ABSTRACT Records of 3716 Nubian goats from the United States (US) were analyzed to estimate relationships between fourteen conformation traits (CT) with lactation average somatic cell score (ASCS). To analyze ASCS, a mixed model was implemented. Linear and quadratic effects of CT traits, days in milk (DIM), and kidding age in months (KA) were considered as fixed covariates, and herd-year (HY) of kidding as a random effect. Correlation coefficients between CT traits and ASCS adjusted for HY and linear and quadratic KA effects were also obtained. The average ± standard deviations for ASCS, DIM, and milk yield were 5.17±0.54 Log2, equivalent to 451.3 cells × 103/mL, 266.3±52.1 days, and 776.3±280.4 kg per lactation, respectively. Significant non-linear relationships with an intermediate maximum were found between ASCS with teat diameter and medial suspensory ligament, while linear relationships were observed with stature, strength, rump width, fore udder attachment, udder depth, teat diameter, teat placement, and medial suspensory ligament. The model explained 53.7% of the ASCS variability, but the contribution of each type variable to increase the coefficient of determination was low (<0.52%). Herd-year explained a large proportion of the variation of ASCS (38.4%). All estimated correlations between CT and ASCS had low values, from −0.04 to 0.11, but most were significant. The results of this study show that conformation traits have few opportunities to contribute phenotypically to assess somatic cell score in Nubian goats.

Abstract The aim of this study was to determine the efficacy of the entomopathogenic fungus, Metarhizium anisopliae strain 134 (Ma134), for dairy cattle naturally infested with Haematobia irritans (L.) An aqueous formulation of 1 x 108 conidia/ml was applied by aspersion on a group of eight cows every seven days for a total of four applications, while a control group was sprayed with the same solution without conidial content. The degree of horn fly infestation was estimated daily in both groups by the direct count of adult flies found resting or feeding on the animals, and Abbott’s formula was used to calculate the effectiveness of the formulation. The Ma134 formulation resulted in a 68.6 % reduction of the fly infestation during the study period, and a significant reduction was observed from the first week post-application (p< 0.05). The results show that the Ma134 formulation is effective in reducing infestations of horn fly, H. irritans, on dairy cattle under natural conditions. Thus, the fungus, Ma134, can be considered a candidate for biological control for the integrated management of H. irritans.

Abstract In this work, we use the records from 643 goats in order to evaluate the phenotypic relationships between conformation traits and milk production in goats. Correlations were estimated using data on goats which included fifteen conformation traits and first lactation milk yield adjusted for age, calving month and 305 milking days (MY1). We also compared the average scores for type traits on the goats under study with those on a sample of goats from the United States of America (USA). Correlations between conformation traits and MY1 were estimated and an analysis was performed to evaluate the nonlinear relationships between them. The highest correlations were found between milk production and udder depth (-0.22), stature (0.18) and rear udder side view (0.12) (p < 0.05), non-linear (cubic) effects for stature and strength being significant (p < 0.05). American goats had a better overall conformation than the Mexican ones but results indicated that goats with better body conformation were not the best for milk production.

Resumen Con el objeto de evaluar las relaciones fenotípicas entre características de conformación y la producción de leche en cabras, se utilizó la información de 643 animales. Los datos de las cabras incluyeron quince rasgos de conformación y la producción de leche de la primera lactancia ajustada a edad, mes de parto y 305 días de ordeño (MY1, por sus siglas en inglés). Se compararon también los promedios de las calificaciones de tipo de las cabras de este estudio y de una muestra de cabras de los Estados Unidos de América (USA, por sus siglas en inglés). Se estimaron correlaciones entre las características de conformación con MY1 y se efectuó un análisis para evaluar las relaciones no lineales entre ellas. Las correlaciones más altas fueron entre MY1 y la profundidad de ubre (-0.22), estatura (0.18) y ubre trasera vista de lado (0.12) (p < 0.05) y los efectos no lineales (cúbicos) para estatura y fortaleza resultaron significativos (p < 0.05). Las cabras de USA tuvieron una mejor conformación general que las cabras de México; sin embargo, los resultados indican que las cabras con mejor conformación corporal no fueron las mejores para producir leche.