Effect of vacuum ageing on quality changes of lamb steaks from early fattening lambs during aerobic display.

The effects of vacuum ageing on the quality changes of lamb steaks during retail display were assessed. Biceps femoris and Quadriceps femoris muscles from thirty early fattening lambs fed barley straw and concentrate or alfalfa and concentrate were used. Half of the muscles were vacuum aged for three weeks (VA), and the other half were not aged (control). Control and VA muscles were sliced and aerobically displayed. Weight loss, pH, aldehyde contents, instrumental color characteristics and color acceptance were measured at display days 1, 3, 7 and 14. At day 1 redness was higher in VA lamb. However, redness of VA lamb decreases more rapidly during further storage. Redness and color acceptance decreased in VA lamb from day 3, whereas in not-aged lamb the decrease was observed from day 7 onwards. From days 7 to 14 a drop of color acceptance accompanied by an increase in pH and a decrease in lightness was observed in control and VA lamb.

Quality characteristics of a dry-cured lamb leg as affected by tumbling after dry-salting and processing time.

The aim of this study was to evaluate selected quality characteristics of a dry-cured lamb leg with different tumbling treatments after salting. The characteristics were measured at different processing times. Three batches of dry-cured lamb legs (nine legs per batch) were prepared with no-, short- and long-tumbling treatments, and microbial counts, NaCl, aw, proximate composition, pH, free fatty acids, water soluble nitrogen, volatile compounds, texture and colour were evaluated at days 1, 22 and 71 of processing. Furthermore, a descriptive sensory analysis (flavour and texture) was performed in the final product (day 71). Time-related changes were observed for most of the characteristics studied. The effect of tumbling was only observed for the sensory attribute pastiness that was higher in tumbled legs. Methyl-branched butanal was only detected in tumbled legs.

Effect of undegradable protein concentration in the post-weaning diet on body growth and reproductive development of Assaf rams.

Twenty-four growing Assaf lambs, divided into four groups of six animals, were used to study the effect of the undegradable protein content of the post-weaning diet on feed intake, body growth and reproductive development. From week 1 to week 21, the four groups were fed ad libitum as follows: group LL was given barley straw and low protein concentrate (LP); group HH was given barley straw and high protein concentrate (HP); group LH was given barley straw and LP concentrate from week 1 to 11 (period 1) and barley straw and HP concentrate from week 12 to 21 (period 2); group HL was given barley straw and HP concentrate in period 1 and barley straw and LP concentrate in period 2. From week 22 to week 26 (period 3), all animals received the same amount of hay and LP concentrate. Barley straw intake was not significantly (P>0.05) affected by dietary treatments. In the 1st period, average concentrate intake and live body weight gain (LWG) were greater in lambs fed HP than LP supplement. In the 2nd period, concentrate intake was not significantly (P>0.05) affected by type of supplement, but LWG was greater for lambs fed HP than LP supplement. Scrotal circumference in week 11 was significantly (P<0.05) lower in lambs fed LP supplement than in lambs fed HP supplement. No significant differences (P>0.05) due to dietary treatments were observed on scrotal circumference in weeks 21 and 25. Dietary treatments had no significant (P>0.05) effect on either circulating concentration of testosterone or ejaculate characteristics. In conclusion, results from this study suggest that supplementing diets with undegradable protein enhanced performance throughout the breeding period and accelerated testis growth. Nevertheless, final testis size, pattern of circulating testosterone and sperm output were unaffected by dietary treatments.