Dynamics of <Emphasis Type="Italic">Mycoplasma hyopneumoniae</Emphasis> seroconversion and infection in pigs in the three main production systems

In this study, we investigated the dynamics of Mycoplasma hyopneumoniae infections in 66 pig farms, with different production systems (one-, two-, and three-site systems), and considered different risk factors. Serological assay was used to detect serum antibodies against M. hyopneumoniae and real time polymerase chain reaction (RT–PCR) was performed to detect M. hyopneumoniae DNA in tracheobronchial swabs. Results demonstrated that M. hyopneumoniae infection status was predominantly influenced by the age of the animals and the type of production system. Infection rates were higher in older animals and the prevalence was higher in the one- and two-site systems than in the three-site systems. Dynamics of infection by RT-PCR showed that earlier M. hyopneumoniae infection on one-site farms occurs earlier, while on two- and three-site farms occurs later but spreads faster, suggesting that contact between animals of different age favors the transmission.     

Dose response of rumen‐protected conjugated linoleic acid supplementation to fattening bulls and heifers on growth,and carcass and meat quality

We investigated the influence of rumen‐protected conjugated linoleic acid (rpCLA) on growth performances, and carcass and meat quality traits in beef. Twenty‐four young bulls and 30 heifers obtained from double‐muscled beef sires and dairy cows were fed a low‐protein ration (110 g/kg DM of crude protein) supplemented with 0, 8 or 80 g/d of a commercial rpCLA product. The animals were monthly weighed and scored for body muscularity and fatness. Blood samples were collected after 140 days on feed. Animals were slaughtered when they reached average in vivo fatness scores of around 2.5 (heifers) and 2.0 (bulls) points respectively. At slaughter, carcasses, various organs and parts of the gastrointestinal tract were weighed; the 5th rib was dissected and its tissue and muscle chemical composition was determined. The rpCLA had little influence on growth performance but decreased the blood urea content by 28% (p < 0.01). The rpCLA × sex interactions for daily gain (p < 0.05), conformation scores (p < 0.01), and blood creatinine content (p < 0.05) suggest that males were more responsive to rpCLA than females when fed a low‐protein ration, probably because of the metabolic protein‐sparing effect of CLA. Only slight differences were observed in carcass weight and quality at slaughter. The results indicate that the response of beef cattle to rpCLA is dependent on sex or on their propensity for lean and fat accretion. It is also possible that counteracting feedback mechanisms compensate for the influence of rpCLA administration over the course of growth.     

Post‐thawing effects of three cryopreservation diluents on Rusa deer (Rusa timorensis) spermatozoa

The aim of this study was to evaluate home‐made and commercial extenders for the cryopreservation of Rusa deer semen. After collection by electroejaculation, six ejaculates were diluted and frozen in TES‐based, Tris‐based and Triladyl^® extenders. Subjective motility, viability, morphology, acrosome integrity and membrane functionality were assessed post‐thawing and after 1‐hr incubation at 37°C (Thermal stress test). Total and progressive motility, and kinematic parameters were also assessed through CASA system. Post‐thawing sperm progressive motility (PM), velocity according to the straight path (VSL) and linearity (LIN) showed significant differences, and higher values were detected for spermatozoa diluted with Triladyl^® and TES (p < 0.05) as compared with Tris (PM of Triladyl^® 14.7% vs. 3.2% TES and 2.5% Tris; VSL 56 for Triladyl^®, 59.2 for TES and 41.7 for Tris; LIN 45.6 for Triladyl^®, 52 for TES and 36.5 for Tris). Triladyl^® and TES extender led to better post‐thawing sperm parameters, but these preliminary results need to be verified through artificial insemination trials.     

Partially defatted black soldier fly larva meal inclusion in piglet diets: effects on the growth performance,nutrient digestibility,blood profile,gut morphology and histological features

Background: The aim of this trial was to investigate the effects of different inclusion levels of a partial y defatted black soldier fly(BSF, Hermetia il ucens L.) larva meal on the growth performance, nutrient digestibility, blood profile, gut morphology and histological features of piglets. A total of 48 newly weaned piglets were individual y weighed(initial body weight(IBW): 6.1 ± 0.16 kg) and randomly al ocated to 3 dietary treatments(4 boxes as replicates/treatment and 4 animals/box). BSF larva meal was included at increasing levels(0% [BSF0], 5% [BSF5] and 10% [BSF10]) in isonitrogenous and isoenergetic diets formulated for two feeding phases: I(from d 1 to d 23) and I(from d 24 to d 61). The weight gain(WG), average daily gain(ADG), average daily feed intake(ADFI) and feed conversion ratio(FCR) were calculated for each feeding phase and for the whole trial. The haematochemical parameters and nutrient digestibility of the piglets were also evaluated. A total of 3 piglets per box were slaughtered on d 61 and the slaughtered piglets were submitted to morphometric investigations and histopathological examinations.Results: No overal significant differences were observed for growth performance(P 0.05), except for the ADFI of phase I, which showed a linear response to increasing BSF meal levels(P 0.05, maximum for the BSF10 group). Dietary BSF meal inclusion did not significantly influence the blood profile, except as far as monocytes and neutrophils are concerned,and these showed a linear and quadratic response, respectively, to increasing BSF meal levels(P 0.05, maximum for the BSF10 and BSF5 groups, respectively). On the other hand, the nutrient digestibility, gut morphology and histological features were not affected by dietary BSF meal inclusion(P 0.05).Conclusions: The obtained results show that a partial y defatted BSF larva meal can be used as a feed ingredient in diets for weaned piglets without negatively affecting their growth performance, nutrient digestibility, blood profile, gut morphology or histological features.     

IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING OF DIFFUSE LEPTOMENINGEAL OLIGODENDROGLIOMATOSIS IN A DOG WITH “DURAL TAIL SIGN”

A case of diffuse leptomeningeal oligodendrogliomatosis affecting the brain and spinal cord of a dog is presented. A 7.5‐year old, male neutered Staffordshire bull terrier presented for evaluation of a chronic history of tetraparesis and seizures, with a multifocal neuroanatomical localization was determined. Extra‐axial intradural lesions with an atypical presentation of a dural tail sign were seen on MRI. Histologically, the lesions were consistent with leptomeningeal oligodendrogliomatosis. To the authors’ knowledge, a dural tail sign has not previously been reported as an MRI characteristic of diffuse leptomeningeal oligodendrogliomatosis in dogs.     

Relationships among neuroscore,magnetic resonance imaging features,and intracranial pressure in sheep affected by slow‐growing brain lesions

Diagnosing high intracranial pressure by clinical and diagnostic imaging is particularly challenging for chronic or slow‐growing lesions. The aim of this prospective case‐control study is to determine whether the neuroscore and brain magnetic resonance imaging (MRI) are related to the direct measurement of intracranial pressure in sheep affected by intracranial slow‐growing lesions due to chronic cerebral coenurosis (Coenurus cerebralis). Seventeen affected and 10 control sheep were included. All animals underwent a neurological examination, MRI of the brain, and direct measurement of intracranial pressure. The severity of clinical signs and MRI findings were scored. Data were statistically analyzed. The invasive intracranial pressure value was higher in affected animals. A severely altered neuroscore is related to an increased intracranial pressure beyond the normal threshold (P < 0.05). The volume of the calvarium was larger in affected animals than in control animals (P = 0.0001) and was positively influenced by the presence and volume of the parasitic cyst (r = 0.7881, P < 0.01). Several degrees of deviation and deformation of both the ventricular system and brain parenchyma were detected by MRI. Subjective MRI findings were not associated with intracranial hypertension. In conclusion, this study shows that in sheep affected by slow‐growing lesions, severe alterations in the neuroscore and the results of objective MRI are related to an increased intracranial pressure beyond the normal threshold.     

Slurry field management and ammonia emissions under Mediterranean conditions

In Spain, farmers are interested in applying pig (Sus scrofa domesticus) slurry (PS) to their fields throughout the year. During the spring and summer months, ammonia (NH₃) volatilization may be high. We studied the potential range of NH₃ losses under a warm and a hot period of the year, using available field practices, and two strategies: PS directly incorporated into the soil, in spring (I‐spring); and PS applied by splash‐plate, in summer time (SP‐summer), both to bare soil. Measurements were conducted, after PS application, using the micrometeorological mass balance integrated horizontal flux method. The cumulative NH₃‐N volatilization was 35% (I‐spring) and 60% (SP‐summer) of total ammonium nitrogen applied, and half of the total NH₃‐N losses happened by 17 h and 8 h, respectively, after application. Incorporation strategy was less effective in avoiding NH₃ losses than is described in the literature. This fact has important consequences for the implementation of NH₃ mitigation measures in Mediterranean agricultural systems.