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This article describes the application of two human-computer interaction tests (IHC) in an Android application© called "+Leite", created to help small milk producers measure the efficiency of their production. One of these tests is called Heuristic Assessment which consists of identifying errors based on the 10 Nielsen heuristics (1998) and classifying them into levels (mild, medium, severe and catastrophic), according to the severity of this error. The other test is called the Cognitive Pathway that consists of the evaluator impersonating the application user and plotting a path to be followed to identify usability problems. In these tests, aspects (positive and/or negative) of the software are raised and, with the possession of these data, it is estimated to improve the application.

The article aims to show methodological criteria for the construction of the Global Sustainability Index (IGS) and its importance in the evaluation of public policies of sustainable milk production in contemporary times. The economic, social, environmental, institutional, and technological dimensions are taken into consideration to better assess the sustainable development of economically active activities. The survey took place in Rondônia with 400 dairy farmers, where the IGS of the activity that reached average sustainability was obtained, IGS = 0.42. The economic dimension presented an index of 0.52, being the most sustainable among the analyzed dimensions. Following the decreasing order, comes social and environmental, with average sustainability of 0,44 and 0,41, respectively, and, with low sustainability, was the technological dimension, which presented an index of 0,39, and the institutional with 0,32 decimal points of sustainability. This result indicates the need for political and technological efforts to improve the sector's performance.

The objectives of this study were to determine the effect of calving to timed artificial insemination (C-TAI) interval on fertility of Bos taurus and Bos indicus cows and to determine the best C-TAI interval to include postpartum cows in TAI programs in each genotype (B. taurus and B. indicus). In experiment 1, a retrospective study was performed, with data from 2,709 TAI in Bos taurus and Bos indicus cows with different C-TAI intervals. There was a positive linear effect of C-TAI interval on the pregnancy probability (p .0001). However, there was no effect or interaction with the genotype. When C-TAI intervals were grouped in classes, pregnancy rate differed in groups (p .05). Receiver operating characteristic (ROC) analysis was performed, and it was observed that 52 days would be the better C-TAI interval to maximize fertility in beef cows. According to the previous result, we further stratified into two C-TAI interval groups (≤ 52 days or 52 days). Cows with C-TAI longer than 52 days (C-TAI 52) had greater pregnancy rate (56%) than cows with short C-TAI (46%; p .01). In experiment 2, 18 postpartum beef cows were subjected to TAI protocol at different C-TAI intervals (n = 6 cows per group): 40, 60 or 80 days postpartum. Cows with 60 days of C-TAI had a greater preovulatory follicle diameter than cows with 80 days postpartum (p .05). The C-TAI interval did not affect (p .05) the ovulation rate nor the proportion of endometrial polymorphonuclear leucocytes. We conclude that C-TAI interval affects pregnancy rate in both Bos taurus and Bos indicus. We recommend a C-TAI interval longer than 52 days to increase fertility of beef cows included in TAI programs.

This study aimed to establish the relationship between antral follicle count (AFC), the time of puberty, and ovarian response in Nelore heifers subjected to timed-AI (TAI) protocols. Prepubescent Nelore heifers (Bos indicus; n = 30) were examined by transrectal ultrasound and videos of the ovaries were recorded for later CFA (? 3 mm). After AFC, heifers were divided into 2 groups, low and high AFC and then further ultrasonic ovarian assessments were performed to determine the onset of puberty. Once puberty was established in all heifers, they were submitted to an FTAI protocol. There were no differences (P > 0.1) between groups on the time of puberty, ovulation rate, the proportion of heifers that expressed estrus, and on preovulatory follicle diameter. However, heifers with low AFC had a smaller ovarian area in the prepubertal period (4.36 ± 0.3 vs. 5.65 ± 0.2 cm2) and, in the FTAI, they had the moment of estrus (48 ± 0.0 vs. 58.5 ± 3.1 h) and earlier ovulation (60 ± 1.8 vs. 72.6 ± 4.7 h) compared to heifers with high AFC (P < 0.05). In addition, heifers in the low AFC group had a higher (P = 0.05) pregnancy per AI (76.9%, 10/13) than the high AFC group (29.4%, 5/17). In this study, heifers with low AFC had the moment of ovulation anticipated and greater pregnancy per AI compared to heifers with high AFC. O objetivo deste estudo foi estabelecer a relação entre contagem de folículos antrais (CFA), idade à puberdade e resposta ovariana em novilhas Nelore submetidas a protocolos de Inseminação Artificial em Tempo Fixo (IATF). Novilhas Nelore pré-púberes (Bos indicus; n = 30) foram avaliadas por ultrassonografia transretal e vídeos dos ovários foram gravados para posterior CFA. Após a CFA, as novilhas foram divididas em 2 grupos, CFA baixa e alta e então avaliações ultrassonográficas dos ovários foram realizadas para determinar a puberdade. Uma vez estabelecida a puberdade em todas as novilhas, elas foram submetidas a protocolo de IATF. Não houve diferenças (P > 0,1) entre os grupos na idade à puberdade, na taxa de ovulação, na proporção de novilhas que expressaram estro e no diâmetro do folículo pré-ovulatório. No entanto, novilhas com baixa CFA apresentaram menor área ovariana no período prépúbere (4,36 ± 0,3 vs. 5,65 ± 0,2 cm2) e, na IATF, tiveram o momento do estro (48 ± 0,0 x 58,5 ± 3,1 h) e ovulação antecipados (60 ± 1,8 vs. 72,6 ± 4,7 h) em comparação com novilhas com alta CFA (P < 0,05). Além disso, as novilhas do grupo de baixa CFA apresentaram maior (P = 0,05) prenhez por IA (76,9%, 10/13) que o grupo de alta CFA (29,4%, 5/17). Nesse estudo, novilhas com baixa CFA tiveram o momento da ovulação antecipado e maior prenhez por IA em comparação com novilhas com alta CFA. El objetivo de este estudio fue establecer la relación entre el conteo de folículos antrales (AFC), el tiempo de pubertad y la respuesta ovárica en novillas Nelore sometidas a protocolos inseminación artificial a tiempo fijo (TAI). Novillas Nelore prepubescentes (Bos indicus; n = 30) fueron examinadas mediante ultrasonido transrectal y se grabaron videos de los ovarios para posterior CFA (? 3 mm). Después de AFC, las vaquillas se dividieron en 2 grupos, AFC bajo y entonces se realizaron evaluaciones de ovario para determinar el inicio de la pubertad. Una vez establecida la pubertad, las vaquillas fueron sometidas a un protocolo FTAI. No hubo diferencias (P > 0.1) entre los grupos en el momento de la pubertad, la tasa de ovulación, la proporción de vaquillas que expresaron celo y el diámetro del folículo preovulatorio. Sin embargo, las vaquillas con AFC bajo tuvieron menor área ovárica en el período prepuberal (4,36 ± 0,3 x 5,65 ± 0,2 cm2) y, en el IATF, tuvieron el momento del estro (48 ± 0,0 x 58,5 ± 3,1 h) y ovulación más temprana (60 ± 1,8 x 72,6 ± 4,7 h) en comparación con novillas con AFC alto (P < 0,05). Además, las vaquillas en el grupo de AFC bajo tuvieron una tasa de preñez más alta (P = 0.05) (76.9 %, 10/13) que el grupo de AFC alto (29.4 %, 5/17). Las vaquillas con AFC bajo tuvieron el momento de ovulación anticipado y mayor preñez por IA en comparación con las vaquillas con AFC alto. Made available in DSpace on 2022-06-02T17:19:41Z (GMT). No. of bitstreams: 1 cpafro-18763.pdf: 119509 bytes, checksum: 4a1721a3d036b32110f6ffd5843c632d (MD5) Previous issue date: 2022

Although prostaglandins are important in the ovulation process, a precise role for prostaglandin F2α (PGF) has not been elucidated. This study aimed to evaluate the regulation of PGF receptor mRNA (PTGFR) in granulosa cells and the local effect of PGF on ovulation and luteinization. In Experiment 1, using samples collected in vivo before (Day 2), during (Day 3) and after (Day 4) follicular deviation, expression of PTGFR in bovine granulosa cells was more abundant in the dominant follicle after deviation than in subordinates (P 0.05). However, the expression of PTGFR was not regulated (P = 0.1) in preovulatory follicles at different time-points (0, 3, 6, 12 and 24 h) after ovulation induction with GnRH. In Experiment 2, to assess the role of systemic PGF treatment on luteinization and vascularization of preovulatory follicles, flunixin meglumine (FM), a nonsteroidal anti-inflammatory drug, was used to inhibit endogenous prostaglandin synthesis. Cows with preovulatory follicles were induced to ovulate with GnRH (0 h) and allocated to three groups: Control, with no further treatment; FM, treated with 2.2 mg/kg FM im 17 h after GnRH treatment; and FM + PGF, treated with FM 17 h after GnRH, followed by 25 mg dinoprost tromethamine (PGF) 23 h after GnRH treatment. FM injection was able to reduce the concentration of PGF in the follicular fluid (FF) (P 0.001). However, contrary to our hypothesis, color Doppler ultrasound evaluations revealed decreased vascular flow in FM + PGF group (P 0.05), and no effect of the treatments on intrafollicular P4 and E2 concentrations 24 h after GnRH. The prostaglandin metabolite (PGFM) concentrations in the FF were greater in cows receiving systemic PGF (P 0.001), which prompted us to further check its role on ovulation. Therefore, in Experiment 3, in a final attempt to demonstrate the local effect of PGF on ovulation, cows with preovulatory follicles received an intrafollicular injection (IFI) of PBS (Control) or 100 ng/mL purified PGF (PGF group). PGF treatment did not affect the time of ovulation after IFI (66 ± 6.4 and 63 ± 8.5 h for control and PGF, respectively; P 0.05), further suggesting that it has no direct effect in the ovulatory process. Based on our findings, we concluded that FM decreased PGF synthesis within the follicle, whereas PGF treatment decreased follicular vascularization. In addition, the in vivo model of intrafollicular injection evidenced that PGF alone is not able to locally induce ovulation.

This study aimed to compare milk production and reproductive performance in high yield Holstein cows that lose BCS early and late in the postpartum period. Lactating dairy cows (n = 76) were received first timed AI at 60 to 75 DIM using the farm-managed estradiol-progesterone-GnRH based timed AI protocol. The BCS of all cows was daily evaluated by automated BCS cameras. Aiming to evaluate the effect of the days in milk (DIM) in which a cow reached the nadir BCS on the reproductive parameters, cows were separated into two groups: Early BCS loss (n = 42), cows that reached the nadir BCS ≤ 34 DIM, and Late BCS loss (n = 34), cows that reached the nadir BCS > 34 DIM. The optimal cut-off point for determining the relationship between days to nadir BCS and pregnancy by 150 DIM (P150) was calculated using the receiver operating characteristic (ROC) curve. From the ROC analysis the cut-off was 34 DIM (Se, 80.9%; Sp, 66.7%; AUC, 0.74; P < 0.01). No differences (P>0.05) were detected between groups on the BCS and milk production. The average of milk production in both groups was 46.65 ± 6.15 Kg/day. Cows that reached the nadir BCS Early postpartum presented lower (P < 0.01) calving interval, and greater (P < 0.01) pregnancy at first AI and P150. In summary, cows that lost BCS early had better reproductive performance and had similar milk yield compared with cows that lost BCS late in the postpartum period.

Sustainable development refers to agricultural and industrial activities and the understanding of sustainability assumes greater complexity, which requires economic, social, environmental, institutional, technological, cultural and geographical emphasis to be considered, because what is sustainable for one region may not be for another. The article aims to show methodological criteria for the construction of the Global Sustainability Index (GSI) and its importance in the evaluation of public policies of sustainable milk production in contemporary times. The methodology considers the economic, social, environmental, institutional and technological dimensions, for better assessing the sustainable of economically active activities. The survey took place in Rondônia with 400 dairy farmers, where we obtained the GSI that achieved average sustainability, GSI = 0.42. The economic dimension presented an index of 0.52, being the most sustainable among the analyzed dimensions. Following the decreasing order, comes the social and environmental, with average sustainability of 0.44 and 0.41, and, with low sustainability, was the technological dimension, which showed an index of 0.39, and, the institutional with 0.32 decimal points of sustainability. This result indicates the need for political and technological efforts for better performance in the sector. Desarrollo sostenible y se refiere a las actividades agrícolas e industriales, la comprensión de la sustentabilidad asume una mayor complejidad, lo que requiere un énfasis económico, social, ambiental, institucional, tecnológico, cultural y geográfico para ser considerado, porque lo que es sostenible para una región puede no serlo para otra. El artículo tiene como objetivo mostrar criterios metodológicos para la construcción del Índice Global de Sustentabilidad (IGS) y su importancia en la evaluación de políticas públicas para la producción sostenible de leche en la contemporaneidad. La metodología considera las dimensiones económica, social, ambiental, institucional y tecnológica, ya que evalúan mejor la sustentabilidad de las actividades económicamente activas. La investigación se realizó en Rondônia con 400 productores de leche, donde se obtuvo el IGS, que alcanzó la sustentabilidad media, IGS=0,42. La dimensión económica presentó un índice de 0,52, siendo la más sostenible entre las dimensiones analizadas. En orden descendente, viene la social y ambiental, con sustentabilidad media de 0,44 y 0,41, y, con sustentabilidad baja, la dimensión tecnológica, que presentó un índice de 0,39, y la dimensión institucional con 0,32 decimales de sustentabilidad. Este resultado indica la necesidad de esfuerzos políticos y tecnológicos para mejorar el desempeño del sector. Desenvolvimento sustentável se refere a atividades agropecuárias e industriais e o entendimento da IGSe assume maior complexidade, que exige ênfases econômica, social, ambiental, institucional, tecnológica, cultural e geográfica a serem consideradas, pois, o que é sustentável para uma região pode não ser para outra. O artigo objetiva mostrar critérios metodológicos para a construção de Índice Global de Sustentabilidade (IGS) e sua importância na avaliação de políticas públicas da produção de leite sustentável em épocas contemporâneas. A metodologia considera as dimensões econômica, social, ambiental, institucional e tecnológicas, por melhor avaliarem a sustentabilidade de atividades economicamente ativas. A pesquisa ocorreu em Rondônia com 400 produtores de leite, onde se obteve o IGS que alcançou sustentabilidade média, IGS=0,42. A dimensão econômica apresentou índice de 0,52, sendo a mais sustentável entre as dimensões analisadas. Seguindo a ordem decrescente, vem a social e ambiental, com sustentabilidade média de 0,44 e 0,41, e, com baixa sustentabilidade, ficou a dimensão tecnológica, que apresentou índice de 0,39, e, a institucional com 0,32 pontos decimais de sustentabilidade. Tal resultado indica a necessidade de esforços políticos e tecnológicos para melhor desempenho do setor.

Introdução: Protocolos baseados em estradiol/progesterona são comumente usados em bovinos de corte devido a necessidade de sincronizar a onda folicular e a ovulação para a IATF. Objetivo: Determinar o momento da ovulação em vacas que receberam ECP e GnRH 34 horas após a retirada do implante de progesterona e se esse protocolo aumentaria a fertilidade. Material e métodos: Este estudo foi dividido em dois experimentos, um com 23 vacas e o outro 62. No início do protocolo, vacas de ambos experimentos receberam um dispositivo liberador de progesterona intravaginal (1,9 g de P4) e 2 mg i.m. de benzoato de estradiol (BE). No dia 8, o implante de progesterona foi removido e todas receberam 150 µg i.m. de d-cloprostenol (análogo de PGF) e 300 UI i.m. de eCG. Sendo divididas no experimento 1 conforme o diâmetro do folículo dominante em 2 grupos: 1) Grupo ECP- GnRH 34h (n=12), vacas que receberam 1 mg i.m. de cipionato de estradiol e 10,5 g i.m. de acetato de buserelina (GnRH) 34 horas após a remoção do dispositivo; 2) Grupo GnRH 34h (n=11), 10,5 g i.m. de acetato de buserelina (GnRH) 34 h após a remoção do dispositivo. O folículo ovulatório foi monitorado por ultrassonografia transretal em intervalos de 12 horas desde a remoção do implante até a ovulação. No experimento 2, as vacas foram distribuídas aleatoriamente em 3 grupos: 1) ECP-GnRH 34h (n = 17); 2) ECP – GnRH 48H * (n = 21); e 3) GnRH (n = 24). Apenas o grupo 3 diferiu no tratamento recebendo GnRH no momento da IATF. Todas as vacas foram inseminadas 48horas após a remoção do implante. Realizaram-se exames de ultrassonografia transretal para diagnóstico da prenhez 30 dias após a IATF. Resultados: Não houve diferença no momento da ovulação entre os grupos ECP-GnRH 34h = 68 % e GnRH 34h = 61,64 %, entretanto, o grupo ECP- GnRH 34h apresentou maior taxa de P/IA (61%) em relação ao GnRH 34h (48%). Conclusão: O resultado sugere que o ECP juntamente com o GnRH 34H após a retirada do implante de progesterona levam a uma maior taxa de P/IA.

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. Thepositive control consisted of the application of 5 µg of gonadotropin-releasing hormone (GnRH, n = 29); the negativecontrol 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 detectovulation and tissue collection. A Chi-square test was used to compare the proportion of animals ovulating. Geneexpressions and number of ovulation were analyzed by one-way ANOVA and Tukey?s test was used to compare meansamong 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). Ep2 gene 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. 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

Estradiol cypionate (EC) or GnRH have been widely used for ovulation induction in timed embryo transfer (TET). EC administration increases the proportion of cows that show estrus, whereas GnRH promotes more synchronized ovulations. The aim of the present study was to evaluate the potential beneficial effects of combining EC and GnRH in TET. In experiment 1, no difference was observed on serum progesterone concentrations on Day 6 and 13 after GnRH treatment between GnRH and EC+GnRH groups. In experiment 2, pregnancy per embryo transfer (P/ET) did not differ (

This study aimed to evaluate the role of prostaglandin F2a (PGF) on ovulation. In Experiment 1, cows were randomly allocated to two treatments to receive 150 ug 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 ug 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 300ug of PGF analog (PGF Group, n = 5), 100ug of Lecirelin (GnRH Group, n = 5) or 2 mL of PBS (Control Group, n = 4). The LH concentration was higher (P 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. O objetivo deste estudo foi avaliar o papel da prostaglandina F2a (PGF) na ovulação. No Experimento 1, as vacas foram alocadas aleatoriamente em dois tratamentos para receber 150 ug 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 ug 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 300ug de análogo de PGF (Grupo PGF, n = 5), 100ug de Lecirelina (Grupo GnRH, n = 5) ou 2 mL de PBS (Grupo Controle, n = 4). A concentração de LH foi maior (P 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 . Made available in DSpace on 2021-05-14T02:20:32Z (GMT). No. of bitstreams: 1 cpafro-18563.pdf: 1421435 bytes, checksum: dade7a90b48343362cf148d99ae6e08a (MD5) Previous issue date: 2021

The objective of this study was to evaluate the effect of a PGF2α-analogue (PGF) on ovulation and pregnancy rates after timed artificial insemination (TAI) in cattle. In Experiment 1 cows received an intravaginal progesterone-releasing device (CIDR) plus 2 mg im of estradiol benzoate (EB) on Day 0. The CIDR devices were removed on Day 8, and all cows received 150 μg im of d-cloprostenol (PGF2α-analogue), 300 IU of eCG and 1 mg of estradiol cypionate (ECP) im. On Day 9, cows were randomly assigned into two groups: 1) ECP Group (n = 17), that did not receive any further treatment; and 2) ECP-PG Group (n = 14) that were given 150 μg of d-cloprostenol (PGF) as adjuvant stimulus for ovulation. No difference between groups was detected in interval for ovulation (P = 0.5), and in the proportion of cows ovulating (P = 0.09). In Experiment 2, multiparous suckling crossbred Aberdeen Angus cows (n = 260), were treated into two groups, similarly as Experiment 1; ECP group (n = 122), and ECP-PG group (n = 138). All females were TAI on Day 10. The proportion of cows treated with ECP that became pregnant was 54.9% (67/122), and cows treated with ECP plus PGF was 55.1% (76/138; P = 0.9). In Experiment 3, 686 Nelore cows, 40 to 50 days postpartum, were treated as Experiment 1 (ECP group), however, on Day 8 cows were divided into 3 groups: ECP Group (n = 216); PGF-SC Group (n = 228), in which cows did not receive ECP and were given an additional subcutaneous injection of PGF on Day 8; and PGF-IM Group (n = 242), in which cows also did not receive ECP on Day 8 and were given an additional injection of PGF im on Day 9. On Day 10, estrus was evaluated at timed AI (TAI). There was no difference in the diameter of the dominant follicle at CIDR removal and at TAI, and pregnancy per AI among groups (P > 0.05). However, the proportion of cows that displayed estrus between CIDR removal and TAI was higher in ECP group than in PGF-SC and PGF-IM groups (P < 0.001). Cows that displayed estrus has higher P/AI than cows that did not (P = 0.008). In conclusion, these results suggested that intramuscular or subcutaneous injection of PGF2α could be successfully used to induce ovulation in cattle undergoing TAI, with similar pregnancy rates when compared with ECP. The subcutaneous injection of PGF on the same day of CIDR removal could be an interesting alternative due it reduces cattle management to obtain similar results. Made available in DSpace on 2018-09-19T00:37:57Z (GMT). No. of bitstreams: 1 THE2018PGFIMSCIATF.pdf: 319271 bytes, checksum: 3e2a7ad3e29c54ce35cfdad5ff59e44e (MD5) Previous issue date: 2018-09-18

This study evaluated the effect of a prostaglandin F2a (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 150 ug of I.M. d-cloprostenol (PGF analogue). On day 10, buffaloes were divided into two groups to receive 150 ug 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 150 ug of d-cloprostenol. On day 9, cows were divided into two groups to receive 150 ug 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. In Experiment 1, there was no difference (P = 0.30) in the ovulation rate between groups, and, on average, 68% of the buffaloes ovulated. Moreover, the treatment did not affect the interval to ovulation (P = 0.61) nor the diameter of the preovulatory follicle (P = 0.47). As for Experiment 2, only one cow, from the PG group, did not ovulate. There were no differences between the CTL and PG groups (P = 0.69) in the moment of ovulation, which occurred in average 82 h after CIDR removal. Finally, in Experiment 3, cows treated with PGF ovulated earlier than those in the CTL group (62.5 ± 5.8 and 94.5 ± 13.5 h, respectively; P = 0.05). Collectively, these results suggest that PGF hastens ovulation in lactating dairy cows, whereas no effect was observed in dairy buffaloes. O objetivo deste estudo foi avaliar o efeito de um análogo de prostaglandina F2a (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 150 ug de d-Cloprostenol (análogo PGF), im. No Dia 10, as búfalas foram divididas em dois grupos para receber 150 ug 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 150 ug de d-Cloprostenol. No Dia 9, as vacas foram divididas em dois grupos para receber 150 ug 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. Made available in DSpace on 2021-01-06T09:02:32Z (GMT). No. of bitstreams: 1 cpafro-18500.pdf: 412784 bytes, checksum: 6dab3ae6a9400c6fa7ec28a30fb9092b (MD5) Previous issue date: 2021

Two experiments evaluated the effects of gonadotropin releasing hormone (GnRH) treatment on fertility of suckled Nelore beef cows treated with an estradiol/progesterone (P4)-based protocol for timed artificial insemination (TAI). Experiment 1 was designed to determine the effect of GnRH administered 34 h after P4 insert removal (GnRH34) on time of ovulation. Suckled cows (n = 34) were treated with 2 mg estradiol benzoate (EB) and an intravaginal insert containing 1.9 g of P4. Eight days later, P4 inserts were removed, and all cows received 150 μg of d-cloprostenol (prostaglandin F2 alpha analogue), 300 IU of eCG, and 1 mg of estradiol cypionate (ECP). On Day 9 (05:00 p.m.), cows were randomly distributed, according to the diameter of the pre-ovulatory follicle, in two treatments: 1) GnRH (n = 17) cows that received 10.5 μg of buserelin acetate, or 2) no further treatment (control, n = 17). Cows treated with GnRH 34 h after P4 insert removal ovulated earlier (P = 0.02) than control cows (66 ± 0.0 and 77.2 ± 4.3 h). Experiment 2 was designed to determine the effect of GnRH34 on the fertility of suckled beef cows. Nelore cows (n = 506) were treated as Experiment 1. On Day 8, cows were painted in the sacrocaudal region to identify cows that displayed estrus. On Day 9 (05:00 p.m.), cows were randomized to receive same treatment as Experiment 1, control (n = 252), or GnRH (n = 254). All cows were TAI 48 h after P4 insert removal. At TAI, estrus was evaluated, and deemed to have occurred in cows without a tail-head chalk mark (75% paint loss). Cows treated with GnRH 34 h after P4 insert removal had greater (P = 0.01) pregnancy per AI (P/AI) than cows that only received ECP (63.0% and 50.4%). No difference (P = 0.5) was observed in the proportion of cows that displayed estrus between treatments. Furthermore, cows that displayed estrus had greater (P 0.01) P/AI than cows that did not. Treatment with GnRH, given at 34 h after P4 insert removal, increased (P 0.05) P/AI in cows that did not show estrus at TAI. In summary, treatment with GnRH 34 h after P4 insert removal was associated with earlier ovulation and resulted in greater P/AI in suckled Nelore cows treated with an estradiol/P4-based protocol for TAI.

Several studies have shown that cows displaying estrus before timed artificial insemination (TAI) are more likely to become pregnant. However, the most frequently used ovulation-inducing agents by South American beef operations, estradiol esters, may artificially induce estrus in treated cows. The hypotheses tested in the present study were: 1) estradiol cypionate (EC) treatment will induce estrus in ovariectomized cows, and 2) cows that exhibit estrus following administration of EC and eCG will have lower P/AI compared to those that do not receive EC. In Experiment 1, 14 ovariectomized cows were used in a cross-over design with an interval of 30 d between replicates. On Day 0, all cows received 2 mg of estradiol benzoate and a CIDR device and 12.5 mg of Dinoprost (PGF2α analogue) on Day 7. On Day 9, the CIDR devices were removed and cows were placed at random into one of two experimental groups and administered either 0.5 mL of canola oil (Control, CTL group, n = 14) or 1 mg of EC (EC group, n = 14). Estrotect estrus detection patches were used and cows were observed 4 times daily to determine the occurrence of estrus. More EC-treated cows showed estrus (12/14, 85.7%) than canola oil-treated cows (0/14; P

Our objective was to retrospectively compare pregnant versus nonpregnant cattle in terms of vascular and morphometric changes in corpora lutea between d 12 and 20 following timed artificial insemination (TAI). Crossbred (Gir × Holstein) lactating dairy cows (n = 136) and heifers (n = 111) were bred after synchronizing ovulations using an estradiol plus progesterone (P4)-based protocol. Corpus luteum (CL) characteristics (area, echotexture, blood flow) were recorded at 48-h intervals from d 12 to 20 following TAI using an ultrasound equipped with color Doppler. Blood samples were collected to determine CL function (plasma P4). Pregnancy diagnosis was performed at d 30. Quantitative assessment of colored pixels within the CL was performed using ImageJ software (National Institutes of Health, Bethesda, MD) and echotexture was quantified using custom software. Continuous variables such as luteal tissue area (LTA), CL blood flow (CLBF), adjusted CLBF (ratio LTA:CLBF), mean pixel value (MPV), pixel heterogeneity (HETER), and plasma P4 were analyzed retrospectively as repeated measures (d 12 to 20) in pregnant versus nonpregnant females using PROC MIXED (SAS Institute Inc., Cary, NC). Main effects were pregnancy status, day of cycle, and their interaction. Further analyses used only data from d 16, because this was the earliest time point of deviation between CLBF of pregnant and nonpregnant animals. We created quartiles for each variable and calculated the risk of pregnancy within quartile. Differences were determined using the chi-squared test. Plasma P4 was significantly higher in prospective pregnant versus nonpregnant cattle on d 18 and 20, whereas LTA differed only on d 20. On d 16, CLBF and adjusted CLBF diverged between pregnant and nonpregnant, followed by a progressive reduction in the latter until d 20. Mean pixel value was not affected by pregnancy status, but HETER was lower on d 20 in pregnant than in nonpregnant cattle. Likelihood of pregnancy increased from quartile (Q)1 (lowest values) to Q4 (highest) of CLBF (Q4 vs. Q1, odds ratio = 32.8, 95% confidence interval: 9.6 to 112.1) and adjusted CLBF [Q4 vs. Q1, odds ratio = 25.4, 95% confidence interval: 8.1 to 80.4), whereas a lower risk of pregnancy was observed only for animals within Q1 of plasma P4 [Q4 vs. Q1, odds ratio = 3.1, 95% confidence interval: 1.3 to 7.2). Day 16 quartiles of LTA, MPV, and HETER did not affect odds of pregnancy. In conclusion, we identified distinct CLBF patterns as early as 16 d after TAI and confirmed that CL function is lost by a reduction in blood flow, which precedes physical regression.

The objectives of this study were to evaluate whether the diameter of the preovulatory follicle and the post-thaw sperm kinematics are factors that affect successful establishment of a pregnancy after timed AI (TAI) of postpartum beef cows. Nelore cows (n = 346) were subjected to an estradiol-progesterone based TAI protocol. At TAI, cows were categorized according to the diameter of the preovulatory follicle (POF) in the Early Ovulation (EO group, n = 184), and Late Ovulation (LO group, n = 162) groups. Sperm were classified, according to CASA analysis, as Hyper-activated (H+), and Non-Hyper-activated (H-). The H + and H- semen was used to inseminate cows that were classified to be in the EO and LO groups. Thus, after distribution, the groups were: EOH+ (n = 89), EOH- (n = 95), LOH+ (n = 96), and LOH- (n = 66). Pregnancy per AI (P/AI) was greater (P < 0.05) for EOH+ (66.3%, 59/89), EOH- (65.3%, 62/95), and LOH- (72.7%, 48/66) groups than for LOH + group (52.1%, 50/96). The results of the study indicate that cows with a smaller POF are less likely to become pregnant when insemination is with semen considered as hyper-activated (H+). In contrast, when inseminations are performed with semen categorized to be non-hyper-activated (H-), cows of the EO and LO groups had acceptable and similar pregnancy rates as a result of timed AI.

Body condition score (BCS) is a categorical variable that is widely accepted as an important tool for subjectively quantifying energy reserves in dairy cows. The aims of this study was to compare milk production and some metabolic parameters of crossbred dairy cows with low, adequate and high BCS in the recent postpartum period (PPP). This study included lactation data from 35 crossbred Girolando (Holstein × Gir) cows from calving to 90 days in milk. Cows were evaluated every 15 days for BCS, milk production, live weight, internal angle of the rump (IAR) and serum concentration of β-hydroxybutyrate (ßHB). BCS loss and nadir of the BCS in PPP were also evaluated. Cows were divided into 3 groups, as follows: High, Adequate and Low BCS, according to the BCS recommendation for cows with less than 100 days in lactation. Cows with Adequate BCS had higher milk production than cows with High BCS (P = 0.01). Cows with High BCS had the highest (P < 0.001) live weight, BCS and IAR among the groups. In addition, these cows had a higher serum ßHB concentration than cows with Adequate BCS (P = 0.001) and had the greatest loss of BCS (P < 0.001) in the PPP. The results of this study showed that Girolando dairy cows with Adequate BCS at calving had higher milk production and better metabolic condition than cows with High BCS at calving. La condición corporal (CC) es una variable categórica ampliamente aceptada como una herramienta importante para cuantificar subjetivamente las reservas de energía en las vacas lecheras. El objetivo de este estudio fue comparar la producción de leche y algunos parámetros metabólicos de vacas lecheras mestizas con CC baja, adecuada y alta en el posparto reciente (PP). Este estudio incluyó datos de lactancia de 35 vacas Girolando (Holstein × Gir) desde el parto hasta los 90 días de lactancia. Las vacas fueron evaluadas cada 15 días para CC, producción de leche, peso vivo, ángulo interno de la grupa (AIG) y concentración sérica de β-hidroxibutirato (ßHB). También se evaluaron la pérdida de CC y el nadir de CC en PP. Las vacas se dividieron en 3 grupos, CC Alta, Adecuada y Baja, de acuerdo con la recomendación de CC para vacas con menos de 100 días de lactancia. Las vacas con CC adecuado tuvieron mayor producción de leche que las vacas con CC alto (P = 0,01). Las vacas con alto CC tuvieron el peso vivo, CC y AGA más altos (P < 0,001) entre los grupos. Además, estas vacas tenían una concentración sérica de ßHB más alta que las vacas con CC Adecuado (P = 0,001) y tenían la mayor pérdida de CC (P < 0,001). Los resultados de este estudio mostraron que las vacas Girolando con CC adecuado al parto tuvieron una mayor producción de leche y una mejor condición metabólica en comparación con las vacas con CC alto al parto. O escore de condição corporal (ECC) é uma variável categórica amplamente aceita como uma importante ferramenta para quantificar subjetivamente as reservas energéticas em vacas leiteiras. O objetivo deste estudo foi comparar a produção de leite e alguns parâmetros metabólicos de vacas leiteiras mestiças com baixo, adequado e alto ECC no período pós-parto (PPP) recente. Este estudo incluiu dados de lactação de 35 vacas mestiças Girolando (Holandês × Gir) do parto aos 90 dias de lactação. As vacas foram avaliadas a cada 15 dias quanto ao ECC, a produção de leite, o peso vivo, o ângulo interno da garupa (AIG) e a concentração sérica de β-hidroxibutirato (ßHB). Também foram avaliados a perda de ECC e o nadir do ECC no PPP. As vacas foram divididas em 3 grupos, Alto, Adequado e Baixo ECC, de acordo com a recomendação de ECC para vacas com menos de 100 dias em lactação. Vacas com ECC adequado apresentaram maior produção de leite que vacas com ECC alto (P = 0,01). Vacas com alto ECC apresentaram o maior (P < 0,001) peso vivo, ECC e o AIG entre os grupos. Além disso, essas vacas apresentaram maior concentração sérica de ßHB do que vacas com ECC Adequado (P = 0,001) e apresentaram a maior perda de ECC (P < 0,001). Os resultados deste estudo demonstraram que vacas Girolando com ECC adequado ao parto apresentaram maior produção de leite e melhor condição metabólica em relação às vacas com alto ECC ao parto.

We aimed to elucidate the effects of PGE2 and PGF2a on the in vitro maturation (IVM) of bovine oocytes. First, cumulus-oocyte complexes were matured in the media supplemented with or without PGE2, PGF2a, or PGE2 plus PGF2a for the final 24, 12, or 6 h of culture. Then, the cumulus-oocyte complexes were matured in the absence or presence of a PG endoperoxide synthase 2 (PTGS2) enzyme inhibitor (NS398) supplemented with PGE2, PGF2a, or PGE2 plus PGF2a. Finally, the expression of genes associated with PGs activity in cumulus cells (PTGS2, PG E-synthase-1 [PTGES1], and aldo-keto reductase 1 [AKR1B1]) or oocytes (receptors for PGE2 [PTGER2] and PGF2a [PTGFR]) of different competencies was quantified. Supplementation of the IVM medium with PGs did not improve in vitro embryo production or embryo quality (P > 0.05). During maturation, the relative abundance of PTGS2 transcripts increased (P < 0.05) only in the less-competent group, whereas those of PTGES1 increased in the less-competent and in the more-competent groups. Conversely, AKR1B1 expression decreased only in the less-competent group (P < 0.05). Receptors for the PGE2 and PGF2a genes were very low or undetectable in oocytes. In conclusion, PGE2 and PGF2a are not recommended for media supplementation during maturation because they have no effect on embryo development. Although genes related to PGs activity are differentially expressed in cumulus cells of cumulus-oocyte complexes of different competence during maturation, the expression of PGE2 and PGF2a receptor genes was either not detectable or was detected at low levels in oocytes. Made available in DSpace on 2020-12-10T09:06:38Z (GMT). No. of bitstreams: 1 cpafro-18481.pdf: 594117 bytes, checksum: 2a43765a8d98e902ce4f1c4059ca2485 (MD5) Previous issue date: 2020

O objetivo deste estudo foi avaliar o potencial ovulatório de diferentes doses de prostaglandina E2 em camundongos fêmeas pré-púberes. Foram utilizadas 18 fêmeas BALB/c pré-púberes, tratadas com 5 UI de eCG via intraperitoneal (i.p.), no Dia 0. No Dia 2, os animais foram divididos aleatoriamente em 6 grupos, para receberem via i.p.; 1) 0.5 mL de PBS (n=3), 2) 5 µg de GnRH (n=3), 3) 25 µg de PGE2 (n=3), 4) 50 µg de PGE2 (n=3), 5) 150 µg de PGE2 (n=3) e 6) 250 µg de PGE2 (n=3). No Dia 3, as fêmeas foram mortas por deslocamento da coluna cervical e os ovidutos foram coletados para contagem de oócitos através da técnica de transiluminação sob estereomicroscópio. Não houve diferença no número de camundongos fêmeas que ovularam e o número de oócitos ovulados nas fêmeas tratadas com GnRH e 250 µg de PGE2, e ambos os grupos apresentaram diferenças em relação ao grupo PBS. Os resultados deste estudo demonstram que a PGE2 na dose de 250 µg é capaz de induzir a ovulação em camundongos fêmeas pré-púberes.

This study evaluated the effect of uterine health on the fertility of postpartum beef cows. Multiparous lactating Nelore cows (Bos indicus; n = 155) were subjected to a timed artificial insemination (TAI) protocol. Cows were included in a progesterone-estradiol based TAI protocol. On Day 0, before the beginning of the protocol, cows were subjected to evaluation of purulent vaginal discharge (PVD) and collection of uterine tissue using the cytobrush technique. Slides for polymorphonuclear (PMN) cells counting were prepared before the same cytobrush was used for RNA extraction and analysis of IL-1β, IL-6, IL-8, TNFα, GAPDH, and βactin gene transcription. Cows were separated into 4 categories according to the proportion of PMN and PVD: 1) Healthy (HE; n = 87), cows with ≤ 4.75% PMN and PVD of 0; 2) Positive Purulent Vaginal Discharge (PVD+; n = 24), cows with ≤ 4.75% PMN and PVD ≥ 1; 3) Subclinical Endometritis (SCE; n = 29), cows with > 4.75% PMN and PVD of 0, and; 4) Subclinical Endometritis + PVD+ (SCEP; n = 15), cows with > 4.75% PMN and PVD ≥ 1. Cows in the HE group had a greater (P 0.05). Cows from the SCE and SCEP groups had a higher (P 0.05). In contrast, transcription of IL-8 was greater (P = 0.02) in SCEP than HE and SCE groups. The relative transcription IL-1β was greater (P

The aim of this study was to evaluate effects of intra-follicular (i.f.) treatment with lipopolysaccharide (LPS) on follicular and luteal development in cows. There were 18 non-lactating cows assigned to two groups to address this aim: control group (n = 9), which received an i.f. injection of saline; and LPS group (n = 9), which received an i.f. injection of 1 μg of LPS per mL of follicular fluid. Cows were treated with an intravaginal P4 releasing device (IVD) and estradiol benzoate on D0. On D4 and D5 cows were treated with cloprostenol sodium and on D7 the IVD was removed. At 12 h after IVD removal, cows were administered the i.f. injection of LPS or saline. After administration of these treatments, follicular development was evaluated every 12 h until ovulation. The LPS treatment increased blood flow in pre-ovulatory follicles (P = 0.05). Follicle growth was reduced by LPS injection (P0.02) resulting a longer period to the time of ovulation for cows in the LPS than control group (P = 0.03). The percentage of cows having ovulations was less for the LPS than control group (P = 0.03). The diameter of the CL, CL blood flow and P4 concentrations 5 and 12 days after ovulation did not differ between groups (P0.05). In conclusion, intra-follicular treatment with LPS resulted in a decreased rate of follicle growth, delayed timing of ovulations and a lesser number of cows having ovulations.

The effect of injectable progesterone was evaluated along with estradiol benzoate (EB) on the fate of the dominant follicle (DF) present in the ovary at the beginning of low progesterone-based TAI protocol. All cattle were given 500 µg cloprostenol im (PGF; Schering-Plough Animal Health for Estrumate, Pointe-Claire, QC, Canada) twice, 11 d apart, and allocated into two groups: Estradiol group (E group, n = 11) and Estradiol-Progesterone group (EP group, n = 11). Ten days after the second PGF (Day 0), all cattle were given an intravaginal progesterone device with half progesterone concentration (Cue-Mate with a single pod containing 0.78 g progesterone). Concurrently, all cattle were given 1.5 mg im of estradiol benzoate in 3 mL of canola oil and PGF im on Day 0 of the protocol in a crossover design, in which each cow received both treatments. Cows in the EP group also received 100 mg im progesterone (Sigma) in 2 mL of canola oil. On Day 8, progesterone devices were removed and all cattle were given PGF im. All statistical analyses were performed with SAS 9.0. The DF present on Day 0 ovulated in 76% (16/21) of cows from E group and 28.6% (6/21) of cows from EP group (P = 0.002). After progesterone device removal, the size of ovulatory follicle did not differ between groups (E group, 15.5 ± 0.43 mm vs EP group, 15.8 ± 0.98 mm; P = 0.82). These follicles ovulated in 81.3 ± 3.1 h in E group and 71.0 ± 6.1 h in EP group (P = 0.13). In conclusion, injectable progesterone reduced the proportion of cows that ovulate the dominant follicle present in the ovary at the beginning of estradiol-progesterone-based protocols. However, no difference was detected on time of ovulation after progesterone device removal between groups. Made available in DSpace on 2018-09-19T00:38:09Z (GMT). No. of bitstreams: 1 BJVRASinjectableP4.pdf: 158379 bytes, checksum: 7dbce189d570bb84f8a1d3bdc5a04589 (MD5) Previous issue date: 2018-09-18

The aim of this study was to evaluate the uterine health and fertility of postpartum beef cows subjected to timed AI (TAI) protocols at different days from calving. Lactating Nelore cows (Bos indicus; n = 244) were used in this study. The TAI protocols were initiated between 20 and 60 days postpartum (DPP). Cows were subjected to an estradiol-progesterone based TAI protocol. The cows were divided into three groups according to the days postpartum at the time the hormonal treatment was initiated: 1) Early (n = 64), cows between 20 and 30 DPP; 2) Middle (n = 115), cows between 31 and 45 DPP; and 3) Late (n = 65), cows between 46 and 60 DPP. At Day 0 of the protocol, endometrial cytobrush samples were collected. Slides for polymorphonuclear (PMN) cell counting were prepared and cytobrush was used for RNA extraction and analysis of relative abundance of il1, il6, il8, and tnf mRNA. Cows from the Early group had less (P < 0.05) pregnancies per AI (P/AI) than cows from Middle and Late groups; 29.7% (19/64), 45.2% (52/115), and 52.31% (34/65), respectively. Accordingly, the Early group had a greater (P < 0.05) proportion of PMN cells in the uterus than Middle and Late groups; 9.0%, 3.8%, and 2.2%, respectively. Relative abundances of il1 and il8 mRNA were greater (P < 0.05) in the Early group than Middle and Late groups. These results indicate that beef cows subjected to TAI protocols early postpartum (< 30 DPP) are less likely to become pregnant, which is associated with increased inflammation and relative abundance of mRNA for the proinflammatory cytokines il1 and il8. Made available in DSpace on 2018-09-19T00:37:45Z (GMT). No. of bitstreams: 1 ARSsaudeuterina2018.pdf: 594443 bytes, checksum: 9d8ba15673f05ae291d440664e2fb4f4 (MD5) Previous issue date: 2018-09-18

The aim of this study was to evaluate if prostaglandin F2α (PGF) can be used to induce ovulation in a GnRHprogesterone based protocol. In Experiment 1 crossbred dairy cows (n = 32) were synchronized with a progesterone-GnRH based protocol for seven days, where the luteolytic dose of 150 μg PGF was given 24 h prior progesterone device removal (CIDR). On Day 8 cows were separated into two groups to receive: 1) 2 mL of Saline (Control Group, n = 15) or 2) 150 μg of PGF (PGF Group, n = 17). Ovulation rate was higher in the PGF than Control group (100% vs 53.3%, P = 0.001, Odds ratio = 30.88). The percentage of cows that ovulated synchronously tended to be higher in the PGF than Control group (P = 0.1, Odds ratio = 9.6). Experiment 2 was performed in a cross-over (3 × 3) design. Crossbred dairy cows (n = 25) received a CIDR for seven days and GnRH on Day 0. Seven days later 150 μg of PGF was given and the progesterone device was removed, and 24 h later cows were distributed into three groups to receive: 1) 2 mL of Saline (Control Group, n = 25), 2) 150 μg of PGF (PGF Group, n = 25) or 3) 1 mg of ECP (ECP Group, n = 23). Diameter of ovulatory follicle was larger in the PGF and Control than ECP Group (P = 0.002, Effect size > 4.0). Synchronized ovulation rate (between 72 and 96 h after CIDR removal) tended to be higher in PGF group in Control group (P = 0.1, Odds ratio = 0.35). Results suggest that PGF is equally efficient to ECP to induce synchronized ovulation in dairy cows subjected to progesterone-GnRH based protocols. Made available in DSpace on 2018-02-20T00:32:35Z (GMT). No. of bitstreams: 1 UseofCastro.pdf: 279259 bytes, checksum: 5f7ebd354e5a9e4a97a2ea76a2d5e47d (MD5) Previous issue date: 2018-02-19

Visual evaluation of body condition score (BCS) is an important method for the subjective quantification of body energy reserves in cattle. The objective of this study was to develop an index to estimate the relationship between BCS and fertility, using 2321 lactating Nelore cows from 29 cohorts in Mato Grosso do Sul and Rondonia states, Brazil enrolled in timed artificial insemination (TAI) programs. All females were evaluated according to BCS (scale 1 to 5) and were included in an estradiol-progesterone-based TAI protocol. Estrus scores were evaluated (scale 1–3) for all cows at TAI. The cows in each TAI protocol were categorized according to pregnancy per AI (P/AI) into low ( 60%, HF) fertility groups. To evaluate whether the BCS of each cow was in accordance with the target BCS (3 to 4) for beef cows to be enrolled in TAI programs, three variables were calculated: (1) adequate BCS rate (ABR), in which cows with BCS on target received 100% and cows with BCS values outside the target range received 0%; (2) the difference between the real BCS and the target BCS (DBCS) ; and (3) the adjusted DBCS (ADBCS), in which DBCS was transformed into an inverse value. Finally, the average between ABR and ADBCS resulted in a BCS index (BCSi). Analysis of variance was used to compare BCSi, BCS, and estrus scores among fertility groups, and Tukey's test was used to compare means among groups. There were differences in BCSi between fertility groups (P