Luteal tissue characteristics of Morada Nova ewes with hCG application 7.5 days after the end of estrus synchronization protocol in the breeding season.

Results with the use of hCG after synchronization protocol are still inconsistent, which may vary according to breed, season, day of application and dose of the drug used. The aim of the present study was to evaluate the functionality of luteal tissue and ovarian perfusion after hCG treatment during early luteal phase. Estrus-synchronized ewes were randomly assigned to receive i.m. injection of 300 IU of hCG (G-hCG; n = 40) or 1 mL of saline (G-Control; n = 32) on Day 7.5 after progesterone withdrawal. Ultrasonographic evaluations of the ovaries and ovarian and iliac arteries were performed on Days 7.5, 10.5, 13.5, and 21.5. The accessory corpus luteum (aCL) formation rate was 52.5% for G-hCG. There was interaction (p > 0.05) for treatment (G-hCG and G-Control), days (7.5, 10.5, 13.5 and 21.5) and PD (Pregnant and Non-pregnant) for the variables of biometric characteristics of the corpus luteum B-Mode and Color Doppler on days 7.5, 10.5, 13.5 and 21.5. There was no difference (p > 0.05) for pregnancy rates and mean fetuses per ewe between the treatment groups. It is concluded that the application of hCG 7.5 days after the hormonal protocol in Morada Nova ewes in a breeding season is efficient in inducing aCL formation and increasing luteal tissue biometry. However, there was no effect on pregnancy rate.

Luteal Function, Biometrics, and Echotextural Attributes in Santa Inês Ewes Superovulated with Different Total Doses of Porcine Follicle-Stimulating Hormone.

Premature regression of corpora lutea (PRCL) may adversely affect the outcome of hormonal ovarian superstimulation in small ruminants, and the total dose of exogenous gonadotropins used may be one of the causes of this condition. There were two major objectives of the present study: (1) to evaluate the effects of different superovulatory doses of porcine follicle-stimulating hormone (pFSH) on the biometry, blood perfusion (Doppler), and echotextural characteristics of luteal structures; and, (2) to determine the usefulness of biometric, vascular, and echotextural luteal variables, as well as measurements of circulating progesterone (P4) concentrations for early detection of PRCL in superovulated Santa Inês ewes. Twenty-seven Santa Inês ewes received an intravaginal P4-releasing device (CIDR) from Days 0 to 8 (Day 0 = random day of the anovulatory period). An IM injection of d-cloprostenol (37.5 µg) was given at the time of the CIDR insertion and withdrawal. On Day 6, all the ewes received 300 IU of eCG IM and were divided into three treatment groups (each n = 9): G100 (100 mg); G133 (133 mg); and G200 (200 mg of pFSH) administered IM every 12 h in eight injections. Transrectal ovarian ultrasonography and jugular blood sampling for serum P4 measurements were performed on Days 11 to 15. On the day of embryo recovery (Day 15), all the ewes underwent diagnostic videolaparoscopy and were classified, based on their luteal characteristics, into three response groups: nCL (ewes with normal CL only); rCL (ewes with regressing CL only); and ewes with both nCL and rCL following the superovulatory regimen. Our present results indicate that the total pFSH doses of 100 mg and 200 mg result in similar ovulatory responses and luteal function/biometrics, although the percentage of donor ewes with nCL was greater (p < 0.05) for G100 compared with the G200 animals. An application of 133 mg of pFSH was associated with diminished luteogenesis. Lastly, circulating P4 concentrations, ultrasonographic estimates of total luteal area, and CL pixel heterogeneity (standard deviation of numerical pixel values) are promising markers of luteal inadequacy in superovulated ewes.

Hormonal protocol used for cervical dilation in ewes does not affect morphological embryo quality but reduces recovery rate and temporarily alters gene expression.

BACKGROUND: Information on the impact of hormonal protocols for cervical dilation on the quality of ovine embryos is scarce. METHODS: To compare the quality of embryos after cervical dilation protocol, ewes (n = 64) were allocated into either a treated group (100 µg estradiol benzoate intravenous and 0.12 mg cloprostenol intramuscularly, 12 hours before embryo collection plus 100 iu oxytocin intravenous 15 minutes before the collection procedure) or a control group (saline). Luteal function was analysed using ultrasonography and P4 measurement. Some collected embryos were frozen/thawed for gene expression, others were cultured in vitro, frozen/thawed for gene expression, and the remaining embryos were fixed for the apoptosis test (TUNEL test). RESULTS: The treatment reduced fluid (p=0.04) and structure (p=0.03) recovery rates, but the morphological quality, development stage, and apoptosis incidence of the embryos were not affected by treatment. The corpora lutea of the control group had greater blood perfusion (p = 0.002) and greater P4 concentrations at 6, 9, and 12 h after the treatment (p < 0.0001). The expression of BAX, BCL2, PRDX1, and HSP90 genes were not affected by the treatment. However, the embryos in the treated group had fewer NANOG and OCT4 transcripts than control embryos (p = 0.008; p = 0.006, respectively). After culture, there was no difference between the groups in any gene. CONCLUSION: The hormonal protocol for cervical dilation reduced the efficiency of embryo collection. In addition, the treatment induced luteolysis and a transient alteration of embryo gene expression, however there were no detectable changes in embryo morphological quality, development stage, or incidence of apoptosis.

Overnutrition of Ewe in Late Gestation and the Impact on Placental Efficiency and Lamb's Performance.

The objective of the study was to evaluate energy or energy/protein supplementation in the ewe diet, in the last third of gestation, on maternal placental and endocrine characteristics, as well as its effects on the behavior of neonatal lambs and productive performance until weaning. A total of 128 ewes were used, and the experimental diet was fed from 100 days gestation until lambing, with the birth of 172 lambs. The ewes were distributed into three treatments: CTL (control, n = 43) with metabolizable energy (ME) and crude protein (CP) intake according to NRC (1985); ME (energy supplementation, n = 44) plus 21% ME; and MECP (energy/protein supplementation, n = 41) plus 26% ME and CP. Body weight, body condition score, serum hormone concentrations, placental characteristics, lamb performance and behavior, and production efficiency of the ewe from lambing to weaning were measured. ME and MECP ewes were heavier before (p = 0.006) and just after lambing (p = 0.002) and had higher serum triiodothyronine (p = 0.001) and cortisol (p = 0.004) concentrations on the day of lambing. ME ewes had higher placental efficiency (p = 0.036) and lower total cotyledon weight (p = 0.011). ME and MECP diets increased both lamb birth weight (p = 0.015) and weaning weight (p = 0.009). Production efficiency at birth and at weaning was not influenced (p > 0.05) by treatments. Lamb behavior was influenced by the ME and MECP diets, reducing the time to kneel (p ≤ 0.05), to try to stand (p ≤ 0.05), and the latency to stand (p ≤ 0.005). It is concluded that overnutrition in the last third of gestation was positive for the ovine production system, with improved production rates, hormonal profile, placental characteristics, and neonatal behavior.

NonSurgical Embryo Recovery from Estrus-Synchronized or Superovulated Morada Nova Ewes: A Feasible Strategy for Sheep Embryo Banking.

This study assessed the feasibility of in vivo embryo production and nonsurgical embryo recovery (NSER) in Morada Nova ewes (an endangered native Brazilian breed of sheep) subjected to different estrus synchronization and/or superovulation protocols. Ewes received intravaginal sponges soaked with 60 mg medroxyprogesterone acetate (MAP), which were kept in place for six (G6; n = 12), nine (G9; n = 12), or 12 (G12; n = 12) days. Half of the ewes in each group remained estrus synchronized only (SYNCH) and the other half was superovulated (SOV) with 133 mg porcine follicle-stimulating hormone (pFSH). There were no differences (p > 0.05) in antral follicle counts determined with ultrasonography 60 hours before MAP sponge removal (or at the time of the first pFSH dose) among G6 (6.4 ± 0.9), G9 (6.2 ± 0.7), and G12 (5.5 ± 0.6). Estrus responses and NSER success rates did not vary (p > 0.05) among the three progestin-treatment groups of ewes for either estrus-induced or superovulated animals. The onset of estrus occurred 10-12 hours later (p < 0.01) in G9SYNCH ewes compared with G6SYNCH and G12SYNCH, and the duration of estrus was ∼19 hours greater (p < 0.01) in G9SOV than in G6SOV. The average duration of the NSER procedure was 32.6 ± 1.3 minutes. At least one structure was recovered in 85.7% of synchronized and in 87.5% of superovulated ewes. Viable embryo recovery rates were also similar (p > 0.05) for G6 (1.0 ± 0.3 and 2.5 ± 1.5), G9 (1.3 ± 0.5 and 4.8 ± 2.0), and G12 groups (1.0 ± 0.3 and 4.8 ± 2.3; estrus-synchronized and superovulated ewes, respectively). In conclusion, progestogen pretreatment of different durations and NSER can be employed in Morada Nova ewes, resulting in reasonable viable embryo recovery rates in both estrus-synchronized and superovulated animals. Therefore, both techniques are suitable for use in commercial settings as well as small ruminant conservation programs.

Luteotropic effects of human chorionic gonadotropin administered 7.5 days after synchronous estrous induction in Morada Nova ewes.

This study was conducted in ewes to assess effects of human chorionic gonadotropin (hCG) administration after imposing an estrous induction treatment regimen. Ewes (n = 115) were treated with a 60 mg medroxyprogesterone-intravaginal-sponge for 6 d plus 200 IU of equine chorionic gonadotropin (eCG) im and 37.5 µg d-cloprostenol im 36 h before sponge removal (Day 0). After natural mating, ewes having at least one corpus luteum (CL; n = 108) were administered either 1 mL of saline (G-Control; n = 53) or 300 IU of hCG (G-hCG; n = 55) on Day 7.5 after sponge removal (Day 0). Ovarian ultrasonography and blood collection were performed on Days 7.5, 13.5, 17.5, 21.5, and 30.5. Accessory CL (aCL) were observed in 81.5 % (G-hCG) and 0.0 % (G-Control) of ewes (P = 0.0001). Diameter, area, and volume of luteal tissue were greater (P < 0.05) in G-hCG from Day 13.5 to 30.5. Progesterone (P4) concentrations were greater (P < 0.05) on Days 13.5, 17.5, 21.5 and 30.5 for ewes of the G-hCG group. Pregnancy percentage was similar (P = 0.25) between groups [47.1 % (G-control) compared with 60.0 % (G-hCG)], although total number of lambs produced by estrous synchronized ewes was greater (P = 0.005) in ewes of the G-hCG group (90.9 % compared with 66.0 %). In conclusion, hCG administration 7.5 days after sponge removal from Morada Nova ewes during the non-breeding season is an effective treatment to induce aCL formation, improve luteal tissue biometry and P4 concentrations, and to enhance the total number of lambs born.

Embryo yield and quality are associated with progestogen treatment during superovulation protocol in lactating Lacaune ewes.

This study assessed the effect of progestogen treatment length on ovarian parameters and embryo yield in superovulated Lacaune ewes collected by nonsurgical embryo recovery. Twenty-three lactating ewes were superovulated 30 d apart using a cross-over design. All ewes received 60 mg of MAP intravaginal sponges for 6 (G-6 group) or 9 (G-9 group) d. A total dose of 133 mg pFSH was given in six decreasing doses (twice a day) starting at 60 h before device removal. Ultrasound examination of the ovaries was performed at the first pFSH injection and one day before embryo recovery, which was performed 6-7 d after the onset of estrus. Embryo recovery was conducted only in ewes that expressed estrus and were mated. There was no difference (P > 0.05) in the total number of follicles between G-6 (15.7 ± 1.0) and G-9 (15.6 ± 0.8) at the time of the first pFSH treatment. The percentage of responding donors with ≥3 corpora lutea (CL; 78.2% [18/23] vs 69.5% [16/23]), mean (±SEM) CL number (7.0 ± 1.2 vs 8.1 ± 1.6), transcervical passage rate (94.4% [17/18] vs 83.3% [15/18], and ova/embryo recovery rate (54.5% [60/110] vs 68.0% [83/122]) were not different (P > 0.05) between the G-6 and G-9 groups. However, the mean number of viable embryos was lower (P < 0.05) in the G-6 group (1.8 ± 0.7) than in the G-9 group. (3.5 ± 1.1). In conclusion, treatment with an intravaginal MAP sponge for 9 d during a superovulation protocol is beneficial for viable embryo yield in Lacaune ewes out of the breeding season.

Transcervical vs. laparotomy embryo collection in ewes: The effectiveness and welfare implications of each technique.

This study assessed animal welfare in ewes subjected to transcervical (TC) or laparotomy (LP) embryo collection, and the efficiency of these two techniques. Santa Inês ewes (n = 57) received a protocol for estrus synchronization and superovulation. Cervical dilation protocol was initiated 12 h before embryo collection in all ewes. Depending on the success of cervical passage, the embryos were collected from ewes by either TC or LP. Records were made of physiological (rectal temperature (RT) and heart rate (HR)), endocrine (cortisol concentration), biochemical (glycaemia, total proteins, globulin and albumin concentrations), and behavioral variables. Data were recorded before fasting (BF) and sedation (BS), during (DC) and immediately after embryo collection (IAC), and 1 h (1hAC), 3 h (3hAC), 6 h (6hAC), 12 h (12hAC), 24 h (24hAC), and 48 h (48hAC) after embryo collection. The LP and TC procedures were applied to 22 and 35 ewes (with 100.0% and 94.3% of procedures being successful, respectively). The use of LP took longer than TC (P = 0.007) but was less effective in the recovery of uterine fluid and structures (P = 0.0002 and P = 0.0180, respectively), with no difference in the number of viable embryos recovered per animal. The TC procedure induced a greater RT at DC (P = 0.002) and IAC moments (P < 0.0001). The heart rate was greater in TC than LP in IAC (P = 0.036). On the other hand, HR was greater with LP at 12hAC (P = 0.033) and 24hAC (P = 0.002). There was no interaction between the procedures and time on total proteins, albumin, or globulin concentrations. The TC procedure induced greater glycaemia than LP in IAC (P < 0.0001). LP induced greater serum cortisol concentration than TC at DC, IAC, 1hAC (P = 0.0004; P = 0.0006; P = 0.036, respectively), even though it was greater in the TC than the LP procedure at 3hAC (P = 0.008). In conclusion, the TC embryo collection was more effective than the traditional LP procedure. Although both embryo collection procedures affected ewes' welfare, the TC procedure is probably less stressor than the LP.

Differences in the thermal sensitivity and seminal quality of distinct ovine genotypes raised in tropical conditions.

For different ovine breeds to maximize their reproductive capacity in countries with tropical climate, it is important to evaluate their potential for thermal resilience and consequences on their reproductive traits. Therefore, the objective of this study was to evaluate the effect of thermal environment temperatures of climate seasons in a tropical climate region on the surface temperatures of the scrotum, testicular biometric characteristics, seminal quality and serum testosterone concentration of rams of different genotypes. Breeders of four different genotypes (Dorper, n = 8, Texel, n = 8, Santa Inês, n = 9 and Morada Nova, n = 8) were used throughout the four climate seasons. Higher thermal challenge was recorded in the spring and summer. In the summer increase in scrotal surface temperature was detected by infrared thermography (P < 0.05), mainly in the regions of the distal testicular pole and tail of the epididymis. The animals of the Texel genotype had higher rectal temperature in the summer. In spring, this genotype also had the highest testicular pole (32.2 ±â€¯0.5 °C; P < 0.05) and distal (29.9 ±â€¯0.4 °C; P < 0.05) temperatures and a higher mean testicular temperature (31.7 ±â€¯0.4 °C; P < 0.05). The Morada Nova genotype showed a higher surface temperature gradient between testicular poles (2.96 ±â€¯0.1 °C; P < 0.05), especially in spring. Genotype-dependent thermal sensitivity was detected for the thermal gradient between the testicular poles, reflecting the seminal quality. There was a positive correlation of the thermal gradient between testicular poles with sperm membrane integrity and negative correlation with total sperm defects. The Texel genotype showed less progressive motility and higher percentage of sperm defects. There was no difference in testosterone concentration between genotypes and in the different seasons (P > 0.05). Thus, the indigenous genotypes showed a greater capability to maintain the scrotum-testicular thermoregulation. Dorper animals resembled the indigenous sheep genotypes, in terms of seminal characteristics, unlike Texel animals, which showed lower adaptability and lower seminal quality.

Cervical transposition test using Hegar dilator at oestrus as a tool to select ewes for transcervical embryo collection.

This study evaluated the cervical transposition method as a tool to select ewes for embryo collection by transcervical route. Adult Santa Inês ewes (n = 50) received Day 0 protocol for superovulation treatments. The cervix transposition test was performed both at oestrus and at the embryo collection time. The latter was preceded by hormonal cervical dilation. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 85.7%, 66.6%, 85.7%, 66.6% and 80.0%, respectively. The kappa index yielded a moderate score (κ = 0.52). In conclusion, the high sensitivity and accuracy indicate that the cervical transposition test is a screening option to select ewes for embryo collection by transcervical route.

Early pregnancy diagnosis in ewes by subjective assessment of luteal vascularisation using colour Doppler ultrasonography.

This study was designed to evaluate early pregnancy diagnosis using colour Doppler ultrasonography (US) for luteal vascularisation assessment. In Study 1, 28 ewes were artificially inseminated (Day 0), and luteal vascularisation was assessed from Day 12 to Day 19 by two evaluators using colour Doppler US, categorising the corpus luteum (CL) on a subjective scale ranging from 1 to 4. Females bearing a CL with score 2 or greater were presumably considered pregnant. Pregnancy was confirmed on Day 30 by B-Mode US. In Study 2, a predictive pregnancy diagnosis was performed on Day 17 in 197 ewes based on the criteria described in Study 1. Pregnancy was confirmed by B-mode US on Day 45. Agreement between evaluators was verified by an intraclass correlation coefficient (ICC) and Kappa index (κ). Performance of colour Doppler US for early pregnancy diagnosis was evaluated calculating sensitivity (Sens), specificity (Spec), negative predictive values (NPV), positive predictive values (PPV) and accuracy (Ac). In Study 1, luteal vascularisation assessment was unable to predict non-pregnant animals between 12 and 14 days after insemination, as all animals still had vascularised CL, and thus were considered pregnant. The colour Doppler US performance improved progressively until Day 17, when it reached maximum values (Sens = 100%, Spec = 76%, PPV = 73%, NPV = 100% and Ac = 86%). The subjective scale for luteal irrigation assessment showed medium to good agreement among evaluators on Day 12 and Day 13 (ICC = 0.66 and 0.68, respectively), and excellent agreement from Day 14 to Day 19 (ICC = 0.90, 0.80, 0.80, 0.84, 0.95 and 0.93, respectively). Agreement was almost perfect for score 1 CLs (κ = 0.87), and moderate for scores 2, 3 and 4 CLs (κ = 0.54, 0.48 and 0.41, respectively). In Study 2, performance of colour Doppler US as a tool to predict pregnancy status in ewes on Day 17 post-insemination was as follows: Sens = 93.5%, Spec = 80.8%, PPV = 85.6%, NPV = 91.1% and Ac = 87.8%. Subjective luteal vascularisation assessment using colour Doppler US to distinguish between pregnant and non-pregnant animals was considered a reliable tool which was highly efficient beginning 17 days after breeding.

Protected fatty acid supplementation during estrus synchronization treatment on reproductive parameters of dairy goats.

This study evaluated the effect of the protected fatty acid inclusion during estrus synchronization on reproductive parameters. Goats (n = 32) received progestagen sponges for 6 days and 200 IU equine chorionic gonadotropin and 30 µg d-cloprostenol were given on Day 5. No difference was found among control (C), 1% protected fatty acid inclusion (C + 1%) or 4% protected fatty acid inclusion (C + 4%) groups, respectively, in estrus (100.0, 100.0 or 90.9%), estrus duration (31.6 ± 12.3; 43.2 ± 12.9 or 40.8 ± 14.1 h), animals ovulating (100.0, 90.0 or 100.0%) or ovulation rate (1.3 ± 0.5; 1.1 ± 0.3 or 1.2 ± 0.4). The interval from sponge removal to ovulation and from estrus to ovulation, respectively, were shorter for C + 4% (45.2 ± 8.0 h; 18.3 ± 11.0 h) compared with C (56.3 ± 12.6 h; 30.6 ± 10.5 h) or C + 1% (57.7 ± 8.7 h; 30.3 ± 11.1 h). The average ovulatory follicle diameter was smaller for C + 4% (6.2 ± 0.7 mm) than C (7.5 ± 0.8 mm), but similar to C + 1% (7.0 ± 1.5 mm). Insulin, insulin-like growth factor 1, glucose and progesterone concentrations were similar among groups. The inclusion of protected fatty acid during synchronization treatment promoted no benefits on ovulation rate, but 4% anticipated the ovulation time.

Does supplemental LH changes rate and time to ovulation and embryo yield in Santa Ines ewes treated for superovulation with FSH plus eCG? / Suplementação com LH modifica a taxa e momento da ovulação e a produção de embriões em ovelhas Santa Inês superovuladas com FSH e eCG?

The objective was to evaluate if supplemental LH given at the end of FSH treatment would synchronize the time of ovulation and increase the ovulation rate and embryo yield in Santa Ines ewes. Twenty superovulatory (SOV) programs were accomplished in cross-over design (60d interval). On D0, a CIDR device was inserted, and the device was replaced with a new one 7 days later, when 37.5µg of d-cloprostenol was administered. On D12, we started the SOV treatment, administering 256mg of pFSH 8 times, 12h apart. On D14, the CIDR was removed, and 200IU of eCG and 37.5µg of d-cloprostenol were administered. On D15, the ewes were allocated into one of two groups, a Control group (n=10) that received no supplemental LH and a LH group (n=10) treated with 7.5mg of LH 24h after CIDR removal. Artificial inseminations (AI) were performed 42 and 48h after CIDR removal. The ovarian structures were evaluated by laparoscopy immediately before each AI and 5 days later (D21) when the embryos were collected. The LH ewes ovulated more frequently (P=0.05) before 42h than between 42 and 48h. Treatment with LH tended to increase the frequency of CL and to decrease the anovulatory follicles (P=0.08). The supplemental LH increased the frequency of ewes with a high SOV response (≥11 CL; P=0.05). In conclusion, supplemental LH increased the frequency of ewes with high SOV response and ovulating prior to 42h, however, there was no synchrony between ovulations. The supplemental LH also decreased the frequency of anovulatory follicles, although the ovulation rate and embryo yield were unaffected.

O objetivo deste trabalho foi avaliar se a suplementação com LH ao final do tratamento gonadotrófico sincroniza o tempo das ovulações e incrementa a taxa de ovulação e produção de embriões em ovelhas Santa Inês. Vinte programas de superovulação (SOV) foram realizados em delineamento cross-over (intervalo de 60 dias). No D0, um CIDR foi inserido, sendo trocado por um novo sete dias após, quando 37,5µg de d-cloprostenol foram administradas. No D12, iniciou-se o tratamento com 256mg de pFSH em 8 administrações (12/12h). No D14, o CIDR foi retirado, 200UI de eCG e 37,5µg de d-cloprostenol foram administradas. No D15, as ovelhas foram alocadas em um dos dois grupos: Controle (n=10), sem suplementação com LH, e LH (n=10), tratado com 7,5mg de LH, 24h após a remoção do CIDR. Inseminações artificiais (IA) foram realizadas 42 e 48h após a remoção do CIDR. As estruturas ovarianas foram avaliadas por laparoscopia imediatamente antes de cada IA e 5 dias após, quando os embriões foram colhidos. As ovelhas que receberam o LH tiveram maior frequência de ovulações antes de 42h (P=0,05). O tratamento com LH tendeu em incrementar a frequência de CL e diminuir a de folículos anovulatórios (P=0,08). A suplementação com LH incrementou (P=0,05) a frequência de ovelhas com alta resposta superovulatória (≥11 CL; P=0,05). Em conclusão, a suplementação com LH incrementou a frequência de ovelhas com alta resposta e ovulações antes de 42h depois da remoção do CIDR, entretanto, não houve sincronia entre as ovulações. A suplementação diminuiu a frequência de folículos anovulatórios, embora a taxa de ovulação e a produção de embriões permaneceram inalteradas.

Dinâmica ovariana e concentração de progesterona de vacas Nelore submetidas a IATF / Ovarian dynamics and progesterone concentration in nellore cows artificially inseminated in fixed time

Objetivando-se subsidiar pesquisas envolvendo sincronização de estros e ovulação em bovinos, pretende-se com este estudo, avaliar a dinâmica folicular e a concentração de progesterona em vacas Nelore submetidas a um protocolo de sincronização e IATF. Para tanto, sete vacas adultas foram submetidas à IATF, seguindo o protocolo: implante intravaginal de progesterona no dia zero (D0) e aplicação de benzoato de estradiol; D7 retirada do implante e aplicação de PGF2alfa; D8 administração de hCG, e D9 IATF. Da retirada do implante até a IATF, as vacas foram submetidas, duas vezes ao dia (manhã e tarde) à ultrassonografia transretal, para avaliação do número e diâmetro folicular em cada ovário. O sangue foi coletado para dosagem de progesterona nos dias: implante, retirada, dois, 10, 15, 18 e 23 dias após a retirada do implante. O diagnóstico de gestação foi realizado 60 dias da IATF por palpação transretal. Após análise de variância, o número e diâmetro folicular entre os ovários direito (OD) e esquerdo (OE) foi comparado pelo Teste F, e a concentração de progesterona pelo SNK (5% de significância). A dinâmica de crescimento folicular durante o período estudado foi semelhante entre os ovários (p>0,05). Observaram-se queda no número médio de folículos na manhã do dia da retirada do implante até a tarde da IATF (5,50 + 2,99 e 4,36 + 2,00 folículos, respectivamente) (p<0,05). O diâmetro médio do maior folículo foi superior no OE que no OD (7,35 + 6,34 mm e 5,49 + 4,59, respectivamente) (p<0,05), embora o OE tenha apresentado diâmetro médio diário semelhante ao observado no OD. No entanto, no dia da IATF à tarde o diâmetro folicular médio diminuiu (3,32 + 3,39 mm) (p<0,05). Já a concentração média de progesterona foi semelhante (p>0,05). Concluí-se que vacas Nelore submetidas a sincronização de estro utilizada nesse estudo apresentaram maior folículo no OE, cujo diâmetro diminuiu no momento da IATF.

The purpose of this study is to evaluate the follicular dynamics and progesterone concentration of Nellore cows artificially inseminated in fixed time. Seven Nellore cows were submitted to FTAI on the following protocol: animals received an intravaginal progesterone device on day zero (D0) and injection of estradiol. After 7 days (D7), the device was removed and PGF2alpha administered. On the eighth day (D8) of hCG were administered, and, on the ninth Day (D9), the FTAI. The animals had their blood collected for the dosage of serum progesterone by the solid-phase radioimmunoassay technique, which was conducted on the days of the insertion, on the removal, on days 2, 10, 15, 18, and 23 after the insertion removal. The same animals were submitted, twice a day (morning and afternoon), to transrectal ultrasonography for the assessment of the moment of the removal of the device until the FTAI, the amount of follicles in each ovarium (right and left) and the diameter of the longest follicle in each of them. The diagnosis of gestation through transrectal palpation was carried out 60 days later. The progesterone concentration was submitted to analysis of variance (AV) and compared throughout the days with Student Newman Keuls test (SNK). The amount of follicles and the diameter of the longest follicle were also submitted to AV, but compared to with the F test. They all considered a 5% significance. The dynamics of follicular growth during the studied period was similar between the ovaries (p>0.05). Decrease of the average amount of follicles in the morning of the day of the device removal until the afternoon of the day of FTAI, from 5.50 + 2.99 to 4.36 + 2.00 follicles, respectively (p<0.05), were noticed. The average diameter of the longest follicle was higher for the left ovarium, 7.35 + 6.34 mm and 5.49 + 4.59, respectively (p<0.05), even though the left ovarium presented daily average diameter similar to that noticed for the right ovarium follicles.

Con el objetivo de subsidiar investigaciones involucrando sincronización de estros y ovulación en bovinos, se buscó con este estudio, evaluar la dinámica ovárica y concentración de progesterona en vacas Nelore sometidas a un protocolo de sincronización e IATF. Para esto, siete vacas adultas fueron sometidas a IATF, siguiendo el protocolo: implante intravaginal de progesterona en el día cero (D0) y aplicación de benzoato de estradiol; D7 remoción del implante y aplicación de PGF2alfa; D8 administración de hCG, y D9 IATF. De la remoción del implante hasta IATF, las vacas fueron sometidas, dos veces al día (mañana y tarde) a ecografía transrectal, para evaluación del número y diámetro folicular en cada ovario. La sangre fue recogida para dosificación de progesterona en los días: implante, remoción, 2, 10, 15, 18 y 23 días tras la remoción del implante. El diagnóstico de preñez se realizó 60 días de IATF por palpación transrectal. Tras análisis de variación, el número y diámetro folicular entre los ovarios derecho (OD) e izquierdo (OE) se comparó por Test F, y la concentración de progesterona por SNK (5% de significación). La dinámica de crecimiento folicular durante el período estudiado fue semejante entre los ovarios (p> 0.05). Se observaron caída en el número medio de folículos en la mañana de la remoción del implante, hasta la tarde de IATF (5.50 + 2.99 y 4.36 + 2.00 folículos) respectivamente (p< 0.05). El diámetro medio del mayor folículo fue superior en el OE que en el OD (7.35 + 6.34 mm y 5.49 + 4.59, respectivamente) (p< 0.05), aunque el OE haya presentado diámetro medio diario semejante al observado en el OD.

Avaliação dos efeitos do flunixim meglumine sobre a concentração sérica de progesterona e ciclo estral em novilhas e vacas mestiças / Assessment on the effects of flunixin meglumine on the serum concentration of progesterone and the estrous cycle in crossbred heifers and cows

Baseando-se nos mecanismos de interrupção da síntese de PGF2a em bovinos, objetivou-se com este estudo avaliar os efeitos do flunixin meglumine (FM) sobre o comprimento do ciclo estral e sobre os níveis de progesterona, em novilhas e vacas mestiças. Após sincronização dos estros, os animais foram divididos em grupos: controle (cinco vacas e quatro novilhas) e tratado (seis vacas e seis novilhas), sendo submetidos à colheita diária de sangue, até o estro subseqüente. Do 13o ao 18o dia, aplicou-se nos animais do grupo tratado 1,65 mg/kg intramuscular de FM, e nos do grupo controle, mesmo volume de solução fisiológica. A determinação da concentração sérica de progesterona foi realizada por RIA. Os resultados do comprimento do ciclo estral foram comparados entre os grupos e entre animais, pelo teste t de Student, enquanto a concentração de progesterona foi normalizada em relação à luteólise, e analisada entre os grupos pelo teste t de Tukey (SAS). Não se observou diferença (P>0,05) no comprimento do ciclo estral entre grupos e entre novilhas e vacas, tratadas e não tratadas. O dia do ciclo estral em relação à concentração de progesterona máxima e inferior a 1,0ng/mL, e a concentração sérica de progesterona entre os animais do grupo controle e tratado, também foram semelhantes entre os grupos (P>0,05). No entanto, observou-se diferença (P<0,05) na curva que evidencia a queda da progesterona em relação ao momento da luteólise entre os animais dos grupos experimentais. Conclui-se que, embora se tenha observado efeito do tratamento, como descrito acima, sua ação seria mais bem caracterizada se a população amostral tivesse sido maior.

This paper reports results from the assessment on the effects of flunixin meglumine (FM) on the estrous cycle and serum levels of progesterone in crossbred cows and heifers. After the estrous synchronization, the animals were separated into two groups: control (5 cows and 4 heifers), and experimental (6 cows and 6 heifers). They were submitted to daily blood sampling until the next estrus. From the 13th to the 18th day of the estrous cycle, each animal from the experimental group received 1.65 mg/kg of FM by intramuscular route, while animals from the control group received equal volumes of sterile saline. Levels of progesterone were measured by radio-immune-assay. The length of estrous cycle was compared among groups and individuals by Student’s t-test, whereas the levels of progesterone were analyzed by Tukey’s t-test. There was no significant difference in the estrous cycle length among groups and individuals. The estrous cycle day, in relation to the concentration of progesterone – highest and lower to 1.0 ng/ml, and the seric concentration of progesterone among animals from both control and experimental groups were also similar (P>0.05). However, there was no difference concerning the concentration of progesterone decrease among theexperimental groups. It was concluded that, under the conditions this study was carried out, even though the effect of the treatment was observed, its action would be better characterized if the sample population were bigger.

Efeito do número de ordenhas diárias sobre o desempenho reprodutivo de vacas mestiças Holandês-Zebu / Effect of the number of daily milking on reproductive performance of crossbred (Holtein x Zebu) cows

Avaliou-se a influência do número de ordenhas diárias sobre o desempenho reprodutivo de 63 vacas mestiças (Holandês-Zebu) com boa condição corporal ao parto, distribuídas em três grupos (G) experimentais: GI – vacas ordenhadas uma vez aodia; GII – vacas ordenhadas duas vezes ao dia; GIII – vacas ordenhadas alternadamente a cada 14 dias, uma ou duas vezesao dia. O retorno ao estro (84,3 dias; 81,7 dias e 71,2 dias); a taxa de manifestação de estro (80,9%; 80,90% e 80,90%); operíodo de serviço (99,0 dias; 114,0 dias e 93,1 dias) e a taxa de gestação até 120 dias pós-parto (66,7%; 57,1%; 66,7%) nãoforam influenciados (P>0,05) pelo aumento do número de ordenhas diárias

This study was carried out to evaluate the influence of the number of daily milking on reproductive performance of 63 crossbred(Holstein-Zebu) cows, with good body condition score at calving, allocatted into three groups (G) according the number of dailymilking: GI – cows milked once a day; GII – cows milked twice a day; GIII - cows milked alternating once or twice a day, everyfourteen days. The return to estrous (84.3 days; 81.7 days and 71.2 days); estrous rates (80.9%; 80.90% e 80.90%); serviceperiod (99.0 days; 114.0 days and 93.1 days) and pregnant rates until 120 day postpartum (66.7%; 57.1%; 66.7%) were notinfluenced (P>0.05) by the number of daily milking

Análise ultra-estrutural de embriöes bovinos da raça Nelore / Ultra-structural analysis of Nelore embryos / Análisis ultra-estructural de embriones bovinos de la raza Nelore

O conhecimento da ultra-estrutura de embriöes bovinos, dentro das diferentes sub-espécies permite estabelecer características inerentes a cada uma delas, possibilitando o desenvolvimento de métodos eficientes para estocagem e conservaçäo desses embriöes. Diante disso,17 embriöes bovinos, da raça Nelore, foram preparados para análise ultra-estrutural, sob microscopia eletrônica. O processamento dos embriöes foi realizado no Departamento de Reproduçäo Animal da UNESP-Jaboticabal. Para tanto, os embriöes foram lavados sucessivas vezes para remoçäo do SFB, utilizado no meio de transporte, fixados em soluçäo de glutaraldeído a 1 por cento em tampäo cacodilato de sódio 0,15M e pH 7,6, desidratados em soluçöes com concentraçöes crescentes de álcool etílico, pré-incluídos, incluídos em cápsulas BEEM (Better equipment for electron microscopy), contendo resina EPON-812, submetidos em estufa à temperatura de 60§C por 72 horas, para polimerizaçäo, e seccionados. Devido às pequenas dimensöes, os embriöes inicialmente foram submetidos a secçöes semifinas(0,5µm), para que a linha de corte propiciasse visualizaçäo do trofoblasto(TF) e massa celular interna(MCI). Após a triagem dos cortes, realizaram-se secçöes ultrafinas (60-70nm), que foram colhidas em grades de cobre, coradas com acetato de uranila e citrato de chumbo e observadas ao microscópio eletrônico. Dos embriöes processados 64,71 por cento foram selecionados para análise ultra-estrutural. Observou-se que as células dos embriöes analisados apresentavam-se semelhantes às descriçöes para blastocistos de bovinos Bos taurus indicus. O trofoblasto era formado por células alongadas que constituíam duas partes distintas; o trofoblasto mural, que delimitava a blastocele, e o trofoblasto polar, que recobria as células da massa celular interna. Suas células estavam intimamente ligadas por complexos juncionais, seguidos por desmossomos. As superfícies externas dessas células eram cobertas por microvilosidades proeminentes, com filamentos axiais, enquanto suas superfícies internas apresentavam-se lisas, com junçöes comunicantes (do tipo gap) com as células da MCI. Possuíam organelas usuais como mitocôndrias, lisossomos, ribossomos e poliribossomos, retículo endoplasmático liso e rugoso e complexo de Golgi com forma e número variados. Observam-se também gotas lipídicas e numerosas vesículas. As células da MCI eram cubiformes, ligadas umas as outras por junçöes desmossômicas, apresentando coloraçäo...