Impact of Equine Chorionic Gonadotropin Associated with Temporary Weaning, Estradiol Benzoate, or Estradiol Cypionate on Timed Artificial Insemination in Primiparous Bos Indicus Cows

The study aimed to determine the impact of equine chorionic gonadotropin (eCG) associated with different timed artificial insemination (TAI) protocols on the pregnancy rate (PR) in Bos indicus cows previously treated with progesterone. Five hundred and fifty-seven primiparous cows were subjected to the following treatments: on day 0 (d0), GeCGTW (group equine Chorionic Gonadotropin+Temporary Weaning;n=178) received 0,558 g intravaginal progesterone (P4)+1.0 mg of estradiol benzoate (EB) (IM); on d8 (P4 removal+0,075 mg D-cloprostenol + 400 IU eCG + TW for 48 h); on d10, TAI + calves return to dam; GeCGEB (group equine Chorionic Gonadotropin+Estradiol benzoate; n=176) the same as GeCGTW without TW + application of 1.0 mg of EB on d9; GeCGEC (group equine Chorionic Gonadotropin+Estradiol Cypionate; n=203), the same as GeCGTW without TW+1.5 mg EC (IM). On d35, post TAI, pregnancy diagnosis (PD) was performed. Non-pregnant animals remained under clean-up bulls for 90 days. After this period, the animals were subjected to PD using ultrasound. The PR of TAI was 51.1%, 47.1%, and 47.8% for GeCGTW, GeCGEB24, and GeCGEC (P>0.05) respectively. The PR under clean-up bulls was 88.3%, 47.3%, and 31.1% (P<0.05). The final PR (TAI+clean-up bulls) of the groups was 94.4%, 72.1%, and 64.0%, respectively (P<0.05). It was concluded that no differences in PR among the protocols related to TAI were detected; PR in the GeCGTW protocol under clean-up bulls was higher compared to others (P<0.05); the overall PR of cows subjected to TAI+clean-up bulls was significantly higher in GeCGTW than in the other groups.

Comportamento supersticioso em estudantes universitários / Superstitious behavior in college students

Este estudo investigou o comportamento supersticioso em estudantes universitários. Participaram do experimento 10 alunos de diferentes cursos de graduação, de ambos os sexos e com a idade entre 18 e 29 anos. O experimento foi realizado em um dos cubículos do LAEC da PUC de Goiás equipado com um microcomputador, mouse e uma filmadora. Os participantes foram instruídos que no decorrer do experimento a palavra “parabéns” apareceria na tela do microcomputador. O local foi equipado com uma folha de papel com uma pergunta. A sessão teve a duração de sete minutos, cinco primeiros ocorriam no esquema de tempo fixo de 20 segundos e os dois últimos minutos eram referentes à extinção (TF 20s + Extinção). Dos registros em vídeo foram retiradas oito categorias dos principais fenômenos comportamentais como “manipulação de objetos”, por exemplo, e 47 subcategorias como “manipular o teclado”, “tocar a folha” e “tocar no celular”. O estudo demonstrou que os participantes tiveram um aumento considerável da frequência das respostas de manipular o computador durante as duas fases do experimento; grande parte dos estudantes não descreveu acontingência a qual foram expostos, em seguida ao experimento. Nove participantes comportaram-se como se existisse uma relação causal entre suas respostas e a apresentação do estímulo reforçador. Desse modo, as relações programadas foram de contiguidade e não de contingência e os efeitos observados podem ser explicados com base nas respostas que executaram no momento em que o reforçador era fornecido...

This study investigated the superstitious behavior in college students. Experiment participants were 10 students from different graduate students of both sexes and at the age between 18 and 29 years. The experiment was conducted in one of the cubicles of Goiás PUC LAEC equipped with a computer, mouse and a camcorder. The participants were told that the experiment of course the word “Congratulations” appear on the PC screen. The place was equipped with a paper sheet with a question. The session lasted seven minutes, five occurred in fixed time schedule of 20 seconds and the last two minutes were referring to extinction (TF 20s + Extinction). The video recordings were taken eight categories of the main behavioral phenomena as “manipulation of objects,” for example, and 47 subcategories like “manipulate the keyboard”, “touch paper sheet” and “touch phone.” The study showed that participants had a significant increase in the frequencyof responses to manipulate the computer during the two phases of the experiment; most students did not describe the contingency to which they were exposed, then the experiment. Nine participants behaved as if there was a causal relationship between their responses and the presentation of the reinforcer. Thus, the set of relations were not contiguity and contingency and the observed effects can be explained based on the answers that performed at the time the reinforcer was provided...

Influence of category-heifers, primiparous and multiparous lactating cows-in a large-scale resynchronization fixed-time artificial insemination program

This study was conducted to evaluate the influence of category (heifers, primiparous or multiparous cows) on pregnancy rates in a large scale resynchronization ovulation program. Nelore heifers (n = 903), primiparous lactating cows (n = 338) and multiparous lactating cows (n = 1,223) were synchronized using a conventional protocol of estradiol/P4-based fixed-time artificial insemination (FTAI). Thirty days after ultrasonography, females who failed the first FTAI were resynchronized with the same hormonal protocol prior to a second FTAI. The pregnancy status of each cohort was evaluated by ultrasonography 30 days after each FTAI. The average conception rate after the first FTAI and resynchronization was 80.5%. Heifers had a higher conception rate (85%) than primiparous (76%) or multiparous cows (78%; p = 0.0001). The conception rate after the first FTAI was similar among heifers (57%), primiparous cows (51%) and multiparous cows (56%; p = 0.193). After the second FTAI, heifers exhibited a higher conception rate (66%) than primiparous or multiparous cows (51%; p = 0.0001). These results demonstrate the feasibility of resynchronization in large beef herds for providing consistent pregnancy rates in a short period of time. We also demonstrated that ovulation resynchronization 30 days after FTAI is particularly effective for heifers, providing a conception rate of up to 66%.

Statistical methods for comparing survival rates at a fixed time point / 中华流行病学杂志

Comparison of survival curves between two groups is an important part of disease prognosis study.Log-rank test is commonly used,but when the two curves' later intersecting opening is too large,the proportion of assumptions is not established,thus the Log-rank test is ineffective.We introduces five statistical tests to compare two survival curves at a fixed time points:classic method,logarithmic transformation,cloglog transformation,arcsine transformation and logit transformation.Through the study we found that if the overall survival curves are difficult to compare between groups tested with Log-rank test method or Two-stage test method,the fixed time point test can effectively determine whether there was significant difference in survival rate at a fixed time point.Among the five fixed time point tests,cloglog transformation could give more precise result.

The effects of intramuscular or intravenous injections of gonadotropin releasing hormone at fixed-time artificial insemination on pregnancy rates of Bos indicus beef cows

The effect of an intramuscular versus intravenous administration of gonadotropin releasing hormone (GnRH) at fixed-time AI (FTAI) on the pregnancy rates of crossbred Bos indicus beef cows was evaluated. Pluriparous nursing calv cows (n=120) were synchronized as follows: d 0 cows received a 2.0 mg injection of estradiol benzoate (EB) and insertion of a controlled intravaginal progesterone releasing device containing 0.558 g of progesterone, d 8 removal of the progesterone device , a 0.15 mg injection of prostaglandin F2α (PGF), a 1.0 mg injection of EB, and 400 IU injection of equine chorionic gonadotropin. Fifty-four hr after PGF, all cows were exposed to FTAI and a 0.084 mg injection of GnRH was administered either via Vena caudalis (n=60), or via Longissimus dorsi (n=60). Cows were inseminated with the same sire and by a single AI technician. Pregnancy was determined by the transrectal ultrasonography on d 40 after AI. Cows receiving the intravenous administration of GnRH had higher (P = 0.04) pregnancy rates than the cows receiving the intramuscular injection of GnRH (65 vs 46.6%, respectively). It was concluded that the intravenous administration of GnRH at the time of AI improved the pregnancy rates of crossbred Bos indicus beef cows submitted to FTAI.

Trypsin digestion method for the long-term formalin-fixed retinal in rats / 中国药理学通报

Aim To investigate the optimum trypsin digestion time and the optimum trypsin concentration of the long-term formalin-fixed retina in rats.Methods Male SD rats were sacrificed by cervical dislocation. The removed eyes were fixed in 4% formaldehyde fixa-tive for 2 days,2 weeks,4 weeks,3 months,5 months and 7 months respectively.Fixed retinas at dif-ferent time were separated and put in 3%,6% and 9% trypsin at 37℃ in incubator.The time required was recorded for complete digestion of retinas,which fixed for different time and digested in different con-centrations of trypsin.The retinal blood vessels were recorded under a microscope after PAS staining of stretched retinal blood vessel.Results After conven-tionally fixed for 48 hours,retinas were digested com-pletely in 3% trypsin at 37℃ for 3.5 hours.The di-gestion time extended to 9 hours and 1 4 hours for the 2 weeks and 1 month fixed eyes,using 3% trypsin, which achieved the same result as conventional fixed eyes.For the 3 months fixed eyes,a complete retinal blood vessel could also be attained by using conven-tional concentrations of trypsin,and only by extending digestion time to 22 hours.It is also indicated that the increased concentration of trypsin did not shorten the time of digestion.In addition,for the fixed eye from 5 months to 7 months,6% and 9% trypsin could short-en,to some extent,the time to 22 hours and 28 hours respectively,which was conductive to obtaining rela-tively complete retinal blood vessels.Conclusions Retinal tissues which fixed time shorter than 3 months can completely be digested using 3% trypsin.Howev-er,for retinal tissue,which fixed from 5 months to 7 months,both the extending time of digestion and the increasing concentration of trypsin to 6% are necessary to get optimum retinal vascular digestion.

Inseminação artificial em tempo fixo em primíparas Nelore lactantes acíclicas / Fixed-time artificial insemination in primiparous lactating Nelore acyclic cows

Avaliou-se a eficiência de um protocolo de inseminação artificial em tempo fixo (IATF), para melhorar o desempenho reprodutivo de vacas Nelore primíparas, lactantes e acíclicas. Utilizaram-se 350 vacas com escore de condição corporal médio de 2,65±0,01 e média de dias pós-parto de 67,35±1,0 dias. A estação de monta (EM) foi de 180 dias. Os animais foram distribuídos em: G1(n=61) e G3(n=116) - vacas com presença de folículos ovarianos ≤8mm de diâmetro e sem corpo lúteo (CL); G2(n=57) e G4(n=116) - vacas com folículos ≥8mm e sem CL. As vacas do G1 e do G2 permaneceram em monta natural (MN) a partir do dia zero da EM. G3 e G4 foram tratados (dia zero) com 2mg de benzoato de estradiol (BE), IM, e dispositivo com 1,0g de P4 por oito dias. Retirou-se a P4, administraram-se 400UI de eCG e 75µg de cloprostenol, IM, 24h após, e 1mg BE, IM. A IATF foi realizada 51-54h após retirar P4. Aos cinco dias após término da IATF, as vacas do G3 e do G4 também foram mantidas em MN. Avaliou-se, por ultrassonografia, a presença de CL e realizou-se o diagnóstico de gestação, aos 45 e 210 dias após início da EM. Aos 45 dias, mais animais do G3, 42,2%, e do G4, 51,7%, estavam gestantes (P<0,05), em relação aos do G1, 0%, e do G2, 3,5%. A porcentagem de CL foi de 6,6%; 28,1%; 50,9%; 62,9% em G1, G2, G3 e G4, respectivamente. Aos 210 dias, 22,9% do G1; 45,6% do G2; 40,5% do G3 e 65,5% do G4 estavam gestantes. Os períodos de serviço foram: em G1, 134,00±11,70 dias; em G2, 119,65±8,27 dias; em G3, 79,91±5,38 dias; e em G4, 81,40±4,59 dias. A IATF foi eficiente para melhorar o desempenho reprodutivo de vacas Nelore primíparas lactantes acíclicas em relação ao manejo apenas da MN.

The aim of this experiment was to evaluate the efficiency of a fixed-time artificial insemination protocol to improve the reproductive performance of lactating primiparous acyclic Nelore cows. A total of 350 cows with average body condition score of 2.65±0.01 and average postpartum days of 67.35±1.0 were used. The breeding season (MS) was 180 days. The animals were distributed into G1 (n = 61) and G3 (n = 116) - cows with ovarian follicles ≤8mm in diameter and without corpus luteum (CL). G2 (n = 57) and G4 (n = 116) groups - cows with follicles ≥8mm and without CL. Cows in G1 and G2 remained in natural mating (NM) from day 0 of MS. G3 and G4 were treated (Day 0) with 2mg of oestradiol benzoate (EB), IM, and 1.0g P4 device for eight days. The withdrawal of P4 was administered with 400IU of eCG and cloprostenol 75μg, IM, after 24h, and 1mg BE, IM. The artificial insemination was performed at 51-54h after removing the P4 device. Five days after the end of the artificial insemination, cows from G3 and G4 were also held in MN. Ultrasonography was performed to evaluate the presence of CL and the pregnancy diagnosis at days 45 and 210 after the onset of MS. At 45 days more animals in G3, 42.2% and G4, 51.7% were pregnant (P <0.05) than in G1, 0% and G2, 3.5%. The CL percentage was 6.6%, 28.1%, 50.9%, 62.9% in G1, G2, G3 and G4, respectively. At 210 days 22.9% in G1, 45.6% in G2, 40.5% in G3 and 65.5% in G4 were pregnant. The service periods were: G1, 134.00±11.70 days; G2, 119.65±8.27 days, in G3, 79.91±5.38 days, and G4, 81.40±4.59 days. The fixed-time artificial insemination was efficient to improve the reproductive performance of primiparous lactating Nelore acyclic cows compared to animals that remained only with natural mating.

Evaluación de la fertilidad de hembras bos indicus, de acuerdo a la intensidad del celo, manejadas en un programa de inseminación artificial a tiempo fijo en condiciones de trópico / Fertility assessment of bos indicus cows according to the estrus intensity, in a fixed time artificial insemination program under tropical conditions

El objetivo del presente estudio fue evaluar la fertilidad obtenida en un hato, según dos tiempos de Inseminación Artificial (IA) a tiempo fijo: 48 y 72 horas, posterior a un programa de sincronización de celos, tomando en cuenta las manifestaciones y la intensidad del estro. Se utilizaron 114 hembras Bos indicus, sincronizadas con 2mg de benzoato de estradiol más un implante intravaginal de progesterona (CIDR), que permaneció in situ por 9 días. Al retiro del CIDR, los animales fueron divididos en 2 grupos: 61 y 53 hembras, que fueron inseminadas 48 horas y 72 horas postratamiento, respectivamente. Todas fueron observadas continuamente durante 90 horas, con el fin de detectar el comportamiento sexual y clasificarlas, de acuerdo a la intensidad del celo, en dos categorías: alta y baja. Se utilizó la prueba de Ji-cuadrado para la comparación de proporciones. El porcentaje de hembras con manifestación estral fue de 68,4 por ciento, sin diferencia entre las categorías alta y baja intensidad (37,7 y 30,7 por ciento, respectivamente). El 85,4 por ciento de los animales con signos de estro ovuló, diferente de las hembras sin manifestación estral, con 63,8 por ciento (P<0,05). El porcentaje global de preñez fue 25,4 por ciento; el 86,2 por ciento de estas gestaciones corresponde al grupo de hembras que manifestaron conducta estral. De acuerdo al momento de IA y la intensidad del estro, los porcentajes de gestaciones para IA a 48 horas fueron 1) alta: 91,6 por ciento, 2) baja: 84,6 por ciento (P<0,05) y 3) sin celo: 25 por ciento, por su parte, en las hembras inseminadas a las 72 horas los porcentajes fueron: 1) alta: 8,4 por ciento, 2) baja: 15,4 por ciento y 3) sin celo: 75 por ciento (P<0,05). Se concluye que las hembras con expresión estral tienen mayor oportunidad de preñarse tras la IA a 48 horas postratamiento hormonal, mientras que en los animales sin manifestación de estros, los mayores porcentajes de gestaciones son a las 72 horas.

The aim of this study was to evaluate the fertility obtained in a herd, according to two times of fixed time AI: 48 and 72 hours, following an estrus synchronization program, taking into consideration the manifestations and the intensity of estrus. One hundred and fourteen Bos indicus females were used; synchronized with 2mg of estradiol benzoate and a progesterone-releasing intravaginal device (PRID), which remained in situ for 9 days. After the removal of the PRID, the animals were divided into two groups: 61 and 53 females that were inseminated, respectively, 48 and 72 hours posttreatment. All were continuously observed for 90 hours, with the objective of detecting sexual behavior and classifying them according to heat intensity into two categories: high and low. Chi-square test was used for the comparison of proportions. The percentage of females with estrus manifestation was 68.4 percent, without difference between high and low intensity categories (37.7 and 30.7 percent, respectively). Of the animals with signs of estrus, 85.4 percent ovulated; different from the females without estrus manifestation, with 63.8 percent (P<0.05). Global pregnancy rate was 25.4 percent; 86.2 percent of these gestations correspond to the group of females that manifested estral behavior. According to the moment of AI and the intensity of the estrus, the percentages of pregnancy for AI at 48 hours were 1) high: 91.6 percent, 2) low: 84.6 percent (P<0.05) and 3) without estrus: 25 percent, on the other hand, in females inseminated at 72 hours, the percentages were: 1) high: 8.4 percent, 2) low: 15.4 percent and 3) without estrus: 75 percent (P<0.05). It is concluded that females with estral manifestation are more likely to get pregnant after AI at 48 hours following hormonal treatment, while for animals without estral manifestation, the higher pregnancy percentages are at 72 hours.