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Se evalúo el efecto de la inclusión de aceite de maíz (AM) en la dieta de ovejas Pelibuey en un protocolo de transferencia de embriones. Veinticuatro ovejas donadoras fueron asignadas al azar a cada uno de dos grupos (G), G1: doce ovejas alimentadas con una dieta base (DB) con AM y, G2: doce ovejas alimentadas con DB sin AM. Los embriones fueron obtenidos 6.5 días después del estro y transferidos a ovejas receptoras formando cuatro tratamientos: T1: receptoras alimentadas con dieta base con AM (DB+AM) transferidas con embriones de una donadora del G1 (n=23), T2: receptoras alimentadas con DB sin AM (DB-AM) transferidas con embriones de una donadora del G1 (n=18), T3: receptoras alimentadas con DB+AM transferidas con embriones de una donadora del G2 (n=9) y T4: receptoras alimentadas con DB-AM transferidas con embriones de una donadora del G2 (n=11). La inclusión de AM en la dieta incrementó (P0.05) en el porcentaje de gestación (43.4, 55.5, 55.5 y 36.3 %) en las receptoras para ninguno de los tratamientos. La inclusión de AM en la dieta de ovejas Pelibuey incrementa la respuesta superovulatoria en un protocolo de transferencia de embriones.

Objetivo. Evaluar la viabilidad económica de incorporar un esquema de complementación alimenticia continua en cabras locales en pastoreo a partir del último tercio de gestación y durante la lactación. Materiales y métodos. Se utilizaron 24 cabras locales; grupo testigo (GT, n=12) y grupo complementado (GC, n=12). Se registró producción de leche diaria (PLD), por lactancia (PLTL) y por etapa de lactancia [temprana (PLLT), media (PLLM) y tardía (PLTR)], duración de la lactancia (DPL), peso vivo final (PVF) y condición corporal final (CCF) en las cabras. En las crías, peso al nacimiento (PN), peso a venta (PVA), edad a venta (EVA) y porcentaje de mortalidad. El análisis económico consideró los costos de complementación, mano de obra, y precios de venta de leche y crías. Resultados. El mejor comportamiento productivo y mayores ingresos se obtuvo en GC (p

La paratuberculosis (Ptb), también conocida como enfermedad de Johne es causada por el Mycobacterium avium subespecie paratuberculosis (Map). La enfermedad es contagiosa en bovinos, ovinos, cabras y otros rumiantes; en humanos está relacionada con la enfermedad de Crohn. En ovinos se manifiesta con pérdida progresiva de peso, y en estados avanzados, con heces aglutinadas y diarrea. Para el diagnóstico de la enfermedad existen diferentes pruebas: una en heces, de donde se obtiene una secuencia de inserción 900 (IS900) del genoma de Map, pudiendo identificar el organismo por la reacción en cadena de la polimerasa (PCR) y otra en suero sanguíneo, por medio de la prueba de inmunodifusión en gel de agar (IDGA). Se seleccionaron estas dos técnicas para estimar la prevalencia de Map. Se analizaron muestras sanguíneas y fecales de 211 ovinos asintomáticos en 32 rebaños de 10 comunidades de Salinas y Villa de Ramos, San Luis Potosí. La prevalencia de Map por rebaño entre comunidades con la prueba de IDAG fluctuó desde 4,35 hasta 33,33%, con promedio de 9,48%. La prevalencia con la prueba de PCR-anidada se presentó de 4,26 a 33,33% y un promedio entre comunidades de 7,58%. La prueba de IDGA detectó 20 ovinos positivos con anticuerpos de Map. La técnica de PCR-anidada detectó 16 ovinos que excretaban Map. Al utilizar la prueba de PCR como prueba de oro, la prueba de IDGA tuvo una sensibilidad de 81% y una especificidad de 96%, con una concordancia kappa de 0,96. Con la presencia de Map en los municipios de Salinas y Villa de Ramos de San Luis Potosí es necesario tomar las medidas pertinentes en su control y erradicación, para evitar la diseminación y pérdidas económicas en las explotaciones pecuarias.

La finalidad del presente estudio fue determinar el efecto del amamantamiento en la duración del intervalo parto-primera ovulación (IPPO), los cambios de peso corporal (CPC) posparto de las hembras y la ganancia diaria de peso (GDP) y mortalidad (M) de los corderos durante los primeros 90 d posparto en la raza Pelibuey. Cuarenta y dos ovejas multíparas con sus crías se asignaron al azar a uno de tres tratamientos: amamantamiento continuo (AC; n=16), amamantamiento restringido (AR; n= 16) y destete precoz (DP; n= 10). Los corderos en AC permanecieron con sus madres las 24 h del día con amamantamiento ad libitum; en AR, los corderos amamantaron durante 30 min al día (08:00 a 08:30); y en DP, las crías se separaron de sus madres desde los 7 d de nacidos sustituyéndose la alimentación con sustituto de leche. Para eliminar el efecto confundido de la época del año en los resultados obtenidos en el manejo del amamantamiento, se integró un grupo testigo con ovejas no gestantes (OV; n= 15). La eliminación del amamantamiento con el destete total (DP) de los corderos a los 7 d de edad aumentó el número de ovejas que ovularon antes de los 56 d posparto, disminuyó el IPPO y la pérdida de peso de las ovejas (P

Abstract: The objective of this work was to evaluate the effect of recombinant bovine somatotropin (rBST) and of the metabolic restorative preparation Metabolase (MR) on the reestablishment of the post-partum ovarian activity of Pelibuey sheep. Ninety-four ewes, with their respective lambs, were randomly assigned to one of the following treatments: T1, continuous suckling (CS); T2, CS + MR; T3, CS + rBST; and T4, CS + MR + rBST. Ovulating percentages, weight changes in ewes and lambs, incidence of estrus, onset and return to estrus, calving, fecundity, and prolificacy were evaluated. The highest ovulation percentages were recorded for CS in T1 and T2, and the lowest ones for rBST in T3 and T4. The treatments had a significant effect on lamb weight. Ewes in T3 had the lowest incidence of estrus (52.9%), besides a greater onset (26.8±1.9 hours) and return to estrus (66.6%). Calving (86.2%) and fecundity (1.8±0.2) were significantly higher in T2. The application of rBST in ewes increases lamb body weight, due to increased milk production, but affects negatively post-partum reproductive activity due to the loss of ewe body weight.

Copyright of Abanico Veterinario is the property of Sistema Superior Editorial and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Abanico Veterinario is the property of Sistema Superior Editorial and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One of the main factors that influences the fertility of cattle in grazing systems in hot tropical climates is heat stress. The objective of this study was to evaluate the effect of season, breed, hormonal and physiological condition on the quantity and quality of cumulus–oocyte complexes (COCs) and embryos produced in vitro, from Romosinuano (RM) and Tropical Milking (TM) donors. Three ovum pick-up and in vitro fertilization (OPU-IVF) were performed, one per season: hot dry (HD; 10, 10), hot humid (HH; 9, 9) and fresh dry (FD; 7, 10) in RM and LT donors. Serum levels of cortisol, insulin and glucose were measured, in addition to heart rate (HR), respiratory rate (RR) and rectal temperature (RT). Effect of season x genotype interaction (p ≤ 0.05) was observed in all COC variables and only in cleavage embryos (CLI) (p ≤ 0.05). Body weight (BW) affected all COC variables (p ≤ 0.01), except unviable (UNV) although affected degenerated embryos (DEG) (p ≤ 0.01) and total blastocysts (BLAST) (p ≤ 0.01). Cow age only affected viable COCs (VIAB) (p ≤ 0.05), code one blastocysts (BC1) and BLAST (p ≤ 0.01). Cortisol affected total COCs (COCsT), VIAB and total matured in vitro (TMIV) (p ≤ 0.01), as well as CLI, BC1 (p ≤ 0.01) and BLAST (p ≤ 0.05). Insulin affected COCsT (p ≤ 0.01), UNV (p ≤ 0.05), denuded oocytes (DE) (p ≤ 0.01), BC1 and code two blastocysts (BC2) (p ≤ 0.01). Glucose affected all COC variables (p ≤ 0.01), except UNV and all embryo variables except BC2. HR affected COCsT, DE, TMIV (p ≤ 0.01), CLI, BLAST and DEG (p ≤ 0.05). RR affected COCsT, UNV, VIAB, CLI (p ≤ 0.05), BC1, BLAST and DEG (p ≤ 0.01). RT only affected DE, VIAB (p ≤ 0.01) and BLAST (p ≤ 0.05). The seasonal climatic year variation of Veracruz and changes in physiological and hormonal variables have diverse effects on the cumulus–oocyte complexes and embryos produced by RM and TM donors.

The production of goat's milk under extensive grazing is very important to ensure an adequate growth of the progeny, but the productivity of local does and their progeny is not accurately characterized, particularly in the semi–arid Region of Northern Mexico. The aim was to evaluate the productive potential performance of local does and their offspring, when does are offered a supplementary feeding program in pre and post–partum period. Twenty–four local does and their progeny (n=40) were used and divided into two groups: 1) Control group; does fed exclusively on grazing, 2) Supplemented group; does were supplemented at 1.5% of live weight 45 d before and 45 d after parturition. Differences due to treatment were found (P0.05). High positive correlations between kid´s weight at birth (KWB) and KWS and KDWG were found (P

Abstract The objective of this work was to determine the nutritional content and the degradability of the dry matter and protein of fruits of Chloroleucon mangense and Acacia cochliacantha and of a 1:1 mixture of both, offered as supplements to Rambouillet sheep. In situ ruminal degradation was evaluated in three adult rams, fitted with a rumen cannula, with different incubation times of 0, 6, 12, 24, 48, and 72 hours. Protein intestinal degradability was quantified with a three-step procedure: in situ ruminal incubation, in vitro enzymatic digestion, and abomasal-intestinal digestion. The fruits of C. mangense and A. cochliacantha contain 21 and 12% crude protein, 47 and 56% neutral detergent fiber, 31 and 43% acid detergent fiber, and 0.9 and 6.0% condensed tannins, respectively. The fruits of C. mangense showed a higher nutritional value and a higher dry matter and crude protein degradability (p

Abstract The objective of this work was to evaluate the effect of the interaction between feeding level (FL) and body condition score (BCS) on the reproductive parameters of Pelibuey hair sheep (Ovis aries). The experimental units (64 ewes) were randomly assigned to one of four treatments: low feeding level and low body condition score; high feeding level and low body condition score; low feeding level and high body condition score; and high feeding level and high body condition score. The effect of sheep body condition score was significant on the pregnancy and lambing rates. The effect of feeding level was significant on the ovulation, estrus returning, pregnancy, and prolificacy rates. The interaction effect between BCS and FL was significant on the ovulation, estrus returning, pregnancy, lambing, and prolificacy rates. The reproductive function is more sensitive to the better nutrition effects in sheep with a low body condition score.

ABSTRACT: The objective of this study was to estimate the good-of-fitness and precision of parameters of the Gompertz-Laird, Logistic, Richards, and Von Bertalanffy growth models, using different data collection periods (DCP). Two hundred and sixty-two Mexican Creole chicks (116 females and 146 males), were individually weighed to form the following sets of data for each sex: DCP1 (weights recorded weekly from hatching to 63 d, and every 2 wk, from 63 to 133 d of age), DCP2 (weights recorded weekly from hatching to 133 d of age), DCP3 (weights recorded every third day, from hatching to 63 d, and every 14 d, from 63 to 133 d of age), and DCP4 (weights recorded every third day, from hatching to 63 d, and weekly, from 63 to 133 d of age). Data were analyzed using the NLIN procedure of SAS (Marquardt algorithm). For all growth models, the width of confidence interval (CI) of each parameter, was estimated (α = 0.05). The adjusted coefficient of determination (AR2), as well as the Akaike (AIC) and Bayesian information criteria (BIC) were used to select the best model. The higher the AR2, and the lower the width of CI, as well as the AIC and BIC values, the better the model. The Gompertz-Laird model, more frequently showed the highest AR2, and the lowest AIC and BIC values compared to the other models. Moreover, for all models, both sexes and all parameters, most confidence interval widths (all with the Gompertz-Laird model) were the lowest with DCP3 when compared to the other sets of data. In conclusion, the Gompertz-Laird model was the best provided that the chickens are weighed every third day from hatching until 63 d of age, and every 2 wk thereafter.

La inducción de la lactancia en el ganado es una forma alternativa de aumentar la vida productiva de las vacas con problemas reproductivos y productivos que, de lo contrario, serían sacrificadas. Se propone un protocolo alternativo de inducción de la lactancia. En este protocolo de 21 días se aprovecha la producción de progesterona endógena y utiliza dosis bajas de estradiol para estimular el crecimiento y la función de la ubre. Se inyectaron 500 mg de somatotropina en los días uno, ocho, catorce y veintiuno a vacas (n= 5) y vaquillas (n= 4) Holstein. Se aplicó el benzoato de estradiol (3-10 mg día-1) desde el día uno hasta el día catorce. A los animales se les administró cloprostenol (500 µg) en la mañana y en la tarde del día 1, y del día 18 al 21 se les inyectó dexametasona (5 mg día-1). Se ordeñaron a las vacas y vaquillas por primera vez el día 22. No se administró progesterona exógena en ningún momento del experimento, pero el protocolo de lactancia comenzó en la fase diestro del ciclo de celo y se inyectó GnRH para inducir la formación de un cuerpo lúteo accesorio. La inducción de la lactancia fue exitosa en todos los animales y la producción de leche varió de 18.3 a 25.5 kg día-1. La producción endógena de progesterona en combinación con dosis reducidas de benzoato de estradiol es suficiente para inducir la lactancia en vacas Holstein.

One of the strategies to genetically improve reproductive traits, despite their low inheritability, has been the identification of candidate genes. Therefore, the objective of this study was to detect candidate genes associated with fecundity through the fixation index (FST) and runs of homozygosity (ROH) of selection signatures in Katahdin ewes. Productive and reproductive records from three years were used and the genotypes (OvineSNP50K) of 48 Katahdin ewes. Two groups of ewes were identified to carry out the genetic comparison: with high fecundity (1.3 ± 0.03) and with low fecundity (1.1 ± 0.06). This study shows for the first time evidence of the influence of the CNOT11, GLUD1, GRID1, MAPK8, and CCL28 genes in the fecundity of Katahdin ewes; in addition, new candidate genes were detected for fecundity that were not reported previously in ewes but that were detected for other species: ANK2 (sow), ARHGAP22 (cow and buffalo cow), GHITM (cow), HERC6 (cow), DPF2 (cow), and TRNAC-GCA (buffalo cow, bull). These new candidate genes in ewes seem to have a high expression in reproduction. Therefore, future studies are needed focused on describing the physiological basis of changes in the reproductive behavior influenced by these genes.

This study tested whether the intravenous application of kisspeptin can stimulate the pulsatile secretion of LH in suckling ewes during postpartum anestrus. Ten days after lambing, Pelibuey ewes were allocated among two groups: (1) continuous suckling (n = 8), where the lambs remained with their mothers; and (2) restricted suckling (n = 8), where the mothers suckled their lambs twice daily for 30 min. On Day 19 postpartum, the ewes were individually penned with ad libitum access to water and feed and given an indwelling catheter in each jugular vein. On Day 20, 4 mL of blood was sampled every 15 min from 08:00 to 20:00 h to determine LH pulse frequency. At 14:00 h, four ewes in each group received 120 μg of kisspeptin diluted in 3 mL of saline as a continuous infusion for 6 h; the remaining four ewes in each group received only saline. The interaction between kisspeptin and suckling type did not affect LH pulse frequency (p > 0.05). Before kisspeptin administration, pulse frequency was similar in all groups (1.50 ± 0.40 pulses per 6 h; p > 0.05). With the application of kisspeptin, pulse frequency increased to 3.50 ± 0.43 pulses per 6 h (p ≤ 0.014), so the concentration of LH (1.11 ± 0.14 ng mL−1) was greater in kisspeptin-treated ewes than in saline-treated ewes (0.724 ± 0.07 ng mL−1; p ≤ 0.040). The frequency of LH pulses was greater with restricted suckling than with continuous suckling (2.44 ± 0.29 versus 1.69 ± 0.29 pulses per 6 h; p ≤ 0.040). We conclude that intravenous application of kisspeptin increases the pulsatile secretion of LH in suckling ewes and that suckling might reduce kisspeptin neuronal activity, perhaps explaining the suppression of ovulation. Moreover, the effects of kisspeptin and suckling on pulsatile LH secretion appear to be independent, perhaps operating through different neural pathways.

Se realizaron dos experimentos con la finalidad de evaluar el selenio y la vitamina E (Se-VE) en ovejas Pelibuey. La aplicación de Se-VE se realizó dos días antes del retiro de la progesterona (P). Se observó el inicio de estro, número de cuerpos lúteos, fertilidad, parición, fecundidad y prolicidad. En el primer experimento se utilizaron 125 hembras asignadas al azar a uno de ocho tratamientos. P (T1; n = 12), P + Se-VE (T2; n = 12), P + Gonadotropina coriónica equina (eCG; T3; n = 12), P + Alimentación dirigida (AD; T4; n = 12), P + Se-VE + eCG (T5; n = 12), P + Se-VE + AD (T6; n = 12), P + eCG + AD (T7; n = 12) y P + Se-VE + eCG + AD (T8; n = 12). Posteriormente se adicionó un noveno tratamiento (T9, Sin fármacos (SF), n = 29). En el segundo experimento se utilizaron 178 hembras asignadas al azar a uno de los siguientes tratamientos. P (T1; n = 62), P + Se-VE + eCG (T2; n = 62) y SF (T3; n = 54). El análisis de datos se realizó mediante pruebas de Chi-cuadrada para las variables en porcentaje, y análisis de varianza para las variables cuantitativas. En el experimento uno, el inicio al estro fue diferente (p < 0.05) para T3 y T5. El T9 fue diferente del resto de los tratamientos (p < 0.05) para fertilidad, parición y fecundidad.