Paraoxonase 1 activity in the sperm-rich portion of boar ejaculates is positively associated with sperm quality

Associations of the activity of the paraoxonase 1 (PON1) enzyme with boar sperm quality still needs to be characterized, since boar ejaculates present distinct portions with differences in sperm concentration and quality. This study evaluated PON1 activity in the serum, in the distinct portions of boar ejaculates and estimated correlations with sperm quality parameters. Ejaculates and blood samples were collected from six boars for three weeks (two per week per boar; n = 36). Serum and post-spermatic portion PON1 activities were positively correlated (P = 0.01) but were both uncorrelated with the PON1 activity in the sperm-rich portion and in the whole ejaculate (P > 0.05). Differences in PON1 activity among boars were only observed in the sperm-rich portion of the ejaculate (P < 0.05). The PON1 activity in the serum and in the post-spermatic portion was generally negatively correlated with parameters of spermatozoa kinetics (P < 0.05). In the sperm-rich portion, PON1 activity was positively correlated with sperm concentration (P < 0.0001), curvilinear distance and velocity (both P < 0.05) and DNA integrity (P < 0.05), but negatively correlated with straightness and linearity (P < 0.05). Thus, boar ejaculates with increased PON1 activity in the sperm-rich portion may present increased concentration and spermatozoa with acceptable curvilinear velocity and distance and DNA integrity, which suggests that PON1 activity may be a biomarker for potential fertility.(AU)

Prostaglandin F2α as ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome / Prostaglandina F2α como estímulo ovulatório em vacas e búfalas leiteiras criadas no bioma Amazônia

This study evaluated the effect of a prostaglandin F2? (PGF) analogue as an ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome. To this end, three experiments were performed in the state of Rondônia, located in the Amazon biome. In Experiment 1, 22 lactating dairy buffaloes received 2 mg of intramuscular (I.M.) estradiol benzoate (EB) on day 0 and an intravaginal progesterone-releasing device (CIDR) from day 0 to day 9 of the protocol. On days 8 and 9, all cows were given 500 ?g of I.M. d-cloprostenol (PGF analogue). On day 10, buffaloes were divided into two groups to receive 500 ?g of PGF (PGF group, n = 8) or no treatment (CTL group, n = 14), respectively. In Experiment 2, 16 lactating crossbred dairy cows (Holstein x Gir) received 2 mg of EB on day 0 and a CIDR insert from day 0 to day 8. On days 7 and 8, all cows were given 500 ?g of d-cloprostenol. On day 9, cows were divided into two groups to receive 500 ?g of d-cloprostenol (PGF group, n = 8) or no treatment (CTL group, n = 8), respectively. In Experiment 3, 16 lactating crossbred dairy cows (Holstein x Gir) were handled and treated similarly as in Experiment 2, although cows did not receive d-cloprostenol on day 8. Single-point outcome variables were analyzed using one-way analysis of variance (ANOVA), while proportions with dichotomous outcomes were analyzed with the chi-square test.(AU)

O objetivo deste estudo foi avaliar o efeito de um análogo de prostaglandina F2α (PGF) como indutor ovulatório em vacas leiteiras e búfalas. Para este fim, três experimentos foram realizados no estado de Rondônia, localizado no bioma Amazônia. No Experimento 1, 22 búfalas leiteiras em lactação receberam 2 mg de benzoato de estradiol (EB) im, no Dia 0 e um dispositivo intravaginal de liberação de progesterona (CIDR) do Dia 0 ao Dia 9 do protocolo. Nos Dias 8 e 9, todas as vacas receberam 150μg de d-Cloprostenol (análogo PGF), im. No Dia 10, as búfalas foram divididas em dois grupos para receber 150μg de PGF (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 14). No experimento 2, 16 vacas leiteiras mestiças (Holandês x Gir) receberam 2 mg de EB no Dia 0 e um dispositivo intravaginal (CIDR) do Dia 0 ao Dia 8. Nos Dias 7 e 8 todas as vacas receberam 150μg de d-Cloprostenol. No Dia 9, as vacas foram divididas em dois grupos para receber 150μg de d-Cloprostenol (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 8). No Experimento 3, 16 vacas leiteiras mestiças (Holandês x Gir) foram tratadas da mesma forma que no Experimento 2, porém, as vacas não receberam d-Cloprostenol no Dia 8. Variáveis quantitativas foram analisados por análise de variância - one-way ANOVA e variáveis dicotômicas foram analisados pelo teste do qui-quadrado. No Experimento 1, não houve diferença (P = 0,30) na taxa de ovulação entre os grupos, em média 68% das búfalas ovularam após o tratamento. Além disso, não houve diferença entre os grupos no intervalo de ovulação (P = 0,61) e no diâmetro do folículo pré-ovulatório (P = 0,47). No Experimento 2, apenas uma vaca do Grupo PG não ovulou. Não houve diferenças no intervalo de ovulação entre os grupos CTL e PG (P = 0,69). Em média, a ovulação ocorreu 82 horas após a remoção do CIDR. No Experimento 3, vacas tratadas com PGF ovularam antes do Grupo CTL (62,5 ± 5,8 vs 94,5 ± 13,5 h; P = 0,05). Coletivamente, esses resultados sugeriram que a PGF antecipa a ovulação em vacas leiteiras em lactação, porém seu efeito não foi observado em búfalas.(AU)

Prostaglandin F2α as ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome / Prostaglandina F2α como estímulo ovulatório em vacas e búfalas leiteiras criadas no bioma Amazônia

This study evaluated the effect of a prostaglandin F2? (PGF) analogue as an ovulatory stimulus in dairy cows and buffaloes raised in the Amazon biome. To this end, three experiments were performed in the state of Rondônia, located in the Amazon biome. In Experiment 1, 22 lactating dairy buffaloes received 2 mg of intramuscular (I.M.) estradiol benzoate (EB) on day 0 and an intravaginal progesterone-releasing device (CIDR) from day 0 to day 9 of the protocol. On days 8 and 9, all cows were given 500 ?g of I.M. d-cloprostenol (PGF analogue). On day 10, buffaloes were divided into two groups to receive 500 ?g of PGF (PGF group, n = 8) or no treatment (CTL group, n = 14), respectively. In Experiment 2, 16 lactating crossbred dairy cows (Holstein x Gir) received 2 mg of EB on day 0 and a CIDR insert from day 0 to day 8. On days 7 and 8, all cows were given 500 ?g of d-cloprostenol. On day 9, cows were divided into two groups to receive 500 ?g of d-cloprostenol (PGF group, n = 8) or no treatment (CTL group, n = 8), respectively. In Experiment 3, 16 lactating crossbred dairy cows (Holstein x Gir) were handled and treated similarly as in Experiment 2, although cows did not receive d-cloprostenol on day 8. Single-point outcome variables were analyzed using one-way analysis of variance (ANOVA), while proportions with dichotomous outcomes were analyzed with the chi-square test.

O objetivo deste estudo foi avaliar o efeito de um análogo de prostaglandina F2α (PGF) como indutor ovulatório em vacas leiteiras e búfalas. Para este fim, três experimentos foram realizados no estado de Rondônia, localizado no bioma Amazônia. No Experimento 1, 22 búfalas leiteiras em lactação receberam 2 mg de benzoato de estradiol (EB) im, no Dia 0 e um dispositivo intravaginal de liberação de progesterona (CIDR) do Dia 0 ao Dia 9 do protocolo. Nos Dias 8 e 9, todas as vacas receberam 150μg de d-Cloprostenol (análogo PGF), im. No Dia 10, as búfalas foram divididas em dois grupos para receber 150μg de PGF (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 14). No experimento 2, 16 vacas leiteiras mestiças (Holandês x Gir) receberam 2 mg de EB no Dia 0 e um dispositivo intravaginal (CIDR) do Dia 0 ao Dia 8. Nos Dias 7 e 8 todas as vacas receberam 150μg de d-Cloprostenol. No Dia 9, as vacas foram divididas em dois grupos para receber 150μg de d-Cloprostenol (Grupo PGF, n = 8) ou nenhum tratamento (Grupo CTL, n = 8). No Experimento 3, 16 vacas leiteiras mestiças (Holandês x Gir) foram tratadas da mesma forma que no Experimento 2, porém, as vacas não receberam d-Cloprostenol no Dia 8. Variáveis quantitativas foram analisados por análise de variância - one-way ANOVA e variáveis dicotômicas foram analisados pelo teste do qui-quadrado. No Experimento 1, não houve diferença (P = 0,30) na taxa de ovulação entre os grupos, em média 68% das búfalas ovularam após o tratamento. Além disso, não houve diferença entre os grupos no intervalo de ovulação (P = 0,61) e no diâmetro do folículo pré-ovulatório (P = 0,47). No Experimento 2, apenas uma vaca do Grupo PG não ovulou. Não houve diferenças no intervalo de ovulação entre os grupos CTL e PG (P = 0,69). Em média, a ovulação ocorreu 82 horas após a remoção do CIDR. No Experimento 3, vacas tratadas com PGF ovularam antes do Grupo CTL (62,5 ± 5,8 vs 94,5 ± 13,5 h; P = 0,05). Coletivamente, esses resultados sugeriram que a PGF antecipa a ovulação em vacas leiteiras em lactação, porém seu efeito não foi observado em búfalas.

Prostaglandin E2 induces ovulation in prepubertal mice / Prostaglandina E2 induz ovulação em camundongos pré-púberes

The objective of this study was to determine the ability of prostaglandin E2 (PGE2) to induce ovulation and expression of PGE2 receptor (EP2 and EP4) and COX genes (COX-1 and COX-2) in the ovary and pituitary of prepubertal mice. The positive control consisted of the application of 5 µg of gonadotropin-releasing hormone (GnRH, n = 29); the negative control applied 0.5 mL of phosphate buffered saline (PBS, n=31); the treatment tested the application of 250 µg of PGE2 (n = 29), making a total of 89 prepubertal mice (BALB/c). Mice were euthanized 14 to 15 h after treatments to detect ovulation and tissue collection. A Chi-square test was used to compare the proportion of animals ovulating. Gene expressions and number of ovulation were analyzed by one-way ANOVA and Tukey's test was used to compare means among groups. A greater proportion of mice (P < 0.001) ovulated after receiving GnRH (89.7%, 26/29) compared to PGE2 group (58.6%, 17/29). However, the proportion was higher compared to those treated with PBS (0%, 0/31). Ep2gene expression in the pituitary was > two-fold higher (P < 0.05) in the PGE2 group compared to the PBS and GnRH groups. Further, PGE2 stimulated Cox1 (2.7 fold, P < 0.05) while GnRH stimulated Cox2 expression (6.5 fold, P < 0.05) in the pituitary when compared to the PBS group. In conclusion, our results support the hypothesis that PGE2 can induce ovulation in prepubertal mice with a concomitant increase in Ep2 and Cox1 gene expression in the pituitary gland.(AU)

O objetivo deste estudo foi determinar a capacidade da prostaglandina E2 (PGE2) em induzir a ovulação e expressão do receptor PGE2 (EP2 e EP4) e genes COX (COX-1 e COX-2) no ovário e na hipófise de camundongos pré-púberes. O controle positivo consistiu na aplicação de 5 µg de hormônio liberador de gonadotrofina (GnRH, n = 29); o controle negativo aplicação 0,5 mL de tampão fosfato-salino (PBS, n=31); o tratamento testado aplicação de 250 µg de PGE2 (n = 29), perfazendo um total de 89 camundongos (BALB/c) pré-púberes. Os camundongos foram sacrificados 14 a 15 h após os tratamentos para detectar ovulações e coleta de tecido. O teste do qui-quadrado foi usado para comparar a proporção de animais ovulando. As expressões gênicas e o número de ovulação foram analisados por ANOVA e o teste de tukey foi usado para comparar as médias entre os grupos. Uma maior proporção de camundongos (P <0,001) ovulou após receber GnRH (89,7%, 26/29) em comparação com o grupo PGE2 (58,6%, 17/29). No entanto, a proporção foi maior em comparação com aqueles tratados com PBS (0%, 0/31). A expressão do gene Ep2 na hipófise foi duas vezes maior (P <0,05) no grupo PGE2 em comparação com os grupos PBS e GnRH. Além disso, a PGE2 estimulou a Cox1(2,7 vezes, P <0,05) enquanto o GnRH estimulou a expressão de Cox2 (6,5 vezes, P <0,05) na pituitária em comparação com o grupo PBS. Em conclusão, nossos resultados suportam a hipótese de que PGE2 é capaz de induzir ovulação em camundongos pré-púberes com aumento concomitante na expressão dos genes Ep2 e Cox1 na glândula pituitária.(AU)

Prostaglandin E2 induces ovulation in prepubertal mice / Prostaglandina E2 induz ovulação em camundongos pré-púberes

The objective of this study was to determine the ability of prostaglandin E2 (PGE2) to induce ovulation and expression of PGE2 receptor (EP2 and EP4) and COX genes (COX-1 and COX-2) in the ovary and pituitary of prepubertal mice. The positive control consisted of the application of 5 µg of gonadotropin-releasing hormone (GnRH, n = 29); the negative control applied 0.5 mL of phosphate buffered saline (PBS, n=31); the treatment tested the application of 250 µg of PGE2 (n = 29), making a total of 89 prepubertal mice (BALB/c). Mice were euthanized 14 to 15 h after treatments to detect ovulation and tissue collection. A Chi-square test was used to compare the proportion of animals ovulating. Gene expressions and number of ovulation were analyzed by one-way ANOVA and Tukey's test was used to compare means among groups. A greater proportion of mice (P < 0.001) ovulated after receiving GnRH (89.7%, 26/29) compared to PGE2 group (58.6%, 17/29). However, the proportion was higher compared to those treated with PBS (0%, 0/31). Ep2gene expression in the pituitary was > two-fold higher (P < 0.05) in the PGE2 group compared to the PBS and GnRH groups. Further, PGE2 stimulated Cox1 (2.7 fold, P < 0.05) while GnRH stimulated Cox2 expression (6.5 fold, P < 0.05) in the pituitary when compared to the PBS group. In conclusion, our results support the hypothesis that PGE2 can induce ovulation in prepubertal mice with a concomitant increase in Ep2 and Cox1 gene expression in the pituitary gland.(AU)

O objetivo deste estudo foi determinar a capacidade da prostaglandina E2 (PGE2) em induzir a ovulação e expressão do receptor PGE2 (EP2 e EP4) e genes COX (COX-1 e COX-2) no ovário e na hipófise de camundongos pré-púberes. O controle positivo consistiu na aplicação de 5 µg de hormônio liberador de gonadotrofina (GnRH, n = 29); o controle negativo aplicação 0,5 mL de tampão fosfato-salino (PBS, n=31); o tratamento testado aplicação de 250 µg de PGE2 (n = 29), perfazendo um total de 89 camundongos (BALB/c) pré-púberes. Os camundongos foram sacrificados 14 a 15 h após os tratamentos para detectar ovulações e coleta de tecido. O teste do qui-quadrado foi usado para comparar a proporção de animais ovulando. As expressões gênicas e o número de ovulação foram analisados por ANOVA e o teste de tukey foi usado para comparar as médias entre os grupos. Uma maior proporção de camundongos (P <0,001) ovulou após receber GnRH (89,7%, 26/29) em comparação com o grupo PGE2 (58,6%, 17/29). No entanto, a proporção foi maior em comparação com aqueles tratados com PBS (0%, 0/31). A expressão do gene Ep2 na hipófise foi duas vezes maior (P <0,05) no grupo PGE2 em comparação com os grupos PBS e GnRH. Além disso, a PGE2 estimulou a Cox1(2,7 vezes, P <0,05) enquanto o GnRH estimulou a expressão de Cox2 (6,5 vezes, P <0,05) na pituitária em comparação com o grupo PBS. Em conclusão, nossos resultados suportam a hipótese de que PGE2 é capaz de induzir ovulação em camundongos pré-púberes com aumento concomitante na expressão dos genes Ep2 e Cox1 na glândula pituitária.(AU)

The role of prostaglandin F2α on ovulation and LH release in cows / A função da prostaglandina F2α na ovulação e na liberação de LH em vacas

This study aimed to evaluate the role of prostaglandin F2α (PGF) on ovulation. In Experiment 1, cows were randomly allocated to two treatments to receive 150 µg of d-Cloprostenol (PGF Group, n = 12) or 2 mL of NaCl 0.9% (Control Group, n = 11) and CIDRs, were removed 4 days later. No cow ovulated in Control and PGF groups. In Experiment 2, cows were randomly separated into two experimental groups to receive 4 injections of 150 µg of d-Cloprostenol (n = 9) or 2 mL of NaCL 0.9% (n = 9). In this experiment, ovulation was not observed in any cows. In Experiment 3, ovariectomized cows receive three injections of 300µg of PGF analog (PGF Group, n = 5), 100µg of Lecirelin (GnRH Group, n = 5) or 2 mL of PBS (Control Group, n = 4). The LH concentration was higher (P <0.0001) in cows from the GnRH group than in the PGF and Control groups. In experiment 4, cows with preovulatory follicles (>11.5 mm) were treated with Saline (Control Group, n = 6); Lecirelin (GnRH Group, n = 7) or Cloprostenol Sodium (PGF Group, n = 6). There was a significant increase in the vascular area of follicles from 0 to 24 h in GnRH and PGF treatments. In conclusion, PGF was not able to induce ovulation in cows with high or low plasma progesterone concentration. Additionally, PGF alone was not able to induce LH release and follicle luteinization, but increased follicular vascularization.(AU)

O objetivo deste estudo foi avaliar o papel da prostaglandina F2α (PGF) na ovulação. No Experimento 1, as vacas foram alocadas aleatoriamente em dois tratamentos para receber 150 µg de d-Cloprostenol (Grupo PGF, n = 12) ou 2 mL de NaCl 0,9% (Grupo Controle, n = 11) e os CIDR, foram removidos 4 dias depois. Nenhuma vaca ovulou nos grupos Controle e PGF. No Experimento 2, as vacas foram separadas aleatoriamente em dois grupos experimentais para receber 4 injeções de 150 µg de d-Cloprostenol (n = 9) ou 2 mL de NaCL 0,9% (n = 9). Não foi observada ovulação em nenhum dos animais deste experimento. No Experimento 3, vacas ovariectomizadas receberam três injeções de 300µg de análogo de PGF (Grupo PGF, n = 5), 100µg de Lecirelina (Grupo GnRH, n = 5) ou 2 mL de PBS (Grupo Controle, n = 4). A concentração de LH foi maior (P <0,0001) nas vacas do grupo GnRH do que nos grupos PGF e Controle. No Experimento 4, vacas com folículos pré-ovulatórios (> 11,5 mm) foram tratadas com solução salina (Grupo Controle, n = 6), Lecirelina (Grupo GnRH, n = 7) ou Cloprostenol Sódico (Grupo PGF, n = 6). Houve um aumento significativo na área vascular dos folículos de 0 a 24h nos tratamentos com GnRH e PGF. Em conclusão, a PGF não foi capaz de induzir ovulação em vacas com alta ou baixa concentração plasmática de progesterona. Além disso, a PGF sozinha não foi capaz de induzir a liberação de LH e a luteinização do folículo, mas aumentou a vascularização folicular.(AU)

The role of prostaglandin F2α on ovulation and LH release in cows / A função da prostaglandina F2α na ovulação e na liberação de LH em vacas

This study aimed to evaluate the role of prostaglandin F2α (PGF) on ovulation. In Experiment 1, cows were randomly allocated to two treatments to receive 150 µg of d-Cloprostenol (PGF Group, n = 12) or 2 mL of NaCl 0.9% (Control Group, n = 11) and CIDRs, were removed 4 days later. No cow ovulated in Control and PGF groups. In Experiment 2, cows were randomly separated into two experimental groups to receive 4 injections of 150 µg of d-Cloprostenol (n = 9) or 2 mL of NaCL 0.9% (n = 9). In this experiment, ovulation was not observed in any cows. In Experiment 3, ovariectomized cows receive three injections of 300µg of PGF analog (PGF Group, n = 5), 100µg of Lecirelin (GnRH Group, n = 5) or 2 mL of PBS (Control Group, n = 4). The LH concentration was higher (P <0.0001) in cows from the GnRH group than in the PGF and Control groups. In experiment 4, cows with preovulatory follicles (>11.5 mm) were treated with Saline (Control Group, n = 6); Lecirelin (GnRH Group, n = 7) or Cloprostenol Sodium (PGF Group, n = 6). There was a significant increase in the vascular area of follicles from 0 to 24 h in GnRH and PGF treatments. In conclusion, PGF was not able to induce ovulation in cows with high or low plasma progesterone concentration. Additionally, PGF alone was not able to induce LH release and follicle luteinization, but increased follicular vascularization.(AU)

O objetivo deste estudo foi avaliar o papel da prostaglandina F2α (PGF) na ovulação. No Experimento 1, as vacas foram alocadas aleatoriamente em dois tratamentos para receber 150 µg de d-Cloprostenol (Grupo PGF, n = 12) ou 2 mL de NaCl 0,9% (Grupo Controle, n = 11) e os CIDR, foram removidos 4 dias depois. Nenhuma vaca ovulou nos grupos Controle e PGF. No Experimento 2, as vacas foram separadas aleatoriamente em dois grupos experimentais para receber 4 injeções de 150 µg de d-Cloprostenol (n = 9) ou 2 mL de NaCL 0,9% (n = 9). Não foi observada ovulação em nenhum dos animais deste experimento. No Experimento 3, vacas ovariectomizadas receberam três injeções de 300µg de análogo de PGF (Grupo PGF, n = 5), 100µg de Lecirelina (Grupo GnRH, n = 5) ou 2 mL de PBS (Grupo Controle, n = 4). A concentração de LH foi maior (P <0,0001) nas vacas do grupo GnRH do que nos grupos PGF e Controle. No Experimento 4, vacas com folículos pré-ovulatórios (> 11,5 mm) foram tratadas com solução salina (Grupo Controle, n = 6), Lecirelina (Grupo GnRH, n = 7) ou Cloprostenol Sódico (Grupo PGF, n = 6). Houve um aumento significativo na área vascular dos folículos de 0 a 24h nos tratamentos com GnRH e PGF. Em conclusão, a PGF não foi capaz de induzir ovulação em vacas com alta ou baixa concentração plasmática de progesterona. Além disso, a PGF sozinha não foi capaz de induzir a liberação de LH e a luteinização do folículo, mas aumentou a vascularização folicular.(AU)

Effect of recombinant bovine somatotropin (rbST) treatment on follicular population and development in non-lactating dairy cows

The aim of this study was to evaluate the long-term effects of recombinant bovine somatotropin (rbST) on follicle population and ovulatory follicle development in non-lactating dairy cows. Twenty-one Jersey cows were allocated in rbST (n=11) or control (n=10) groups. On day -60, cows in rbST group received 500 mg of somatotropin (s.c. Lactotropin®, Elanco). On day 0, control and rbST cows received an intravaginal progesterone-releasing device (1.9 g, CIDR®, Zoetis) and GnRH (100 mg, IM, Factrel®, Zoetis). On day 8, cows received PGF2α (25 mg, IM, Lutalyse®, Zoetis) and the CIDR® was removed. Twelve hours after device removal (D8), serum, follicular fluid and granulosa cells samples were collected. Serum and follicular concentration of estradiol (E2) and progesterone (P4) were analyzed. Total RNA was extracted from granulosa cells to measure gene expression of LHCGR, STAR, HSD-3B1, CYP11A1, CYP19A1, CYP17A1, IGFR and PAPPA by real-time PCR. Ultrasonography was performed on days -60, -53, -46, -14, -7, 0 and 8 for antral follicle count. Results were analyzed by repeated measures ANOVA and t-test. There was no effect of rbST treatment on the number of follicles during the 60 days period, as well as no effect on serum and follicular fluid E2 and follicular fluid P4 at the moment of follicle aspiration. There was a reduction in PAPPA (P = 0.006), CYP11A1 (P = 0.04) and CYP19A1 (P = 0.002) mRNA levels in granulosa cells of the pre-ovulatory follicle of rbST treated cows. In conclusion, a single dose of rbST did not have long-term effects on antral follicle population, serum and follicular E2/P4 concentrations in non-lactating dairy cows. Despite that, rbST injection decreased granulosa cell expression of genes related to steroidogenesis in the pre-ovulatory follicle.

Effect of recombinant bovine somatotropin (rbST) treatment on follicular population and development in non-lactating dairy cows

The aim of this study was to evaluate the long-term effects of recombinant bovine somatotropin (rbST) on follicle population and ovulatory follicle development in non-lactating dairy cows. Twenty-one Jersey cows were allocated in rbST (n=11) or control (n=10) groups. On day -60, cows in rbST group received 500 mg of somatotropin (s.c. Lactotropin®, Elanco). On day 0, control and rbST cows received an intravaginal progesterone-releasing device (1.9 g, CIDR®, Zoetis) and GnRH (100 mg, IM, Factrel®, Zoetis). On day 8, cows received PGF2α (25 mg, IM, Lutalyse®, Zoetis) and the CIDR® was removed. Twelve hours after device removal (D8), serum, follicular fluid and granulosa cells samples were collected. Serum and follicular concentration of estradiol (E2) and progesterone (P4) were analyzed. Total RNA was extracted from granulosa cells to measure gene expression of LHCGR, STAR, HSD-3B1, CYP11A1, CYP19A1, CYP17A1, IGFR and PAPPA by real-time PCR. Ultrasonography was performed on days -60, -53, -46, -14, -7, 0 and 8 for antral follicle count. Results were analyzed by repeated measures ANOVA and t-test. There was no effect of rbST treatment on the number of follicles during the 60 days period, as well as no effect on serum and follicular fluid E2 and follicular fluid P4 at the moment of follicle aspiration. There was a reduction in PAPPA (P = 0.006), CYP11A1 (P = 0.04) and CYP19A1 (P = 0.002) mRNA levels in granulosa cells of the pre-ovulatory follicle of rbST treated cows. In conclusion, a single dose of rbST did not have long-term effects on antral follicle population, serum and follicular E2/P4 concentrations in non-lactating dairy cows. Despite that, rbST injection decreased granulosa cell expression of genes related to steroidogenesis in the pre-ovulatory follicle.(AU)

Systemic inflammatory and stress markers in cattle and sheep submitted to different reproductive procedures / Marcadores sistêmicos de inflamação e estresse em bovinos e ovinos submetidos a diferentes procedimentos reprodutivos

Previous studies have evaluated the effects of different reproductive procedures on discomfort markers in sheep and cattle. Such studies may help stimulate the adoption of techniques that are more beneficial for animal welfare. However, markers that are commonly used to evaluate discomfort are highly influenced by external factors. To overcome this, several systemic markers can be evaluated to more precisely identify stress, pain, and inflammation. Such markers include cortisol, acute phase proteins, bradykinin, and substance P. We aimed to review the potential markers of stress, pain, and inflammation, and discuss how and when they are regulated after different stimuli related to reproductive procedures in cattle and sheep. Furthermore, we aimed to review how reproductive procedures with different degrees of invasiveness cause stress and provide information that may help develop strategies to limit animal discomfort.(AU)

Estudos anteriores avaliaram o efeito de diferentes procedimentos reprodutivos sobre marcadores de desconforto em bovinos e ovinos. Tais estudos podem estimular a adoção de técnicas que preservem o bem-estar animal. Entretanto, os marcadores comumente utilizados apresentam alta influência de fatores externos. Para contornar isso, a avaliação conjunta de diferentes parâmetros sistêmicos pode ser utilizada para determinar com maior precisão a presença de estresse, dor ou inflamação, como cortisol, proteínas de fase aguda, a bradicinina e a substância P. O objetivo desta revisão é relacionar potenciais marcadores de inflamação e estresse, discutindo como e quando são regulados frente aos estímulos em bovinos e ovinos. Ainda, pretende-se revisar de que forma procedimentos reprodutivos com diferentes graus de invasividade acarretam em desconforto, fornecendo informações para a elaboração de estratégias que possibilitem minimizá-lo.(AU)

Seroprevalence estimate and associated risk factors for neosporosis in dairy cattle in the northwest region of Rio Grande do Sul State, Brazil / Estimativa da soroprevalência e fatores de risco para neosporose em rebanhos leiteiros na região Noroeste do estado do Rio Grande do Sul, Brasil

The aim of this study was to estimate neosporosis seroprevalence and its associated risk factors in milk herds (Bos taurus taurus) located in the northwestern region of Rio Grande do Sul State, Brazil. Three hundred twenty-two blood samples were collected from dairy cows on 18 farms in 17 cities of this region. An epidemiologic questionnaire was completed for each farm. It consisted of questions about the general characteristics of the herd, reproduction, and animal management. Serum samples were tested for Neospora caninum using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Results indicated a seroprevalence of Neospora in 88.9% (16/18) of herds and 31.1% (100/322) of individuals. Risk factor analyses demonstrated that culling by reproductive disorder (OR = 0.6), flooding (OR = 0.5), and commercial sale (OR = 0.4) were associated with seroprevalence. Nevertheless, the purchase of replacement animals in the herd played an important role in disease occurrence (OR = 2.2). Results of this study suggested that Neospora caninum was present in the studied herds under investigation and that there are risk factors associated with its seroprevalence on the farms of the northwestern of Rio Grande do Sul.(AU)

O objetivo desse estudo foi estimar a soroprevalência da neosporose e os possíveis fatores de risco em rebanhos (Bos taurus taurus) localizados na mesorregião Noroeste do Rio Grande do Sul, Brasil. Foram coletadas 322 amostras de sangue de bovinos leiteiros, em 18 propriedades localizadas em 17 munícipios desta mesorregião. Um questionário epidemiológico foi aplicado em cada propriedade, contendo questões relacionadas às características gerais dos rebanhos, dados reprodutivos e manejo animal. As amostras de soro foram testadas através do teste de imunoensaio enzimático (ELISA) para Neospora caninum. Os resultados demonstraram uma soroprevalência de Neospora de 88,9% (16/18) entre os rebanhos e 31,1% (100/322) entre os indivíduos. Entre os fatores de risco analisados foi observado que descarte por problemas reprodutivos (OR=0,6), presença de áreas alagadiças (OR=0,5) e venda comercial (OR=0,4) estavam associados a soroprevalência. No entanto, a compra de animais substituídos no rebanho desempenhou um papel significativo na ocorrência da doença (OR=2,2). Os resultados desse estudo sugerem que o Neospora caninum esteve presente nos rebanhos estudados, bem como, existem fatores associados com a soroprevalência nas propriedades da mesorregião do Noroeste do Rio Grande do Sul.(AU)

Serum metabolic markers pre and postpartum in holstein cows according to the mastitis occurrence

Background: Bovine mastitis causes major economic losses for milk producers by reducing the quantity and the quality of the milk or even leading to the complete loss of the mammary gland secretory capacity. During the transition period, dairy cows are susceptible to infectious diseases; therefore, markers that allow early identification of cows in higher risk of developing diseases are especially useful at this time. Therefore, the aim of this study was to evaluate serum markers in the pre and postpartum of multiparous dairy cows with clinical mastitis and with health condition in the postpartum period in a semi-extensive management system.Materials, Methods & Results: Thirty-Six Holstein cows were monitored daily during milking until 59 days postpartum and were categorized according to the pre-milking strip cup test into clinical mastitis (mastitis group (MG)) and absence of symptoms (control group (CG)) that were negative to the test, representing the health cows. All cows were reared as one group and maintained in a semi-extensive pasture-based system. Blood samples were collected weekly after morning milking via venipuncture of the coccinea vein into tubes without anticoagulant and grouped for prepartum (-21 to 0 days from calving), early postpartum (0 to 30 days from calving), and late postpartum (30 to 59 days from calving) periods. Milk production was recorded daily. The serum markers albumin, aspartate aminotransferase (AST), phosphorus, gammaglutamyltransferase (GGT) and non-esterified fatty acids (NEFA) were measured. Statistical analyses were performed using SAS®. The cases of clinical mastitis occurred on average at 37.2 ± 4.9 days postpartum. Health cows (CG) had higher milk production compared to the mastitis group (MG) only in the late postpartum period (P 0.05).[...]

Calcium and magnesium urinary excretion in dairy cows with different fee of glucose metabolization / Excreção urinária de cálcio e magnésio em vacas leiteiras com diferentes taxas de metabolização de glicose

Background: The post-partum period in dairy cows is accompanied by a low glucose metabolism in adipose tissue and skeletal muscle tissue, being glucose conducted to the milk production. In humans, low glucose metabolism is associated with metabolic syndromes, the high glucose levels reduce tubular reabsorption of Magnesium (Mg) and Calcium (Ca), leading to hypomagnesemia and hypocalcemia. These minerals are important to the dairy cow, as their decrease leads to diseases. The aim of this study was to evaluate the relationship between glucose metabolism rate with the urinary excretion of Ca and Mg in multiparous dairy cows during the post-partum period.Materials, Methods & Results: Twenty dairy cows were used from a commercial farm southern Brazil, in the semi-extensive system. Glucose tolerance tests were performed (TTG) on day 9 relative to calving. The cows were categorized into three groups according to the glucose metabolism rate (area under the glucose curve, glucose half-life and glucose consumption rate): High Glucose Metabolization (GA); Intermediate Glucose Metabolizing (GI); and Low Glucose Metabolization (GL). Blood and urine samples were collected on days 0, + 3, + 6, + 9, +16 and +23 in relation to calving for to determine the levels of Ca, Mg, insulin (Ins), non-esterified fatty acids (NEFA) and Glu. In urine was evaluated the excretion of Ca and Mg. The cows were milked twice a day (at 3:00 a.m. and 3:00 p.m.) and the milk yield (kg/cow) was recorded daily and averages were generated every five days from day 15 to day 60 postpartum. The statistical analyses were performed with the MIXED procedure to assess the main effect of group, time (in days) and their interaction by using version 9.2 SAS software.[...]

Calcium and magnesium urinary excretion in dairy cows with different fee of glucose metabolization / Excreção urinária de cálcio e magnésio em vacas leiteiras com diferentes taxas de metabolização de glicose

Background: The post-partum period in dairy cows is accompanied by a low glucose metabolism in adipose tissue and skeletal muscle tissue, being glucose conducted to the milk production. In humans, low glucose metabolism is associated with metabolic syndromes, the high glucose levels reduce tubular reabsorption of Magnesium (Mg) and Calcium (Ca), leading to hypomagnesemia and hypocalcemia. These minerals are important to the dairy cow, as their decrease leads to diseases. The aim of this study was to evaluate the relationship between glucose metabolism rate with the urinary excretion of Ca and Mg in multiparous dairy cows during the post-partum period.Materials, Methods & Results: Twenty dairy cows were used from a commercial farm southern Brazil, in the semi-extensive system. Glucose tolerance tests were performed (TTG) on day 9 relative to calving. The cows were categorized into three groups according to the glucose metabolism rate (area under the glucose curve, glucose half-life and glucose consumption rate): High Glucose Metabolization (GA); Intermediate Glucose Metabolizing (GI); and Low Glucose Metabolization (GL). Blood and urine samples were collected on days 0, + 3, + 6, + 9, +16 and +23 in relation to calving for to determine the levels of Ca, Mg, insulin (Ins), non-esterified fatty acids (NEFA) and Glu. In urine was evaluated the excretion of Ca and Mg. The cows were milked twice a day (at 3:00 a.m. and 3:00 p.m.) and the milk yield (kg/cow) was recorded daily and averages were generated every five days from day 15 to day 60 postpartum. The statistical analyses were performed with the MIXED procedure to assess the main effect of group, time (in days) and their interaction by using version 9.2 SAS software.[...](AU)

Serum metabolic markers pre and postpartum in holstein cows according to the mastitis occurrence

Background: Bovine mastitis causes major economic losses for milk producers by reducing the quantity and the quality of the milk or even leading to the complete loss of the mammary gland secretory capacity. During the transition period, dairy cows are susceptible to infectious diseases; therefore, markers that allow early identification of cows in higher risk of developing diseases are especially useful at this time. Therefore, the aim of this study was to evaluate serum markers in the pre and postpartum of multiparous dairy cows with clinical mastitis and with health condition in the postpartum period in a semi-extensive management system.Materials, Methods & Results: Thirty-Six Holstein cows were monitored daily during milking until 59 days postpartum and were categorized according to the pre-milking strip cup test into clinical mastitis (mastitis group (MG)) and absence of symptoms (control group (CG)) that were negative to the test, representing the health cows. All cows were reared as one group and maintained in a semi-extensive pasture-based system. Blood samples were collected weekly after morning milking via venipuncture of the coccinea vein into tubes without anticoagulant and grouped for prepartum (-21 to 0 days from calving), early postpartum (0 to 30 days from calving), and late postpartum (30 to 59 days from calving) periods. Milk production was recorded daily. The serum markers albumin, aspartate aminotransferase (AST), phosphorus, gammaglutamyltransferase (GGT) and non-esterified fatty acids (NEFA) were measured. Statistical analyses were performed using SAS®. The cases of clinical mastitis occurred on average at 37.2 ± 4.9 days postpartum. Health cows (CG) had higher milk production compared to the mastitis group (MG) only in the late postpartum period (P < 0.05). There was no difference among groups for albumin and NEFA concentrations in all periods evaluated (P > 0.05).[...](AU)

Paraoxonase activity in the serum of peripartum dairy cows with different placental lactogen concentrations / Atividade sérica de Paraoxanase durante o periparto de vacas leiteiras com diferentes concentrações de Lactogênio Placentário

The action of the bovine placental lactogen (bPL) hormone on maternal metabolism is still poorly known. Some markers, such as the acute phase protein paraoxonase (PON1), are used as indicators of liver function and help to determine the metabolic condition during the transition period in dairy cows. The aim of this study was to evaluate the activity of paraoxonase (PON1) in the serum of peripartum dairy cows with different levels of bPL. Based on the plasma bPL concentration, 18 cows were divided equally into three groups: LOW ( < 2,68 ng bPL mL-1), MEDIUM (2,682,80 ng bPL mL-1), and HIGH ( > 2,80 ng bPL mL-1). The experiment was conducted between 21 days prepartum and 28 days postpartum. Serum samples were collected during the experiment for the determination of bPL concentrations and PON1 activity. The bPL concentration was significantly different between the experimental groups (P ≤ 0,0001) and the days of serum collection (P ≤ 0,0001). In the prepartum dairy cows, the PON1 levels were different between the groups (P ≤ 0,05) and the days of serum collection (P ≤ 0,05). Cows with high bPL concentration had lower serum PON1 activity (P ≤ 0,05), while cows with low hormone levels had higher enzyme activity (P ≤ 0,05). In the postpartum period, there was a significant difference between the days of serum collection (P ≤ 0,0001) and the interaction between groups and collections(P ≤ 0,01). The group with high concentrations of bPL had lower levels of PON1 (P ≤ 0,01), while thegroup with low bPL maintained higher concentrations of PON1 (P ≤ 0,01). It was concluded that thecows with higher concentrations of bPL in the prepartum period present a reduction in the serum activityof the PON1 enzyme during the peripartum period.(AU)

A ação do hormônio Lactogênio Placentário Bovino (bLP) no metabolismo materno ainda é poucoconhecida. Alguns marcadores, como a proteína de fase aguda Paraoxanase (PON1), são utilizadoscomo indicadores da função hepática auxiliando na determinação da condição metabólica no período de transição em vacas leiteiras. O objetivo deste trabalho foi avaliar a atividade sérica de PON1 duranteo periparto em vacas leiteiras com diferentes níveis de bLP. As vacas foram divididas em três gruposde acordo com as concentrações plasmáticas de bLP, em que BAIXO < 2,68 ng mL-1 (n=6), MÉDIO> 2,68 ng mL-1 e < 2,80 ng mL-1 (n=6) e ALTO > 2,80 ng mL-1 (n=6). O período experimental ocorreuentre os 21 dias pré-parto e 28 dias pós-parto. Amostras de soro foram coletadas para a determinaçãodas concentrações de bLP e atividade sérica de PON1. Houve diferença entre os três grupos (P ≤ 0,0001)de acordo com as concentrações de bLP, assim como entre os dias coletados (P ≤ 0,0001). No pré-parto,os níveis de PON1 apresentaram diferença entre grupos (P ≤ 0,05) e coletas (P ≤ 0,05). Vacas com altaconcentração de bLP apresentaram menor atividade sérica de PON1 (P ≤ 0,05), enquanto vacas combaixos níveis do hormônio obtiveram maior atividade da enzima (P ≤ 0,05). No pós-parto não houvediferença entre grupos (P ≥ 0,10), houve diferença entre os dias coletados (P ≤ 0,0001) e interação entregrupos e coletas (P ≤ 0,01). O grupo com altas concentrações de bLP apresentou menores níveis dePON1 (P ≤ 0,01), enquanto vacas do grupo com baixo bLP mantiveram maiores concentrações de PON1(P ≤ 0,01). Conclui-se que, vacas com maiores concentrações de bLP no período pré-parto apresentamredução na atividade sérica da enzima PON1 durante o período periparto.(AU)

Evaluation of the diagnosis of perihepatitis in swine after slaughter and relationship with the levels of liver enzymes / Avaliação do diagnóstico de perihepatite em suínos após o abate e sua relação com os níveis de enzimas hepáticas

The liver is an organ with a differential value on the market. However, due to its metabolic functions it is susceptible to various types of alterations, including a large rate of disposal by perihepatitis. The aim of this study was to evaluate the sensitivity and specificity of the diagnosis of perihepatitis by the Federal Inspection Service (FIS), according to histopathological examination and correlate these findings with plasmatic concentrations of AST and GGT. One hundred and fifty four culled sows of the Landrace breed were used. Slaughter was performed by the method of desensitization by electrical stimulation and subsequent exsanguination. Then 5 mL of whole blood was collected to evaluate concentrations of GGT and AST. During evisceration, liver condition was assessed by visual inspection and classified as good or condemned by perihepatitis. Also, fragments of the liver were collected to histopathologic examination. The alterations in the liver parenchyma were classified as degenerative, inflammatory or reparative. The alterations found in liver tissues, considered as perihepatitis by visual inspection, were often due to fibrosis, fatty degeneration or mild hepatitis. The serum concentrations of GGT were high. Moreover, it concentrations were higher in livers with lesions of inflammatory and degenerative nature when compared to livers without injuries (p 0.05).However, the same was not observed for AST concentrations (p>0.05). Concluding, the perihepatitis diagnosis from the FIS showed low specificity and sensitivity, and the enzyme GGT was a good indicator of liver injuries in swine.(AU)

O fígado é um órgão de valor comercial diferenciado, porém, em virtude das suas funções metabólicas, é susceptível a diversos tipos de alterações, destacando-se um grande número de descartes por perihepatite. O objetivo deste estudo foi avaliar a sensibilidade e especificidade do diagnóstico desta alteração pelo Serviço de Inspeção Federal (SIF), segundo exame histopatológico, e correlacionar estes achados com os níveis plasmáticos de AST e GGT. Foram utilizadas 154 matrizes da raça Landrace de descarte. O abate foi feito com o método de insensibilização por estímulo elétrico e posterior sangria, sendo coletados 5 mL de sangue total, para determinação dos níveis de GGT e AST. Durante a evisceração, foi avaliada a condição do fígado pela inspeção sanitária classificando-o como liberado ou condenado por perihepatite. Fragmentos de fígado foram colhidos, para fins de comparações histopatológicas. Na presença de alteração do parênquima hepático, essa foi classificada em degenerativa, inflamatória ou reparativa. Os resultados do estudo demonstraram que as lesões encontradas no tecido hepático, consideradas como perihepatite pela inspeção sanitária, tratavam-se muitas vezes de alterações hepáticas como fibroses, degeneração gordurosa ou hepatites discretas. Os níveis de GGT se apresentaram elevados, sendo exacerbados em lesões de caráter inflamatório e degenerativo, em comparação com animais sem lesão hepática (p<0,05), o que não foi observado para os níveis de AST (p>0,05). Assim, observou-se que o diagnóstico de perihepatite pelo SIF apresentou baixa especificidade e sensibilidade, e que a enzima GGT é um bom indicador de lesões hepáticas em suínos.(AU)

The use of sodic monensin and probiotics for controlling subacute ruminal acidosis in sheep / O uso de monensina sódica e probióticos para o controle de acidose ruminal subaguda em ovinos

It was to validated a protocol for induction of subacute ruminal acidosis (SARA) (Experiment 1) and test the efficiency of probiotic Saccharomyces cerevisiae or monensin to avoid pH ruminal drops in sheep (Experiment 2). In Experiment 1, six ewes were fasted for two days and then fed most with concentrate during four days. Ewes in this protocol had ruminal fluid pH below 6.0 and kept it for 75 consecutive hours. In Experiment 2, 18 sheep were distributed into three groups: Control (CG, n = 6), monensin (MG, n = 6) and probiotic group (PG, n = 6). SARA was induced according Experiment 1. PG had lower pH (5.7 ± 0.1) than CG (6.0 ± 0.1) (P = 0.05), while MG (5.7 ± 0.1) was similar to both during SARA induction. SARA induction reduced ruminal protozoa population (P < 0.05) and increased chloride concentrations in ruminal fluid (P < 0.01). In serum, SARA increased concentrations of phosphorus (P < 0.01), AST (P < 0.01) and GGT (P < 0.01), but reduced LDH (P < 0.01). In conclusion, the protocol used for SARA induction was able to maintain ruminal pH between 5.5-6.0 for more than 48 hours. However, monensin and probiotics supplementation was not effective in preventing changes in ruminal and serum parameters during SARA.(AU)

Foi validado um protocolo para a indução de acidose ruminal subaguda (SARA) (Experimento 1) e testar a eficácia do probiótico Saccharomyces cerevisiae ou monensina na prevenção da queda do pH do fluido ruminal em ovinos (Experimento 2). No Experimento 1, seis ovelhas foram mantidas em jejum por dois dias e, em seguida, alimentadas basicamente com concentrado durante quatro dias. Nesse protocolo as ovelhas mantiveram o pH do fluido ruminal abaixo de 6,0 por 75 horas consecutivas. No Experimento 2, 18 ovelhas foram distribuídas em três grupos: controle (GC, n = 6), monensina (GM, n = 6) e o grupo probiótico (GP, n = 6). A SARA foi induzida de acordo com o Experimento 1. GP apresentaram valores de pH mais baixos (5,7 ± 0,1) do que o GC (6,0 ± 0,1) (P = 0,05), enquanto GM (5,7 ± 0,1) foi semelhante durante a indução de SARA. A indução SARA reduziu a população de protozoários no rúmen (P < 0,05) e aumentou a concentração de cloreto no líquido ruminal (P < 0,01). Durante a SARA observou-se aumento das concentrações séricas de fósforo (P < 0,01), AST (P < 0,01) e GGT (P < 0,01), mas reduziu a de LDH (P < 0,01). Em conclusão, o protocolo utilizado para a indução de SARA foi capaz de manter o pH do rúmen entre 5,5-6,0 por períodos superiores a 48 horas. No entanto, a suplementação com monensina e probióticos não foi eficaz na prevenção das alterações nos parâmetros ruminais e séricos durante SARA.(AU)

Effect of porcine somatotropin on metabolism and testicular characteristics of prepubertal pigs / Efeito da somatotrofina suína sobre o metabolismo e características testiculares de suínos pré-púberes

The effect of pST on the testicular characteristics and metabolic parameters of prepubertal pigs was evaluated. Experiment 1 aimed to determine the interval between applications of pST based on the concentrations of circulating IGF-I. Experiment 2 aimed to evaluate the effect of pST on metabolic parameters, testicular characteristics, and expression of GHR, IGF-I and PCNA. In Experiment 1 twelve piglets with 30 days of age were used. The pST Group (n = 6) was submitted to one i.m. injection of pST and the Control Group (n = 6) to one placebo injection. Blood collections were performed until day 7 post pST application to determine IGF-I concentration and metabolic profile. In Experiment 2 twelve piglets with 22 days of age were used. The pST Group was submitted to pST injections every three days, and the Control Group received placebo doses during 30 days. Blood collections were performed every 3 days. Samples of liver and testicular tissue were collected to determine gene expression and testicular characteristics. In Experiment 1 IGF-I concentration was higher for the pST Group (P = 0.02). In Experiment 2 the pST Group had higher body and testicular weight (P=0.06) and increased gene expression of PCNA in testes (P < 0.05). However, a reduction in the number of seminiferous tubules, and Sertoli cells, and in GHR expression (P < 0.05) was observed. Thus, pST administration increased body and testis development in prepubertal pigs, however it reduced the density of seminiferous tubules and Sertoli cells.(AU)

Foi investigado o efeito da pST sobre características testiculares e metabolismo de suínos pré-púberes. O Experimento 1 determinou o intervalo entre aplicações de pST, baseado nas concentrações de IGF-I. O Experimento 2 avaliou o efeito da pST sobre o metabolismo, características testiculares e expressão gênica de GHR, IGF-I e PCNA. No Experimento 1, foram usados 12 leitões com 30 dias de idade. O grupo pST (n = 6) foi submetido a uma injeção IM de pST e o grupo Controle (n = 6) a uma injeção de placebo. Coletas de sangue foram realizadas até o dia sete após a aplicação de pST para determinação dos níveis de IGF-I e parâmetros metabólicos. No Experimento 2, foram usados 12 leitões com 22 dias de idade. O grupo pST foi submetido às aplicações de pST a cada 3 dias, e o grupo Controle, às doses de placebo, durante 30 dias. Coletas de sangue foram realizadas a cada três dias. Amostras de fígado e testículo foram coletadas para determinar a expressão gênica e características testiculares. No Experimento 1, a concentração de IGF-I foi maior no grupo pST (P = 0,02). No Experimento 2, o grupo pST teve maior peso corporal e testicular (P = 0,06) e aumento na expressão de PCNA no testículo (P < 0,05). Contudo, foi observada uma redução no número de túbulos seminíferos, células de Sertoli e GHR (P < 0,05). Assim, a administração de pST aumentou o desenvolvimento testicular e corporal de suínos pré-púberes, porém reduziu a densidade de túbulos seminíferos e células de Sertoli.(AU)

Efeitos da restrição alimentar e administração de somatotropina recombinante bovina nos parâmetros plasmáticos de novilhas da raça Holandês durante o período pré-parto / Effect of Prepartum Feed Restriction and Bovine Recombinant Somatotropin Injection on Plasmatic Parameters of Prepartum Holstein Heifers

Background: During the transition period negative energy balance (NEB) occurs due to the difference between input and output of nutrients. At this period, these nutrients are directed to milk production and lipolysis is the major mechanism of adaptation. There is an increase of the non-esterified fatty acids (NEFA) reduce dry matter intake (DMI). The feed restriction during the prepartum period improve milk production and plasmatic concentration of glucose and insulin through the adaptation of liver enzymes and increased DMI at the postpartum period. The administration of recombinant bovine somatotropin (rbST) also improve milk production on postpartum period and alters lipogenesis and lipolysis through effects on adipose tissue and lipid metabolism. The aim of this study was to evaluate the effects of feed restriction and injections of rbST on parameters of energetic, protein, enzymatic and mineral metabolism of prepartum dairy heifers. Materials, Methods & Results: Fourty four heifers with BW = 477.2 ± 7.4 kg at the beginning were used. The experimental period ranged from 35 days prepartum to calving. These heifers were divided in four groups with 11 heifers each: bST: fed to allow 100% of the DMI plus rbST injections; RbST: fed to allow 80% of the DMI plus rbST injections; CON: fed to allow 100% of the DMI plus placebo injections and RES: fed to allow 80% of the DMI plus placebo injections. The heifers receive three injections of rbST and placebo 14 days apart in the prepartum period. The diets of group bST and CON was according to 100% of requirements and DMI was calculates using the body weight, BCS, age, period of gestation and growth. The serum glucose, NEFA, calcium and phosphorus concentration were analyzed in blood samples through colorimetry method. Gamma glutamyltransferase and aspartate aminotransferase activity were measured by spectrophotometer. All statistical analyses were made using softweare SAS. Glucose, NEFA, urea, calcium, phosphorus and relashioship C:P, GGT and AST were analyzed through MIXED procedure and the Tukey-Kramer test was applied for comparision means. For the BCS analyzis was applied Kruskal-Wallis test.The BST group had higher plasmatic concentrations of glucose than CON group (P = 0.0011). Similarly urea concentration was lower for BST group (P = 0.0099) during prepartum. The NEFA concentration was higher in REST than CON group (P = 0.0015). We did not find difference between groups for BCS, mineral profile and enzymatic profile. Discussion: The feed restriction increased NEFA concentration due to decreased DMI. On the BST group, we observed higher concentrations of glucose when compared with CON group, resembling to the results found by others. In accordance to our results previous studies, no difference concerning urea concentration in prepartum period in cows submitted to feed restriction or mineral profile for cows submitted to feed restriction and bST treatment was found. This strategy will also result in increased lipolysis, causes protein degradation stemmed from muscle tissue in an attempt to maintain the levels of glucose from gluconeogenesis from amino acids. Disagreeing the results described here, others observed higher BCS in cows submitted to ad libitum diet compared with feed restriction cows during prepartum. In this study feed restriction and bST on prepartum period can improve metabolic adaptation, but these two strategies do not act in synergy.