Some of the mechanisms underlying the invasion and intracellular survival of B. melitensis are still unknown, including the role of a subfamily of NUDIX enzymes, which have been described in other bacterial species as invasins and are present in Brucella spp. We have generated a mutation in the coding gene of one of these proteins, the invA gene (BMEI0215) of B. melitensis strain 133, to understand its role in virulence. HeLa cell invasion results showed that mutant strain survival was decreased 5-fold compared with that of the parental strain at 2 h pi (P < 0.001). In a goat macrophage infection assay, mutant strain replication was 8-fold less than in the parental strain at 24 h pi (P < 0.001); yet, at 48 h pi, no significant differences in intracellular replication were observed. Additionally, colocalization of the invA mutant with calregulin was significantly lower at 24 h pi compared with that of the parental strain. Furthermore, the mutant strain exhibited a low level of colocalization with cathepsin D, which was similar to the parental strain colocalization at 24 h pi. In vivo infection results demonstrated that spleen colonization was significantly lower with the mutant than with the parental strain. The immune response, measured in terms of antibody switching and IFN-γ transcription, was similar for Rev1 and infection with the mutant, although it was lower than the immune response elicited by the parental strain. Consequently, these results indicate that the invA gene is important during invasion but not for intracellular replication. Additionally, mutation of the invA gene results in in vivo attenuation.

Goat milk composition is affected by feeding, and in semiarid rangeland, information on Creole goat milk physicochemical composition is lacking. For the fulfillment of this objective, three agroecological regions (AR) considering altitude (lowland 87, highland 779, and mountain 1309 m above sea level) with different botanical compositions were chosen. Every AR analyzed accounted for 30 goat herds, with a total of 90 herds. The results demonstrated that altitude had an influence mainly on density and protein. Milk density increases as altitude increases; conversely, milk protein increases as altitude decreases. On the other hand, in the mountain and lowland ARs, the salts and solids not fat (SNF) percentages were higher compared to that of the highland AR (p < 0.05). The freezing point (FP) was higher at highland altitudes compared to that of mountain and lowland ARs (p < 0.01). In the milk fatty acids (FA) profile, only the C14:1 value was affected by altitude, whereas goat milk at lowland and mountain altitudes had higher values compared to that at highland altitudes (p < 0.05). Additionally, late lactation stage fat, FP, and pH values were higher compared to early lactation values. The opposite effect was observed for salts and SNF. In the FA profile, late lactation values were higher for C10:0 and C8:0 compared to early lactation values. The opposite trend was observed for C18:2n6t. The thrombogenic index was significantly higher at lowland altitudes compared to highland altitudes, and similar to the mountain AR. These goat milk characteristics could be explained as a consequence of animal nutrition, as well as the goat’s meat-type phenotype.

La tricomoniasis bovina es una enfermedad capaz de provocar abortos en bovinos, se caracteriza por presentarse de forma asintomática en los machos y generalmente se transmite por vía venérea. La presencia de tricomoniasis bovina en un hato implica pérdidas económicas por la disminución de la producción de becerros. Considerando que Tamaulipas se caracteriza por la producción de bovinos, es importante evaluar enfermedades abortivas como la tricomoniasis bovina debido a que se ha reportado en estados colindantes como Veracruz al Sur y Texas EUA al Norte. El objetivo de esta investigación fue buscar la presencia de Tritrichomonas foetus en la zona centro de Tamaulipas mediante el uso de la PCR punto final, a partir de muestras de cavidad prepucial de bovinos. Se obtuvieron y procesaron 45 muestras de bovinos de razas cárnicas de Tamaulipas en un periodo de un año; todas las muestras fueron negativas a T. foetus. En este estudio es posible que la alta tecnificación reproductiva en la zona de estudio favorezca la probabilidad de la ausencia de este parásito.

This study evaluated the effects of dietary supplementation with guanidinoacetic acid (GAA) and zilpaterol hydrochloride (ZLH) on productive performance, carcass traits, and blood chemistry in non-castrated male lambs over 60 days. Twenty-four Pelibuey × Dorper crossbred lambs (16.3 ± 2.7 kg) were adapted to housing and diet for 14 days before being randomly assigned to one of three treatments: (1) Control: total mixed ration (TMR) without additives; (2) GAA: TMR with 0.06% GAA; and (3) ZLH: TMR with 6 mg/kg dry matter (DM) of ZLH for the last 30 days. No significant differences were observed in productive performance or carcass traits among treatments. However, lambs fed GAA showed higher serum glucose and creatinine levels than the control group (p < 0.05), suggesting a potential effect on energy metabolism. ZLH supplementation had no measurable impact on the parameters evaluated. These findings indicate that while GAA may influence certain metabolic indicators, further research with extended feeding periods or varying dosages is needed to clarify its effects on growth and carcass characteristics in lambs.

El propósito en esta revisión bibliográfica es investigar el potencial forrajero del género Celtis en la alimentación de los animales, teniendo en cuenta su valor nutricional y el uso en sistemas de producción animal. Encontramos que existe información limitada del uso de esta planta en la alimentación animal. Celtis contiene altos niveles de proteína cruda (hasta 24.3 %), digestibilidad y perfiles minerales que cubren requerimientos esenciales en diversos animales domésticos. Es un recurso forrajero utilizado en distintas regiones, principalmente zonas áridas y semiáridas en continentes como América, África e India. El aprovechamiento alimenticio también ha sido empleado naturalmente por distintas especies de fauna silvestre. El género Celtis tiene un papel importante en la nutrición animal, sin embargo, hacen falta más estudios que amplíen y profundicen los conocimientos sobre esta especie en la alimentación animal.

Linear body measurements (LBM) can be used to develop selection criteria for breeding animals. They are an indirect way to estimate live weight (BW) in some herbivores. The objective of this study was to obtain a formula to estimate the BW of unscaled female goats from five MCLs. Body length (CL), thoracic perimeter (TP), rump width (WG), rump height (HH), withers height (HC) and PV with scale were recorded in 206 Creole goat females from the Altiplano region (RA) and San Fernando Valley (SFVR) of the state of Tamaulipas. Student's t-tests for comparison of means, Pearson correlations and generalized linear models were performed to obtain multiple regressions. Goats from the RVSF presented lower LC and AC compared to those from the RA (P<0.01). Correlations in both districts were positive and significant. The proposed formula for PV estimation in the RA was (0.80 × PT) -29.83 and for the RVSF (0.89 × PT)-37.30. No differences were observed between the live weight obtained with scale (PVB) and the estimated live weight (PVE). Las medidas corporales lineales (MCL) se pueden utilizar para desarrollar criterios de selección de animales de cría. Estas son una forma indirecta de estimar el peso vivo (PV) en algunos herbívoros. El objetivo de este estudio fue obtener una fórmula que permita estimar el peso vivo de hembras (PVH) caprinas sin báscula (PVH) a partir de cinco MCL. Se registró la longitud corporal (LC), perímetro torácico (PT), anchura de la grupa (AG), altura de la grupa (ALG), altura de la cruz (AC) y PV con báscula (PVB) en 206 hembras caprinas criollas de la región del Altiplano (RA) y el Valle de San Fernando (RVSF) del estado de Tamaulipas. Se realizaron pruebas "t" de Student para la comparación de medias, correlaciones de Pearson y modelos lineales generalizados para obtener regresiones múltiples. Las cabras del RVSF presentaron una menor LC y AC comparada con las del RA (P<0,01). Las correlaciones en ambos distritos fueron positivas y significativas. La fórmula propuesta para la estimación del PVH en la RA fue (0.80 × PT) -29.83 y para el RVSF (0.89 × PT)-37.30. No se observaron diferencias entre el PVH y el peso vivo estimado (PVE).