Effect of storage and single layer centrifugation before cryopreservation on stallion sperm cryosurvival.

The objectives of this study were to evaluate the effect of a short, cooled storage before cryopreservation on sperm progressive motility (PM) and compare the effect of different centrifugation methods on post-thaw PM of stored samples. Semen was diluted in chilling extender and aliquoted in 6 protocols: i) Standard centrifugation (SC) followed by freezing; ii) Single Layer Centrifugation (SLC) followed by freezing; iii) Storage for 8 h/5 °C before SC; iv) Storage for 8 h/5 °C before SLC; v) Storage for 8 h/15 °C before SC; and vi) Storage for 8 h/15 °C before SLC. PM was assessed before centrifugation, after centrifugation, and post-thawing. Stallions were classified as "good freezers" (GF) or "bad freezers" (BF). The PM in samples immediately frozen was greater than in the stored ones (71.98 ± 14.2, 52.91 ± 17.8, 53.93 ± 18.9 for no storage, 5 ºC storage and 15 ºC storage, respectively) (P˂ 0.0001). There was an effect of storage condition (p ˂ 0.0001), centrifugation method (p ˂ 0.0001), and freezability (P=0.0016), with an interaction between them (P= 0.0004), on PM after centrifugation. Post-thaw PM was greater in samples treated by SLC than in samples processed by SC, for all storage conditions (p ˂ 0.05). All BF stallions 'showed post-thaw PM ˂ 30 % when samples were previously stored. Storage at 5 ºC or 15º C for 8 h maintains an appropriate quality in GF stallions. Applying a sperm selection technique as SLC is suggested to improve post-thaw motility, allowing GF straws to be frozen after storage, although BF semen should be prepared by SLC immediately after collection.

Repeated trans-cervical embryo recoveries in Santa inês ewes subjected to short- or long-term superovulatory treatment regimens.

Outcomes of short- (6.5 days) and long-term (14.5 days) estrous synchronization for 6.5 d (G-6.5d) or 14.5 d (G-14.5d) and followed by the 4-day or 3-day declining-dose follicle-stimulating hormone superovulatory regimen, respectively, were compared using 16 estrous-cycling Santa Inês ewes. Non-surgical embryo recovery (NSER) procedures were performed 60 d apart starting 6 or 7 d after the onset of estrus; an i.m. injection of estradiol benzoate and of d-cloprostenol at 16 h was followed by an i.v. oxytocin injection administered 20 min before NSER. There was a longer (P < 0.05) period before estrous onset in ewes during the second (September) compared with the first study replicate (July) by approximately 14 h. The NSER could be performed in 11 of 15 ewes that were in estrus, with an average of three viable-embryos/donor and the mean duration of the procedure being 29 min. There were no differences in superovulatory responses between the two groups of ewes, but there were only degenerated embryos in ewes of the G-6.5d group. In summary: i. the duration of progestin-priming and of multiple-dose pFSH treatment had a limited effect on superovulatory responses in estrous-cycling Santa Inês ewes; ii. NSER is a safe and repeatable method of embryo collection in ewes subsequent to superovulation; and iii. duration of the superovulatory treatment regimen may alter the effects of endogenous steroids on oocyte/embryo quality in ewes.

Hormonal mechanisms regulating follicular wave dynamics II: Progesterone decreases diameter at follicle selection regardless of whether circulating FSH or LH are decreased or elevated.

Selection of a single dominant follicle is morphologically manifested by diameter deviation between the future dominant follicle (F1) and the future largest subordinate follicle (F2). Conventional deviation is defined as F2≥7 mm when F1 reaches ∼8.5 mm whereas, undersized deviation is if F2<7 mm when F1 reaches ∼8.5 mm. Greater frequency of undersized deviation has been temporally associated with greater circulating progesterone (P4) and greater FSH but reduced LH in observational studies. Experiment 1 was conducted to directly test if elevating P4 increased the likelihood of undersized deviation and altered circulating concentrations of LH and FSH. Experiment 2 was conducted to test if increasing LH action by treatment with exogenous porcine LH or human chorionic gonadotropin (hCG) in the presence of elevated P4, would stimulate growth of F2 and increase the likelihood of conventional deviation. Ovaries were evaluated by ultrasound and blood samples collected every 12 h after development of a new wave following follicle ablation on D6 (D0 = ovulation). Data were normalized to F1≥7.5 mm and compared using SAS software. In experiment 1 (n = 20), the CL was regressed by prostaglandin F2α treatment and heifers were randomized on D6 into control (no P4 treatment) or P4 treatment (75 mg every 12 h for 5.5 d) beginning when F1 reached ∼3 mm (P4-3 mm group) or ∼6 mm (P4-6 mm group). The P4 treatment significantly increased the frequency of undersized deviation from 0% (controls) to 54%, decreased LH by 44%, and increased FSH by 32%. In experiment 2 (n = 27) heifers were randomized on D6 into control (saline) or treatment with the LH analogs - pLH (1.25 mg porcine LH/12 h) or hCG (160 IU initially and subsequently 96 IU/24 h). Treatment with LH analogs significantly increased P4 (control, 4.6 ±â€¯0.3 ng/mL; pLH, 6.6 ±â€¯0.4 ng/mL; and hCG, 8.9 ±â€¯0.4 ng/mL) and decreased FSH (control, 0.46 ±â€¯0.03 ng/mL; combined-pLH/hCG, 0.34 ±â€¯0.02 ng/mL). However, F1 and F2 diameter and frequency of conventional (37%) and undersized (48%) deviations were similar between the control and combined-pLH/hCG groups. In conclusion, elevated P4 was directly linked to undersized deviation but the P4 effect on decreasing F2 diameter occurred independently of the P4 effects on FSH and LH concentrations.

Disruption of bovine sperm functions in the presence of aplastic midpiece defect.

BACKGROUND: Bulls are of great importance in the productive chain and for this reason they should have a good semen quality. There is no doubt that sperm morphology is very important to bull fertility, although little is known about how exactly the abnormal morphologies may affect sperm functions. OBJECTIVES: To detail the morphological description of the aplastic midpiece defect (AMD), as well as to understand its consequences for male fertility based on membrane and acrosome status, mitochondrial membrane potential and DNA integrity parameters. MATERIALS AND METHODS: The bulls were divided into two groups: control, consisting of satisfactory potential breeders (n = 3); and AMD, consisting of unsatisfactory potential breeders with a high percentage of AMD (n = 3). Bulls were evaluated by the breeding soundness evaluation; five ejaculates were collected from each animal and analyzed by flow cytometry. RESULTS: Spermatozoa from AMD group exhibited lower sperm motility and vigor (p < 0.05). In addition, it also exhibited lower mitochondrial membrane potential (p < 0.05), a higher percentage of spermatozoa with DNA fragmentation (p < 0.05), lower acrosome and plasma membrane integrity (p < 0.05), and higher lipid bilayer sperm membrane disorganization (p < 0.05) in comparison with control bulls. DISCUSSION: These findings may be due to oxidative stress and a reduction of the energy production capacity in addition to an alteration in the structural composition of the sperm cell. Moreover, semen with a high percentage of AMD may also be undergoing apoptosis. CONCLUSION: Bulls with a high percentage of AMD in their semen are not suitable for reproduction. Furthermore, it suggests there is a putative genetic basis for this sperm defect.

Effect of somatotropin on survival and diameter of bovine preantral follicles / Efeito da somatotropina na sobrevivência e no diâmetro de folículos pré-antrais de bovinos

The aim of this study was to evaluate the effect of Recombinant bovine somatotropin (rbST) on survival and diameter of bovine preantral ovarian follicles (PAOF) cultured in vitro. Ovaries were collected from adult cows and fragments of ovarian cortex were immediately fixed (non-cultured control) or cultured in vitro in α-MEM+ alone or containing 10, 50, 100 or 1,000ng/mL rbST. The fragments were processed for Classical Histology and Transmission Electron Microscopy. After one and seven days of culture, the percentage of normal follicles in the non-cultured control was superior (P< 0.05) to the follicles cultured in α-MEM+ alone or with different rbST concentrations. The oocyte and follicular mean diameter did not increase during the culture for one and seven days, both in media containing rbST and in the medium without this hormone. The only medium in which there was no reduction in follicular diameter with the time of culture was the medium without rbST. Ultrastructural damage in PAOF cultured in vitro was found. It is concluded that the use of rbST at different concentrations in in situ culture of bovine preantral follicles has no beneficial effects on survival and growth of bovine PAOF.(AU)

O objetivo deste trabalho foi avaliar o efeito da somatotropina recombinante bovina (rbST) sobre a sobrevivência e o diâmetro de folículos ovarianos pré-antrais (FOPA) bovinos cultivados in vitro. Ovários foram coletados de vacas adultas e fragmentos do córtex ovariano foram imediatamente fixados (controle não cultivado) ou cultivados in vitro em α-MEM + sozinho ou contendo 10, 50, 100 ou 1.000ng/mL de rbST. Os fragmentos foram processados para histologia clássica e microscopia eletrônica de transmissão. Após um e sete dias de cultivo, o percentual de folículos normais no controle não cultivado foi superior (P<0,05) aos cultivados em α-MEM + sozinho ou acrescido de diferentes concentrações de rbST. Os diâmetros médios oocitário e folicular não aumentaram durante o cultivo por um e sete dias, tanto nos meios contendo rbST, como no meio sem esse hormônio (α-MEM + ). O único meio em que não houve redução no diâmetro folicular com o tempo de cultivo foi o sem rbST. Verificaram-se ainda danos ultraestruturais em FOPA cultivados in vitro. Conclui-se que o uso de rbST em diferentes concentrações no cultivo in situ de folículos pré-antrais bovinos não tem efeitos benéficos na sobrevivência e no crescimento de FOPA bovinos.(AU)

Cervical penetration rates and efficiency of non-surgical embryo recovery in estrous-synchronized Santa Inês ewes after administration of estradiol ester (benzoate or cypionate) in combination with d-cloprostenol and oxytocin.

The effects of estradiol esters, d-cloprostenol and oxytocin on induction of cervical dilation prior to non-surgical embryo recovery in Santa Inês ewes (Days 6-7 estrous cycle) were assessed in this study. In Trial 1, transcervical embryo flushing was performed in estrous-induced ewes administered 37.5 µg of d-cloprostenol i.m. 10 h before and 50 IU of oxytocin i.v. 20 min before uterine flushing with (EB-PGF-OT; n = 13) or without (PGF-OT; n = 11) 1 mg of estradiol benzoate i.m. administered concurrently with d-cloprostenol injection. In Trial 2, the estrous-synchronized animals were treated with 1 mg of estradiol benzoate (EB-PGF-OT; n = 12) or estradiol cypionate (EC-PGF-OT; n = 12) i.m. along with 37.5 µg of d-cloprostenol i.m. 16 h before and 50 IU of oxytocin i.v. 20 min before uterine flushing. In Trial 1, uterine flushing could be accomplished in 38% of ewes in the EB-PGF-OT and 27% those in the PGF-OT (P>0.05) group. Flushing fluid recovery averaged 90% and there were 1.0 ± 1.1 embryos/ewe collected with mean duration of the flushing procedure being ˜36 min. In Trial 2, uterine flushing was accomplished in 78% of ewes in the EB-PGF-OT and 44% of those in the EC-PGF-OT group (P>0.05) with mean flushing fluid recovery rate being 88% and time elapsing to complete flushing being ˜33 min. Within the subsets of animals treated with EB, the percentages of successful transcervical penetrations were 38% compared with 78% in Trials 1 and 2, respectively (i.e., with EB administered 10 h compared with 16 h before uterine flushing: P<0.05). The interval from EB administration to the beginning of transcervical penetration can affect the efficacy of embryo recovery procedures utilizing a combined EB/d-cloprostenol/oxytocin pre-treatment.

Hormonal mechanisms regulating follicular wave dynamics I: Comparison of follicle growth profiles under different physiological conditions in heifers.

Follicle diameter deviation has been identified as the pivotal morphological manifestation of follicle selection, however, many of the hormonal mechanisms leading to this key event and regulating variation between individual follicular waves remain undefined. This study compared circulating FSH, LH, and P4 with the follicular dynamics during three different physiological conditions. We hypothesized that these end-points would: 1) be similar for a spontaneous wave 2 vs one induced by follicular aspiration, 2) but would differ between wave 1 and 2, and 3) between conventional (F2 > 7.0 mm at deviation) vs undersized (F2 < 7.0 mm) deviations in either wave. Holstein dairy heifers (N = 24) were studied daily during an interovulatory interval. All heifers were evaluated during wave 1 and randomized 6 days after ovulation into an induced wave 2 and a spontaneous wave 2. Values were normalized to the day of expected diameter deviation (day 0) and compared for day -2 to 0 and 0 to 2. Hypothesis 1 was supported that an induced wave 2 from ablation of follicles of wave 1 and spontaneous wave 2 have similar follicle dynamics. However, the peak FSH surge was more prominent at emergence of an induced wave 2 (P < 0.003). Hypothesis 2 was supported that waves 1 and 2 differ in follicle and hormone dynamics. Circulating P4 was lower and LH was greater (P < 0.01) with no difference in diameter of F1 but with a greater (P < 0.01) diameter of F2 on day 0 in wave 1 (7.3 ±â€¯0.2 mm) than in wave 2 (6.6 ±â€¯0.2 mm). Differences between waves were not found when each follicular wave was categorized into conventional vs undersized deviation and analyzed separately. Hypothesis 3 was supported as there were differences in circulating hormones between conventional and undersized deviations. Growth rate of F2 differed (P < 0.0005) during days -2 to 0 (conventional, 2.6 ±â€¯0.2 mm/2d; undersized, 1.4 ±â€¯0.3 mm/2d). However, circulating FSH and P4 concentration on days -1 and 0 tended to be greater (P < 0.06) in undersized than conventional deviations. In conclusion, the effect of different hormonal conditions on follicle dynamics was observed for F2 and not for F1. Furthermore, understanding the physiology that produces conventional vs undersized deviations is crucial since these categories explained most differences in follicular dynamics and circulating FSH observed in these different physiological conditions. In addition, future studies of wave 2 may be facilitated by using an induced wave 2 since it was similar to a spontaneous wave 2.

The use of ultrasonography in the reproductive evaluation of boars.

The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty-six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.

Ovarian follicular dynamic and plasma progesterone concentration in Alpine goats on the breeding season / Dinâmica folicular ovariana e concentração plasmática de progesterona em cabras Alpinas durante a estação reprodutiva

Os objetivos deste estudo foram relatar a dinâmica folicular ovariana e a concentração plasmática de progesterona durante ciclos estrais de duração irregular em cabras da raça Alpina. Vinte e nove cabras tiveram sua atividade ovariana monitorada diariamente por ultrassonografia transretal durante um, dois ou três períodos interovulatórios consecutivos. Amostras de sangue foram coletadas para análise da concentração plasmática de progesterona. Dos 47 ciclos avaliados, 28 (59,57%) foram de duração normal (17 a 25 dias), sete (14,89%) de curta duração (<17 dias) e 12 (25,53%) de longa duração (>25 dias). Os ciclos estrais de curta duração tiveram 6,14±0,69 dias e uma onda folicular que emergiu no dia 0,43±1,13. Os ciclos estrais de longa duração tiveram entre 26 e 79 dias, com duas a nove ondas foliculares. Os ciclos estrais de curta duração ocorreram durante a estação reprodutiva e foram associados à regressão prematura do corpo lúteo (CL). Os ciclos estrais de longa duração ocorreram na transição entre o anestro e a estação reprodutiva e foram associados principalmente à persistência do CL ou à fase folicular prolongada.(AU)

Genome-wide association study and annotating candidate gene networks affecting age at first calving in Nellore cattle.

We performed a genome-wide mapping for the age at first calving (AFC) with the goal of annotating candidate genes that regulate fertility in Nellore cattle. Phenotypic data from 762 cows and 777k SNP genotypes from 2,992 bulls and cows were used. Single nucleotide polymorphism (SNP) effects based on the single-step GBLUP methodology were blocked into adjacent windows of 1 Megabase (Mb) to explain the genetic variance. SNP windows explaining more than 0.40% of the AFC genetic variance were identified on chromosomes 2, 8, 9, 14, 16 and 17. From these windows, we identified 123 coding protein genes that were used to build gene networks. From the association study and derived gene networks, putative candidate genes (e.g., PAPPA, PREP, FER1L6, TPR, NMNAT1, ACAD10, PCMTD1, CRH, OPKR1, NPBWR1 and NCOA2) and transcription factors (TF) (STAT1, STAT3, RELA, E2F1 and EGR1) were strongly associated with female fertility (e.g., negative regulation of luteinizing hormone secretion, folliculogenesis and establishment of uterine receptivity). Evidence suggests that AFC inheritance is complex and controlled by multiple loci across the genome. As several windows explaining higher proportion of the genetic variance were identified on chromosome 14, further studies investigating the interaction across haplotypes to better understand the molecular architecture behind AFC in Nellore cattle should be undertaken.

Testosterone serum profile, semen characteristics and testicular biometry of Mangalarga Marchador stallions in a tropical environment.

This study was conducted to characterize the daily profile of testosterone secretion and its mean concentrations in the four seasons as well as to evaluate the semen characteristics and testicular biometry of Mangalarga Marchador stallions throughout the year in a tropical region. Three stallions were submitted to semen collections and evaluation of testicular biometry every 14 days along a year. Blood samples were collected once at the middle of each season, in a 20-min interval during 24 hr in order to evaluate the testosterone secretion profiles among seasons. Testosterone concentrations along the day were higher at the beginning of the afternoon (from 12:00 to 15:00 hr), but a circadian secretion was not clearly observed. Mean testosterone concentrations did not differ among seasons (p > .05), but a pattern of secretion along the day showed variations with higher concentrations in the afternoon during the winter. Ejaculate volume was higher during summer; however, sperm motility decreased in summer and spring. Total sperm in ejaculate, sperm morphology and testicular biometry kept constant along the year showing no differences among the seasons. The results demonstrated that in a tropical region, reproductive aspects of stallions did not show a clearly defined seasonal variation, and months of autumn and winter were not unsuitable for reproduction of the males.

Adição da proteína específica do oviduto de porcas (pOSP) e da melatonina em meios de maturação e o efeito na clivagem in vitro de embriões suínos / Addition of the oviduct specific protein of porcine (pOSP) and melatonin in maturation media and their effect on the in vitro production of pig embryos

No presente estudo, utilizou-se a melatonina e a proteína específica do oviduto (pOSP) nos meios de maturação in vitro. Foram avaliadas a expansão do complexo cumulus-ovócito (CCOs), as concentrações intracelulares de espécies reativas de oxigênio (ROS) e o desenvolvimento embrionário nos diferentes grupos (C = controle; T1 = somente com melatonina; T2 = com melatonina e pOSP e T3 somente com pOSP). No tocante à expansão do CCOs, houve diferença (P<0,05) dos valores obtidos no grupo C em relação aos valores médios dos grupos T1, T2 e T3, porém não houve diferença entre os valores obtidos nos tratamentos (P>0,05). Na dosagem de ROS, não houve diferença entre os valores médios obtidos no grupo C (26,4±10,9) e o valor verificado no grupo T1 (23,4±7,8), porém no grupo T2 (21,3±9,7) o valor médio mostrou-se satisfatório em relação ao valor do grupo C. No entanto, o valor médio do grupo T3 (16,6±10,5) foi o que demonstrou resultado mais satisfatório quando comparado aos demais grupos (P<0,05). A produção de embriões foi avaliada por meio da taxa de clivagem. Não houve diferença (P >0,05) entre os valores obtidos entre o grupo C (48,9 %) e os valores verificados nos grupos T1 (51,5 %), T2 (50 %), T3 (57,7 %), nem destes entre si. Este estudo permitiu concluir que a proteína específica do oviduto recombinante e a melatonina foram eficientes em melhorar a expansão dos CCOs. Além disso, as células tratadas com pOSP mostraram-se com menor quantidade de ROS, podendo a pOSP ser considerada um antioxidante proteico.(AU)

The present study used melatonin and recombinant oviduct specific protein (pOSP) in in vitro maturation medium (IVM). The expansion of the cumulus-oocyte complexes (COCs), the intracellular concentrations of reactive oxygen species (ROS) and embryo development of the different groups were evaluated (C = control; T1 = melatonin; T2 = melatonin and pOSP and T3 = pOSP). Regarding the COCs expansion, the groups T1, T2 and T3 showed satisfactory results compared with group C (P<0.05), but there was no difference between treatments (P>0.05). In the ROS dosage, there was no difference between the mean values obtained in group C (26.4 ± 10.9) and group 1 (23.4 ± 7.8). However, in group 2 (21.3 ± 9.7), the average value was found to be satisfactory in relation group C. Despite that, the average value of treatment 3 (16.6 ± 10.5) was the most satisfactory result found compared to the other groups (P<0.05). The production of embryos was evaluated by cleavage rate, there was no difference between the values obtained in group C and the values recorded in groups T1 (51.5 %), T2 (50 %), T3 (57.7 %), and among them. This study showed that the pOSP and the melatonin were effective in the improvement of the expansion of COCs cells. In addition, the cells that were treated with pOSP presented a lower amount of ROS, allowing the pOSP to be considered a proteic antioxidant.(AU)

Antibody response between pigs of Piau and a commercial breed naturally infected with Porcine circovirus 2 / Resposta sorológica entre suínos da raça Piau e linhagem comercial em rebanho naturalmente infectado pelo Porcine circovirus 2

Brazilian pig population is made up of several naturalized breeds; among them the Piau breed is known for its rusticity and large fat stores. The naturalized breeds, in comparison with commercial ones, may have an increased resistance to diseases circulating in their territory. Thus, this study aimed to verify if there are differences between the serologic profile against Porcine circovirus 2 (PCV2) of Piau pigs and that of a commercial breed from a farm naturally infected by PCV2. The serum viral load was measured by qPCR, and levels of anti-PCV2 antibodies were measured by ELISA. The results showed that the serum viral load was similar across all animals. However, Piau piglets showed higher levels of antibodies compared to commercial piglets (P= 0.05), while sows of the commercial breed showed higher levels than the Piau breed (P< 0.01). There was not a statistical difference between pigs of different production stages in the seroprevalence of PCV2 or the blood viral load. This work demonstrates that, with regard to a natural PCV2 infection, the Piau breed has a different humoral immune response compared to the response developed by the commercial pigs. The results support the importance of conservation of native breeds.(AU)

O rebanho de suínos brasileiro é constituído por diversas raças naturalizadas, entre elas a raça Piau, que é conhecida por sua rusticidade e pela grande deposição de toucinho. As raças naturalizadas, em comparação com as linhagens comerciais, podem ter uma maior resistência a doenças que circulam em seu território. Dessa forma, o presente estudo teve como objetivo verificar se existem diferenças no perfil sorológico contra o Porcine circovirus 2 (PVC2) entre suínos da raça Piau e de uma linhagem comercial de uma granja naturalmente infectada pelo PCV2. Foram realizadas mensurações da carga viral sérica por qPCR e dos níveis de anticorpos anti-PCV2 por meio da técnica de ELISA. Os resultados mostraram que a carga viral sérica se manteve homogênea em todos os animais e que os leitões da raça Piau apresentaram níveis de anticorpos superiores em comparação com os leitões da linhagem comercial (P=0,05), enquanto as porcas de linhagem comercial apresentaram níveis superiores aos da raça Piau (P<0,01). Este trabalho fornece indícios de que a raça Piau apresenta uma resposta imune humoral distinta diante de uma infecção natural pelo PCV2, quando comparada com a resposta desenvolvida pela linhagem comercial. Os resultados obtidos reforçam a importância da conservação das raças nativas.(AU)

Influência da condição corporal ao parto no balanço energético e desempenho reprodutivo de cabras leiteiras no pós-parto / Influence of body condition at calving on energy balance and reproductive performance of dairy goats in the postpartum

O estudo teve como objetivo avaliar a influência da condição corporal (CC) ao parto no balanço energético (BE) e o desempenho reprodutivo de cabras Alpinas no pós-parto. Foram utilizadas 68 cabras distribuídas em três grupos (G), sendo: G1- cabras com baixa CC (CC entre 1,5 e 2,5); G2: cabras com moderada CC (entre 2,75 e 3,5) e G3: cabras com alta CC (entre 3,75 e 5,0). Os animais receberam dieta (silagem de milho e concentrado, com 18% de proteína bruta e 1,7Mcal/kg de matéria seca de energia líquida) ad libitum. As avaliações foram feitas nas oito primeiras semanas de lactação, para determinação do BE, do intervalo do parto à primeira ovulação e ao primeiro estro e da concentração plasmática de progesterona. Os dados foram analisados por análise de variância a 5% de probabilidade. Não houve efeito da CC ao parto sobre o BE dos animais. Todas as cabras apresentaram BE negativo ao parto, com mudança para BE positivo aos 51, 58 e 64 dias pós-parto, respectivamente. Não houve diferença na concentração plasmática de progesterona nos três grupos, sendo caracterizada função luteal (concentração ≥1ng/dL) em apenas 5,9% dos animais avaliados. O intervalo do parto à primeira ovulação foi de 46 dias. Apenas 4,4% das cabras exibiram estro. Cabras leiteiras de média produção, entre 2,5 e 3,0kg de leite/dia, entram em BE negativo ao parto, independentemente da CC apresentada, influenciando negativamente o reinício da atividade ovariana no pós-parto.(AU)

The concentration of progesterone in the blood was used to study the effect of body condition score (BCS) on the post-partum ovarian activity of dairy goats. Sixty-eight female goats were distributed between three treatments. Treatment 1: goats with BCS between 1.00 and 2.75; Treatment 2: goats with BCS between 2.75 and 3.50; and Treatment 3: goats with BCS between 3.50 and 5.00. The goats had the blood collected immediately after birth, and from that time up to the eighth week post-partum at three day intervals. The progesterone analysis on the blood was used to determine the interval between the birth and the first ovulation. The females were teasing two times per day for estrus detection and determination of the time interval from birth to first estrus. No significant difference was found on the progesterone concentration between treatments. The luteal functionality was characterized in only 5.9% of goats, with a concentration higher than 1ng/mL. The period from birth to first ovulation was 46 days. The detectable estrus was found in only 4.4% of goats. The BCS at birth did not influence the recovery of ovarian activity of dairy goats.(AU)

Effect of cyclodextrin-loaded cholesterol conjugates on plasma membrane viability of Piau swine breed frozen/thawed spermatozoa.

The objective of this study was to investigate the effect of cyclodextrin-loaded cholesterol conjugates addition to freezing extenders on plasma membrane viability of frozen-thawed spermatozoa of the Piau swine breed. Twenty semen samples were used from five males. The freezing extender was based on lactose-egg yolk extender, added to 2% glycerol, 3% dimethylacetamide. The addition of cyclodextrin-loaded cholesterol conjugates was performed after centrifugation, when semen was diluted with the cooling extender. Four groups were subjected to the following treatment: without addition (group 1); 1.5 mg of cyclodextrin-loaded cholesterol/120 × 10(6) sperm (group 2); 1.5 mg of cyclodextrin-loaded cholestanol/120 × 10(6) sperm (group 3); 1.5 mg of cyclodextrin-loaded desmosterol/120 × 10(6) sperm (group 4). To check post-thawing sperm quality sperm motility and sperm morphology evaluation were used. Additionally, to check sperm viability the hypoosmotic swelling test, supravital staining, and fluorescent assay were used. The mean values recorded for total sperm motility of semen immediately after thawing were 54.5 ± 5.8, 55.5 ± 5.3, 53.7 ± 6.7, and 52.5 ± 6.6% respectively for groups one to four, without difference between themselves (p > 0.05). Regarding fluorescent assay the results were 28.3 ± 13.2, 26.9 ± 12.2, 22.2 ± 11.4, and 32.0 ± 15.3% respectively for groups one to four, also without difference between groups (p > 0,05). Similarly, complementary tests for evaluating the integrity and functionality of the plasma membrane showed no difference between treatments (p > 0.05). In conclusion, use of cyclodextrin-loaded cholesterol conjugates added to the plasma membrane of sperm did not demonstrate any additive effect on increasing and/or maintaining sperm motility.

Expressão gênica em ovócitos suínos de diferentes classificações morfológicas / Gene expression in swine oocytes in different morphological classifications

A produção in vitro de embriões suínos tem alcançado resultados insatisfatórios: ovócitos maturados in vivo produzem uma porcentagem maior de embriões em relação aos maturados in vitro. O sucesso da maturação in vitro está diretamente relacionado com a competência ovocitária. Somente ovócitos competentes são capazes de serem fecundados e terem desenvolvimento embrionário normal. A competência ovocitária pode ser avaliada por vários parâmetros. Recentemente têm sido utilizados como parâmetro os estudos da expressão de genes associados com a competência. O presente trabalho teve por objetivo avaliar diferenças na expressão dos genes BMP15, RYBP, MATER e ZAR1 em ovócitos imaturos de diferentes classes morfológicas, sendo elas: 1, 2, 3 e 4, com a finalidade de proporcionar importantes marcadores moleculares relacionados com a capacidade ovocitária. O RNA total dos ovócitos foi extraído e utilizado como molde para a síntese da primeira fita de cDNA. Os resultados da expressão gênica foram analisados utilizando-se modelo misto, considerando os dados de expressão gênica variável dependente e as classes ovocitárias variáveis independentes. Os genes BMP15, ZAR1 e RYBP apresentaram expressão semelhante nas classes ovocitárias 1, 2 e 3; somente a categoria 4 diferiu na expressão desses genes (P<0,05). O gene MATER foi expresso de forma semelhante em todas as classes ovocitárias estudadas (P>0,05). A técnica de RT-qPCR foi eficiente para detecção desses transcritos em ovócitos de diferentes classes. No entanto, para melhor entendimento do envolvimento desses transcritos na aquisição da competência ovocitária, são necessários mais estudos avaliando ovócitos de diferentes classes morfológicas, em diferentes fases de desenvolvimento, e implicação de outros genes envolvidos com a competência ovocitária.

The in vitro production of pig embryos has achieved unsatisfactory results; in vivo matured oocytes produce a higher percentage of embryos compared to in vitro maturation. The success of in vitro maturation is directly related to oocyte competence. Only competent oocytes are capable of being fertilized and have normal embryonic development. The oocyte competence can be assessed using several parameters. Recently these parameters have been used for gene expression studies associated with competence. This work aimed to evaluate differences in gene expression BMP15, RYBP, MATER, ZAR1 as endogenous control and the constitutive gene GAPDH in immature oocytes of different morphological classes which are: 1, 2, 3 and 4, in order to provide significant molecular markers linked to the ability of development. Oocytes Total RNA was extracted and used as a template for synthesis of the first cDNA strand. The results of gene expression were analyzed using a mixed model, considering the dependent gene expression data and independent ovocitary variable classes. The genes BMP15, RYBP ZAR1 and showed similar ovocitary expression in classes 1, 2 and 3 differ only in category 4 in their expression (P<0.05). The MATER gene was similarly expressed in all ovocitary classes studied (P>0.05). The RTQ-PCR technique was effective for detection of these transcripts in oocytes from different classes. However, for better understanding of the involvement of these transcripts in the acquisition of oocyte competence more studies are needed to evaluate different morphological classes of oocytes at different stages of development and the implication of other genes involved in oocyte competence.

Cryopreservation of Piau-Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes.

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post-thaw viability of Piau-breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800 g for 10 min and 2400 g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour - freezing 1 and automated cooling using a programmed freezing machine - freezing 2) were tested. Therefore, the treatments were divided into M3 - centrifugation at 2400 g for 3 min and freezing 2; M10 - centrifugation at 800 g for 10 min and freezing 2; R3 - centrifugation at 2400 g for 3 min and freezing 1; and R10 - centrifugation at 800 g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post-thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo-osmotic test (HO), sperm-egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post-thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.

Influência do Hormônio do Crescimento na concentração de testosterona plasmática e nas características seminais de touros jovens e adultos da raça Nelore / Influence of Growth Hormone on plasma testosterone concentration and seminal characteristics of young and adult Nellore bulls

Estudou-se o efeito do Hormônio do Crescimento bovino (bGH) sobre os parâmetros seminais e a concentração sérica de testosterona de touros da raça Nelore. Dezesseis touros foram distribuídos em um delineamento fatorial 2 x 2 (duas idades e dois níveis de r-bST), com quatro animais em cada tratamento. As aplicações de r-bST foram realizadas a cada 14 dias, totalizando nove aplicações por animal, em um período experimental de 120 dias. As coletas de sêmen foram realizadas a cada 15 dias e, para determinar as concentrações de testosterona, foram realizadas coletas de sangue a cada quatro horas, num total de 24 horas, e a cada 30 dias a partir da primeira aplicação de r-bST. O sêmen dos touros adultos tratados com r-bST apresentaram maior motilidade e vigor (P<0,05) em relação aos animais controles (79,70±11,56% vs 64,06±23,65%) e (3,80±0,88 vs 2,92±1,25), respectivamente; entretanto, as demais características seminais não foram influenciadas (P>0,05) pelo tratamento com r-bST. Os aspectos físicos do sêmen dos touros jovens não foram afetados (P>0,05) pelo tratamento com r-bST. Entretanto o tratamento com r-bST diminuiu os defeitos morfológicos menores (delgado, gigante normal, pequeno normal, globoso, cabeça isolada normal, abaxial, cauda dobrada e enrolada levemente e gota distal) em relação aos jovens não tratados (P<0,05). As concentrações séricas de testosterona foram influenciadas (P<0,05) pelo tratamento, aos 120 dias após a primeira aplicação do r-bST, e apresentaram tendência de três picos no período de 24 horas.

The aim of this trial was to study the effect of Growth Hormone (GH) on the seminal parameters and testosterone profile from Nellore bulls. Sixteen bulls were allocated in a 2 x 2 factorial arrangement (two ages and two r-bST levels), with four animals per treatment. The r-bST was injected every 14 days, with a total of nine injections per animal, during the 120 days of the experimental period. The semen collections were done every 15 days and blood samples were collected in four hour intervals for 24 hours, and in 30 day intervals from the first r-bST injection for testosterone profile. The semen of adult bulls treated with r-bST showed greater MOT and VIG (P<0.05) in relation to the control (79.70±11.56% vs 64.06±23.65%) and (3.80±0.88 vs 2.92±1.25) respectively; however, the other evaluated seminal parameters were not affected (P>0.05) by the r-bST treatment. The physical measurements of the semen of young animals was also unaffected (P>0.05) by r-bST injection. However, the treatment with r-bST decreased the number of minor morphologic defects (narrow head, giant head, small normal head, round head, free normal head, abaxial implantation, simple bent tail and distal droplet) compared to untreated young bulls (P<0.05). The serum testosterone concentration was influenced (P<0.05) by treatment, at 120 days after the first injection of r-bST and they showed a tendency of three picks in a 24 hour period of sampling.