Assessment of sow herd frequency of PCV-2 using placental umbilical cord serum and serology in 18 breeding farms in Brazil.

Porcine circovirus type 2 (PCV-2) is the agent of one of the most important diseases in the swine industry. Although it has been controlled through vaccination, viremic piglets at birth may represent a risk by reducing vaccination efficacy. Since there are few reports on the viremic status of pre-suckling piglets regarding PCV-2 infection, we assessed the PCV-2 frequency in sows housed in 18 breeding farms with no history of clinical PCVAD in Brazil, using placental umbilical cord serum (PUCS). The selection criteria were: breeding farms with more than 1,000 sows; sows not vaccinated for PCV-2 at least for 2 years prior to the study; farms with no history of PCV-2 clinical disease in the last 12 months; and production systems with a maximum of two sites. Blood from the umbilical cords in sow placenta or directly from piglet's immediately after birth was collected from 30 litters on each farm for PCR. In addition, blood from 538 sows was collected for PCV-2 antibody detection. A total of 17.29% of the PUCS tested positive. The PCV-2 DNA was detected in PUCS from 94.4% of all farms. A total of 94.8% of the sows was positive for PCV-2 antibodies. However, seronegative sows were detected in 44.4% of farms. All 18 farms had at least 46.9% seropositive dams. A higher percentage of seronegative sows was observed for farms with more than 10% of PCV-2-positive litters compared to those with ≤10% of PCV-2 positive litters (8.9 +/-1.7% vs. 1.5 +/- 0.7%, p < 0.01, respectively).

Performance, biochemical and physiological parameters of Dorper × Santa Ines lambs fed with three levels of metabolizable energy.

This study aimed to evaluate the performance and the blood biochemical and physiological parameters of Dorper × Santa Ines lambs receiving three levels of metabolizable energy (ME). A completely randomized design with three treatments (ME levels) and eight replicates (lambs) was used. Twenty-four non-castrated male lambs of four months of age and 21.07 ± 3.91 kg body weight (BW) received a diet composed of 40% Tifton 85 hay and 60% concentrate feed, on a dry matter basis. The amount of feed supplied was adjusted to meet 115, 201, and 288 kcal ME per kg of metabolic weight (MW = BW0.75) daily. Average daily gain and the intake of dry matter (g/day and % BW0.75/day), nutrients, and energy increased linearly (P < 0.001) with ME level. The dry matter intake relative to BW (% BW/day) and feed conversion ratio showed quadratic responses (P < 0.05) to ME level. Serum creatinine decreased linearly (P = 0.038), whereas plasma glucose increased linearly (P = 0.045) with ME level. Serum urea presented a high variation (standard error range = ±1.98-6.07 mg/dL) in response to 288 kcal/kg0.75/day of ME supply, and did not stabilize during the trial. Respiratory rate increased linearly (P < 0.001) with ME level at each time of day (morning/afternoon), but with higher intensity in the afternoon. Heart rate and rectal temperature increased linearly (P < 0.001) with ME level. Given that the range of ME level simulated a restricted-to-ad libitum ME intake, the best response in terms of feed efficiency can be obtained with 252 kcal/kg0.75/day of ME supply, which probably reflects the best balance of metabolic and physiological parameters. Thus, in order to achieve high productive performance in tropical environments, feedlot lambs should be fed with high-concentrate diets.

Olive oil-enriched diet reduces brain oxidative damages and ameliorates neurotrophic factor gene expression in different life stages of rats.

Our aim was to assess the influence of maternal diet rich in monounsaturated fatty acids on oxidative and molecular parameters in brains of mouse pups as well as their body weight during their lifetime. Female rats received a diet containing 20% of olive oil-enriched diet (OOED) and a standard diet control diet (CD) in different periods: pregnancy, lactation and after weaning until pups' adulthood. On the last prenatal day (Group 1), embryos from OOED group showed smaller body weight, brain weight and lower levels of sulphydryl groups glutathione reduced (GSH) in the brain. On postnatal delay-21 (PND21) (Group 2), pups from OOED group showed higher body weight and brain weight, reduced brain weight/body weight ratio and lower brain lipid peroxidation (LP). On PND70 (Group 3), pups from OOED group showed lower brain LP and higher levels of GSH in prefrontal cortex and lower brain levels of reactive species in the hippocampus. Interestingly, the group of animals whose diet was modified from OOED to CD on PND21 showed greater weight gain compared to the group that remained in the same original diet (OOED) until adulthood. Furthermore, OOED consumption during pregnancy and lactation significantly increased BDNF only, as well as its main transcripts exon IV and VI mRNA levels in the prefrontal cortex. In addition, OOED significantly up-regulated FGF-2 mRNA levels in the prefrontal cortex. These findings open a pioneering line of investigation about dietary adjunctive therapeutic strategies and the potential of healthy dietary habits to prevent neonatal conditions and their influence on adulthood.

Prolonged consumption of trans fat favors the development of orofacial dyskinesia and anxiety-like symptoms in older rats.

Polyunsaturated fatty acids (FAs) are cell membrane components involved in brain functions. We hypothesized that long-term trans fat consumption is able to modify the membrane FAs composition impairing behavioral parameters related to aging. In this study, a comparison of behavioral parameters at 10 and 15 months of trans fat consumption by male Wistar rats was made. Animals were fed for 10 and 15 months from weaning with diets containing either 20% w/w soybean oil (SO), rich in n-6 PUFA, hydrogenated vegetable fat (HVF), rich in trans FAs, or a standard diet (control - C). At both evaluation times, HVF-fed rats showed progressively increased parameters of orofacial dyskinesia, fear and anxiety-like symptoms. The HVF diet reduced locomotor and exploratory activities progressively over 10 and 15 months of supplementation, while the standard and SO diets did not. In this study, we showed that chronic trans FAs consumption from weaning is able to favor the development of neuromotor and neuropsychiatric diseases, whose intensity was time dependent.

Short term dietary fish oil supplementation improves motor deficiencies related to reserpine-induced parkinsonism in rats.

Fish oil (FO) supplementation could cause an increase in the concentration of plasmatic free fatty acids and, consequently, could compete with pro-inflammatory arachidonic acid (ARA) derived from brain biomembranes metabolism in the cerebrospinal fluid. Essential fatty acids (EFA) (n-3) have been reported by their antioxidant and neuroprotective properties, and therefore the influence of the FO supplementation on the reserpine-induced motor disorders was studied. Wistar rats were orally treated with FO solution for 5 days, and co-treated with reserpine (R; 1 mg/kg/mL) or its vehicle for 3 days (every other day). Reserpine-induced orofacial dyskinesia and catalepsy (P < 0.05) were prevented by FO (P < 0.05). Biochemical evaluations showed that reserpine treatment increased the lipid peroxidation in the cortex and striatum (P < 0.05), while the FO supplementation prevented this oxidative effect in both brain regions (P < 0.05). Our results showed the protective role of FO in the brain lipid membranes, reinforcing the beneficial effect of n-3 fatty acids in the prevention of degenerative and motor disorders.

Comparative study between n-6, trans and n-3 fatty acids on repeated amphetamine exposure: a possible factor for the development of mania.

In the last decades, foods rich in omega-3 (ω-3) fatty acids (FA) have been replaced by omega-6 (ω-6) and trans FA, which are found in processed foods. The influence of ω-6 (soybean oil--SO), trans (hydrogenated vegetable fat--HVF) and ω-3 (fish oil--FO) fatty acids on locomotor and oxidative stress (OS) parameters were studied in an animal model of mania. Rats orally fed with SO, HVF and FO for 8 weeks received daily injections of amphetamine (AMPH--4 mg/kg/mL-ip) for the last week of oral supplementation. HVF induced hyperactivity, increased the protein carbonyl levels in the cortex and decreased the mitochondrial viability in cortex and striatum. AMPH-treatment increased the locomotion and decreased the mitochondrial viability in all groups, but its neurotoxicity was higher in the HVF group. Similarly, AMPH administration increased the protein carbonyl levels in striatum and cortex of HVF-supplemented rats. AMPH reduced the vitamin-C plasmatic levels of SO and HVF-fed rats, whereas no change was observed in the FO group. Our findings suggest that trans fatty acids increased the oxidative damage per se and exacerbated the AMPH-induced effects. The impact of trans fatty acids consumption on neuronal diseases and its consequences in brain functions must be further evaluated.

Beneficial effects of gradual intense exercise in tissues of rats fed with a diet deficient in vitamins and minerals: a pilot study.

OBJECTIVE: This study evaluated the preliminary effects of intense physical training (swimming) on oxidative stress in rats with nutritional deficiencies. METHODS: Rats were fed with a standard diet or a diet deficient in vitamins and minerals for 4 months. The deficient diet contained one-fourth of the recommended vitamin and mineral levels for rats. From the second month, half of the animals were subjected to a swimming exercise in a plastic container with water maintained at 34 +/- 1 degrees C for 1 h/d, five times per week, for 11 wk. The rats were subjected to swimming exercise with loads attached to the dorsal region, which were progressively increased according to their body weight (1% to 7%). Sedentary rats were transported to the experimental room and handled as often in a similar way as the exercise group, except that they were not put in water. RESULTS: In the exercised group, blood lactate levels were significantly lower and the heart weight/body weight ratio was significantly higher than in the sedentary group (P < 0.05). Increased lipid peroxidation was observed in the liver, heart, and skeletal muscle of rats fed with the deficient diet, but it was completely reversed by exercise. Exercise also decreased lipid peroxidation levels in the heart and skeletal muscle of rats fed with the standard diet (P < 0.05). CONCLUSION: This pilot study leads to the continuity of the studies, because the partial results observed suggest that inadequate nutrition may enhance oxidative stress, and that intense chronic physical training may activate antioxidant defenses, possibly by hormesis.

Intense exercise potentiates oxidative stress in striatum of reserpine-treated animals.

Regular physical activity exerts beneficial effects for mental and physical health, but an intense exercise can cause oxidative stress (OS) in dopaminergic regions and intensify the harmful effects of reserpine. Reserpine-induced neurotoxicity can be accessed by behavioral and biochemical evaluations. The objective of this study was to examine the effect of a gradual intensifying exercise program on an animal model of oxidative stress. Male rats were submitted to swimming sessions (1 h/day, for eleven weeks), and they were loaded gradually during the adaptation period (two weeks) with a weight corresponding to 1-7% of their body weight tied to their back. After the last training, the animals were treated with two doses of vehicle or reserpine (1 mg/kg-sc), an agent that induces orofacial dyskinesia. After behavioral evaluations, the striatum was dissected for enzymatic and biochemical assays. Development of cardiac hypertrophy demonstrated the effectiveness of the physical training. The gradual intense exercise and reserpine increased lipid peroxidation and striatal catalase activity. The results confirm the importance of catalase activity in orofacial dyskinesia which can be related to lipid peroxidation in striatal dopaminergic brain tissue. These results indicate that intense exercise can have some deleterious effect on striatal dopaminergic system.

Influence of chronic exercise on reserpine-induced oxidative stress in rats: behavioral and antioxidant evaluations.

Several neurological diseases are related to oxidative stress (OS) and neurotoxicity. Considering that physical exercise may exert beneficial effects on antioxidant defenses, our objective was to evaluate the influence of a swimming exercise on an OS animal model (reserpine-induced orofacial dyskinesia). In this model, the increased dopamine metabolism can generate OS and neuronal degeneration, causing involuntary movements. The increase in vacuous chewing movements and facial twitching caused by reserpine (1 mg/kg s.c.) was partially prevented by exercise. An increase in catalase activity and a decrease in GSH levels were observed in the striatum. Physical training did not change the effects of reserpine on catalase, however it partially recovered GSH. Exercise per se caused a significant GSH decrease. There was a positive correlation between catalase and OD (r=0.41; r=0.47, P<0.05) and a negative correlation between GSH and OD (r=0.61; r=0.71, P<0.05). These results reveal the benefit of exercise in attenuating the motor disorder related to OS.