 and 0.511%, respectively, for CaV diets.     

Increasing levels of supplementation for crossbred steers on pasture during the dry period of the year

The aim of this study was to evaluate the effect of increasing concentrate supplementation levels on the intake, nutrient digestibility, and performance of crossbred steers during the dry period of the year. The experiment was developed on Princesa do Mateiro farm, in the municipality of Ribeirão do Largo, located in the southwest region of Bahia State, Brazil. Forty uncastrated male crossbred (½ Holstein-Zebu) steers with an average body weight (BW) of 232.55?±?24.97 kg were distributed into four treatments in a completely randomized design with ten replicates. The animals were managed in an experimental area formed by Brachiaria brizantha cv. Marandu, in an intermittent grazing system. Treatments consisted of the following supplementation levels: 0.2% BW, with 60% crude protein (CP); 0.3% BW, with 40% CP; 0.4% BW, with 30% CP; and 0.5% BW, with 24% CP. The intakes of forage dry matter in kg/day and %BW and neutral detergent fiber corrected for ash and protein (NDFap) in %BW decreased linearly, whereas the intake of non-fibrous carbohydrates corrected for ash and protein in kg/day and average daily gain increased linearly. Therefore, the use of supplementation at 0.5% BW (24% crude protein) to provide gains of up to 0.500 kg/day is recommended for grazing steers during the post-weaning period in the dry season of the year.     

Epidemiological investigation of <Emphasis Type="Italic">Borrelia burgdorferi</Emphasis> in horses in the municipality of Sinop—MT,Brazil

Borrelia burgdorferi sensu stricto is the main etiological agent of Lyme disease (LD) in the USA. In Brazil, it is believed that a similar spirochete is the causal agent of the Baggio–Yoshinari syndrome (BYS), a zoonosis also transmitted by ticks, whose clinical manifestations are similar to those of LD. Despite the epidemiological importance, there are no studies reporting the presence and the prevalence of B. burgdorferi among horses in Mato Grosso State. The aim of this study was to detect and measure the frequency of IgG antibodies anti-B. burgdorferi American strain G39/40 in horses in the municipality of Sinop, MT—Brazil, using the indirect enzyme-linked immunosorbent assay (ELISA) for serological diagnosis. Blood samples from 367 horses were collected in 81 farms. An epidemiological questionnaire was applied during the visits to obtain information related to the animals and the farms. From the 367 horses, 214 were positive for B. burgdorferi sensu stricto according to the results of the ELISA test, representing an apparent prevalence of 54.04% [CI?=?0.4548051–0.6237234]. Concomitantly, 89 blood samples were taken for molecular analysis by nested polymerase chain reaction (PCR). According to the PCR test results, none of the samples were reactive, although 53 of these samples were reactive according to ELISA. Seventy five farms (92.59%) had at least one reactive horse for B. burgdorferi. Our results support the hypothesis of the presence of anti-Borrelia spp. antibodies in horses in Mato Grosso, reaching a high animal prevalence. Besides that, leisure/sport purposes proved to be a risk factor, with an odds ratio of 3.16. These findings clearly indicate the need of borreliosis control in Sinop and make a significant contribution to the knowledge of the disease in Mato Grosso.     

Frequency of enterotoxins,toxic shock syndrome toxin-1, and biofilm formation genes in <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolates from cows with mastitis in the Northeast of Brazil

Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.     

Label‐free proteome of water buffalo (Bubalus bubalis) seminal plasma

The study aimed to describe the Bubalus bubalis seminal plasma proteome using a label‐free shotgun UDMS^E approach. A total of 859 nonredundant proteins were identified across five biological replicates with stringent identification. Proteins specifically related to sperm maturation and protection, capacitation, fertilization and metabolic activity were detected in the buffalo seminal fluid. In conclusion, we provide a comprehensive proteomic profile of buffalo seminal plasma, which establishes a foundation for further studies designed to understand regulation of sperm function and discovery of novel biomarkers for fertility. MS data are available in the ProteomeXchange with identifier PXD003728.     

Transient Myocardial Thickening in Cats Associated with Heart Failure

Background

Cats with hypertrophic cardiomyopathy (HCM) and congestive heart failure (CHF) can have resolution of both left ventricular hypertrophy and CHF.

Objectives

To describe the clinical characteristics of cats with transient myocardial thickening (TMT) and CHF compared with a control population of cats without resolution of HCM.

Animals

A total of 21 cats with TMT, 21 cats with HCM.

Methods

Retrospective study. Clinical records at 4 veterinary centers were searched for TMT cases and a control group of cats with HCM and CHF. TMT was defined as initial maximal left ventricular wall thickness (LVWT) ≥6 mm with left‐sided CHF, with subsequent resolution of CHF, reduction in left atrium/aorta (LA/Ao), and LVWT<5.5 mm. HCM was defined as persistent LVWT ≥6 mm.

Results

Cats with TMT were younger (2 [0.4–11.4] years) than cats with HCM (8 [1.6–14] years) (P < 0.0001), and antecedent events were more common (15/21 versus 6/21, respectively) (P = 0.01). In cats with TMT, LVWT normalized from 6.8 [6.0–9.7] mm to 4.8 [2.8–5.3] mm and LA/Ao decreased from 1.8 [1.6–2.3] to 1.45 [1.2–1.7] after a mean interval of 3.3 (95% CI: 1.8–4.7) months. CHF recurred in 1 of 21 TMT and 15 of 21 cats with HCM. Cardiac treatment was discontinued in 20 of 21 cats with TMT and 0 of 21 HCM cats. All cats with TMT survived, whereas 8 of 19 cats with HCM died during the study period.

Conclusions and Clinical Importance

TMT occurs in younger cats, and antecedent events are common. The prognosis is better in cats with CHF associated with TMT than HCM.     

Energy and protein requirements for growth of Holstein × Gyr heifers

There is little information regarding the nutritional requirements for dairy heifers, leading the majority of nutrient requirement systems to consider dairy heifers to be similar to beef heifers. Therefore, we evaluated the muscle protein metabolism and physical and chemical body composition of growing Holstein × Gyr heifers and estimated the energy and protein requirements. We performed a comparative slaughter experiment with 20 Holstein × Gyr heifers at an initial body weight of 218 ± 36.5 kg and an average age of 12 ± 1.0 months. Four heifers were designated as the reference group, and the 16 remaining heifers were fed ad libitum . The 16 heifers were distributed using a completely randomized design in a 2 × 2 factorial arrangement with two roughages (corn silage or sugarcane) and two concentrate levels (30 or 50%) for 112 days. Greater (p  <  0.05) values for fractional rates of muscle protein synthesis, degradation and accretion were observed for heifers that were fed 50% concentrate. The following equations were obtained to estimate the net energy for gain (NE _g) and net protein for gain (NP _g): NE _g (Mcal/day) = 0.0685 × EBW ^0.75 × EBWG ^1.095 and NP _g (g/day) = 203.8 × EBWG  ? 14.80 × RE , respectively, in which EBW is the empty body weight, EBWG is the empty body weight gain and RE is the retained energy. We concluded that increased rates of protein turnover are achieved when a greater quality diet is provided. In the future, these results can be used to calculate the nutritional requirements for growth of Holstein × Gyr heifers after equation validation rather than using the recommendations provided by other systems, which use values developed from beef heifers, to determine the nutritional requirements of dairy cattle.     

Changes in cardiovascular performance,biochemistry, gastric motility and muscle temperature induced by acute exercise on a treadmill in healthy military dogs

Changes in physiological parameters that are induced by acute exercise on a treadmill in healthy military dogs have not been thoroughly investigated, especially with regard to age. This study investigated the effects of acute exercise on a treadmill on cardiovascular function, biochemical parameters and gastric antral motility in military dogs. Thermography was used to assess variations in superficial hindlimb muscle temperature. Nine healthy dogs were distributed into three groups according to their age (Group I: 25 ± 7 months; Group II: 51 ± 12 months; Group III: 95 ± 10 months) and sequentially subjected to running exercise on a treadmill for 12 min (3.2 km/h at 0° incline for 4 min, 6.4 km/h at 0° incline for 4 min and 6.4 km/h at 10° incline for 4 min). Heart rate, systolic and diastolic arterial pressure (DAP), gastric motility, haematocrit and biochemical analyses were performed at rest and after each session of treadmill exercise. Infrared thermographic images of muscles in the pelvic member were taken. Exercise decreased DAP in Group I, increased systolic arterial pressure in Groups II and III and increased mean arterial pressure in Group III (all p < 0.05). After the exercise protocol, plasma creatine kinase and aspartate aminotransferase levels increased only in Group I (p < 0.05). Exercise increased heart rate and decreased the gastric motility of a solid meal at 180 min in all groups (all p < 0.05). Exercise also elevated temperature in the femoral biceps muscles in Group I compared with the older dogs. The results indicate that acute exercise decreased gastric motility in dogs, regardless of age, and caused more pronounced cardiovascular changes in older dogs than in younger dogs. Acute exercise also altered biochemical parameters and superficial hindlimb muscle temperature in younger military dogs.