Glutathione and IGF-1 in bovine seminal cryopreservation: oxidative stress response and pregnancy rate / [Glutationa e IGF-1 na criopreservação seminal bovina: resposta do estresse oxidativo e taxa de gestação]

The objective of this study was to evaluate the rate of conception, metabolic, and structural conditions of cryopreserved bovine sperm cells, plus extender with IGF-1 and glutathione (GSH). 12 ejaculations of Nelore bulls were used, submitted to treatments: control, gSH (2mM/mL), IGF-1 (100ng/mL) and gSH (1mM/mL) + IGF-1 (50ng/mL). After cryopreservation and thawing the semen passed the fast thermo resistance test (TTR), plasma membrane and acrosomal integrity (PIAI), mitochondrial membrane potential (AP), oxidative stress, and conception rate. Tukey test was used for the statistical analysis of the parametric variables and the Friedman test for nonparametric. The gestation percentage was compared by the Chi-square test. There was no statistical difference (P<0.05) between treatments for the TTRr variable. Otherwise in the oxidative stress evaluated with the CellROX probe was noted that the IGF-1 showed the highest number of reactive cells (P<0.05). The PIAI, AP and gestation rate showed no difference among treatments (P>0.05), with an average of conceptions of 36.58%. It is concluded that IGF-1, gSH and their association did not cause changes in sperm motility, mitochondrial potential, plasma and acrosomal membrane integrity. IGF-1 increased oxidative stress, however, there was no difference in the gestation rate among the treatments.(AU)

Objetivou-se avaliar a taxa de concepção, as condições metabólicas e estrutural das células espermáticas bovinas criopreservadas, acrescidas de diluidores com fator de crescimento semelhante à insulina do tipo 1(IGF-1) e glutationa (GSH). Foram utilizados 12 ejaculados de touros da raça Nelore, submetidos aos tratamentos: controle, gSH (2mM/mL), IGF-1 (100ng/mL) e gSH (1mM/mL) + IGF-1 (50ng/mL). Após a criopreservação e descongelação, o sêmen passou pelos testes de termorresistência rápida (TTRr), integridade de membrana plasmática e acrossomal (PIAI), alto potencial mitocondrial (AP), estresse oxidativo e taxa de concepção. Utilizou-se o teste de Tukey para as análises estatísticas das variáveis paramétricas e o teste de Friedman para as não paramétricas, com significância de 5%. A percentagem de gestação foi comparada pelo teste do qui-quadrado. Não hove diferença estatística (P<0,05) entre os tratamentos para a variável TTRr. Já no estresse oxidativo avaliado com a sonda CellROX, observou-se que o IGF-1 apresentou maior quantidade de células reativas (P<0,05), 36,38± 24,10. A PIAI, o AP e a taxa de gestação não apresentaram diferença entre tratamentos (P>0,05), com média de concepções de 36,58%. Conclui-se que o IGF-1, a gSH e a sua associação não causaram mudanças na motilidade espermática, no potencial mitocondrial, na integridade da membrana plasmática e acrossomal. O IGF-1 aumentou o estresse oxidativo, porém sem diferença na taxa de gestação entre os tratamentos.(AU)

Does supplementation of vitamin C, reduced glutathione or their association in semen extender reduce oxidative stress in bovine frozen semen? / A suplementação de vitamina C, glutationa reduzida ou sua associação no diluidor de sêmen reduz o estresse oxidativo no sêmen congelado bovino?

The aim of this study was to evaluate the addition of vitamin C, reduced glutathione and the association thereof to the bovine semen cryopreservation extender. The ejaculate from nine bulls were divided into four fractions, each corresponding to a treatment, namely: control group-semen diluted with Tris-yolk extender; vitamin C group-semen diluted in Tris-yolk extender supplemented with vitamin C (2.5mmol/mL); glutathione group-semen diluted in Tris-yolk extender supplemented with reduced glutathione (2.5mmol/mL) and associated group-semen diluted in Tris-yolk extender supplemented with vitamin C (1.25mmol/mL) and reduced glutathione (1.25mmol/mL). Afterwards, the semen was packed into French straws and submitted to cryopreservation using automated equipment. After cryopreservation, the semen was thawed and evaluated considering sperm motility, morphology, plasma membrane, acrosome, mitochondrial potential and oxidative stress, as well as the thermo resistance test. Extender's supplementation with the association of vitamin C and reduced glutathione showed benefic effects on sperm motility and preservation of plasma and acrosomal membranes during semen cryopreservation, being also the group that showed higher values of reactive oxygen species. Thus, the association of both antioxidants contributed to the preservation of sperm cells in every analyzed characteristic, suggesting its use on bovine semen cryopreservation.(AU)

O objetivo deste estudo foi avaliar a adição de vitamina C, glutationa reduzida e sua associação ao diluidor de criopreservação de sêmen bovino. O ejaculado de nove touros foi dividido em quatro frações, cada uma correspondendo a um tratamento, a saber: grupo controle - sêmen diluído em Tris-gema; grupo vitamina C - sêmen diluído em Tris-gema, suplementado com vitamina C (2,5mmol/mL); grupo glutationa - sêmen diluído em Tris-gema, suplementado com glutationa reduzida (2,5mmol/mL) e grupo sêmen associado - diluído em Tris-gema, suplementado com vitamina C (1,25mmol/mL) e glutationa reduzida (1,25mmol/mL ). Posteriormente, o sêmen foi envasado em palhetas francesas e submetido à criopreservação por meio de equipamento automatizado. Após a criopreservação, o sêmen foi descongelado e avaliado quanto à motilidade espermática, à morfologia, à membrana plasmática, ao acrossoma, ao potencial mitocondrial e ao estresse oxidativo, bem como pelo teste de resistência térmica. A suplementação de extensor com a associação de vitamina C e glutationa reduzida mostrou efeitos benéficos sobre a motilidade espermática e a preservação das membranas plasmática e acrossomal durante a criopreservação de sêmen, sendo também o grupo que apresentou maiores valores de espécies reativas de oxigênio. Assim, a associação de ambos os antioxidantes contribuiu para a preservação dos espermatozóides em todas as características analisadas, sugerindo sua utilização na criopreservação de sêmen bovino.(AU)

Intrauterine Growth Restriction Modifies the Accumbal Dopaminergic Response to Palatable Food Intake.

Intrauterine growth restriction (IUGR) associates with increased preference for palatable foods and altered insulin sensitivity. Insulin modulates the central dopaminergic response and changes behavioral responses to reward. We measured the release of dopamine in the accumbens during palatable food intake in IUGR rats both at baseline and in response to insulin. From pregnancy day 10 until birth, gestating Sprague-Dawley rats received either an ad libitum (Control), or a 50% food restricted (FR) diet. In adulthood, palatable food consumption and feeding behavior entropy was assessed using an electronic food intake monitor (BioDAQ®), and dopamine response to palatable food was measured by chronoamperometry recordings in the nucleus accumbens (NAcc). FR rats eat more palatable foods during the dark phase, and their eating pattern has a higher entropy compared to control rats. There was a delayed dopamine release in the FR group in response to palatable food and insulin administration reverted this delayed effect. Western blot showed a decrease in suppressor of cytokine signaling 3 protein (SOCS3) in the ventral tegmental area (VTA) and an increase in the ratio of phospho-tyrosine hydroxylase to tyrosine hydroxylase (pTH/TH) in the NAcc of FR rats. Administration of insulin also abolished this latter effect in FR rats. FR rats showed metabolic alterations and a delay in the dopaminergic response to palatable foods. This could explain the increased palatable food intake and behavioral entropy found in FR rats. IUGR may lead to binge eating, obesity and its metabolic consequences by modifying the central dopaminergic response to sweet food.

Desempenho de bezerras de corte em pastagem de azevém recebendo farelo de arroz com ou sem monensina / Beef heifers performance in ryegrass pasture supplemented with rice bran with or without monensin

Foi estudado o desempenho de bezerras de corte em pastagem de azevém (Lolium multiflorum Lam.), com animais exclusivamente em pastejo ou recebendo farelo de arroz integral (FAI) em nível de 0,8% do peso corporal, associado ou não à monensina. O método de pastejo foi contínuo com número variável de animais. O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo, com três tratamentos e três repetições de área. O uso de FAI associado ou não à monensina não expressou alteração na área pélvica das bezerras, na taxa de lotação e no ganho de peso por área. As bezerras que receberam FAI, com ou sem monensina, apresentaram maior ganho diário de peso corporal, peso corporal, escore de condição corporal e relação peso corporal:altura. O fornecimento de suplementação energética para bezerras de corte é uma alternativa viável em sistemas de produção que visam à redução da idade ao primeiro acasalamento.(AU)

The experiment was carried out with the objective of evaluating beef cattle heifer performance when exclusively grazing Italian ryegrass (Lolium multiflorum Lam.) pasture or supplemented with whole rice bran (WRB), equivalent to 0.8% of body weight, associated or not with monensin. The grazing method was "put-and-take" stocking, in a completely randomized experimental design, with replicated measures over time, with three treatments and three replications of area. The use of WRB, associated or not with monensin, did not affect heifers' pelvic area, stocking rate and area weight gain. Animals fed WRB, with or without monensin, showed greater average daily gain, body weight, body condition score, and body weight:height ratio. Energetic supplementation for beef heifers is one viable option in production systems seeking age reduction at the first mating.(AU)

Feed can be a source of Campylobacter jejuni infection in broilers.

1. The aim was to determine the importance of a contaminated diet as a possible cause of Campylobacter jejuni infection in broilers. 2. This study evaluated the viability of C. jejuni in both starter and finisher diets and the interference from other mesophilic bacteria in this viability. 3. Starter and finisher samples of broiler diet were deliberately contaminated with 3 or 5 log CFU·g-1 of C. jejuni (NCTC 11351) and then maintained at two different storage temperatures (25°C or 37°C) for 3 or 5 d. 4. C. jejuni survived during this period and, when inoculated at 103 CFU·g-1, multiplied with greater proliferation at a storage temperature of 37°C. There was no relationship between the amount of mesophilic bacteria and C. jejuni viability. 5. This study highlights the importance of the diet in the epidemiology of C. jejuni in broilers.

Uso de suplementos para acasalamento de bezerras Angus aos 14 meses de idade / Use of supplements for mating Angus heifers at 14 months

O experimento foi conduzido com o objetivo de avaliar o desenvolvimento de novilhas de corte em três sistemas alimentares: exclusivamente em pastagem de azevém (Lolium multiflorum Lam.) ou em pastagem de azevém e recebendo 0,93% do peso corporal de grão de milho inteiro ou grão de aveia branca como suplemento. O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo. A utilização da pastagem de azevém, com ou sem uso de grão de milho ou aveia como suplemento, possibilita desenvolvimento reprodutivo para que as bezerras sejam acasaladas aos 14 meses de idade. O peso corporal ao início da utilização da pastagem é determinante para que as bezerras atinjam adequado desenvolvimento reprodutivo no início da estação de acasalamento.(AU)

The experiment was carried out to evaluate the development of beef heifers in three feeding systems: exclusively on ryegrass pasture (Lolium multiflorum Lam.) or in ryegrass pasture and receiving 0.93% of body weight of corn whole grain or oats grain as a supplement. The experimental design was completely randomized with repeated measures in time. The utilization of ryegrass pasture, with or without the use of corn or oats grain as a supplement, provides reproductive development of heifers in order for them to be mated at 14 months of age. The body weight at the beginning of pasture utilization is crucial for heifers to reach adequate reproductive development at the beginning of the mating season.(AU)

Intrauterine growth restriction modifies the hedonic response to sweet taste in newborn pups - Role of the accumbal µ-opioid receptors.

Intrauterine growth restriction (IUGR) is associated with increased preference for palatable foods. The hedonic response to sweet taste, modulated by the nucleus accumbens µ-opioid-receptors, may be involved. We investigated hedonic responses and receptor levels in IUGR and Control animals. From pregnancy day 10, Sprague-Dawley dams received either an ad libitum (Control), or a 50% food restricted (FR) diet. At birth, pups were cross-fostered, and nursed by Adlib fed dams. The hedonic response was evaluated at 1 day after birth and at 90 days of life, by giving sucrose solution or water and analyzing the hedonic facial responses (within 60s). Control pups exposed either to water or sucrose resolved their hedonic responses after 16 and 18s, respectively, while FR hedonic responses to sucrose persisted over 20s. FR pups had deceased phospho-µ-opioid-receptor (p=0.009) and reduced phosphor:total mu opioid receptor ratio compared to controls pups (p=0.003). In adults, there was an interaction between group and solution at the end of the evaluation (p=0.044): Control decreased the response after sucrose solution, FR did not change over time. There were no differences in phosphorylation of µ-opioid-receptor in adults. These results demonstrate IUGR newborn rats exhibit alterations in hedonic response accompanied by a decrease in µ-opioid-receptor phosphorylation, though these alterations do not persist at 3 months of age. Opioid system alterations in early life may contribute to the development of preference for highly palatable foods and contribute to rapid weight gain and obesity in IUGR offspring.

Neonatal handling alters the structure of maternal behavior and affects mother-pup bonding.

During early life, a mother and her pups establish a very close relationship, and the olfactory learning of the nest odor is very important for the bond formation. The olfactory bulb (OB) is a structure that plays a fundamental role in the olfactory learning (OL) mechanism that also involves maternal behavior (licking and contact). We hypothesized that handling the pups would alter the structure of the maternal behavior, affect OL, and alter mother-pup relationships. Moreover, changes in the cyclic AMP-response element binding protein phosphorylation (CREB) and neurotrophic factors could be a part of the mechanism of these changes. This study aimed to analyze the effects of neonatal handling, 1 min per day from postpartum day 1 to 10 (PPD 1 to PPD 10), on the maternal behavior and pups' preference for the nest odor in a Y maze (PPD 11). We also tested CREB's phosphorylation and BDNF signaling in the OB of the pups (PPD 7) by Western blot analysis. The results showed that handling alters mother-pups interaction by decreasing mother-pups contact and changing the temporal pattern of all components of the maternal behavior especially the daily licking and nest-building. We found sex-dependent changes in the nest odor preference, CREB and BDNF levels in pups OB. Male pups were more affected by alterations in the licking pattern, and female pups were more affected by changes in the mother-pup contact (the time spent outside the nest and nursing).

Effect of AV3V lesion on the cardiovascular, fluid, and electrolytic changes induced by activation of the lateral preoptic area.

In this study we investigated the effect of the anteroventral third ventricle (AV3V) lesion on the pressor, bradycardic, natriuretic, kaliuretic, and dipsogenic responses induced by the injection of the cholinergic agonist carbachol into the lateral preoptic area (LPOA) in rats. Male Holtzman rats with sham or electrolytic AV3V lesion were implanted with stainless steel cannula directly into the LPOA. Injection of carbachol (7.5 nmol) into the LPOA of sham rats induced natriuresis (405 +/- 66 microEq/120 min), kaliuresis (234 +/- 44 microEq/120 min), water intake (9.5 +/- 1.7 ml/60 min), bradycardia (-47 +/- 11 bpm), and increase in mean arterial pressure (28 +/- 3 mmHg). Acute AV3V lesion (1-5 days) reduced the natriuresis (12 +/- 4 microEq/120 min), kaliuresis (128 +/- 27 microEq/120 min), water intake (1.7 +/- 0.9 ml/60 min), and pressor responses (14 +/- 4 mmHg) produced by carbachol into the LPOA. Tachycardia instead of bradycardia was also observed. Chronic (14-18 days) AV3V lesion reduced only the pressor response (10 +/- 2 mmHg) induced by carbachol. These results showed that acute, but not chronic, AV3V lesion reduced the natriuretic, kaliuretic, and dipsogenic responses to carbachol injection into the LPOA. The pressor response was reduced in acute or chronic AV3V-lesioned rats. The results suggest that the lateral areas may control the fluid and electrolyte balance independently from the AV3V region in chronic AV3V-lesioned rats.