Carcass composition and physicochemical and sensory attributes of breast and leg meat from native Mexican guajolote (Meleagris g. gallopavo) as influenced by sex

The aim of the study was to compare carcass composition and physicochemical and sensory attributes of breast and leg meat from native Mexican guajolote (Meleagris g. gallopavo) as influenced by sex. For this, slaughter weight and carcass characteristics of male (n = 8 ) and female (n = 8 ) guajolotes raised traditionally under extensive systems with similar housing and feeding conditions were recorded. Also, physical characteristics, proximate composition, the fatty acid profile, and sensory attributes were determined in breast and leg meat using standard procedures. The results showed that males had higher (P < 0.001 ) slaughter weight, hot and cold carcass weights, and dressing percentage, as well as carcass part weights, while females had higher (P < 0.001 ) abdominal fat weights than males. The lightness (L * ), yellowness (b * ), and drip loss values of breast meat, as well as redness (a * ) and water-holding capacity values of leg meat, were significantly (P < 0.05 ) influenced by sex. Male breast meat had higher (P < 0.05 ) moisture content, crude protein, erucic acid (C22:1n9), ∑  MUFAs (total monounsaturated fatty acids), ∑  UFAs (unsaturated fatty acids), ∑  DFAs (desirable fatty acids), ∑  UFA /  ∑  SFA (total saturated fatty acid) ratio, ∑  PUFA (total polyunsaturated fatty acid) /  ∑  SFA ratio, and chewiness scores than females. Likewise, leg meat from males showed higher (P < 0.05 ) ash content, myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9c), palmitoleic acid (C16:1n7), ∑  SFAs, ∑  OFAs (odd fatty acids), thrombogenic index, and atherogenic index, whereas females had high fat content. In conclusion, it would be suggested that, from a nutritional point of view, the meat from male guajolotes was preferable to the meat from females.

[Spatio-temporal pattern of larvae and eggs of gastrointestinal nematodes in cattle pastures in Veracruz, Mexico]

The spatial and temporal distribution of gastrointestinal nematodes of cattle has been little studied in Mexico. Previous studies have described periods of higher larval presence, vertical and horizontal migration in grasslands, and the frequency of adult nematodes; as well as the effect of pasture trichomes on the migration and survival of Haemonchus larvae. The aim of this study was to determine the time-space layout and spread of gastrointestinal nematode larvae on pasture, and to estimate the effect of ivermectin applied to cattle on the time-dependent abundance of their eggs in a ranch in Veracruz. To determine the spatio-temporal arrangement, monthly morning grass samples were obtained from 30 sampling points from July 2008 to June 2009. Third stage larvae (L3) from each point were counted, and aggregation patterns were estimated through variance/mean and negative binomial K indices. Additionally, the number of eggs per gram in cattle feces was determined, from samples with (CI) and without ivermectin (SI), using standard techniques. A total of 20 276 L(3) larvae were recovered in the pasture, of which an 80% corresponded to Haemonchus contortus. The highest nematode density with more than 5 000L(3)/kgDM was detected in October 2008, and the lowest in February and March 2009. The L3 showed an aggregated spatial pattern of varying intensity throughout the year. The number of eggs in the stool was not reduced with the ivermectin application to cattle, which suggested a failure of control. However, the highest parasite loads were observed from July to November 2008. We concluded that the application of ivermectin was not effective to control nematodes eggs, and that L3 populations fluctuated on pasture for ten months, providing an infection source to grazing animals afterwards.