RESUMO
This experiment was undertaken to provide information on the effect of feeding system applied during the finishing period (100-150kg) on the quality of Iberian pig meat. Four feeding systems were applied: pigs fed under free-range conditions with acorns and grass fully available during 111 days (FR(111)), pigs fed concentrate diet in confinement during 28 days and free-range with acorns and grass fully available during 83 days (CDC(28)+FR(83)), pigs fed concentrate diet in confinement during 65 days and free-range with acorns and grass fully available during 46 days (CDC(65)+FR(46)) and pigs fed concentrate diet in confinement with a feed average daily amount of 3.1kg during 111 days (CDC(111)). The CDC(111) pigs had more muscular carcasses characteristics than the remaining groups of pigs. However, the higher concentration of C18:1 n-9 in subcutaneous backfat was found in FR(111) pigs. In the neutral lipids from intramuscular fat of Longissimus dorsi only the C18:2 n-6 and C18:3 n-3 proportions were affected by feeding system, and the n-6/n-3 ratio observed was lower in FR(111) and CDC(28)+FR(83) pigs than in CDC(111) pigs. In the neutral lipids from hepatic fat the proportion of n-6 fatty acids was lower in FR(111) pigs than in CDC(65)+FR(46) and CDC(111) pigs.
RESUMO
Twelve barrow Iberian pigs with an average weight at slaughter of 109.2kg were used to evaluate bioelectrical impedance procedures to predict the body composition of live pigs. Twelve hours before slaughter pigs were weighed, and a four-terminal body composition analyser (Model BIA-101, RJL Systems, Detroit, MI) was utilized to determine resistance (R(s) in Ω) and reactance (X(c) in Ω). The length values (L in cm) were measured between detector electrodes with a flexible steel tape. Twenty four hours after slaughter the left side of each carcass was separated using a scalpel into fat, lean, bone and skin. Multiple regression equations for estimating lean, fat, bone and skin amounts and lean, fat, bone and skin proportions with respect to slaughter weight were calculated. The live weight (LW) and L independent variables predicted 85.3% and 64.3% of the variability of the lean amount and lean proportion, respectively. The LW, X(c) and L variables accounted for 96% and 91.6% of the variation in fat quantity and fat proportion, respectively. The LW and R(s) accounted for 58.9% of the variation in bone amount, and the same variables predict 79.1% of the variability of bone percentage. The R(s) and L variables explained 68% of the variability of skin quantity and LW, R(s) and X(c) predicted 83.1% of the variation of skin proportion. Results from this experiment indicate that bioelectrical impedance may be of interest for body composition prediction of live Iberian pigs.
RESUMO
Forty three-castrated male Iberian pigs of the Torbiscal line with an average initial weight of 102.27kg were used. A group of 22 pigs was fed according to the traditional way in free-range conditions with acorn and grass from November to January. Another group of 21 animals was fed 3.72kg/day of a conventional feed that contained 12.53MJME/kg, 16.21% crude protein, 4.94% fat and 6.64% of crude fiber, during the same period. Measurements of backfat thickness and Longissimus dorsi muscle area at the last rib were taken by means of a real-time ultrasound device (Kretz Technick Inc., 600 V-V2.32, Sonovet, Austria) in all pigs before slaughter. After slaughter, carcass, ham and foreleg weights and backfat and muscle area measurement from the last rib chop were recorded. The average daily gain, carcass yield, fat thickness, loin area, ham weight and proportion of hams were significantly higher (P<0.05) in the pigs fed in confinement than in those fed extensively (653.36g, 77.97%, 56.46mm, 3031mm(2), 22.26kg and 14.32% vs 501.48g, 76.94%, 51.74mm, 2673mm(2), 21.52kg and 13.79%, respectively). This paper shows the prediction equations for hams, forelegs and total hams and forelegs weights and proportions with respect to slaughter weight and live ultrasound measurements in pigs fed either extensively or in confinement. The ultrasound measurements better predicted the carcass cuts absolute amounts (R(2)=0.591-0.875) than the carcass cuts proportions (R(2)=0.23-0.40). The use of real-time ultrasound should be used with caution to predict the absolute quantities of hams and forelegs from Iberian pigs since the ultrasound measurements are only moderately accurate.
RESUMO
The efficiency of manure separation by a conveyor belt under a partially slatted floor for fattening pigs was determined for two types of belts, a flat belt with an incline of up to 6 degrees transversely and a concave belt with an incline of up to 1 degrees longitudinally. A 31.20% and 23.75% dry matter content of the solid fraction was obtained for the flat and concave belt, respectively. The flat belt was more efficient at 6 degrees than other slope angles. The residence time of the manure on the two belt types influenced the separation efficiency from a live weight of 63.00 kg upwards. The quantity of residue produced with this system was reduced to 25-40% with respect to a pit system under slat. This could mean a remarkable reduction in costs of storage, transport and application of manure.