ABSTRACT The white-toothed woodrat (Neotoma leucodon) inhabits the arid zones of north-central Mexico and it is important for rural communities for food and economic income. The objective was to characterize the habitat of the white-toothed woodrat in the Potosino-Zacatecano Plateau. In 44 sites with burrows and 44 random sites, the altitude, slope, slope exposure, ground cover: shrubs, grasses, rock, woody material and bare soil, as well as the density of prickly pear cactus, agave, shrubs and palms were recorded. In addition, 21 hunter-gatherers (H-G) were surveyed about woodrat habitat conditions. The woodrat builds its burrows in agaves (40.4 %) and 47.6 % of the H-Gs stated that the woodrat was more frequent in prickly pear cactus. Ninety % of the burrows were located on terrain with low slopes (≤ 4 %), where shrub density and cover were dominant (2085.6 ± 1825 ha -1, 36.1 ± 17.5%, respectively). Rat burrows are associated with shrubs and cactus, as they provide them with food and protection from predators. The H-G consider that in order to conserve the woodrat it is necessary to allow them to reproduce, establish hunting seasons and maintain the vegetation.

RESUMEN La rata nopalera (Neotoma leucodon) habita las zonas áridas del centro-norte de México y es importante para las comunidades rurales como alimento e ingreso económico. El objetivo fue caracterizar el hábitat de la rata nopalera en el Altiplano Potosino-Zacatecano. En 44 sitios con madrigueras y 44 aleatorios, se registró la altitud, la pendiente, exposición de la pendiente, la cobertura del suelo: arbustivas, gramíneas, roca, material leñoso y suelo desnudo, así como la densidad de nopal, maguey, arbustos y palmas. Asimismo, se encuestaron 21 cazadores-recolectores (C-R) acerca de las condiciones del hábitat de la rata. Ésta construyó sus madrigueras en maguey (40.4 %) y el 47.6 % de los C-R aseguran que la rata es más frecuente en los nopales. El 90 % de las madrigueras se ubicaron en terrenos con pendientes bajas (≤ 4 %) donde la densidad y la cobertura de arbustivas fueron dominantes (2085.6 ± 1825 ha -1, 36.1 ± 17.5%, respectivamente). Las madrigueras de rata se asocian con arbustos y nopales, ya que les brindan alimento y protección contra depredadores. Los C-R consideran que para conservar la rata es necesario dejar que se reproduzcan, establecer temporadas de caza y mantener la vegetación.

Abstract Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis (PTB), disease that causes a syndrome of bad nutrient absorption, weight loss and eventually death. The intestine is the main target organ where the infection develops; however, there is evidence of infection by MAP in extra-intestine sites of sheep, including mesenteric nodes and semen. The aim of the study was to identify the presence of MAP in reproductive tissue and semen of infected Pelibuey rams in clinical state of PTB. Seven rams were used in clinical PTB state and a non-infected ram by MAP of the Pelibuey breed, confirmed by serology, nPCR and bacteriological culture, with average weight and age of 57.23 ± 1.73 kg and 2.91 ± 0.17 years, respectively. The presence of MAP was identified in different tissue samples: spleen (1/7, 14.3% and 2/7, 28.6%), small intestine (3/7, 42.9% and 4/7, 57.1%) and mesenteric lymph nodes (3/7, 42.9% and 3/7, 42.9%), with nPCR and culture, respectively. It was also identified in epididymis tissue (1/7, 14.3%), Cowper gland (2/7, 28.6%) and prostate (1/7, 14.3%), using nPCR, although without detection in culture. It was identified in testicular tissue in 42.8% (3/7; culture or nPCR technique), but in 28.6% (2/7) with both techniques. Finally, the presence of MAP was identified in 42.9% (3/7) of semen samples with nPCR; however, it was not detected through culture. In conclusion, the presence of MAP was identified in lymphatic, digestive tissue, and semen; the presence of MAP was reported for the first time in epididymis, Cowper gland, prostate and testicles of infected Pelibuey rams.

Abstract The Spotted Owl (Strix occidentalis lucida) is a threatened species and little has been studied in Mexico. In this study, we characterized its habitat at roosting sites (reproductive and non-reproductive) and at random sites (sites where the species is distributed randomly without a pattern) in Aguascalientes, Durango and Zacatecas and identified the physical and biological (habitat) variables they select. We used descriptive statistics and determined through a Poisson Regression (PRA) those variables that had an effect on the registered owls; we also grouped the variables identified by the PRA with a Simple Correspondence (ACS) analysis and performed a Kruskal-Wallis test to detect possible significant differences between sites (rest and random). We located 29 owls (pairs, chicks and solitary individuals) in 11 roosting sites in oak-pine forests (63.6%) and in slopes with northern exposure and more inclined than those of random sites. The reproductive sites were located at a higher elevation, compared with non-reproductive and random sites; we also found at these sites, a greater tree density and with perching and dead trees of greater dimensions compared with trees found at non-reproductive and at random sites. However, only the tree density variable was statistically different (P < 0.05) between sites. The vegetation variables that were most associated with the roosting sites of the spotted owl were the tree height of the perch tree, the shrub cover and DBH of the perch tree. This information can be used in management and conservation plans of the subspecies in Mexico.

Resumen El búho manchado (Strix occidentalis lucida) es una especie amenazada y poco estudiada en México. En este estudio caracterizamos el hábitat de sus sitios de descanso (reproductivos y no reproductivos) y aleatorios (sitios en donde la especie se distribuye aleatoriamente sin un patrón) en Aguascalientes, Durango y Zacatecas e identificamos las variables físicas y biológicas (hábitat) que seleccionan. Usamos estadística descriptiva y determinamos mediante Regresión de Poisson (ARP) aquellas variables de hábitat que tuvieron un efecto sobre los búhos registrados; asimismo, agrupamos las variables identificadas por el ARP con un análisis de Correspondencia Simple (ACS) y realizamos una prueba de Kruskal-Wallis con el objeto de identificar posibles diferencias significativas entre sitios (descanso y aleatorios). Localizamos en total 29 búhos (parejas, polluelos e individuos solitarios) en 11 sitios de descanso en bosques de encino-pino (63.6%), en laderas con exposición norte y más inclinadas que la de los sitios aleatorios. Los sitios reproductivos estuvieron en una elevación más alta, comparada con los sitios no reproductivos y aleatorios; asimismo, en estos sitios encontramos una mayor densidad de árboles, con árboles usados como percha y árboles muertos (en pie) de dimensiones más grandes, comparados con los árboles encontrados en los sitios de descanso no reproductivos y aleatorios. Sin embargo, sólo la variable densidad de árboles fue diferente estadísticamente (P < 0.05) entre sitios. Las variables de vegetación que se asociaron más a los sitios de descanso del búho manchado fueron la altura del árbol de percha, la cobertura arbustiva y DAP del árbol de percha. Esta información la podemos utilizar en planes de manejo y conservación de la subespecie en México.

Resumo: O objetivo deste trabalho foi avaliar o efeito da somatotropina bovina recombinante (rBST) e do reconstituinte metabólico Metabolase (MR) no reestabelecimento da atividade ovariana pós-parto de ovelhas Pelibuey. Noventa e quatro ovelhas, com seus respectivos cordeiros, foram distribuídas ao acaso a um dos seguintes tratamentos: T1, amamentação continua (AC); T2, AC + MR; T3, AC + rBST; e T4, AC + MR + rBST. Foram avaliados percentagem de ovulação, alterações de peso em ovelhas e carneiros, incidência do estro, início e retorno ao estro, parição, fecundidade e prolificidade. As maiores percentagens de ovulação foram registradas para AC em T1 e T2, e as menores para rBST em T3 e T4. Os tratamentos tiveram efeito significativo sobre peso dos cordeiros. As ovelhas em T3 apresentaram menor incidência de estro (52,9%), além de maior início (26,8±1,9 horas) e retorno ao estro (66,6%). A parição (86,2%) e a fecundidade (1,8±0,2) foram significativamente maiores em T2. A aplicação da rBST nas ovelhas incrementa o peso corporal dos cordeiros, em razão do aumento na produção de leite, mas afeta negativamente a atividade reprodutiva pós-parto, em razão da perda de peso corporal das ovelhas.

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.

Abstract: The aspiration of oocytes by laparoscopy for the transfer of embryos is a technique used in the extraction of oocytes from a genetically superior animal, with the purpose of producing in vitro embryos to implant them in a female, which allows to increase the response to selection in a program of genetic improvement, by obtaining animals above the population average and because the generation interval can be reduced. Prior to the aspiration of the oocytes, it is necessary to prepare the donor and recipient females based on exogenous hormones, to achieve maximum production and extraction of oocytes in the same donor female and, consequently, a greater probable number of embryos produced and transferred. With the aim of describing the different protocols used in the aspiration of oocytes by the laparoscopic technique for the transfer of embryos in goats, the present literature review was carried out through scientific publications.

Resumen: La aspiración de ovocitos por laparoscopía para la transferencia de embriones es una técnica utilizada en la extracción de ovocitos de un animal genéticamente superior, con la finalidad de producir embriones in vitro para implantarlos en una hembra, lo cual permite incrementar la respuesta a la selección en un programa de mejoramiento genético, al obtener animales superiores al promedio de la población y porque se puede reducir el intervalo de generación. Previo a la aspiración de los ovocitos, es necesario preparar a las hembras donantes y receptoras a base de hormonas exógenas, para lograr la producción y extracción máxima de ovocitos en una misma hembra donante y, por consecuencia, un mayor número probable de embriones producidos y transferidos. Con el objetivo de describir los diferentes protocolos utilizados en la aspiración de ovocitos por la técnica de laparoscopía para la trasferencia de embriones en cabras, se realizó la presente revisión de literatura mediante publicaciones científicas.

Abstract In animal reproduction, natural methods like male effect (ME) and the action of neuroexcitatory amino acids accelerate puberty and induce ovulation in ewe lambs. In this study it was found that the biostimulation of the ewe and the neurotransmitter action of amino acids of a commercial energy tonic (CET, Metabolase®) may change the pulse frequency of luteinizing hormone (LH) and induce ovulation in prepubertal ewes. The objective was to evaluate the ME and CET action to induce ovulation and characterize the preovulatory peak of LH in prepubertal Pelibuey ewes. The experimental design included two factors (CET and ME) on two levels each (without: wo, and with: w). The treatments were randomized to 46 ewes: T1 (n = 12) control group: ewes without CET and without ME (woCETwoME), T2 (n=12) ewes with CET and without ME (wCETwoME), T3 (n=10) ewes without CET and with ME (woCETwME) and T4 (n=12) ewes with CET and with ME (wCETwME). Ovarian activity (OA) and the ovulation rate (OR) were evaluated by laparoscopy. The characteristics of the preovulatory peak of LH were evaluated in response to ME to confirm the first ovulation. The action of the CET, the male effect as well as their interaction, did not increase (p>0.05) the number of ovarian follicles of different diameters. The male effect and its interaction with the energy tonic increased (p≤0.05) the OR (woCETwME: 0.70 and wCETwME: 0.75). The response of the preovulatory peak of LH was similar (p>0.05) in ewes with ME with or without CET (wCETwME: 91.7 % and woCETwME: 70.0 %). The male effect and its interaction with CET induce the preovulatory LH peak and the first ovulation in prepubertal Pelibuey ewes.

Resumen En la reproducción, los métodos naturales como el efecto macho (EM) y la acción de los aminoácidos neuroestimuladores aceleran la pubertad e inducen la ovulación en corderas. En el presente estudio se consideró que la bioestimulación del carnero y la acción neurotransmisora de los aminoácidos, en un reconstituyente energético comercial (REC, Metabolase®), podrían modificar la frecuencia de pulsos de la hormona luteinizante (LH) e inducir la ovulación en ovejas prepúebres. El objetivo fue evaluar el EM y la acción del REC para inducir la primera ovulación y caracterizar el pico preovulatorio de LH en ovejas Pelibuey prepúberes. El diseño experimental fue con un arreglo de dos factores (REC y EM) en dos niveles cada uno (sin: s; con: c) y los tratamientos fueron asignados al azar a 46 ovejas: T1 (n=12) testigo, ovejas sin REC y sin EM (sRECsEM); T2 (n=12) ovejas con REC y sin EM (cRECsEM); T3 (n=10) ovejas sin REC y con EM (sRECcEM); y T4 (n=12) ovejas con REC y con EM (cRECcEM). La actividad ovárica (AO) y la tasa ovulatoria (TO) se evaluaron por laparoscopía. Las características del pico preovulatorio de LH se evaluaron en respuesta al EM para confirmar la primera ovulación. La acción del REC, el efecto macho, así como su interacción, no aumentaron (p>0.05) la cantidad de folículos ováricos de diferente diámetro. El efecto macho y su interacción con el REC aumentaron (p≤0.05) la TO (sRECcEM: 0.70 y cRECcEM: 0.75). La respuesta del pico preovulatorio de LH fue similar (p>0.05) en las ovejas con EM con o sin REC (cRECcEM: 91.7 % y sRECcEM: 70.0 %). El efecto macho y su interacción con el REC inducen el pico preovulatorio de LH y la primera ovulación en ovejas Pelibuey prepúberes.

Bone Morphogenetic Protein 15 (BMP15), also known as Growth and Differentiation Factor 9B (GDF9B), is a member of the superfamily of Transforming Growth Factor β (TGFβ) and it expression in the oocyte is essential for follicular development and growth. Polymorphisms in the BMP15 gene are associated to the increase in ovulation rate or prolificacy in some sheep breeds. The objectives of this study were to determine the FecX G, FecX L and FecX H polymorphisms with a mutation of a single base (SNP- single nucleotide polymorphisms) on the BMP15 gene, and to estimate the association of the three polymorphisms with the lambing type in Pelibuey sheep. Blood samples were taken from the jugular vein of 253 adult Pelibuey ewes in reproductive age to determine the SNPs, according to the most probable producing ability (MPPA) in prolificacy. Through the tetraprimer ARMS-PCR technique (Amplification Refractory Mutation System-Polymerase Chain Reaction), the polymorphisms were determined for the first time in Pelibuey sheep. Of the 253 ewes, 1050 births were used, where the wild (CC) and mutated (TT) homozygous genotypes of polymorphism FecX G with 45% and 43%, respectively, and the wild (GG) and mutated (AA) homozygous genotype of polymorphism FecX L with 66% and 29%, respectively, were associated to a higher number of double lambing (p≤0.01). In polymorphism FecX H only CC genotype was found, with 52% double lambing (p≤0.01). In conclusion, polymorphisms FecX G and FecX L of the BMP15 gene were determined for the first time in Pelibuey ewes, and they are associated to a higher number of double lambing.

La proteína 15 morfogénica ósea (BMP15), también conocida como factor 9B de crecimiento y diferenciación (GDF9B), es miembro de la superfamilia de factores β de crecimiento (TGFβ) y su expresión en el ovocito es esencial para el desarrollo y crecimiento folicular. Polimorfismos en el gen BMP15 están asociados con el aumento de tasa ovulatoria o prolificidad en algunas razas de ovinos. Los objetivos del presente estudio fueron determinar los polimorfismos FecX G, FecX L y FecX H con una mutación de una sola base (SNP) en el gen BMP15, y estimar la asociación de los tres polimorfismos con el tipo de parto en ovejas Pelibuey. En 253 ovejas Pelibuey adultas en edad reproductiva se tomaron muestras sanguíneas de la vena yugular para determinar los SNPs, de acuerdo con la mejor aptitud de producción probable (MPPA) de prolificidad. Mediante la técnica tetraprimer ARMS-PCR (Amplification Refractory Mutation System-Polymerase Chain Reaction), se determinaron por primera vez los polimorfismos en las ovejas Pelibuey. De las 253 ovejas se usaron 1050 partos, donde los genotipos homocigoto silvestre (CC) y mutado (TT) del polimorfismo FecX G con 45% y 43%, respectivamente, y el homocigoto silvestre (GG) y mutado (AA) del polimorfismo FecX L con 66 % y 29%, respectivamente, se asociaron con un número mayor de partos dobles (p≤0.01). En el polimorfismo FecX H sólo se encontró el genotipo CC con 52% de parto doble (p≤0.01). En conclusión, los polimorfismos FecX G y FecX L del gen BMP15 fueron determinados por primera vez en ovejas Pelibuey, y están asociados con un número mayor de tipo de parto doble.