No abstract

As doutrinas apresentadas são da exclusiva responsabilidade do autor.

No abstract

No abstract

Ultrasonic measurements were taken on 46 sheep using a real-time ultrasound machine equipped with 2 probes (5 and 7.5 MHz). Measurements of subcutaneous fat thickness (SC) and muscle LM depth (MD) and area (MA) were taken at 2 locations: over the 13th thoracic vertebra (SC13, MD13, and MA13, respectively) and at the interval between the third and fourth lumbar vertebrae (SC34, MD34, and MA34, respectively). Fat thickness was also measured over the third sternebra of the sternum. The relationship between carcass and in vivo ultrasound measurements was high for all the measurements (r(2) between 0.54 and 0.96, P < 0.01). Concerning MD and SC, the 7.5 MHz probe estimates were consistently more precise than the 5-MHz estimates (r(2) increased between 0.09 and 0.13), but the reverse occurred with the MA estimates, although to a lesser extent. Estimates of carcass composition for muscle, subcutaneous fat, intermuscular fat, internal fat, and total fat based on BW explained a large amount of variation in muscle (87%), subcutaneous fat (85%), intermuscular fat (79%), internal fat (74%), and total fat (87%). In most cases (55 of 70) the introduction of one ultrasound measurement in addition to BW in the multiple regression equations further improved the explanation of variation for weight of carcass tissues, internal fat, and total fat. For carcass muscle estimation, the ultrasound measurements of muscle provided an increase of r(2) between 0.05 and 0.10 (P < 0.01). The SC13 and SC34 gave the best improvements in estimating subcutaneous fat, intermuscular fat, internal fat, and total fat (r(2) increased between 0.05 and 0.17; P < 0.01). Prediction of the proportions of the carcass components (internal and total fat from BW) was clearly lower than the prediction of the absolute amounts of these traits. Inclusion of one or more ultrasound measurements in addition to BW increased the predictive ability of the equations. Both probes were useful to estimate carcass muscle depth and area and fat depth, but the 7.5-MHz probe showed a greater ability to estimate depth. For all traits, the stepwise procedure demonstrated that the best fit was obtained with BW and one or more ultrasound measurement with the 7.5-MHz probe.

An experiment was conducted to assess the potential of long-chain alcohols (LCOH), in alternative or combined with alkanes and long-chain fatty acids (LCFA), as faecal markers to estimate the diet composition of goats grazing heathland vegetation with associated improved pastures. A total of seven diets were offered across the grazing season. The diets were composed of mixtures of herb species (Lolium perenne and Trifolium repens) and woody species (Erica spp., Calluna vulgaris and Ulex gallii) in an attempt to simulate diet selection of goats on these complex vegetation areas. The diet composition was estimated using LCOH markers alone or combined with alkanes, LCFA and alkanes+LCFA, by least square optimization procedures. The data showed large differences between plant species in their LCOH profile. Generally, plant species showed higher LCOH concentrations than those of alkanes and lower than LCFA markers. Faecal recovery of LCOH was incomplete and increased in a linear manner (P < 0.001) with the carbon-chain length, and was influenced by diet composition and its digestibility. The diet composition estimates based on LCOH alone were more accurate (P < 0.05) than those using alkanes or LCFA alone. Results showed that the combination of LCOH with alkanes, LCFA and alkanes+LCFA resulted in more accurate (P < 0.05) estimates of diet composition, indicating that LCOH provided different discriminatory information to that of alkanes and LCFA, helping in the discrimination of the plant species used in this experiment. Results indicate that correction of faecal LCOH concentrations to incomplete faecal recovery is necessary to obtain more accurate estimates of diet composition. Nevertheless, it seemed that the use of a less accurate recovery correction on LCOH markers had a lower impact on the accuracy of estimates than that of alkanes and LCFA.

Even though sheep and goat processed meat products are not as popular as pork, beef or poultry and are generally considered not as important, they have a very important role in meat consumption around the world. A concise review of the origin and type of the most important sheep and goat processed meat products produced in different countries and world regions is made. The manuscript also summarizes the most recent studies on sheep and goat processed meats on the physicochemical characterizations, sensory quality, microbiological quality and safety. Some conclusions and future trends in production, processing and commercial potentiality for sheep and goat processed meat products are discussed. Several possibilities exist to make them more diversified and appealing to the market. Processing meat from culled animals is an interesting way to value animals with low market acceptability. Some as fermented sausages, cured legs and pâtés have great commercial potential as highly acceptable consumer commodities. An interesting field of food research is the rediscovery of a new generation of goat and sheep meat products as functional foods that will respond to the constant innovation required by the meat industry. Everything related to food safety must be considered in the future.

No abstract