Relationship of residual feed intake with semen parameters and testicular ultrasound of Nellore bulls

The objective of this study was to evaluate characteristics of the testicular parenchyma and vascular parameters of the pampiniform plexus obtained by ultrasound, semen quality parameters, and sperm freezability in Nellore bulls classified based on residual feed intake (RFI). Twenty-seven bulls (21.82±0.88 months of age) evaluated for feed efficiency were sampled for the study, including 15 with low RFI (−0.592±0.09 kg dry matter/day) and 12 with high RFI (0.792±0.10 kg dry matter/day). In ultrasound and Doppler assessment, the most efficient animals (low RFI) showed higher pulsatility and resistive indexes, as well as a tendency towards greater heterogeneity of the testicular parenchyma (0.625±0.032 vs. 0.508±0.032, 1.012±0.072 vs. 0.802±0.072, and 12.9±0.96 vs. 10.2±0.96, respectively, for low vs. high RFI). However, these animals tended to have lower peak diastolic velocity (5.19±0.50 for low RFI vs. 6.54±0.50 for high RFI). Analysis of fresh semen showed a lower percentage of minor defects in low RFI animals (2.67±1.19%) compared with high RFI animals (8.10±1.19%), without differences in the other parameters in fresh or thawed semen and after thermoresistance testing. Evaluation of flow cytometry parameters showed a higher quality of mitochondrial respiration in semen samples of low RFI animals (22.04±2.50%) compared with high RFI animals (12.29±2.71%). Therefore, although RFI exerts an effect on the Doppler parameters of the pampiniform plexus, it is not sufficient to affect the quality of fresh or thawed semen.(AU)

Growth performance, reproductive parameters and fertility measures in young Nellore bulls with divergent feed efficiency

The growth, sexual maturity and fertility-related parameters related of young Nellore bulls with divergent residual feed intake (RFI) raised on pasture were evaluated. After classification of 48 young males as low and high RFI (more and less efficient, respectively), the animals were evaluated for growth and reproductive parameters at 28-day intervals from 14.3 to 24.6 months of age. The semen was cryopreserved in the last sampling and fresh and post-thaw semen samples were evaluated. Low RFI bulls exhibited higher initial and final body weight (P < 0.05), but feed intake, body condition score and growth measures evaluated by carcass ultrasound were unaffected by RFI (P > 0.05). The scrotal circumference, sperm concentration, defects, and quality of fresh semen, and ultrasonographic testicular characteristics were unaffected by RFI (P > 0.05). However, velocity parameters such as average path and curvilinear velocities determined by computer-assisted sperm analysis of thawed semen submitted to the rapid thermoresistance test were improved (P < 0.05) in low RFI bulls, but this improvement in quality did not enhance in vitro sperm fertilizing ability. Our results demonstrated significant differences in metabolism and growth performance between bulls of divergent RFI. In addition, there was slight improvement in the semen quality of bulls with low RFI bulls, but this did not enhance in vitro fertilizing ability. Selection of beef bulls for RFI can be performed, which will result in economic benefits by improving the growth performance of the animals without affecting reproductive parameters.(AU)

Cinética e integridade de espermatozoides caprinos criopreservados utilizando Red Cushion® como estratégia de proteção espermática durante a centrifugação do sêmen / Kinetics and integrity of cryopreserved goat sperm using Red Cushion® as a strategy to sperm protection during semen centrifugation

Objetivou-se avaliar o efeito do gradiente de Iodixanol (Red Cushion®, RC) como método deproteção espermática durante a centrifugação (CE) do sêmen caprino destinado à criopreservação. Foramrealizadas colheitas de sêmen de cinco reprodutores caprinos da raça Anglo Nubiana (N= cincoejaculados/bode). Os ejaculados foram divididos em três grupos experimentais: GC (Controle); G1 (CEutilizado 1ml de RC) e G2 (foi utilizado 0,5mL de RC, misturado ao pellet espermático após a CE). Asamostras foram centrifugadas, diluídas, envasadas e criopreservadas. A cinética espermática foi avaliada porsistema computadorizado de análise (CASA) após a descongelação e pós-teste de termorresistência (TTR), efoi avaliada a integridade de membrana plasmática e acrossomal (MPAI, %). Não foram observadasdiferenças para a motilidade total (p=0,1849) avaliada pós-descongelação (GC=45,1%, G1=51,86% eG2=55,28%) ou pós-TTR (GC=10,32%, G1=11,44% e G2=13,16%), bem como para nenhum outroparâmetro cinético avaliado. Também não foram encontradas diferenças para a MPAI (GC=43,70% ±16,60; G1=36,68 ± 17,40; G2=41,72 ± 14,76; p=0,2523). Conclui-se que a utilização de Red Cushion®não promove nenhum benefício à manutenção da cinética e integridade de espermatozoides caprinossubmetidos a centrifugação previamente ao processo de criopreservação do sêmen.(AU)

The aim of this study was to evaluate the efficacy of iodixanol gradient centrifugation (RedCushion®, RC) as a method of protection of goat semen submitted to centrifugation previously tocryopreservation process. Semen were collected from five Anglo Nubian goats (n = five ejaculates/goat).The ejaculates were divided into three experimental groups: GC (Control; conventional centrifugation);G1 (centrifugation using 1ml RC) and G2 (centrifugation using 0.5 mL RC, mixed to sperm pellet beforethe cryopreservation). Samples were centrifuged (CE) at 600xg for 10 minutes, diluted, packed andcryopreserved. Sperm kinetics were evaluated using a computer assisted semen analysis (CASA) afterthawing and after thermoresistance test (TTR), and the integrity of the plasma and acrosomal membranewas evaluated (MPAI, %). No differences were observed for total motility (P =0.1849) assessed afterthawing (GC=45.1%, G1=51.86% and G2=55.28%) or post-TTR (GC=10.32%, G1=11.44% andG2=13.16%), as well as for the other kinetic parameters analyzed. Furthermore, no differences for MPAI(CG =43.70% ± 16.60; G1=36.68 ± 17.40; G2=41.72 ± 14.76; P=0.2523) were found comparing thedifferent groups. In conclusion, Red Cushion® was not able to improve the kinetics and integrity of thegoat semen submitted to the cryopreservation process.(AU)

Cinética e integridade de espermatozoides caprinos criopreservados utilizando Red Cushion® como estratégia de proteção espermática durante a centrifugação do sêmen / Kinetics and integrity of cryopreserved goat sperm using Red Cushion® as a strategy to sperm protection during semen centrifugation

Objetivou-se avaliar o efeito do gradiente de Iodixanol (Red Cushion®, RC) como método deproteção espermática durante a centrifugação (CE) do sêmen caprino destinado à criopreservação. Foramrealizadas colheitas de sêmen de cinco reprodutores caprinos da raça Anglo Nubiana (N= cincoejaculados/bode). Os ejaculados foram divididos em três grupos experimentais: GC (Controle); G1 (CEutilizado 1ml de RC) e G2 (foi utilizado 0,5mL de RC, misturado ao pellet espermático após a CE). Asamostras foram centrifugadas, diluídas, envasadas e criopreservadas. A cinética espermática foi avaliada porsistema computadorizado de análise (CASA) após a descongelação e pós-teste de termorresistência (TTR), efoi avaliada a integridade de membrana plasmática e acrossomal (MPAI, %). Não foram observadasdiferenças para a motilidade total (p=0,1849) avaliada pós-descongelação (GC=45,1%, G1=51,86% eG2=55,28%) ou pós-TTR (GC=10,32%, G1=11,44% e G2=13,16%), bem como para nenhum outroparâmetro cinético avaliado. Também não foram encontradas diferenças para a MPAI (GC=43,70% ±16,60; G1=36,68 ± 17,40; G2=41,72 ± 14,76; p=0,2523). Conclui-se que a utilização de Red Cushion®não promove nenhum benefício à manutenção da cinética e integridade de espermatozoides caprinossubmetidos a centrifugação previamente ao processo de criopreservação do sêmen.

The aim of this study was to evaluate the efficacy of iodixanol gradient centrifugation (RedCushion®, RC) as a method of protection of goat semen submitted to centrifugation previously tocryopreservation process. Semen were collected from five Anglo Nubian goats (n = five ejaculates/goat).The ejaculates were divided into three experimental groups: GC (Control; conventional centrifugation);G1 (centrifugation using 1ml RC) and G2 (centrifugation using 0.5 mL RC, mixed to sperm pellet beforethe cryopreservation). Samples were centrifuged (CE) at 600xg for 10 minutes, diluted, packed andcryopreserved. Sperm kinetics were evaluated using a computer assisted semen analysis (CASA) afterthawing and after thermoresistance test (TTR), and the integrity of the plasma and acrosomal membranewas evaluated (MPAI, %). No differences were observed for total motility (P =0.1849) assessed afterthawing (GC=45.1%, G1=51.86% and G2=55.28%) or post-TTR (GC=10.32%, G1=11.44% andG2=13.16%), as well as for the other kinetic parameters analyzed. Furthermore, no differences for MPAI(CG =43.70% ± 16.60; G1=36.68 ± 17.40; G2=41.72 ± 14.76; P=0.2523) were found comparing thedifferent groups. In conclusion, Red Cushion® was not able to improve the kinetics and integrity of thegoat semen submitted to the cryopreservation process.

Assessment of different in vitro sperm challenges and in vivo fertility of bovine semen batches / Avaliação de diferentes desafios espermáticos in vitro e da fertilidade in vivo de partidas de sêmen bovino

The aim of this work was to submit sperm cells to different laboratory challenges and to compare in vitro results with in vivo semen fertility. Four different batches from the same Brangus bull were used in a timed-AI program of 332 Brangus cows. Each batch (B) was submitted to the following procedure: semen sample was thawed at 36°C for 30 seconds (control). Sperm motility parameters, plasma membrane integrity, sperm morphology, and concentration were assessed. Then, an aliquot of thawed sample was incubated in a water bath at 45°C for 40 min (thermal challenge group; TCG) and another aliquot was centrifuged at 500 xg (Percoll gradient 45%/90%) for 15 min (centrifugation challenge group; CCG). Centrifuged semen was also submitted to another thermal challenge, being incubated (water bath) at 45°C for 40 min (centrifugation + thermal challenge group; CTCG). At the end of each challenge (CCG, TCG, and CTCG), the same laboratory tests used for control group were repeated. The following conception rates (CR) were observed for each batch: B1 = 48.9% (44/90); B2 = 44.2% (23/52); B3 = 55.5% (40/72); B4 = 43.2% (51/118); (p < 0.10). In the lab, B3 presented higher (p ≤ 0.05) progressive motility (PM) than B4 after thawing (control group) and after all sperm challenges (TCG, CCG, and CTCG). However, despite B3 and B4 having demonstrated a similar percentage of plasma membrane integrity (PMI) to the control group (B3 = 66.7 ± 1.3 and B4 = 65.2 ± 3.3), B3 demonstrated higher (P ≤ 0.05) percentage of PMI (37.2 ± 2.5) than B4 (26.7 ± 3.3) after passing through the most stressing in vitro challenge (CTCG). The semen batch presenting the highest resistance to in vitro challenges was the one that presented a trend for higher in vivo fertility, suggesting that submitting semen samples to laboratory challenges may be an interesting alternative for selecting batches with greater field fertility.(AU)

O objetivo deste estudo foi estressar células espermáticas em diferentes desafios laboratoriais e comparar os resultados in vitro com a fertilidade in vivo do sêmen. Quatro partidas de um mesmo touro Brangus foram utilizadas em um programa de IATF de 332 vacas Brangus. Cada partida foi submetida ao seguinte procedimento: a amostra de sêmen foi descongelada a 36°C por 30 segundos (grupo controle). Foram avaliados parâmetros de motilidade espermática (CASA), integridade da membrana plasmática (PMI), morfologia e concentração espermática. Em seguida, uma alíquota da amostra descongelada foi incubada em banho-maria a 45°C durante 40 minutos (grupo de desafio térmico, TCG) e outra alíquota foi centrifugada a 500 xg (gradiente de Percoll 45%/90%) durante 15 min (grupo desafio de centrifugação, CCG). Uma aliquota do sêmen centrifugado foi ainda submetida ao desafio térmico, sendo incubado a 45°C durante 40 min (grupo de desafio térmico + centrifugação, CTCG). No final de cada desafio (CCG, TCG e CTCG), os mesmos testes laboratoriais utilizados para o grupo de controle foram realizados. A seguinte taxa de concepção (CR) foi observada para cada partida (B): B1 = 48,9% (44/90), B2 = 44,2% (23/52), B3 = 55,5% (40/72) e B4 = 43,2% (51/118); (P < 0,10). No laboratório, B3 apresentou maior (P ≤ 0,05) motilidade progressiva (PM) do que B4 logo após o descongelamento (grupo controle) e após todos os desafios laboratoriais (TCG, CCG e CTCG). Porém, apesar de B3 e B4 demonstrarem similar porcentagem de PMI no grupo controle (B3 = 66,7 ± 1,3 e B4 = 65,2 ± 3,3), B3 apresentou maior (P ≤ 0,05) PMI (37,2 ± 2,5%) do que B4 (26,7 ± 3,3%) após passar pelo maior desafio laboratorial (CTCG). A partida seminal que in vitro apresentou maior resistência aos desafios laboratoriais foi a mesma que apresentou tendência para maior fertilidade in vivo. Assim, sugere-se que submeter amostras seminais a desafios laboratoriais pode ser uma alternativa interessante para selecionar partidas com maior fertilidade a campo.(AU)

Assessment of different in vitro sperm challenges and in vivo fertility of bovine semen batches / Avaliação de diferentes desafios espermáticos in vitro e da fertilidade in vivo de partidas de sêmen bovino

The aim of this work was to submit sperm cells to different laboratory challenges and to compare in vitro results with in vivo semen fertility. Four different batches from the same Brangus bull were used in a timed-AI program of 332 Brangus cows. Each batch (B) was submitted to the following procedure: semen sample was thawed at 36°C for 30 seconds (control). Sperm motility parameters, plasma membrane integrity, sperm morphology, and concentration were assessed. Then, an aliquot of thawed sample was incubated in a water bath at 45°C for 40 min (thermal challenge group; TCG) and another aliquot was centrifuged at 500 xg (Percoll gradient 45%/90%) for 15 min (centrifugation challenge group; CCG). Centrifuged semen was also submitted to another thermal challenge, being incubated (water bath) at 45°C for 40 min (centrifugation + thermal challenge group; CTCG). At the end of each challenge (CCG, TCG, and CTCG), the same laboratory tests used for control group were repeated. The following conception rates (CR) were observed for each batch: B1 = 48.9% (44/90); B2 = 44.2% (23/52); B3 = 55.5% (40/72); B4 = 43.2% (51/118); (p < 0.10). In the lab, B3 presented higher (p ≤ 0.05) progressive motility (PM) than B4 after thawing (control group) and after all sperm challenges (TCG, CCG, and CTCG). However, despite B3 and B4 having demonstrated a similar percentage of plasma membrane integrity (PMI) to the control group (B3 = 66.7 ± 1.3 and B4 = 65.2 ± 3.3), B3 demonstrated higher (P ≤ 0.05) percentage of PMI (37.2 ± 2.5) than B4 (26.7 ± 3.3) after passing through the most stressing in vitro challenge (CTCG). The semen batch presenting the highest resistance to in vitro challenges was the one that presented a trend for higher in vivo fertility, suggesting that submitting semen samples to laboratory challenges may be an interesting alternative for selecting batches with greater field fertility.(AU)

O objetivo deste estudo foi estressar células espermáticas em diferentes desafios laboratoriais e comparar os resultados in vitro com a fertilidade in vivo do sêmen. Quatro partidas de um mesmo touro Brangus foram utilizadas em um programa de IATF de 332 vacas Brangus. Cada partida foi submetida ao seguinte procedimento: a amostra de sêmen foi descongelada a 36°C por 30 segundos (grupo controle). Foram avaliados parâmetros de motilidade espermática (CASA), integridade da membrana plasmática (PMI), morfologia e concentração espermática. Em seguida, uma alíquota da amostra descongelada foi incubada em banho-maria a 45°C durante 40 minutos (grupo de desafio térmico, TCG) e outra alíquota foi centrifugada a 500 xg (gradiente de Percoll 45%/90%) durante 15 min (grupo desafio de centrifugação, CCG). Uma aliquota do sêmen centrifugado foi ainda submetida ao desafio térmico, sendo incubado a 45°C durante 40 min (grupo de desafio térmico + centrifugação, CTCG). No final de cada desafio (CCG, TCG e CTCG), os mesmos testes laboratoriais utilizados para o grupo de controle foram realizados. A seguinte taxa de concepção (CR) foi observada para cada partida (B): B1 = 48,9% (44/90), B2 = 44,2% (23/52), B3 = 55,5% (40/72) e B4 = 43,2% (51/118); (P < 0,10). No laboratório, B3 apresentou maior (P ≤ 0,05) motilidade progressiva (PM) do que B4 logo após o descongelamento (grupo controle) e após todos os desafios laboratoriais (TCG, CCG e CTCG). Porém, apesar de B3 e B4 demonstrarem similar porcentagem de PMI no grupo controle (B3 = 66,7 ± 1,3 e B4 = 65,2 ± 3,3), B3 apresentou maior (P ≤ 0,05) PMI (37,2 ± 2,5%) do que B4 (26,7 ± 3,3%) após passar pelo maior desafio laboratorial (CTCG). A partida seminal que in vitro apresentou maior resistência aos desafios laboratoriais foi a mesma que apresentou tendência para maior fertilidade in vivo. Assim, sugere-se que submeter amostras seminais a desafios laboratoriais pode ser uma alternativa interessante para selecionar partidas com maior fertilidade a campo.(AU)

Caracterização citogenética das raças bovinas caracu, junqueira, pantaneira e patuá / Cytogenetical characterization of bovine breeds Caracu, Junqueira, Pantaneiro and Patua

Durante o processo adaptativo às condições locais as raças bovinas europeias introduzidas no Brasil na época da colonização, adquiriram características fisiológicas e fenotípicas que as diferenciaram das raças originais. O presente estudo teve como objetivo comparar a morfologia dos cromossomos sexuais de bovinos de quatro raças, naturalizadas brasileiras, bem como verificar a incidência de anomalias cromossômicas. Foi analisado o cariótipo de 332 animais de quatro raças: Caracu (115 fêmeas e 159 machos), Junqueira (13 fêmeas e 3 machos), Pantaneiro (8 machos) e Patuá (21 fêmeas e 13 machos), utilizando-se a coloração convencional de Giemsa. Os animais das raças estudadas apresentaram o complemento cromossômico normal da espécie (2n=60), constituído de 58 cromossomos autossomos de morfologia acrocêntrica e dois cromossomos sexuais X submetacêntricos nas fêmeas e um X e um Y nos machos. Na raça Caracu, as linhagens selecionadas para corte e para leite foram formadas por indivíduos portadores de cromossomo Y acrocêntrico e submetacêntrico, sendo que a linhagem de corte apresentou maior percentagem de cromossomo Y acrocêntrico (P<0,01). Em duas fêmeas e em dois machos nascidos de partos gemelares da raça Caracu, foi observado quimerismo 60,XX/60,XY. O cariótipo 60,XX/61,XXY foi observado em outra fêmea da mesma raça. Nas outras três raças, nenhuma anomalia cromossômica foi observada. A morfologia do cromossomo Y das raças Pantaneira e Patuá apresentou dimorfismo do cromossomo Y acrocêntrico e submetacêntrico. Na raça Junqueira, apenas a morfologia submetacêntrica foi observada.

During the adaptive process to Brazilian conditions, the native cattle breeds acquired physiological and phenotypic characteristics wich differs them from European breeds, from which they derive. The objectives of present study were to compare the sex chromosomes morphologies between four Brazilian native cattle breeds as well as the incidence of chromosomal abnormalities. The karyotype of 332 animals from four breeds were analyzed: Caracu (115 females and 159 males), Junqueira (13 females and 3 males), Pantaneiro (8 males) and Patua (21 females and 13 males). The Giemsa coloring were used to read the chromosome. All cattle breeds studied showed the normal chromosome (2n=60) consisting of 58 acrocentric autosomes and two submetacentric X chromosomes in females, and one X and one Y in males. In Caracu breed, selected for dairy or beef, it was developed by animals dimorphism carriers of Y chromosome (acrocentric and submetacentric), and the beef bloodlines showed higher percentage of acrocentric Y chromosome. There was 1% significant difference in Chi-Square test. In two females and two male born from twin birth of Caracu breed it was observed chemerism 60, XX/ 60, XY, and in other female from same breed it was observed 60, XX/ 61 XXY. For other three breeds, no chromosomal abnormality was observed. The Y chromosome morphology of the Pantaneiro and Patua breeds showed dimorphism of Y chromosome (submetacentric an acrocentric). In the Junqueira breed, only submetacentric morphology was observed.

Caracterização citogenética das raças bovinas caracu, junqueira, pantaneira e patuá / Cytogenetical characterization of bovine breeds Caracu, Junqueira, Pantaneiro and Patua.

Durante o processo adaptativo às condições locais as raças bovinas europeias introduzidas no Brasil na época da colonização, adquiriram características fisiológicas e fenotípicas que as diferenciaram das raças originais. O presente estudo teve como objetivo comparar a morfologia dos cromossomos sexuais de bovinos de quatro raças, naturalizadas brasileiras, bem como verificar a incidência de anomalias cromossômicas. Foi analisado o cariótipo de 332 animais de quatro raças: Caracu (115 fêmeas e 159 machos), Junqueira (13 fêmeas e 3 machos), Pantaneiro (8 machos) e Patuá (21 fêmeas e 13 machos), utilizando-se a coloração convencional de Giemsa. Os animais das raças estudadas apresentaram o complemento cromossômico normal da espécie (2n=60), constituído de 58 cromossomos autossomos de morfologia acrocêntrica e dois cromossomos sexuais X submetacêntricos nas fêmeas e um X e um Y nos machos. Na raça Caracu, as linhagens selecionadas para corte e para leite foram formadas por indivíduos portadores de cromossomo Y acrocêntrico e submetacêntrico, sendo que a linhagem de corte apresentou maior percentagem de cromossomo Y acrocêntrico (P<0,01). Em duas fêmeas e em dois machos nascidos de partos gemelares da raça Caracu, foi observado quimerismo 60,XX/60,XY. O cariótipo 60,XX/61,XXY foi observado em outra fêmea da mesma raça. Nas outras três raças, nenhuma anomalia cromossômica foi observada. A morfologia do cromossomo Y das raças Pantaneira e Patuá apresentou dimorfismo do cromossomo Y acrocêntrico e submetacêntrico. Na raça Junqueira, apenas a morfologia submetacêntrica foi observada.(AU)

During the adaptive process to Brazilian conditions, the native cattle breeds acquired physiological and phenotypic characteristics wich differs them from European breeds, from which they derive. The objectives of present study were to compare the sex chromosomes morphologies between four Brazilian native cattle breeds as well as the incidence of chromosomal abnormalities. The karyotype of 332 animals from four breeds were analyzed: Caracu (115 females and 159 males), Junqueira (13 females and 3 males), Pantaneiro (8 males) and Patua (21 females and 13 males). The Giemsa coloring were used to read the chromosome. All cattle breeds studied showed the normal chromosome (2n=60) consisting of 58 acrocentric autosomes and two submetacentric X chromosomes in females, and one X and one Y in males. In Caracu breed, selected for dairy or beef, it was developed by animals dimorphism carriers of Y chromosome (acrocentric and submetacentric), and the beef bloodlines showed higher percentage of acrocentric Y chromosome. There was 1% significant difference in Chi-Square test. In two females and two male born from twin birth of Caracu breed it was observed chemerism 60, XX/ 60, XY, and in other female from same breed it was observed 60, XX/ 61 XXY. For other three breeds, no chromosomal abnormality was observed. The Y chromosome morphology of the Pantaneiro and Patua breeds showed dimorphism of Y chromosome (submetacentric an acrocentric). In the Junqueira breed, only submetacentric morphology was observed.(AU)

Efeitos da suplementação com fontes de ácidos graxos em doadoras da raça holandesa durante o pré e pós-parto sobre o retorno à ciclicidade e produção in vitro de embriões / Effects of fatty acid supplementation in Holstein cows at pre and postpartum period, on estrous cycle return and in vitro production of embryos

A suplementação de bovinos leiteiros com fontes de ácidos graxos poli-insaturados (AGPs) é uma prática utilizada para aumentar o nível energético das dietas, além de proporcionar efeitos positivos nas funções reprodutivas de importantes tecidos, incluindo hipotálamo, hipófise, ovários e útero. O trabalho foi conduzido com objetivo de avaliar as condições reprodutivas do pós-parto, número de folículos, presença de corpo lúteo (CL), concentração de progesterona (P), quantidade de oócitos viáveis e totais e a produção in vitro de embriões (PIVE) de doadoras multíparas da raça Holandesa suplementadas com dieta rica em AGPs protegido (principalmente ácido linoleico - n-6) e não protegido (principalmente ácido linolênico - n-3) durante o pré e pós-parto. As dietas foram fornecidas por 30 dias pré-parto e 60 dias pós-parto. As doadoras foram divididas aleatoriamente em 3 grupos: Controle (n=6), Megalac-E® (n=5; suplementados com fonte de gordura protegida 100 g/doadora/dia no pré-parto e 300 g/doadora/dia no pós-parto) e linhaça (n=5); fonte de gordura não protegida contendo 1 kg/doadora/dia no pré-parto e 1,5 kg/ doadora/dia no pós-parto). Os animais foram submetidos à aspiração folicular (OPU) nos dias 30, 45 e 60 pós-parto. Os oócitos recuperados foram selecionados e os viáveis submetidos aos procedimentos da PIVE. Os dados foram analisados pelo método dos quadrados mínimos utilizando análise de variância pelo procedimento GLM. As diferenças entre as médias foram comparadas pelo teste de Tukey com significância de 5%. Não foi detectado efeito de tratamento de suplementação, de dias de aspirações pós-parto e das interações sobre as variáveis: quantidade de oócitos viáveis, taxa de oócitos viáveis, número de clivagem, de PIVE, taxa de doadoras com CL concentração de P. (P>0,05). No entanto, foi observado maior número de folículos e de oócitos totais no grupo suplementado com linhaça em relação ao grupo Megalac-E® e Controle (P<0,05). A suplementação com AGPs não aumentou o número de oócitos viáveis, a PIVE e o retorno à ciclicidade.

The supplementation of dairy cattle with sources of polyunsaturated fatty acids (PUFA) can be used to increase the energy level of the diet in addition to having positive effects on reproductive functions of important tissues including the hypothalamus, pituitary, ovaries and uterus. The aims of this study were to evaluate the reproductive conditions of the postpartum, number of follicles, corpus luteum (CL) presence, concentration of progesterone (P4), aspirated oocytes, amount of viable oocytes and in vitro production of embryos (IVPE) of the Holstein multiparous donors supplemented with rich diet in protected PUFA (especially linoleic acid - n-6) and non-protected (especially linolenic acid - n-3) during pre and postpartum. The diets had been given for pre-partum during 30 d and postpartum 60 d. The donors were divided into three groups: Control (n=6), Megalac-E® (n=5; supplemented with protected fat source 100 g/donor/day in pre-partum and 300 g/donor/day in postpartum) and linseed (n=5; supplemented with fat source unprotected containing 1 kg/donor/day pre-partum and 1.5 kg/donor/day in postpartum). The animals were submitted to ovum pick-up (OPU) on days 30, 45 and 60 d postpartum. The recovered oocytes were selected and the viable ones were submitted to IVPE procedures. The data were analyzed by the method of least squares variance using the GLM protocol. The differences between averages were compared by Tukey test with 5% significance. There was no detectable effect of treatment, aspirations of postpartum days and interactions on variables: CL presence, concentration of P4, amount of viable oocytes, viable oocytes rate, IVPE and embryos production rate. However, was observed in the group supplemented with linseed more follicles and total oocytes than Megalac-E® and Control group. Supplementation with PUFA didn't increase the number of viable oocytes and IVPE.

Efeitos da tricostatina A sobre a acetilação de histonas, proliferação celular e diferenciação de células tronco embrionárias murinas / Effects of Trichostatin A on Histone Acetylation, Cell Proliferation and Differentiation of Murine Embryonic Stem Cells

Background: Embryonic stem cells are cells derived from early-stage embryos that are characterized by pluripotency and self- renewal capacity. The in vitro cultured murine embryonic stem cells can indefinitely propagate in an undifferentiated state in the presence of leukemia inhibitory factor (LIF). However, when stimulated, these cells can differentiate into cell lines derived from all three embryonic germ layers. The trichostatin A (TSA) is an epigenetic modifier agent and several studies have used the TSA to stimulate cellular differentiation. However, most of these studies only assessed one TSA concentration. Therefore, this study aimed to evaluate the effects of different TSA concentrations on histone hyperacetylation during in vitro cell differentiation of murine pluripotent embryonic stem cells, cultured with or without LIF, in the quest of to standardize their application on early cultures of embryonic stem cells. Materials, Methods & Results: Undifferentiated murine embryonic stem cells were plated in the presence of different TSA concentrations (0 nM, 15 nm, 50 nM and 100 nM) in the presence or absence of LIF. Thus, the treatments were evaluated in undifferentiated embryonic stem cells cultured in the presence of LIF (Control group: 0 nM LIF + ; Group 15 nM LIF + ; Group 50 nM LIF + and Group 100 nM LIF + ), and in embryonic stem cells cultured in the absence of LIF (Control group: 0 nM LIF - ; Group 15 nM LIF - ; Group 50 nM LIF - and Group 100 nM LIF - ). Treatment with TSA was performed for 24 h. After that the medium was replaced with fresh medium without TSA. Samples were collected at 0, 12, 24, 36 and 48 h after the beginning of the experiment. Three replicates were performed in each experimental group. The relative amount of Histone H3 lysine 9 acetylation was analyzed in all groups, as well as the cell proliferation in the embryonic stem cells cultured in the presence of LIF.

Efeitos da tricostatina A sobre a acetilação de histonas, proliferação celular e diferenciação de células tronco embrionárias murinas / Effects of Trichostatin A on Histone Acetylation, Cell Proliferation and Differentiation of Murine Embryonic Stem Cells

Background: Embryonic stem cells are cells derived from early-stage embryos that are characterized by pluripotency and self- renewal capacity. The in vitro cultured murine embryonic stem cells can indefinitely propagate in an undifferentiated state in the presence of leukemia inhibitory factor (LIF). However, when stimulated, these cells can differentiate into cell lines derived from all three embryonic germ layers. The trichostatin A (TSA) is an epigenetic modifier agent and several studies have used the TSA to stimulate cellular differentiation. However, most of these studies only assessed one TSA concentration. Therefore, this study aimed to evaluate the effects of different TSA concentrations on histone hyperacetylation during in vitro cell differentiation of murine pluripotent embryonic stem cells, cultured with or without LIF, in the quest of to standardize their application on early cultures of embryonic stem cells. Materials, Methods & Results: Undifferentiated murine embryonic stem cells were plated in the presence of different TSA concentrations (0 nM, 15 nm, 50 nM and 100 nM) in the presence or absence of LIF. Thus, the treatments were evaluated in undifferentiated embryonic stem cells cultured in the presence of LIF (Control group: 0 nM LIF + ; Group 15 nM LIF + ; Group 50 nM LIF + and Group 100 nM LIF + ), and in embryonic stem cells cultured in the absence of LIF (Control group: 0 nM LIF - ; Group 15 nM LIF - ; Group 50 nM LIF - and Group 100 nM LIF - ). Treatment with TSA was performed for 24 h. After that the medium was replaced with fresh medium without TSA. Samples were collected at 0, 12, 24, 36 and 48 h after the beginning of the experiment. Three replicates were performed in each experimental group. The relative amount of Histone H3 lysine 9 acetylation was analyzed in all groups, as well as the cell proliferation in the embryonic stem cells cultured in the presence of LIF.(AU)

Efeito da idade sobre as principais características andrológicas de touros Brangus-Ibagé criados extensivamente no estado do Mato Grosso do Sul - Brasil / Effect of age on the andrological characteristics of Brangus-Ibagé bulls extensively reared in Mato Grosso do Sul state - Brazil

Bull fertility is extremely important for beef cattle production systems and has a multiplier impact on the economical and zootechnical indexes of the herd. Bulls raised in tropical conditions may present varied seminal characteristics due to, among other causes, different management practices and quality of pastures. Another factor that influences the semen characteristics is the age of the sire. The reproductive potential of bull evaluated through the andrological exam aims to ensure the semen quality and to improve the herd reproductive efficiency. The aim of this study was to evaluate the main semen parameters of Brangus- Ibagé bulls extensively reared in eastern Mato Grosso do Sul state and to verify the effect of age on the andrological characteristics analyzed. It was also evaluated the correlation between age, scrotal circumference, and physical and morphological sperm characteristics produced by the Brangus bulls.[...]

Efeito da idade sobre as principais características andrológicas de touros Brangus-Ibagé criados extensivamente no estado do Mato Grosso do Sul - Brasil / Effect of age on the andrological characteristics of Brangus-Ibagé bulls extensively reared in Mato Grosso do Sul state - Brazil

Bull fertility is extremely important for beef cattle production systems and has a multiplier impact on the economical and zootechnical indexes of the herd. Bulls raised in tropical conditions may present varied seminal characteristics due to, among other causes, different management practices and quality of pastures. Another factor that influences the semen characteristics is the age of the sire. The reproductive potential of bull evaluated through the andrological exam aims to ensure the semen quality and to improve the herd reproductive efficiency. The aim of this study was to evaluate the main semen parameters of Brangus- Ibagé bulls extensively reared in eastern Mato Grosso do Sul state and to verify the effect of age on the andrological characteristics analyzed. It was also evaluated the correlation between age, scrotal circumference, and physical and morphological sperm characteristics produced by the Brangus bulls.[...](AU)

Puberdade em novilhas Nelore provenientes de duas linhas de seleção para peso

O presente trabalho teve como objetivo avaliar por ultrassonografia os ovários e suas estruturas e os cornos uterinos, além de quantificar os níveis séricos de progesterona para estudar suas relações com o desenvolvimento e idade à puberdade em novilhas Nelore provenientes de duas linhas de seleção para peso. Em 1980, o rebanho Nelore foi divido em duas linhas de seleção para peso ao sobreano, rebanhos Nelore Controle (NeC) e Nelore Seleção (NeS). No rebanho NeS são selecionados animais com maiores diferenciais de seleção para peso, enquanto no rebanho NeC são selecionados animais com diferenciais próximos de zero. As primeiras novilhas a entrarem na puberdade foram as do rebanho NeS aos 18,4 meses, mas ao final das avaliações (aos 24,4 meses de idade), não foi houve diferença significativa entre os rebanhos (NeC=52% e NeS=48%) na manifestação da puberdade. As novilhas que apresentaram puberdade ao final do trabalho foram aquelas de maior peso ao desmame e à puberdade e com idades menores em relação às não púberes. Não foram encontradas diferenças entre os rebanhos nas medidas reprodutivas estudadas por ultrassonografia, porém quando avaliadas por puberdade, as novilhas púberes comparadas às não púberes apresentaram maior área dos ovários, espessura do endométrio e tônus uterino. Há evidências que apenas o peso a desmama e o peso à puberdade tiveram efeito positivo (P<0,001) na manifestação da puberdade, e a seleção para peso não alterou as características reprodutivas avaliadas em novilhas criadas em um sistema de manejo a pasto. Dentre as medidas reprodutivas avaliadas, a área dos ovários, espessura do endométrio e tônus do útero foram as que apresentaram efeito positivo (P<0,001) na manifestação da puberdade num sistema de manejo a pasto

This study aimed to evaluate ovaries, its structures and uterine horns by ultrasound, and to measure serum progesterone levels, correlating them with body development and age at puberty in two Nellore lines of selection for yearling weight. In 1980, the Nellore herd was divided in two selection lines for yearling weight, herds Control Nellore (NeC) and Selection Nellore (NeS). In NeS herd animals are selected based on the greatest selection differential for yearling weight, while in NeC herd animals are selected based on selection differential around zero. Heifers from NeS herd initiated puberty earlier, (18.4 months of age), however, at the end of the study (at 24.4 months of age), no significant difference was observed between herds (NeC=52% and NeS=48%) in puberty manifestation. Heifers which entered puberty at the end of the study were heavier at weaning and at puberty and presented younger ages than non-puberty heifers. No significant differences were detected on reproductive measures evaluated by ultrasound between herds, but when measured by puberty, pubertal heifers compared to nonpubertal heifers had greater ovaries area, height of uterine horn and uterine tone. There are evidences that weaning weight and weight at puberty had a significant effect (P<0.001) on puberty manifestation and selection for post weaning weight did not change reproductive traits studied in heifers reared in grazing management system. Among reproductive characteristics evaluated, ovaries area, height of uterine horn and uterine tone were the ones that presented significant effect (P<0.001) on puberty manifestation in grazing management system