Effect of Brosimum alicastrum Foliage on Intake, Kinetics of Fermentation and Passage and Microbial N Supply in Sheep Fed Megathyrsus maximus Hay.

An experiment was carried out to assess the effect of the incorporation of sun-dried foliage of Brosimum alicastrum into rations based on hay of Megathyrsus maximus on intake, rumen fermentation, kinetics of passage, microbial nitrogen supply to the small intestine, apparent digestibility in Pelibuey hair sheep. Four rations were randomly allotted to four rumen-cannulated lambs (BW = 37.4 ± 4.9 kg) using a 4 × 4 Latin square design to assess the effect of increasing levels (0, 15, 30 and 45% DM basis) of foliage of Brosimum alicastrum on a basal ration of M. maximus. Organic matter intake and water consumption increased linearly (p < 0.01) with increasing levels of B. alicastrum in the ration. The rate and potential extent of rumen fermentation of OM and CP of B. alicastrum were 10.6%/h and 86.6% and 11.4%/h and 95.2%, respectively, but no effect (p > 0.05) was found on the potential rumen degradation of DM (40.2%) or on the rate of degradation of DM (0.033%/h) of M. maximus, although a positive effect was found in the rumen degradation rate of NDF (p < 0.05). VFA and ammonia concentration in the rumen and the rate of passage of solids and liquids through the rumen (k1) increased linearly (p < 0.01) with increasing levels of B. alicastrum. Rumen pH was not affected by the incorporation of B. alicastrum (p > 0.05). Microbial nitrogen supply to the small intestine (p < 0.001), apparent digestibility of dry matter (p < 0.01) and NDF (p < 0.05) of the rations were also significantly increased as a result of the incorporation of B. alicastrum foliage. Results from this experiment suggest that the foliage of Brosimum alicastrum can be readily incorporated at around 30% of the ration of dry matter in hair sheep with beneficial effects on feed intake, rate of passage and microbial N supply to the lower tract.

Prevalence and Progression of Gingivitis in Domestic Cats in Subtropical Mexico.

With the objective to characterize the gingival index (GI) and its progression, 218 domestic cats in a subtropical region of Mexico were studied. All teeth of each cat were examined with a periodontal probe to determine the GI; in addition, the absence of teeth was recorded. Six months later, the teeth of the 38 cats were again examined to assess any progression of the GI and loss of teeth. From the 218 cats, 33.0% of them develop some degree of gingival inflammation; from those, 61.5% were classified as GI 1. Age, sex, and neutered status were associated with tooth affections. Missed teeth were observed in 35% of the cats, particularly for molars 109 and 209 in both sexes. After six months, the number of teeth with GI 1 decreased to 20%. The gingival problems in cats have not been well studied, particularly at the speed they progress and how this can affect the loss of teeth; under the conditions of this study, a high frequency of gingival inflammation even at early age was demonstrated, with a rapid tooth loss. Although young males were more prone to develop gingivitis, females tend to loss more teeth. Non-neutered cats tended to develop more dental affections.

Evidence of differentiation and population structure in Charolais cattle of Mexico.

Charolais is one of the most important beef cattle breeds in the world. In Mexico, it was introduced almost a century ago, and it has been suggested that particular breeding management and genetic material origin have caused a process of divergence among the current population. By a high-density SNP array genome-wide analysis, this study aimed to assess the proposed differentiation and population structure of local populations by genetic distances and structure approaches, and a European Charolais sample was included as a reference population. The differentiation statistics indicated that local populations exhibit moderate divergence, confirming a significant differentiation process between northeastern and northwestern Charolais populations (Fst≥ 0.043, D≥ 0.031). These results were strongly supported by PCA and structure analysis. Genetic isolation and low genetic flow between populations and divergent origins of introduced genetic material (i.e., semen) are likely the main drivers of the outcomes. Some implications are discussed.

Congenital Transmission of Trypanosoma cruzi in Naturally Infected Dogs.

Background: Congenital transmission (CT) of Trypanosoma cruzi in dogs has not been clearly demonstrated, even though dogs are important reservoirs of this agent. Materials and Methods: Seventeen late pregnant dogs seropositive for T. cruzi were selected, and a total of 84 fetuses were obtained. Blood and heart tissues from the fetuses and dams, and placental tissue from dam were collected. All tissues were analyzed by quantitative polymerase chain reaction (qPCR) for T. cruzi DNA (TcDNA) and inflammatory infiltrate and pathology by histological examination. CT was determined when physical, histological, or molecular evidence of T. cruzi was detected in blood or tissues of the fetuses. Results: A general transmission frequency of 59% was found, and 0.20 ± 0.24 of fetuses per litter were infected. Dams that were qPCR positive for TcDNA in cardiac tissue or blood displayed a transmission frequency of 100% and 67%, respectively. The highest parasite burden was noted in dams that were positive for TcDNA in both blood (82E-01 ± 1.54E-01) and cardiac (5.28E+03 ± 8.85E+03) tissues. In fetuses, higher parasitic burden in blood and cardiac tissue was found in those carried by dams that were seropositive and qPCR positive for TcDNA in cardiac tissue and blood. No amastigote nests were recorded in the cardiac tissue of fetuses in the histopathological studies, but typical lesions of T. cruzi infection were identified in all fetuses where CT occurred. Conclusions: CT of T. cruzi occurred at a high frequency in naturally infected pregnant dogs from the endemic areas.

Male Layer Chicken's Response to Dietary Moringa oleifera Meal in a Tropical Climate.

This study was conducted to evaluate the effects of different dietary amounts of Moringa oleifera meal (MOM), consisting of leaves and small edible green stems, on growth performance, carcass traits, and blood parameters of finisher male layer-type slow-growing chickens raised with outdoor access. A total of 198 Dominant Blue D 107, 72-day-old male chickens were randomly assigned to tree dietary treatments containing 0, 30, and 60 g/kg MOM that corresponded to T1 or control, T2, and T3, separately. Each treatment was divided into 6 replicates of 11 birds apiece, and all birds had access to the outdoors. After 7 weeks of experimental rearing, live weight was 2218.1, 2164.4, and 2176.6 g for birds raised in T1, T2 and T3, respectively, without statistical differences (p ≥ 0.05). Live weight gain and daily live weight gain increased (p ≤ 0.05) in favor of the control group during the first 4 weeks but decreased (p ≤ 0.05) in the last 3 weeks of the trial. Overall feed intake was not influenced by the treatments (p ≥ 0.05). Birds raised with MOM in their diets had higher feed conversion (p ≤ 0.05). T2 diet considerably increased (p ≤ 0.05) birds' breast and gizzard weight and yield while decreasing feet weight and yield, in comparison to T1. Dietary MOM inclusion did not impair or improve (p ≥ 0.05) blood parameters. The results of this study suggest that up to 60 g/kg MOM could be included in the diets of slow-growing Dominant Blue D 107 male chickens grown with access to outdoors without compromising their productive performance (except for feed conversion), slaughter characteristics, and health status.

Molecular characterization of bacterial microbiota associated with infectious bovine keratoconjunctivitis in Michoacán, Mexico / Caracterización molecular de la microbiota bacteriana asociada con queratoconjuntivitis infecciosa bovina en Michoacán, México / Caracterização molecular da microbiota bacteriana associada à ceratoconjuntivite bovina infecciosa em Michoacán, México

Abstract Background: The most common ocular disease affecting cattle worldwide is infectious bovine keratoconjunctivitis (IBK), which has been associated with Moraxella bovis bacterium. Objective: To report the molecular characterization of the ocular bacterial microbiota and its relation to IBK in cattle in two dairy regions in Michoacán, Mexico. Methods: A total population of 761 bovines were evaluated, of which 17 (2.23%) showed symptoms of IBK. Thirty-eight bacterial isolates from ocular samples of bovines with IBK were characterized by Gram-staining and antimicrobial sensitivity. In addition, isolates were identified by sequence comparisons of the 16S ribosomal gene. Results: The genus Moraxella was one of the most abundant bacteria and M. bovoculi was the most predominant species. Conclusion: The bacterial isolates identified in eye lesions of cattle and associated to IBK are diverse. To the author´s knowledge, this is the first study on the subject in Mexico; therefore, more research is needed to estimate the incidence of IBK and determine its associated microbiota.

Resumen Antecedentes: la enfermedad ocular más común que afecta al ganado en todo el mundo es la queratoconjuntivitis infecciosa bovina (IBK), que se ha asociado con la bacteria Moraxella bovis. Objetivo: reportar la caracterización molecular de la microbiota bacteriana ocular y su relación con IBK en ganado de dos regiones lecheras en Michoacán, México. Métodos: se evaluó una población total de 761 bovinos de los cuales 17 (2,23%) mostraron síntomas de IBK. Se obtuvieron treinta y ocho aislamientos bacterianos de muestras oculares de bovinos con IBK, los cuales se caracterizaron por tinción de Gram y sensibilidad antimicrobiana. Además, los aislamientos se identificaron mediante comparaciones de secuencias del gen ribosomal 16S. Resultados: el género Moraxella fue una de las bacterias más abundantes y M. bovoculi fue la especie más predominante. Conclusión: los aislamientos bacterianos identificados en lesiones oculares de bovinos y asociados a IBK son diversos. Hasta donde sabemos, este es el primer estudio sobre el tema realizado en México; por lo tanto, es necesario ampliar esta investigación para estimar la incidencia de IBK y determinar la microbiota asociada con la misma.

Resumo Antecedentes: a doença ocular mais comum que afeta o gado no mundo é a ceratoconjuntivite bovina (IBK), que tem sido associada à bactéria Moraxella bovis. Objetivo: relatar a caracterização molecular da microbiota bacteriana ocular e sua relação com a IBK em bovinos de duas regiões leiteiras de Michoacán, México. Métodos: foi avaliada uma população total de 761 bovinos, más apenas 17 (2,23%) apresentaram sintomas de IBK. Trinta e oito isolados bacterianos de amostras de olho bovino com IBK foram caracterizados por coloração de Gram e sensibilidade antimicrobiana. Além disso, os isolados foram identificados por comparação de sequências do gene ribossômico 16S. Resultados: a microbiota bacteriana associada à IBK foi diversa, sendo o gênero Moraxella uma das mais abundantes e M. bovoculi a espécie predominante. Conclusão: de acordo com o conhecimento dos autores, este é o primeiro estudo sobre o tema no México até o momento, portanto é necessário expandir essa pesquisa para estimar a incidência de IBK e determinar a microbiota associada à mesma.

Effect of Leptin, Pituitary Transcription Factor and Luteinizing Hormone Receptor Genes Polymorphisms on Reproductive Traits and Milk Yield in Holstein Cattle

Abstract The aim of this study was to estimate allelic and genotypic frequencies of markers in the leptin (LEP), pituitary transcription factor (PIT-1) and luteinizing hormone receptor (LHR) genes and evaluate their effects on reproductive traits and milk yield of Holstein cattle. Data from 147 cows from department of Francisco Morazán, Honduras, were collected and PCR-Restriction Fragment Length Polymorphism (RFLP) assays were performed to characterize the PIT-1-HinfI, LEP- A59V and LHR-rs41256848 polymorphisms. To estimate the effect of genotypes on reproductive traits and milk yield fixed and mixed linear models were fitted. The frequencies of the genotypes CC, CT and TT of A59V, AA, AB and BB of HinfI, and CC, CG and GG of rs41256848 were 0.46, 0.33 and, 0.21; 0.09, 0.32 and 0.58; and 0.37, 0.61 and 0.02, respectively. The genotypes of LEP and LHR showed deviations from Hardy-Weinberg equilibrium. The A59V polymorphism was significantly associated with the calving to conception interval (CCI) (p=0.01), being the C allele favorable. The HinfI and rs41256848 polymorphism were significantly associated (p=0.08 and p=0.04) with age to first calving (AFC), being the A and G the alleles favorable associated, respectively. The results suggest that LEP, PIT and LHR polymorphisms can probably act as candidate to be used in marker-assisted selection for AFC and CCI traits.

Ovarian dynamics of buffalo (Bubalus bubalis) synchronized with different hormonal protocols.

The study evaluates the effect of three hormonal protocols on ovarian dynamics and progesterone (P4) secretion of buffalo (Bubalus bubalis). Twenty-nine pluriparous Murrah buffaloes were used. The protocols were as follows: OVSYNCH (n = 10): 100 µg of gonadorelin (day 0), 500 µg of cloprostenol (day 7), and 100 µg of gonadorelin (day 9). CIDR+EB (intravaginal device (CIDR®) + estradiol benzoate; n = 10): CIDR plus 2 mg of EB (day 0), withdrew of CIDR, 500 µg of cloprostenol (day 7) and 1 mg of EB (day 8). CIDR+eCG (n = 9): CIDR plus 2 mg of EB (day 0), withdrew of CIDR, 500 µg of cloprostenol and 400 IU of eCG (day 7). Follicles were counted with an ultrasound and measured at 0, 24, and 54 h. The maximum follicle diameter and ovulation were evaluated at 70, 80, and 94 h after CIDR withdrew. Estrous was detected per 1 h three times daily. Blood samples were collected on days 0, 7, 10, 15, and 22 to determine P4 concentration. In CIDR+EB protocol, 50% of buffaloes presented estrous, at 69.6 h. All buffaloes ovulated. CIDR+eCG group had the shortest (69 h) ovulation time. No treatment differences for follicular population, maximum follicle diameter, and P4 concentration on days 7 and 10 (P > 0.05) were found. The P4 concentration in OVSYNCH and CIDR+eCG protocols were > 1 ng/ml, on days 15 and 22 (P < 0.05). There was no difference in ovarian activity; however, the P4 secretion was normal in the OVSYNCH and CIDR+eCG protocols compared to the CIDR+EB protocol.

Factors associated with pregnancy rate in fixed-time embryo transfer in cattle under humid-tropical conditions of México.

The objective was to determine the effect of some factors on pregnancy rate of fixed-time embryo transfer (FTET), in cows and heifers kept under Mexican tropical conditions. Recipients females (n=405) grazing in pastures were selected according to breed group (Zebu and crosses), parity (nulliparous and multiparous), body condition score (BCS) and the presence of a corpus luteum (CL). The females were synchronized on day 0 using a progesterone vaginal device and 2 mg estradiol benzoate (EB), two groups were established. Group 1 (conventional protocol) were animals in which the progesterone device was removed on day 7. At this time, also received an injection of 50 mg cloprostenol sodium and 1 mg estradiol cypionate. Animals also received 300 IU (heifers) or 360 IU (cows) of eCG. Group 2 (J-Synch protocol) were animals in which the progesterone device was removed on day 6. Cloprotenol and eCG injections were applied as in Group 1. Additionally, on day 9, animals of group 2 received 0.01 mg buserelin acetate. Embryo transfer of in vivo or in vitro was done on day 16 and pregnancy diagnosis was realized by ultrasonography on days 23 and 53 after FTET. Statistical analyses were carried out using Chi-square tests and logistic regression. Pregnancy rate varied between farms (P<0.05). The highest pregnancy rate was for multiparous cows (66%). The recipient utilization rate was better in the J-Synch protocol (85%), and in vivo embryos (75%) had higher pregnancy rate. The diameter of the follicle and the CL had no effect on pregnancy rate (P>0.05). However, the logistic regression determined that the only significant factor on pregnancy rate was the type of embryo. In conclusion, pregnancy rate in FTET females was higher for in vivo embryos than for in vitro embryos in cows evaluated under humid tropical conditions in Mexico.

Factores ambientales asociados con los días no-productivos de cerdas en el trópico mexicano / Environmental factors associated with lifetime non-productive days of sows in the Mexican tropics

RESUMEN Objetivo. Estimar el número de días no productivos (DNP) de por vida, la proporción de DNP (%DNP) y días no productivos por cerda por año (DNP/Y), y determinar el efecto de factores de hato y cerda sobre las características aquí estudiadas en tres granjas comerciales en el trópico mexicano. Materiales y métodos. Los datos de 6703 cerdas de tres granjas comerciales fueron usados. El modelo que describió las características de interés incluyeron los efectos fijos de granja, año de primer parto, época de primer parto, edad al primer parto, causa de desecho, interacción de año por época y error residual. Resultados. Las medias de DNP de por vida, %DNP y DNP/Y fueron 64 días, 12% y 39.3 días, respectivamente. Todos los factores tuvieron efectos significativos (p<0.01) en todas las características. Las cerdas con primer parto a mayor edad y las eliminadas por razones reproductivas tuvieron más DNP en el hato. Además, las cerdas eliminadas en el primer parto tuvieron menor DNP y mayor %DNP que las cerdas desechadas en partos subsecuentes. Conclusiones. La eliminación temprana de cerdas incrementó la proporción de días no productivos, que a su vez podrían reducir la rentabilidad de las granjas.

ABSTRACT Objectives. To estimate the lifetime non-productive days (NPD), lifetime proportion of NPD (%NPD) and non-productive days per sow per year (NPD/Y), and to determine the effect of herd and sow level factors on the traits here studied in three pig farms in the Mexican tropics. Materials and methods. Data from 6703 sows from three commercial farms were used. The model that described the traits studied comprise the fixed effects of farm, year and season of first farrowing, age at first parity, reasons of removal of sows, year x season interaction and the residual error. Results. The means for lifetime NPD, %NPD and NPD/Y were 64 days, 12.0% and 39.3 days, respectively. All fixed factors had significant effects (p<0.01) on the characteristics evaluated. Sows having their first parity at an old age and sows culled because of reproductive reasons had the highest lifetime NPD. In addition, sows culled at first parity had lower lifetime NPD and higher %NPD than sows culled in subsequent farrowing. Conclusions. The early culling of sows increased the percentage of non-productive days, which in turn is expected to reduce the profit of farms.

Risk factors associated with the seroprevalence of paratuberculosis in sheep flocks in the hot-arid region of Sonora, México.

Paratuberculosis is caused by Mycobacterium avium subspecies paratuberculosis (MAP), a chronic disease of a negative economic impact on sheep production. In the state of Sonora, Mexico, there are no reports on the prevalence of MAP in sheep and risk factors associated with it. The objective of this study was to estimate the seroprevalence of MAP and risk factors associated by testing antibody-positive in sheep flocks located in the arid and hot region of Sonora, Mexico. A cross-sectional study was conducted from February 2012 to December 2014, in 43 flocks. Serum samples from 1178 individual sheep were obtained to detect antibodies against MAP by immunodiffusion in agar-gel. During blood sampling, information about animal and flock management risk factors were obtained by applying a questionnaire to the owners. Risk factors associated with seroprevalence of MAP were estimated using binary logistic regression. The true prevalence of MAP was 7.48% (95% CI 5.98, 8.98) and 53.5% of flocks had at least one seropositive animal. An animal was more likely to be seropositive if it was from a large flock (> 300 animals; OR 3.52, 95% CI 1.24, 9.99) and was born outside the farm (OR 6.24; 95% CI 2.9-1, 3.52). This is the first report of Mycobacterium avium subspecies paratuberculosis seroprevalence in sheep, in Sonora, Mexico. Large flocks and the entry of new animals to the flock were critical risk factors associated with MAP seropositivity.

Effects of Outdoor Access and Indoor Stocking Density on Behaviour and Stress in Broilers in the Subhumid Tropics.

Studies investigating the welfare of commercial-line broiler chickens raised in houses with outdoor access in the tropics are scarce, and none have investigated whether responses vary according to indoor conditions. Hence, we assessed the effects of providing outdoor access at two indoor stocking densities on broiler chickens' growth, behaviour, stress responses and immunity in a tropical region of Mexico. One hundred and sixty chickens were assigned to one of four treatments in a factorial design: with or without outdoor access and low or high stocking density indoors. Ad libitum sampling was used to build a purpose-designed ethogram. Scan sampling was used to record the number of birds engaged in each activity of this ethogram, both indoors and outdoors. Heterophil/lymphocyte (H/L) ratio and serum corticosterone levels were tested in weeks four and six of age. When the birds were 42 days old, they were slaughtered, and the bursa and spleen harvested and weighed. In an interaction between stocking density and outdoor access, birds at the high stocking density with no outdoor pens spent the least time walking and preening and more time lying (p < 0.05). Birds given outdoor access foraged more, but only at indoor low stocking densities (p < 0.05). Outdoor access reduced heterophil/lymphocyte ratio, indicating reduced stressor response. Birds with low stocking density indoors and outdoor access appeared more responsive to stressors, with elevated corticosterone and reduced spleen and bursa weights (p < 0.05). There were welfare benefits of outdoor access, principally in terms of increased activity, which were reflected in slower growth in the birds with outdoor access.

Describing the growth curve of local turkey using non-linear models / Descripción de la curva de crecimiento de pavos locales usando modelos no lineales

ABSTRACT Objective. Determine the best non-linear model to fit the growth curve of local turkeys managed under confinement in Michoacan, Mexico. Material and methods. Twenty-four and 43 female and male turkeys, reared under commercial conditions were given commercial feed. Birds were weighed weekly from hatch to 29 weeks of age. The Gompertz, Brody, Richards, von Bertalanffy and Logistic models were chosen to describe the age-weight relationship. Results. The best fitting model was selected based on the multiple determination coefficient (R2), the Akaike information criterion (AIC) and visual analysis of the observed and predicted curves. In both female and male, von Bertalanffy was the best model. The highest estimates of parameter A (mature weight) for both females and males were obtained with the von Bertalanffy model followed by the Gompertz and Logistic. The estimates of A were higher for males than for females. The highest estimates of parameter k (rate of maturity) for both females and males were, in decreasing order, for the Logistic, Gompertz, and von Bertalanffy models. k values for female turkeys was higher than for males. The age at the point of inflection (ti) and body weight at the age of point of inflection (WI) varied with the model used. The largest values of TI and WI corresponded to the Logistic model. Between sexes, the largest TI and WI values corresponded to males. Conclusions. The best models to describe turkey growth was the von Bertalanffy because it present the highest R2 and lowest AIC values.

RESUMEN Objetivo. Determinar el modelo no lineal que mejor ajuste la curva de crecimiento de pavos locales criados en confinamiento. Material y métodos. Veinticuatro y 43 pavos hembras y machos, respectivamente, criados en confinamiento fueron alimentados con dietas comerciales. Cada animal se pesó desde el nacimiento hasta la semana 29 de edad. Los modelos de Gompertz, Brody, Richards, von Bertalanffy y Logístico fueron elegidos para describir la relación edad-peso. El mejor modelo se seleccionó con base en el coeficiente de determinación (R2), el criterio de información de Akaike (AIC) y el análisis visual de las curvas observadas y predichas. Resultados. El mejor ajuste (machos y hembras) correspondió al modelo von Bertalanffy. El más alto valor del parámetro A (edad a la madurez), para hembras y machos correspondió al modelo von Bertalanffy, seguido de Gompertz y Logístico. El estimador A fue mayor para machos que hembras. El mayor valor del parámetro k (tasa de madurez), para hembras y machos, variaron según el modelo utilizado. Los valores de k fueron más altos para hembras que para machos. La edad al punto de inflexión (T:) y peso vivo al punto de inflexión (W:) también variaron de un modelo a otro. Los valores más altos de T, y Wj correspondieron al modelo Logístico. Entre sexos, los valores mayores de T: y WI correspondieron a los machos. Conclusiones. El mejor modelo que describió la curva de crecimiento de los pavos locales fue el de von Bertalanffy.

Reproductive behavior in hair sheep rams under tropical conditions.

The reproductive efficiency of sheep herds depends to a great extent on the ram. Male reproductive evaluation allows to select for the best and eliminate those with reproductive problems. The objective was to evaluate the effect of breed and age group on the reproductive behavior of hair sheep rams in the tropics of Mexico. Pelibuey (n = 42), Blackbelly (n = 30), Dorper (n = 44), and Katahdin (n = 30) rams of two age groups: young (n = 74, 1-1.5 years old) and adult (n = 72, 2-4 years old) were evaluated. Serving capacity (10-min duration) and breeding soundness evaluation (BSE) tests were carried out in each ram. In the first test, rams were classified as suitable and unsuitable, and in the BSE test, they were classified as satisfactory, questionable, or unsatisfactory. The response variables were analyzed using chi-square test or analyses of variance (ANOVA). ANOVA included the fixed effects of breed, age group, and their interaction. In the serving capacity test, 79.5% of the rams were considered suitable, with no breed differences (P > 0.05). Adult rams (90.3%) had the highest proportion of suitable rams (P < 0.05). In the BSE test, 80.2% of the rams were satisfactory; only breed being significant (P < 0.05). Pelibuey breed had the highest proportion of satisfactory rams (91.4%). Breed × age interaction was no significant for any trait. After serving capacity and BSE tests, a high proportion of rams was found not suitable for reproduction (36.3%), which is expected to cause low fertility in the flock.

Effect of season on follicular population, quality and nuclear maturation of bovine oocytes under tropical conditions.

The aim was to determine the effect of season of the year and the presence of a corpus luteum (CL) on follicular population (FP) and the quality of the oocytes, and of season on nuclear maturation of the bovine oocytes under tropical conditions. Three seasons were evaluated: hot-dry (March-June), hot-humid (July-October) and fresh-humid (November-February). In a first study, 1112 bovine ovaries were obtained from a local slaughterhouse. Follicles were classified as small (≤4mm), middle (4.1-8mm) and large (≥8.1mm); and the maximum diameter of the follicle (MDF) and CL (MDCL) were also recorded. The oocytes were collected by aspiration and classified as viable (grade I and II) and damaged (grade III and IV). In the second study, 2261 viable oocytes were matured in vitro, and then fixed and stained with Lacmoid to classify the stage of development as mature (metaphase II), immature or degenerate. Data were analyzed using analysis of variance and chi-square procedures. The largest FP of large follicles (0.67), MDF (1.18mm), MDCL (1.87mm), and the highest proportion of viable oocytes (34.19%) were obtained during the hot-humid season (P<0.05). The ovaries without CL had the greatest FP (10.34) with more viable oocytes (24.44%). The highest proportion of mature oocytes (76.92%) was also obtained in the hot-humid season. In conclusion, season influenced FP, MDF, MDCL, and the quality and nuclear maturation of oocytes. The presence of a CL in the ovary resulted in a decrease of FP and viability of oocytes.

Presence of Toxoplasma gondii in Drinking Water from an Endemic Region in Southern Mexico.

Toxoplasmosis can be acquired through the ingestion of contaminated drinking water with oocysts of Toxoplasma gondii, highly resistant to the routinely disinfection processes; based on chlorination commonly used in the water supply industry. The aim of this study was to determine the presence of T. gondii DNA in samples of public drinking water from an endemic region of southern Mexico. In total 74 samples of water (5 L each) were collected from the three well fields (I, II, and III) and 71 independent wells, distributing public drinking water to the city of Merida Yucatan, after passing through the chlorination process. Water samples were filtered and concentrated by a sucrose solution, then DNA was extracted and evaluated through a nested-PCR (nPCR) specific for T. gondii. Positive samples were detected in 5.4% (4/74) of the water samples. This is the first report of the presence of T. gondii DNA in public drinking water from a large city in southern Mexico, where their consumption without any postpurification treatment could pose a risk for acquiring the infection in the urban population.

Effect of season and breed group on the follicular population and cyclicity of heifers under tropical conditions.

The aim was to determine the effect of season and breed group on follicular population, and presence and size of CL of heifers under tropical conditions. The seasons were hot-dry (March-June), hot-humid (July-October), and fresh-humid (November-February). Thirty Zebu (Brahman) and 38 F1 (Simmental × Brahman) heifers were used. Five evaluations were made in each season, at intervals of 7 days, to assess ovarian activity by ultrasound. Follicles were classified as small (≤4 mm), middle (4.1-8 mm), and large (≥8.1 mm) sizes, and also the size of CL, when present, was measured. Data were analyzed using analysis of variance and logistic regression procedures. Mean number of small follicles was 11.6 ± 2.3 with no effect of season, breed group, or their interaction (P > 0.05). Mean number of middle follicles was influenced by season and breed group; the highest average was found in the fresh-humid season (4.0 ± 0.2) and in F1 heifers (3.6 ± 0.2; P < 0.05). The highest mean number of large follicles was in the hot-humid season (1.4 ± 0.1; P < 0.05). The highest maximum follicle diameter (MFD) mean was registered in the hot-humid season (1.3 mm; P < 0.05) and the lowest proportion of heifers with CL occurred in fresh-humid season (33.3%; P < 0.05). No effect of season, breed group, and interaction on the maximum diameter of the CL was found. In conclusion, season was a very important source of variation. Heifers in the hot-humid season had the largest follicles and MFD, and better cyclicity.

A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico.

INTRODUCTION: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. OBJECTIVE: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. METHODS: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. RESULTS: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. CONCLUSION: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

INTRODUCCIÓN: Leptospirosis es una enfermedad zoonótica que afecta principalmente la población humana de bajos recursos. Infección aguda por leptospirosis durante el embarazo se ha asociado con aborto espontáneo y muerte fetal durante el primer trimestre del embarazo. OBJETIVO: Estimar la frecuencia de infección por Leptospira interrogans en mujeres con aborto espontáneo en el estado de Yucatán, México. MÉTODOS: Se efectuó un estudio transversal en 81 mujeres con aborto espontáneo. La prueba de referencia para Leptospirosis, prueba de microaglutinación, se utilizó para estimar la frecuencia de la serovar infectante. El ELISA IgM indirecto se utilizó para detectar infección reciente por L. interrogans. Se extrajo ADN a partir de tejido embebido en parafina de placenta para la detección de L. interrogans por PCR. RESULTADOS: La frecuencia global de la infección con L. interrogans en 81 mujeres con aborto, fue del 13.6%. Se encontró cinco de 12 serovares de Leptospira. Dos de las 11 mujeres con aborto espontáneo y positivo a microaglutinación también fueron positivas a la prueba ELISA IgM. Ninguna muestra fue positiva hacia el diagnóstico PCR de Leptospira. CONCLUSION: Dos mujeres podrían estar asociados con el aborto espontáneo debido a la leptospirosis, porque mostraron anticuerpos contra L. interrogans en la microaglutinación y ensayos de ELISA IgM. Diferencias entre regiones fueron encontradas con respecto a las prevalencias de leptospirosis.

A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico / Estudio transversal de leptospirosis y muerte fetal en Yucatán, México

Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous abortion was conducted. Serum samples were tested for Leptospirosis by the microaglutination test, to estimate the frequency of the infecting serovar. The indirect ELISA IgM was used to detect recent infection by L. interrogans. DNA was extracted from paraffin-embedded tissue of placenta for PCR detection of L. interrogans. Results: Overall frequency of infection with L. interrogans in the 81 women with abortion was 13.6%. Five of the 12 serovars evaluated were found and included. Two of the 11 women with abortion and positive to microaglutination test were also positive to the ELISA IgM test. None samples were positive for PCR Leptospira diagnosis. Conclusion: two women could be associated with spontaneous abortion due to leptospirosis, because they showed antibodies against L. interrogans in the microaglutination test and ELISA IgM assays. Differences between regions were found with respect to the prevalences of lesptospirosis.

Introducción: Leptospirosis es una enfermedad zoonótica que afecta principalmente la población humana de bajos recursos. Infección aguda por leptospirosis durante el embarazo se ha asociado con aborto espontáneo y muerte fetal durante el primer trimestre del embarazo. Objetivo: Estimar la frecuencia de infección por Leptospira interrogans en mujeres con aborto espontáneo en el estado de Yucatán, México. Métodos: Se efectuó un estudio trasversal en 81 mujeres con aborto espontáneo. La prueba de referencia para Leptospirosis, prueba de microaglutinación, se utilizó para estimar la frecuencia de la serovar infectante. El ELISA IgM indirecto se utilizó para detectar infección reciente por L. interrogans. Se extrajo ADN a partir de tejido embebido en parafina de placenta para la detección de L. interrogans por PCR. Resultados: La frecuencia global de la infección con L. interrogans en 81 mujeres con aborto, fue del 13.6%. Se encontró cinco de 12 serovares de Leptospira. Dos de las 11 mujeres con aborto espontáneo y positivo a microaglutinación también fueron positivas a la prueba ELISA IgM. Ninguna muestra fue positiva hacia el diagnóstico PCR de Leptospira. Conclusion: Dos mujeres podrían estar asociados con el aborto espontáneo debido a la leptospirosis, porque mostraron anticuerpos contra L. interrogans en la microaglutinación y ensayos de ELISA IgM. Diferencias entre regiones fueron encontradas con respecto a las prevalencias de leptospirosis.

Breed and environmental factors of sows and their repeatabilities in central Mexico / Factores raciales y ambientales que afectan características reproductivas de las cerdas y sus repetibilidades en México central / Fatores raciais e ambientais que afetam características reprodutivas das porcas e suas repetibilidades em México central

Background: reproductive traits influence lifetime productivity of sows.Objective: to determine the effects of year and season of farrowing, parity number, and breed, on litter size at birth, weaning to service interval (WSI), farrowing to service interval (FSI), and to estimate their repeatabilities. Methods: data from years 1998 to 2008 from a farm in La Piedad, Michoacan, Mexico, were used. Sow breeds were Camborough 22 (PIC), Yorkshire (Y), F1 Landrace x Yorkshire (F1 LY), and ¼ Landrace x ¾ Yorkshire (LY3/4). The studied traits were total pigs born at birth (TPB, n = 45,798), number of pigs born alive (PBA, n = 45,798), WSI (n = 41,156), and FSI (n = 41,156). The statistical model for TPB and PBA included the effects of farrowing year, farrowing season, parity number, breed, and year/season interaction. The model for WSI and FSI included the above factors plus the linear and quadratic effects of lactation length. Results: the overall means for TPB, PBA, WSI, and FSI were 9.31 pigs, 8.60 pigs, 7.87 days, and 29.9 days, respectively. All effects included in the statistical models were significant (p<0.05), except season for TPB and PBA. TPB and PBA increased up to parity 4 and decreased thereafter. The LY3/4 and PIC breed groups had the highest litter size means. The shortest WSI and FSI corresponded to the fall season and the largest to the summer season. WSI and FSI decreased with parity. The Y breed had the shortest and the F1 LY sows had the highest WSI and FSI. The repeatability estimates for TPB, PBA, WSI, and FSI were 0.13, 0.12, 0.14, and 0.14, respectively. Conclusion: year, parity, breed, and lactation length affected litter size, WSI, and FSI. Repeatabilities were low, suggesting that environmental factors are more important than genetic factors for improving the reproductive traits.

Antecedentes: las características reproductivas afectan el tiempo de vida productivo de la cerda. Objetivo: determinar el efecto del año de parto, época de parto, número de parto y grupo racial sobre características de la camada al nacimiento, intervalo destete servicio (WSI), intervalo parto servicio (FSI), y estimar sus repetibilidades. Métodos:se utilizaron los datos de 1998 a 2008 de una granja en La Piedad, Michoacán, México. Las cerdas pertenecían a los grupos raciales Camborough línea 22 (PIC), Yorkshire (Y), F1 Landrace x Yorkshire (F1LY), y ¼ Landrace ¾ x Yorkshire (LY3/4). Las características estudiadas fueron el total de lechones nacidos (TPB, n = 45.798), número de lechones nacidos vivos (PBA, n = 45.798), intervalo destete a servicio (WSI, n = 41.156) e intervalo parto a servicio (FSI, n = 41.156). El modelo estadístico para TPB y PBA incluyó los efectos de año de parto, época de parto, número de parto, grupo racial, y la interacción de año por época. El modelo para WSI y FSI incluyó además los efectos lineal y cuadrático de duración de la lactación. Resultados: las medias para TPB, PBA, WSI y FSI fueron 9,31 lechones, 8,60 lechones, 7,87 días y 29,9 días, respectivamente. Todos los efectos incluidos en los modelos fueron significativos (p<0,05), excepto época para TPB y PBA. TPB y PBA aumentaron hasta el cuarto parto para disminuir posteriormente. Los grupos raciales LY3/4 y PIC tuvieron las mayores medias para tamaño de camada. Los WSI y FSI más cortos correspondieron a la época de otoño. WSI y FSI disminuyeron con el número de parto. La raza Y tuvo los WSI y FSI más cortos y el grupo F1 LY los intervalos más largos. Las repetibilidades para TPB, PBA, WSI y FSI fueron: 0,13, 0,12, 0,14 y 0,14, respectivamente. Conclusión: el año, número de parto, grupo racial y duración de la lactación afectaron los tamaños de camada, WSI y FSI. Las repetibilidades fueron bajas, lo que sugiere que los factores ambientales son más importantes que los factores genéticos cuando se quiere mejorar las características reproductivas.

Antecedentes: as características reprodutivas afetam a produtividade de por vida da porca. Objetivo: determinar o efeito de ano de parto, época de parto, número de parto e grupo racial sobre características da ninhada ao nascimento, intervalo desmama serviço (WSI), intervalo parto serviço (FSI) e estimar suas repetibilidades. Objetivo: o presente trabalho objetivou-se adaptar e validar o método Saraz para determinar o fluxo de NH3 (SMDAE) emitida dos galpões avícolas submetidos à ventilação natural. Métodos: utilizaram-se os dados de 1998 a 2008 de uma granja em La Piedad, Michoacán, México. As porcas pertenciam aos grupos raciais Camborough línea 22 (PIC), Yorkshire (Y), F1 Landrace x Yorkshire (F1 LY) y ¼ Landrace ¾ x Yorkshire (LY3/4). As características estudadas foram o total de leitões nascidos (TPB, n = 45.798), número de leitões nascidos vivos (PBA, n = 45.798), WSI (n = 41.156) e FSI (n = 41.156). O modelo estadístico para TPB e PBA inclui os efeitos de ano de parto, época de parto, número de parto, grupo racial e a interação de ano por época. O modelo para WSI e FSI inclui ademais os efeitos lineais e quadráticos do largo de lactação. Resultados: as medias para TPB, PBA, WSI e FSI foram 9,31 leitões, 8,60 leitões, 7,87 dias e 29,9 dias, respectivamente. Todos os efeitos incluídos em os modelos foram significativos (p<0,05), exceto época para TPB e PBA. TPB e PBA aumentaram hasta o quarto parto para diminuir posteriormente. Os grupos raciais LY3/4 e PIC mostraram as maiores meias para tamanho de ninhada. Os WSI e FSI mais curtos corresponderam má a época de outono. WSI e FSI diminuíam com o número de parto. A raça Y tubo os WSI e FSI mais curtos e os grupo F1LY os intervalos mais largos. As repetibilidades para TPB, PBA, WSI e FSI fórum: 0,13, 0,12, 0,14 e 0,14, respetivamente. Conclusão:o ano, número de parto, grupo racial e largo de lactação afetaram o tamanho de ninhada WSI e FSI. As repetibilidades foram baixas, o que sugere que os fatores ambientais são mais importantes que os fatores genéticos em a melhora das características reprodutivas.