Infertility associated with the duration of luteal phase in postpartum cows

After first postpartum ovulation most cows have a short luteal phase due to a premature secretion of PGF2 from the uterus. Pregnancy rate in estrous cycles with short luteal phases is essentially nil. The lack of exposure of the uterus to P4 and estrogen prior to first postpartum ovulation decreases the concentration of P4 receptors and up regulates oxytocin receptors. The inadequate number of P4 receptors and presence of endometrial oxytocin receptors earlier in cows with short than normal luteal phases allows premature release of PGF2a and the resultant regression of the CL. During luteolysis, uterine and luteal PGF2a cause death of the embryos mainly during the transition from morula to blastocyst when the embryos are more susceptible to embryotoxic effect

The time interval between ovarian stimulation with FSH/LH and ovum-pick up affects the quantity, quality and developmental competence of oocytes retrieved from Ecuadorian creole heifers

El objetivo del estudio fue evaluar los efectos del tratamiento con gonadotropina y el intervalo entre la estimulación ovárica con FSH/LH y la sesión de aspiración folicular, sobre la cantidad y calidad de los complejos cúmulus ovocitos (COCs) obtenidos por ovum pick up (OPU) en vaquillas criollas ecuatorianas. Cuatro novillas fueron asignadas aleatoriamente a cuatro grupos (FHS/LH 40h; FSH/LH 48h; control 40h; control 48h). En dos grupos se aplicó una dosis (0.011 mg, IM) de GnRH el día 0, seguida de 500 UI, IM, de FSH/LH el día 2, y la sesión de OPU a los 40 (FSH/LH 40 h) o 48 horas (FSH/LH 48h) después de la aplicación de la gonadotropina. En los otros dos grupos, la FSH/LH se reemplazó por una solución fisiológica. No hubo diferencia estadística en la tasa de recuperación de los COCs entre FSH/LH 40h y FSH/LH 48h, pero se obtuvo aproximadamente el doble de COCs (p<0.05) que en aquellos que no recibieron estimulación ovárica. Se consiguió 2.4 veces más COCs de calidad A en el tratamiento de FSH/LH 48h que en el de FSH/LH 40h. El 100% de estas estructuras reaccionaron positivamente al Azul Brillante de Cresilo (BCB+), lo que significa que terminaron el crecimiento y fueron competentes para iniciar la maduración in vitro. Se concluye que el tratamiento con FSH/LH 48h permitió obtener un mayor número de COCs competentes para la maduración in vitro.The aim of this study was to evaluate the effects of gonadotropin treatment and the interval between ovarian stimulation with FSH/LH and the follicular aspiration session, on the quantity and quality of the cumulus oocyte complexes (COCs) obtained by ovum pick up (OPU) ) in Ecuadorian Creole heifers. Four heifers were randomly assigned to four groups (FHS/LH 40h; FSH/LH 48h; control 40h; control 48h). In two groups a dose (0.011 mg, IM) of GnRH was applied on day 0, followed by 500 IU, IM, of FSH/LH on day 2, and the OPU session at 40 (FSH/LH 40 h) or 48 hours (FSH/LH 48h) after the application of gonadotropin. In the other two groups, FSH/LH was replaced by a physiological solution. There was no statistical difference in the recovery rate of COCs between FSH/LH 40h and FSH/LH 48h, but approximately twice as many COCs (p<0.05) were obtained than in those who did not receive ovarian stimulation. In addition, 2.4 times more COCs of quality A were achieved in the treatment of FSH/LH 48h than in that of FSH/LH 40h. All (100%) of these structures reacted positively to Brilliant Cresyl Blue (BCB+), which means that they finished the growth and were competent to initiate in vitro maturation. It is concluded that the treatment with FSH/LH 48h allowed to obtain a greater number of COCs competent for in vitro maturation

Factors affecting reproductive response in anestrous crossbred cows treated with intravaginal progesterone or calf removal for 120 hours

To study the effect of season (August-October, EP1; February- March, EP2), predominant breed (Bos taurus, BT; Bos indicus, BI), and number of parturitions (primiparous, PC; multiparous, MC) on reproductive response, 167 crossbred anestrous cows that were 90 to 130 d postpartum were allotted randomly to one of the following treatments: IP (n = 59), intravaginal sponge with 250 mg of medroxyprogesterone acetate (MAP) for 7 d; first day of treatment (Day 0), 50 mg MAP and 5 mg 17B-estradiol (17B-E) intramuscular (im); Day 5, 500 IU of eCG; 24 h after sponge removal (Day 8), 1.5 mg 17B-E im. CR (n = 57), temporary calf removal for 120 h. CG (n = 51), control group without treatment. Data were analyzed using Chi-square and GLM procedures. Season did not affect the reproductive response under the IP treatment; however, in EP2 cows under CR and/or CG had better reproductive response than in EP1: estrous rate (ER) was: CG: 36.8 vs 13.8%, respectively (P < 0.06), pregnancy rate at 30 d (TP30): CR: 40 vs 16.6%, (P < 0.02) and CG: 26.3 vs 3.4%, respectively (P < 0.06), pregnancy rate at 60 d (TP60): CR: 55 vs 23.3%, respectively (P < 0.02), interval parturition to 1st service (PFS): CG: 146.6 vs 181.8 d, respectively (P < 0.01), and interval parturition to conception (PCI): CR: 135.8 vs 156.7 d, (P < 0.05) and CG: 147.1 vs 171.1 d, respectively (P < 0.05). Predominant breed did not affect the reproductive response within any of the experimental group, except that under IP, BI cows had a greater TP60 than BI (62.5 vs 43.5%; P < 0.05). Primiparous cows under CR had lower ER than multiparous (39.5% vs 68.2%; P < 0.05); whereas in CG TP60 was 3.5 times lower in PC than in MC cows (7.7 vs 27.3%; P < 0.07). Also, in CG the PFS was shorter in MC than PC cows (153.8 vs 173.7 d; P < 0.05). Overall, the IP treatment followed by CR gave greater estrous rate, accumulated pregnancy at 30 and 60 d post-treatment and reestablished pregnancy in a shorter period after calving than the non-treatment control

Effect of estrous cycle stage on oocyte in vitro maturation of domestic cats reared under tropical conditions

La maduración de los ovocitos es un paso crítico para la producción de embriones in vitro. En las gatas, los hallazgos sobre la influencia de la fase del ciclo estral en la calidad y maduración de los ovocitos son contradictorios. Se sabe poco sobre este fenómeno en las gatas en los trópicos. El objetivo de este estudio fue evaluar el efecto de la fase del ciclo estral sobre la calidad de los ovocitos y la posterior capacidad de completar la maduración nuclear en gatas de un ambiente tropical. Se recogieron ovarios de 18 gatas sexualmente maduras durante la ovariohisterectomía. Los complejos cúmulo–ovocito (COCs) fueron obtenidos de los folículos mediante el corte y la fragmentación de la corteza ovárica. Según sus características morfológicas, los COCs se clasificaron en grados I–II (aptos) y III–IV (no aptos). Sólo los COCs de buena calidad de cada gata se cultivaron para su maduración in vitro. La maduración nuclear de los ovocitos se evaluó por la presencia de una placa en telofase I o metafase II con extrusión del primer corpúsculo polar. Se obtuvo un número significativamente mayor de ovocitos por ovario en las gatas en fase inactiva que en fase folicular o lútea. Las proporciones de COCs fueron similares entre los grupos. La tasa de maduración de los ovocitos no difirió entre las fases del ciclo estral, ni tampoco la proporción de ovocitos no maduros o degenerados. La edad de las gatas no afectó al porcentaje de maduración de los ovocitos. En conclusión, la calidad y la tasa de maduración de los ovocitos fueron similares en las tres etapas del ciclo estral examinadas.Oocyte maturation is a critical step for in vitro embryo production. In female cats, findings on the influence of the estrous cycle stage on oocyte quality and maturation are contradictory. Little is known about this phenomenon in female cats in the tropics. This study aimed to assess the effect of the estrous cycle stage on oocyte quality and subsequent capacity to complete nuclear maturation in cats in a tropical environment. Ovaries from 18 sexually matured cats were collected during ovariohysterectomy. Cumulus–oocyte complexes (COCs) were released from follicles by slicing and fragmentation of the ovarian cortex. According to morphological characteristics, COCs were classified into grades I–II (suitable) and III–IV (no suitable). Only suitable COCs from each cat were cultured for in vitro maturation. Nuclear oocyte maturation was assessed by the presence of a telophase I or metaphase II plate with extrusion of the first polar corpuscle. A significantly greater number of oocytes per ovary were collected from queens in inactive than in follicular or luteal phase. Proportions of suitable COCs were similar among groups. Rate of oocyte maturation did not differ among stages of the estrous cycle, nor did the proportion of non–matured or degenerated oocytes. The age of the queens did not affect the percentage of oocyte maturation. In conclusion, the quality and rate of oocytes maturation were similar in the three stages of estrous cycle examined

SA 03. Bacteria in the posterior respirator tract of healthy calves

Forty seven (47) clinically healthy calves (15 to 120 days old) were sampled in order to demostrate the bacteria present in the posterior respirator tract and to determine the sensibility of isolated microorganism to fifteen (15) antibiotics. The tracheal - bronquial - secretion were obtained by the transtracheal aspiration technique. Fifteen (15) antibiotic were used to stablish the sensibility pattern. Calf samples were taken from six (6) forms located into a dry tropical forest environment in the Zulia State, Venezuela. SAS was used for statistical evaluation of the data. Six (6) bacterial groups were isolated from forty seven (47) samples representing the 87.3 %, they were Staphilococcus aureus (58.5 %), Escherichia coli (17.1 %), Proteus mirabilis (12.2), Klebsiela pneumoniae (4.9 %), Citrobacter diversus (4.9 %), Enterobacter aglomerans (2.4 %). Most isolated microorganism had a high sensibility to antibiotics such as: Gentamycin (97.6 %), and Chloranphenicol (92.7 %), and high resistence to Ampicillin (78.0 %), Penincillin (77.2 %) and oxillin (70.07 %)

Lunar cycle influences production of tilapia (Oreochromis spp) eggs in an intensive outdoor production system in the tropics

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America. Records of two tilapia strains (Nile tilapia [Oreochromis niloticus; n = 75] and Red tilapia [Oreochromis spp.; n = 1335]) reared in concrete tanks in a commercial fish farm were analyzed. Over a 3-year period, 60,136 captures were made in intervals of 12 to 14 days and 6,600 females were manually spawned. The number of females spawned and the volume of eggs collected from each tank (n = 9) were recorded. Data was analyzed by the general linear model and means were compared by least squares means method. A very slight or no variation was observed when the lunar cycle was split into two halves (crescent and waning). The proportions of females spawned and the volume of eggs per spawned female and per female in the tank varied considerably across the eight periods of the lunar cycle, with greater values in the waning than in the crescent phase. A significantly greater proportion of tilapia spawned and yielded more eggs around the full moon than around the new moon and remaining days of the lunar cycle. The moon cycle affected the reproductive activity of tilapia, which were more reproductively active around the full moon and most of the waning phase

FR 16. Ultrasonographic evaluation of the cervical involution in tropical crossbred dairy cows

The ultrasonographic evaluation of the involution of the cervix (IC) was studied in 8 crossbred cows with 1 (n=4) and 2 (n=4) parturition. Reasearch was conducted at the university farm La Esperanza, located in a dry tropical forest area, mean temperature 28 ºC and anual rainfall 996 mm. The transducer was introduced into the rectum and rotated 90º related to the insertion plane at the level of the second posterior cervical ring. The dorsoventral and lateral-lateral diameters were measured. Cervical involution was considered completed when the diameters were not smaller and the measure was exactly the same in two consecutive observations. IC was estimated by linear and quadratic regression, analysis of variance and Pearson correlation accomplished by procedure GLM of SAS. IC ended at 32.5 days postpartum; no differences were observed between cows of 1 or 2 parturition (32.5 ± 3.4 and 32.5 ± 4.4 days, respectively). Correlation between the average mean diameter of the cervix and postpartum days, square and cubic days postpartum were - 0.79, - 0.76, - 0.72 (P<.001). The regression equation was: Y = 6.0884 - 0.2491x + 0.003x2. Ultrasonography was considered a valuable tool to study the cervical uterine involution in crossbred cows

Taxa de fertilidade ao primeiro serviço em vacas resultantes do cruzamento alternado entre Red Brahman e Red Holstein de acordo com a predominância racial, geração (mães e filhas) e época de parto

The fertility rate at 1st service (FPS) is the percentage relationship between the cows that become pregnant at the 1st service and those that are served for the first time, and constitutes an important reproductive index that allows evaluating the reproductive efficiency of the herd (González-Stagnaro, 2001). The effect of racial predominance and season on FPS in tropical mestizo cows was previously described (Perea et al., 2005; Perea and González-Stagnaro, 2005). In Bos indicus predominant cows, FPS is higher than in Bos taurus predominant cows (Perea et al., 2006). The dry season favors a higher FPS in both genetic groups (Perea et al., 2006). Considering a population of mestizo cows subject to alternate crossbreeding between the Red Holstein and Red Brahman breeds, the objective of this study was to evaluate the FPS in predominantly Brahman or Holstein mothers and daughters according to three calving seasons in the year.La tasa fertilidad al 1er servicio (FPS) es la relación porcentual entre las vacas que se preñan al 1er servicio y las que se sirven por primera vez, y constituye un importante índice reproductivo que permite evaluar la eficiencia reproductiva del rebaño (González-Stagnaro, 2001). Previamente se describió el efecto del predominio racial y de la época sobre la FPS en vacas mestizas tropicales (Perea et al., 2005; Perea y González-Stagnaro, 2005). En las vacas de predominio Bos indicus las FPS es mayor que en las de predominio Bos taurus (Perea et al., 2006). La época seca favorece una mayor FPS en ambos grupos genéticos (Perea et al., 2006). Considerando una población de vacas mestizas sujetas a cruce alterno entre las razas Holstein Rojo y Brahman Rojo se estableció como objetivo de este estudio evaluar la FPS en madres e hijas predominantemente Brahman o Holstein según tres épocas de parto en el año.A tarefa fertilidad al 1er service (FPS) é a relação porcentual entre as vagas que preñan al 1er servicio e as que são servidas por primeira vez, e constitui um índice reprodutivo importante que permite avaliar a eficiência reprodutiva do rebaño (González-Stagnaro, 2001). Anteriormente, descreve-se o efeito do domínio racial e da época sobre o FPS em férias mestiças tropicais (Perea et al., 2005; Perea y González-Stagnaro, 2005). En las vacas de predominio Bos indicus las FPS es mayor que en las de predominio Bos taurus (Perea et al., 2006). A época favoreceu um prefeito FPS e ambos os grupos genéticos (Perea et al., 2006). Considerando uma población de vacas mestizas sujetas a cruce alterno entre as razas Holstein Rojo e Brahman Rojo, estabeleci-se como objetivo deste estudo avaliar o FPS em madres e hijas principalmente Brahman ou Holstein según tres épocas de parto en el año

Efecto de la suplementación dietética con harina de morera (Morus alba) sobre el rendimiento productivo de las codornices en crecimiento (Coturnix coturnix japonica)

El estudio tuvo como objetivo evaluar el comportamiento productivo de codornices de engorde (Coturnix coturnix japonica) alimentadas con alimento balanceado y suplementadas con harina de morera (Morus alba). El experimento se desarrolló en el Estado Trujillo, Venezuela, durante seis semanas. Se aplicó un diseño completamente aleatorizado con tres tratamientos (dietas) y cinco repeticiones por tratamiento (4 aves por repetición). Las dietas fueron: T0: 100% alimento balanceado (AB) comercial; T1: 90% AB + 10% de harina de morera (HM); T2: 80% AB + 20% HM. Se determinó el peso final (PF), ganancia diaria de peso (GDP), consumo de alimento, tasa de crecimiento específica (TCE), conversión alimenticia (CA), rendimiento en canal (RC), mortalidad y relación costo beneficio (CB). Los datos fueron procesados mediante el análisis de varianza usando el procedimiento GLM del programa SAS. El PF y la GDP fueron mayores en T1 y T2 (PF: T0: 139.1 ± 1.9; T1: 147.2 ± 2.0; T2: 147.1 ± 1.9 (p<0.03) (GDP: T0: 3.1 ± 0.05; T1: 3.3 ± 0.05; T2: 3.3 ± 0.05 (p<0.03). Las aves de T1 y T2 consumieron más alimento que las de T0 (p<0.01). La TCE fue menor (p<0.05) en T0 (7.01%) que en T1 (7.13%) y T2 (7.14%). La CA y el RC no variaron entre tratamientos. La relación CB favoreció a las aves de T1 y T2. Se concluye que la adición de HM en la ración mejoró el PF, la GDP y la relación CB, constituyendo una alternativa para reducir los costos de alimentación de los establecimientos comerciales, sin menoscabo de los índices productivos de las aves.© 2019 Universidad Nacional Mayor de San Marcos. All rights reserved. The aim of this study was to evaluate the productive performance of growing quail (Coturnix coturnix japonica) fed with a commercial balanced feed and supplemented with mulberry meal (Morus alba). The experiment was carried out in Trujillo, Venezuela, for six weeks. A completely randomized design was applied with three treatments (diets) and five repetitions per treatment (4 birds per repetition). The diets were: T0: 100% commercially balanced feed (AB); T1: 90% AB + 10% of mulberry meal (HM); T2: 80% AB + 20% HM. The final body weight (FW), daily weight gain (DWG), feed consumption (DI), specific growth rate (SGR), feed conversion (FC), carcass yield (CY), mortality and cost-benefit ratio were determined (CB). The data were processed by analysis of variance using the GLM procedure of the SAS program. The FW and the DWG were higher in T1 and T2 (PF: T0: 139.1 ± 1.9, T1: 147.2 ± 2.0, T2: 147.1 ± 1.9, (p<0.03) (DWG: T0: 3.1 ± 0.05, T1: 3.3 ± 0.05; T2: 3.3 ± 0.05 (p<0.03). The birds of T1 and T2 consumed more feed than those of T0 (p<0.01). The SGR was lower (p<0.05) in T0 (7.01%) than in T1 (7.13%) and T2 (7.14%). FC and CY did not vary between treatments. The CB ratio favored the birds of T1 and T2. It is concluded that the addition of HM in the ration improved FW, DWG and CB, constituting an alternative to reduce the feeding costs of the commercial farms without diminishing the productive indices of the birds

Influence of size, variety and male female ratio in the production of tilapia (Oreochromis spp.) eggs in concrete tanks at the Venezuelan Andean foothills

The aim of this study was examine the effect of the variety, size and male female ratio in the egg production of tilapia Chitralada (CH: Oreochromis niloticus) and Taiwanese Red (TR: O. mossambicus x O. niloticus) reared in tanks of concrete. The study was conducted in a fish farm located at the Venezuelan Andean foothill of Trujillo state, Venezuela. A 2x2x3 factorial arrangement was applied: two varieties (CH and TR), two sizes (small and large) and three sexual relations (1♀ : 1♂; 2♀: 1♂; 3♀: 1♂). The data were processed by analysis of variance using the general linear model of the SAS. The CH females produced 1.5 times more eggs, which weighed 1.6 times more and had a fecundity 1.6 greater than the TR (PSe evaluó el efecto de la variedad, tamaño de las hembras y relación hembra macho en la producción de huevos de tilapias Chitralada (CH: Oreochromis niloticus) y Taiwanesa Roja (TR: O. mossambicus x O. niloticus), en tanques de concreto, en una unidad de producción piscícola localizada en el Pie de Monte Andino del estado Trujillo, Venezuela, mediante un diseño en arreglo factorial 2x2x3: dos variedades (CH y TR), dos tamaños (grades y pequeñas) y tres relaciones sexuales (1♀:1♂; 2♀:1♂; 3♀:1♂). Los datos se procesaron mediante el análisis de varianza utilizando el modelo lineal general del SAS. Las hembras CH produjeron 1,5 veces más huevos, que pesaron 1,6 veces más y tuvieron una fecundidad 1,6 mayor que las TR (