Influence of long-term thermal stress on the in vitro maturation on embryo development and Heat Shock Protein abundance in zebu cattle

The objective of this study was to investigate the influence of long-term temperature stress during the in vitro maturation (IVM) of oocytes on the in vitro embryo production (IVP) and the abundance of HSP70 and HSP90 in zebu cattle. Viable cumulus-oocyte complexes (COCs) were incubated for 24 h at 37 °C, 38.5 °C, or 40 °C for the low-, physiological, and high-temperature stress treatments, respectively. Thereafter, they were subjected to in vitro fertilization and culture. Temperature did not affect the polar body extrusion. However, IVP was adversely affected when IVM took place at 37 °C and 40 °C. The highest abundance of HSP70 was observed in cumulus cells after maturation of COCs at 40 °C. In contrast, HSP70 was more abundant in oocytes at both 37 °C and 40 °C; however, at 40 °C, the difference to the control group (38.5 °C) was not significant. In contrast, the highest abundance of HSP90 was observed in oocytes and cumulus cells at 37 °C. It appears that HSP70 and HSP90 respond to cold and heat stress in different ways. In conclusion, moderately high (40 °C) and low (37 °C) thermal stress for 24 h during IVM is detrimental to the developmental competence of oocyte and is accompanied by changes in the abundances of HSP70 and HSP90, especially in cumulus cells.

Influence of long-term thermal stress on the in vitro maturation on embryo development and Heat Shock Protein abundance in zebu cattle

The objective of this study was to investigate the influence of long-term temperature stress during the in vitro maturation (IVM) of oocytes on the in vitro embryo production (IVP) and the abundance of HSP70 and HSP90 in zebu cattle. Viable cumulus-oocyte complexes (COCs) were incubated for 24 h at 37 °C, 38.5 °C, or 40 °C for the low-, physiological, and high-temperature stress treatments, respectively. Thereafter, they were subjected to in vitro fertilization and culture. Temperature did not affect the polar body extrusion. However, IVP was adversely affected when IVM took place at 37 °C and 40 °C. The highest abundance of HSP70 was observed in cumulus cells after maturation of COCs at 40 °C. In contrast, HSP70 was more abundant in oocytes at both 37 °C and 40 °C; however, at 40 °C, the difference to the control group (38.5 °C) was not significant. In contrast, the highest abundance of HSP90 was observed in oocytes and cumulus cells at 37 °C. It appears that HSP70 and HSP90 respond to cold and heat stress in different ways. In conclusion, moderately high (40 °C) and low (37 °C) thermal stress for 24 h during IVM is detrimental to the developmental competence of oocyte and is accompanied by changes in the abundances of HSP70 and HSP90, especially in cumulus cells.(AU)

Supplementation of cows with linseed: effects on antral follicle count, oocyte quality, and nutritional and plasma metabolite parameters / Suplementação de fêmeas girolando com linhaça: efeitos sobre contagem de folículos antrais, qualidade oocitária, parâmetros nutricionais e metabólitos plasmáticos

Linseed is distinguished by its composition of fatty acids, which are rich in unsaturated acids, and by the slow release of oil in the rumen, consequently providing a greater amount of lipids of interest for intestinal absorption. The aim of this study was to evaluate the effect of linseed supplementation on the antral follicle count (AFC) and oocyte quality of Girolando cows, as well as their digestive parameters and plasma metabolite. Twelve Girolando cows were used in the study and were randomly distributed in two experimental groups: control (CTL, n = 6) and linseed (LINS, n = 6). During the 126 days of supplementation, seven transvaginal ultrasound-guided ovum pick-up (OPU) sessions were performed at intervals of 21 days. AFC was performed in each OPU session. The cows fed with linseed showed no significant difference in the dry matter coefficient of digestibility (63.11 and 62.88), crude protein (62.7 and 55.26), neutral detergent fiber (NDF; 75.36 and 77.15), or acid detergent fiber (ADF; 72.45 and 74.77) for LINS and CTL, respectively. On the contrary, a higher level of ethereal extract was observed for LINS (69.31 vs. 40.7). There was no effect (p > 0.05) of lipid supplementation on plasma metabolite between groups and OPU sessions. There was no difference (p > 0.05) in the mean number of antral follicles (CTL: 31.14 ± 1.97; LINS: 25.52 ± 2.68), cumulus oocyte complexes recovered (CTL: 6.45 ± 1.66; LINS: 5.28 ± 1.18), or oocyte quality (CTL: 60.48% ± 8.46; LINS: 64.54% ± 7.77). The supplementation of 800g of linseed in the diet of Girolando cows did not alter the apparent digestibility of nutrients, AFC, or quality of oocytes obtained by OPU.

A linhaça destaca-se pela composição de ácidos graxos insaturados e por apresentar lenta liberação do óleo no rúmen e consequentemente fornecendo maior quantidade de lipídios de interesse para absorção intestinal. O objetivo deste estudo foi avaliar o efeito da suplementação com linhaça sobre a contagem de folículos antrais e a qualidade oocitária de vacas Girolando, bem como parâmetros digestivos e metabólitos plasmáticos. Foram utilizadas doze fêmeas bovinas da raça Girolando distribuídas aleatoriamente em 2 grupos experimentais: controle (CTL n = 6) e linhaça (LINS, n = 6). Durante os 126 dias de suplementação foram realizadas 7 sessões de aspiração folicular guiada por ultrassonografia (OPU) com intervalo de 21 dias entre si. A cada sessão de OPU a CFA era realizada. Os animais alimentados com linhaça não apresentaram diferença no coeficiente de digestibilidade de matéria seca (63,11 vs. 62,88), proteína bruta (62,7 vs. 55,26), fibra em detergente neutro (75,36 vs. 77,15), fibra em detergente ácido (72,45 vs. 74,77) para LINS e CTL respectivamente. Por outro lado, os níveis de extrato etéreo foram superiores para LINS (69,31 vs. 40,7). Não houve efeito (P > 0,05) da suplementação lipídica sobre os metabólitos plasmáticos entre os grupos e as sessões de OPU. Não houve diferença (P > 0,05) no número médio de folículos antrais (31,14±1,97 vs. 25,52±2,68), COCs recuperados (6,45±1,66 vs. 5,28±1,18) e na qualidade dos oócitos (60,48%±8,46 vs. 64,54%±7,77) para LINS e CTL respectivamente. A suplementação de 800 g de linhaça na dieta de vacas Girolando não alterou a digestibilidade aparente dos nutrientes, bem como o número e a qualidade dos oócitos obtidos por OPU.

Supplementation of cows with linseed: effects on antral follicle count, oocyte quality, and nutritional and plasma metabolite parameters / Suplementação de fêmeas girolando com linhaça: efeitos sobre contagem de folículos antrais, qualidade oocitária, parâmetros nutricionais e metabólitos plasmáticos

Linseed is distinguished by its composition of fatty acids, which are rich in unsaturated acids, and by the slow release of oil in the rumen, consequently providing a greater amount of lipids of interest for intestinal absorption. The aim of this study was to evaluate the effect of linseed supplementation on the antral follicle count (AFC) and oocyte quality of Girolando cows, as well as their digestive parameters and plasma metabolite. Twelve Girolando cows were used in the study and were randomly distributed in two experimental groups: control (CTL, n = 6) and linseed (LINS, n = 6). During the 126 days of supplementation, seven transvaginal ultrasound-guided ovum pick-up (OPU) sessions were performed at intervals of 21 days. AFC was performed in each OPU session. The cows fed with linseed showed no significant difference in the dry matter coefficient of digestibility (63.11 and 62.88), crude protein (62.7 and 55.26), neutral detergent fiber (NDF; 75.36 and 77.15), or acid detergent fiber (ADF; 72.45 and 74.77) for LINS and CTL, respectively. On the contrary, a higher level of ethereal extract was observed for LINS (69.31 vs. 40.7). There was no effect (p > 0.05) of lipid supplementation on plasma metabolite between groups and OPU sessions. There was no difference (p > 0.05) in the mean number of antral follicles (CTL: 31.14 ± 1.97; LINS: 25.52 ± 2.68), cumulus oocyte complexes recovered (CTL: 6.45 ± 1.66; LINS: 5.28 ± 1.18), or oocyte quality (CTL: 60.48% ± 8.46; LINS: 64.54% ± 7.77). The supplementation of 800g of linseed in the diet of Girolando cows did not alter the apparent digestibility of nutrients, AFC, or quality of oocytes obtained by OPU.(AU)

A linhaça destaca-se pela composição de ácidos graxos insaturados e por apresentar lenta liberação do óleo no rúmen e consequentemente fornecendo maior quantidade de lipídios de interesse para absorção intestinal. O objetivo deste estudo foi avaliar o efeito da suplementação com linhaça sobre a contagem de folículos antrais e a qualidade oocitária de vacas Girolando, bem como parâmetros digestivos e metabólitos plasmáticos. Foram utilizadas doze fêmeas bovinas da raça Girolando distribuídas aleatoriamente em 2 grupos experimentais: controle (CTL n = 6) e linhaça (LINS, n = 6). Durante os 126 dias de suplementação foram realizadas 7 sessões de aspiração folicular guiada por ultrassonografia (OPU) com intervalo de 21 dias entre si. A cada sessão de OPU a CFA era realizada. Os animais alimentados com linhaça não apresentaram diferença no coeficiente de digestibilidade de matéria seca (63,11 vs. 62,88), proteína bruta (62,7 vs. 55,26), fibra em detergente neutro (75,36 vs. 77,15), fibra em detergente ácido (72,45 vs. 74,77) para LINS e CTL respectivamente. Por outro lado, os níveis de extrato etéreo foram superiores para LINS (69,31 vs. 40,7). Não houve efeito (P > 0,05) da suplementação lipídica sobre os metabólitos plasmáticos entre os grupos e as sessões de OPU. Não houve diferença (P > 0,05) no número médio de folículos antrais (31,14±1,97 vs. 25,52±2,68), COCs recuperados (6,45±1,66 vs. 5,28±1,18) e na qualidade dos oócitos (60,48%±8,46 vs. 64,54%±7,77) para LINS e CTL respectivamente. A suplementação de 800 g de linhaça na dieta de vacas Girolando não alterou a digestibilidade aparente dos nutrientes, bem como o número e a qualidade dos oócitos obtidos por OPU.(AU)

Performance and digestive characteristics in dairy cattle maintained under grazing regime and supplemented with linseed / Desempenho e características digestivas em bovinos leiteiros mantidos em regime de pastoreio suplementados com linhaça

Linseed is characterized by the rich unsaturated fatty acids and slow release of oil in the rumen. The objective of the present study was to evaluate the intake, rumen degradability, and digestibility of dairy cattle maintained under grazing regime and supplemented with linseed. Twelve Girolando (¾ Holstein × » Gir) cows with a mean age of 5.2 ± 1.9 years and body weight of 583.9 ± 67.6 kg were used. The cows were maintained in a rotational grazing system on the mombaça grass (Panicum maximum) and divided into 2 experimental groups. The CONTR (n = 6) group received only the base diet (pasture) and the LINS group (n = 6) received pasture plus linseed. Initially, a fifteen-day adaptation period was established to stabilize the desired consumption amount. After this period, the animals received 800 g of linseed for 126 d. The ruminal degradability was evaluated using 2 males with a cannula in the rumen, and they were provided the same experimental diet. The measured dry matter production of pasture did not show differences during the experimental period. The intake of crude protein and ethereal extract was higher, whereas neutral detergent fiber content was lower in the cows supplemented with linseed. However, this did not alter the weight gain and digestibility coefficients, except the digestibility coefficient of the ethereal extract. At the ruminal level, linseed showed low effective and potential degradability with negative effect on grass degradability.(AU)

A linhaça destaca-se pela composição de ácidos graxos ricos em ácidos insaturados e por apresentar lenta liberação do óleo no rúmen. O presente estudo teve como objetivo avaliar o consumo, a degradabilidade ruminal e a digestibilidade em bovinos leiteiros mantidos em regime de pastoreio e suplementados com linhaça em grão. Foram utilizadas 12 vacas da raça Girolando (¾ Holandês x » Gir) com idade media de 5,2 ± 1.9 anos com peso médio de 583.9 ± 67.6 kg, mantidas em sistema de pastoreio rotacionado de capim-mombaça (Panicum maximum) e divididas em 2 grupos experimentais. O grupo CONTR (n=6) recebeu apenas a dieta base (pastagem) e o grupo LINS (n=6) recebeu suplementação com 800 g/animal/dia de linhaça. Inicialmente foi realizado um período de adaptação de quinze dias para estabilização do consumo desejado. Após esse período os animais receberam 800 gramas de linhaça por 126 dias. A degradabilidade ruminal foi avaliada utilizando-se 2 machos fistulados no rúmen e submetidos a mesma dieta. A produção de matéria seca do capim não apresentou diferenças durante o período experimental. As vacas suplementadas com linhaça consumiram mais proteína bruta e extrato etéreo e tiveram menor consumo de fibra em detergente neutro, porém não foi suficiente para alterar o ganho de peso e os coeficientes de digestibilidade, exceto do extrato etéreo. Em nível ruminal a linhaça apresentou baixa degradabilidade efetiva e potencial, tendo efeito negativo sobre a degradabilidade do capim.(AU)

Anti-Müllerian hormone (AMH) as a predictor of antral follicle population in heifers

Antral follicular population (AFP) and anti-Müllerian hormone (AMH) concentration are strongly associated. Thus, analyzing AMH concentration is a reliable method to predict animals with high AFP, an important feature to select donor cows for embryos and oocytes. However, not much is known about this parameter in heifers, particularly in crossbred animals. The aim of this study was to assess AFP in heifers and cows and its relation to serum AMH levels. Bos taurus indicus cows (36–60-months-old; n = 30) and heifers (12–14-months-old; n = 17) of the same breed were evaluated. A single procedure of follicular counting was performed by ultrasound for each animal. Random sampling was performed to analyze serum AMH concentration. Cows showed higher AFP than heifers; nonetheless, plasma AMH concentration did not differ between the categories. A high correlation of AFP with plasma AMH concentration was observed in Girolando heifers. Thus, it is suggested that AMH concentration could be a reliable and less invasive method for selecting heifers with high AFP.(AU)

Anti-Müllerian hormone (AMH) as a predictor of antral follicle population in heifers

Antral follicular population (AFP) and anti-Müllerian hormone (AMH) concentration are strongly associated. Thus, analyzing AMH concentration is a reliable method to predict animals with high AFP, an important feature to select donor cows for embryos and oocytes. However, not much is known about this parameter in heifers, particularly in crossbred animals. The aim of this study was to assess AFP in heifers and cows and its relation to serum AMH levels. Bos taurus indicus cows (36–60-months-old; n = 30) and heifers (12–14-months-old; n = 17) of the same breed were evaluated. A single procedure of follicular counting was performed by ultrasound for each animal. Random sampling was performed to analyze serum AMH concentration. Cows showed higher AFP than heifers; nonetheless, plasma AMH concentration did not differ between the categories. A high correlation of AFP with plasma AMH concentration was observed in Girolando heifers. Thus, it is suggested that AMH concentration could be a reliable and less invasive method for selecting heifers with high AFP.

Antral follicles population in heifers and cows of Nelore and Girolando breeds / População de folículos antrais em vacas e novilhas da raça Nelore e Girolando

The aim of this study was to evaluate ovarian antral follicle populations (OAFP) of Nelore and Girolando breed heifers (1218 months old) and cows (2460 months old). Animals were assigned to four groups: (1) Nelore cows (n = 18), (2) Girolando cows (n = 20), (3) Nelore heifers (n = 7), and (4) Girolando heifers (n = 7). Cows were treated to synchronize follicular wave emergence by implantation of an intravaginal device containing 1.9 g of progesterone, as well as intramuscular administration of 2 mg of estradiol benzoate and 25 mg of dinoprost. This synchronization treatment was administered at a random day of the estrous cycle of each cow, designated D0. Intravaginal devices were removed on D7, and on D11, OAFP counts were performed by transvaginal ovarian ultrasound. For each cow, all follicles ?3 mm in diameter were counted in both ovaries and counts were performed three times at 35-day intervals. Counts were also obtained from heifers, but these animals were not treated for synchronization of follicular wave emergence. Analysis of variance (ANOVA) with Tukeys test and Pearsons correlation test were used to compare mean OAFPs between counts as well as mean OAFPs between breed and age groups. No differences were observed in mean OAFPs between Nelore and Girolando cows (30.9 vs. 26.7, respectively; P > 0.05) or heifers (16.2 vs. 18.1, respectively; P > 0.05). However...(AU)

Este estudo objetivou avaliar a população folicular antral ovariana (PFAO) de novilhas (12 a 18 meses) e vacas (24 a 60 meses) das raças Nelore e Girolando. Os animais foram divididos em quatro grupos: 1) vacas Nelore (n = 18); 2) vacas Girolando (n=20); 3) Novilhas Nelore (n=7) e; 4) Novilhas Girolando (n=7). Nos grupos das vacas, os animais receberam um dispositivo intravaginal com 1.9 g de progesterona, 2 mg de benzoato de estradiol IM e 25 mg de dinoprost IM, em um dia aleatório do ciclo estral (D0). No D7 o dispositivo de progesterona foi retirado. Os animais foram submetidos à ultrassonografia ovariana via transvaginal para contagem da PFAO no D11. Foram contados todos os folículos ? 3 mm de diâmetro em ambos os ovários. O procedimento de contagem da PFAO foi repetido três vezes, com intervalos de 35 dias entre as repetições. Para os grupos de novilhas foram adotados os mesmos procedimentos descritos acima, porém estes animais não receberam o tratamento de sincronização da emergência da onda folicular. Para avaliação da PFAO entre as contagens e da média das contagens entre as raças e os grupos, foi realizada análise de variância (ANOVA) seguida de Teste de Tukey a 5% de probabilidade e correlação de Pearson, através do programa SAS, utilizando o Proc GLIMMIX. Não foi observada diferença significativa (p>0.05) entre as médias das contagens da PFAO de vacas Nelore e...(AU)

Performance and digestive characteristics in dairy cattle maintained under grazing regime and supplemented with linseed / Desempenho e características digestivas em bovinos leiteiros mantidos em regime de pastoreio suplementados com linhaça

Linseed is characterized by the rich unsaturated fatty acids and slow release of oil in the rumen. The objective of the present study was to evaluate the intake, rumen degradability, and digestibility of dairy cattle maintained under grazing regime and supplemented with linseed. Twelve Girolando (¾ Holstein × » Gir) cows with a mean age of 5.2 ± 1.9 years and body weight of 583.9 ± 67.6 kg were used. The cows were maintained in a rotational grazing system on the mombaça grass (Panicum maximum) and divided into 2 experimental groups. The CONTR (n = 6) group received only the base diet (pasture) and the LINS group (n = 6) received pasture plus linseed. Initially, a fifteen-day adaptation period was established to stabilize the desired consumption amount. After this period, the animals received 800 g of linseed for 126 d. The ruminal degradability was evaluated using 2 males with a cannula in the rumen, and they were provided the same experimental diet. The measured dry matter production of pasture did not show differences during the experimental period. The intake of crude protein and ethereal extract was higher, whereas neutral detergent fiber content was lower in the cows supplemented with linseed. However, this did not alter the weight gain and digestibility coefficients, except the digestibility coefficient of the ethereal extract. At the ruminal level, linseed showed low effective and potential degradability with negative effect on grass degradability.

A linhaça destaca-se pela composição de ácidos graxos ricos em ácidos insaturados e por apresentar lenta liberação do óleo no rúmen. O presente estudo teve como objetivo avaliar o consumo, a degradabilidade ruminal e a digestibilidade em bovinos leiteiros mantidos em regime de pastoreio e suplementados com linhaça em grão. Foram utilizadas 12 vacas da raça Girolando (¾ Holandês x » Gir) com idade media de 5,2 ± 1.9 anos com peso médio de 583.9 ± 67.6 kg, mantidas em sistema de pastoreio rotacionado de capim-mombaça (Panicum maximum) e divididas em 2 grupos experimentais. O grupo CONTR (n=6) recebeu apenas a dieta base (pastagem) e o grupo LINS (n=6) recebeu suplementação com 800 g/animal/dia de linhaça. Inicialmente foi realizado um período de adaptação de quinze dias para estabilização do consumo desejado. Após esse período os animais receberam 800 gramas de linhaça por 126 dias. A degradabilidade ruminal foi avaliada utilizando-se 2 machos fistulados no rúmen e submetidos a mesma dieta. A produção de matéria seca do capim não apresentou diferenças durante o período experimental. As vacas suplementadas com linhaça consumiram mais proteína bruta e extrato etéreo e tiveram menor consumo de fibra em detergente neutro, porém não foi suficiente para alterar o ganho de peso e os coeficientes de digestibilidade, exceto do extrato etéreo. Em nível ruminal a linhaça apresentou baixa degradabilidade efetiva e potencial, tendo efeito negativo sobre a degradabilidade do capim.

Antral follicles population in heifers and cows of Nelore and Girolando breeds / População de folículos antrais em vacas e novilhas da raça Nelore e Girolando

The aim of this study was to evaluate ovarian antral follicle populations (OAFP) of Nelore and Girolando breed heifers (1218 months old) and cows (2460 months old). Animals were assigned to four groups: (1) Nelore cows (n = 18), (2) Girolando cows (n = 20), (3) Nelore heifers (n = 7), and (4) Girolando heifers (n = 7). Cows were treated to synchronize follicular wave emergence by implantation of an intravaginal device containing 1.9 g of progesterone, as well as intramuscular administration of 2 mg of estradiol benzoate and 25 mg of dinoprost. This synchronization treatment was administered at a random day of the estrous cycle of each cow, designated D0. Intravaginal devices were removed on D7, and on D11, OAFP counts were performed by transvaginal ovarian ultrasound. For each cow, all follicles ?3 mm in diameter were counted in both ovaries and counts were performed three times at 35-day intervals. Counts were also obtained from heifers, but these animals were not treated for synchronization of follicular wave emergence. Analysis of variance (ANOVA) with Tukeys test and Pearsons correlation test were used to compare mean OAFPs between counts as well as mean OAFPs between breed and age groups. No differences were observed in mean OAFPs between Nelore and Girolando cows (30.9 vs. 26.7, respectively; P > 0.05) or heifers (16.2 vs. 18.1, respectively; P > 0.05). However...

Este estudo objetivou avaliar a população folicular antral ovariana (PFAO) de novilhas (12 a 18 meses) e vacas (24 a 60 meses) das raças Nelore e Girolando. Os animais foram divididos em quatro grupos: 1) vacas Nelore (n = 18); 2) vacas Girolando (n=20); 3) Novilhas Nelore (n=7) e; 4) Novilhas Girolando (n=7). Nos grupos das vacas, os animais receberam um dispositivo intravaginal com 1.9 g de progesterona, 2 mg de benzoato de estradiol IM e 25 mg de dinoprost IM, em um dia aleatório do ciclo estral (D0). No D7 o dispositivo de progesterona foi retirado. Os animais foram submetidos à ultrassonografia ovariana via transvaginal para contagem da PFAO no D11. Foram contados todos os folículos ? 3 mm de diâmetro em ambos os ovários. O procedimento de contagem da PFAO foi repetido três vezes, com intervalos de 35 dias entre as repetições. Para os grupos de novilhas foram adotados os mesmos procedimentos descritos acima, porém estes animais não receberam o tratamento de sincronização da emergência da onda folicular. Para avaliação da PFAO entre as contagens e da média das contagens entre as raças e os grupos, foi realizada análise de variância (ANOVA) seguida de Teste de Tukey a 5% de probabilidade e correlação de Pearson, através do programa SAS, utilizando o Proc GLIMMIX. Não foi observada diferença significativa (p>0.05) entre as médias das contagens da PFAO de vacas Nelore e...