ABSTRACT This study was conducted to develop predictive equations for carcass characteristics and primal cut weights of native Mexican guajolotes using body measurements (BM). For this study, a total of 36 male guajolotes (Meleagris gallopavogallopavo), aged 6 to 10 months, and mean slaughter body weight (SBW) of 4543.14 ± 656.60 g, were used. The birds were kept under traditional extensive conditions. ThefollowingBMswererecorded24 h before slaughter: thoracicperimeter (TP), body circumference (BC), body length (BL), wing length (WL), keel length (KL), shank length (SL) and shank diameter (SD). After slaughter, hot carcass weight (HCW), cold carcass weight (CCW), hot dressing percentage (HDP), cold dressing percentage (CDP), organs and viscera weight (VIS) and abdominal fat weight (AFW) were recorded. The carcasses were dissected in to five primal cut (breast, thigh, drumstick, back and wing). The SBW and BMs showed moderate to high positive correlations (p<0.01; 0.34≤r<0.97) with carcass characteristics and primal cut weights. In the equations generated to predict HCW, CCW, HDP, CDP, VIS and AFW, the R2 ranged from 0.40 to 0.96, and the predictor variables were SBW, KL, BC, WL and SL. Regarding the equations developed to predict the primal cut weights, R2 ranged from 0.58 to 0.91. In these models, SBW, BC, SD, WL and KL explained most of the observed variation. The prediction equations obtained in the study had moderate to high accuracy; therefore, they can be used by researchers, technicians and poultry producers to obtain information on the carcass composition of native Mexican guajolotes.

ABSTRACT The study was done to predict egg weight from the external traits of the Guinea fowl egg using the statistical methods of multiple linear regression (MLR) and regression tree analysis (RTA). A total of 110 eggs from a flock of 23-week-old Guinea fowl were evaluated. Egg weight (EW) and external traits: eggshell weight (ESW), egg polar diameter (EPD), egg equatorial diameter (EED), egg shape index (ESI), and egg surface area (ESA) were measured. Descriptive statistics, Pearson correlation coefficients, and regression equations using the MLR were obtained; additionally, a RTA was done using the CHAID algorithm with the SPSS software (IBM ver. 22). EW presented positive correlations (p<0.0001) with ESA (r = 0.72), EPD (r = 0.65), and EED (r = 0.49). EW can be predicted through MLR using ESA as a predictor variable (R2 = 72%). Predictive accuracy improves when adding EPD and EED traits to the model (R2 = 75%). The RTA built a diagram using ESA, EED, and EPD as significant independent variables; of these, the most important variable was ESA (F = 50,295, df1 = 4, and df2 = 105; Adj. p<0.000) and the variation explained for EW was 74%. Likewise, the RTA showed that the highest egg weight (41.818 g) is obtained from eggs with a surface area > 59.03 cm2 and a polar diameter > 5.10 cm. The proposed statistical methods can be used to reliably predict the egg weight of Guinea fowl.

Abstract This study analyzed the arboreal stratum richness, uses, economic and social importance, and the changes in the dynamics of land uses of the mangrove community of Rancho Playa, Papantla de Olarte, Veracruz, Mexico. GIS tools were used to divide the area into a total of 22 sites of 100x100 m pixels each using a two-staged cluster sampling. The National Forest and Soil Inventory’s methodology was applied to estimate the richness and abundance of the mangrove community in the region. Additionally, 48 surveys were distributed among the people living in the town (10 %) to assess the importance and uses they give to this resource. The results show that the use of the resource as fuel and housing material have contributed to its decline in the region. Residents ranging between 24 and 50 years old tend to value more the scenery aspect and prefer conserving mangrove for its exploitation through ecotouristic schemes. The diversity indices of the tree stratum, that of richness observed given by Margalef (1) and another of proportional abundance by Shannon-Wiener (0.72) suggest little diversity of species in the region, being the Rhizophora mangle L the most frequent one. However, this species has decreased its share over the last 10 years as a result of human activity; it is thought that ecotourism might help mitigate this loss.

Resumen En este trabajo se analiza la riqueza de especies del estrato arbóreo, usos, importancia económica y social, y la dinámica de uso de suelo en la comunidad de manglar en Rancho Playa, Papantla de Olarte, Veracruz, México. Se usaron herramientas de Sistemas de Información Geográfica y se dividió el área en pixeles de 100x100 m con un total de 22 sitios, mediante un muestreo por conglomerados en dos etapas, y aplicando la metodología del Inventario Nacional Forestal y de Suelos, se estimó la riqueza y abundancia del manglar en la región. Adicionalmente se aplicaron 48 encuestas a personas (10 % de la población), para valorar la importancia y usos que le dan a este recurso. Los resultados muestran que el empleo como combustible y material de vivienda han contribuido a la disminución del recurso en la región. Pobladores entre 24 y 50 años tienden a valorar más el paisaje en comunidades de manglar y optan por su conservación, proponen un aprovechamiento a través de esquemas ecoturistas. Los índices de diversidad en estrato arbóreo, uno de riqueza observada dado por Margalef (1) y otro de abundancia proporcional de Shannon-Wiener (0.72) sugieren pocas especies en la región y mayor frecuencia de una, en específico Rhizophora mangle L. Sin embargo, esta especie ha disminuido su proporción en los últimos 10 años como resultado de la actividad humana; al respecto el ecoturismo podría ayudar a mitigar esta pérdida.

ABSTRACT The aim of this research was to evaluate the effect of partial substitution of vitamin E (VE) by grape seed extract (GSE) on glutathione peroxidase activity (GPxA), nitric oxide (NO) concentration and lipid peroxidation [malondialdehyde (MDA) concentration] in the plasma, lungs, heart and liver, and live performance of broilers raised at 2278 m of altitude. One-d-old Ross 308 male chickens (n = 420) were randomly distributed into three treatments: Control-AL (basal diet containing 40 IU of VE and fed ad libitum; AL), Control-FR (basal diet and feed restriction; FR) and GSE-AL [basal diet containing 10 mg of GSE (equivalent to 30 IU VE) plus 10 IU of VE and fed AL]. The data were analyzed using one-way analysis of variance. Glutathione peroxidase activity, and NO and MDA concentrations in the plasma were evaluated on d 46. On d 47, MDA was evaluated in the lungs, heart and liver. Live performance parameters were recorded weekly. There were no significant differences (p>0.05) in live performance and NO concentration among treatments. Birds from the GSE-AL treatment presented the lowest (p<0.05) GPxA, the highest (p<0.05) MDA concentration in the plasma, heart and liver, and intermediate MDA concentration in the lungs. Our results suggest that GSE may partially replace VE in broiler diets without impairment of live performance. However, further research is required to determine the optimal level of dietary GSE inclusion to reduce lipid peroxidation in the plasma, lungs, heart, and liver of broilers raised at 2278 m of altitude.