An experiment was conducted to investigate the influence of the main cereal (cooked maize or cooked rice) and the inclusion of cooked and expanded oat hulls (0, 20 or 40 g/kg) in the diet on total tract apparent nutrient digestibility (TTAD) and productive performance of piglets weaned at 21 days. Each of the six treatments was replicated eight times (five piglets penned together) and the trial lasted for 33 days. From 21 to 41 days of age piglets were given their respective experimental complex diets that contained 530 g/kg cooked cereal and from 41 to 54 days they received a common starter diet based on maize, barley and soya-bean meal. Growth promoters were not included in the diets. The TTAD was determined at 27 and 37 days of age and pig performance was measured at 31, 41 and 54 days of age. Nutrient digestibility increased with age (P<0·001) and in general were higher for rice- than for maize-based diets (P<0·001 for dry matter, organic matter and gross energy andP<0·05 for ether extract). From 21 to 41 days of age piglets given rice had higher food intake (FI,P<0·05) and average daily gain (ADG,P<0·01) than piglets given maize but food conversion ratio was not affected. The differences observed were maintained until the end of the trial. The inclusion of oat hulls in the diet did not affect TTAD of the nutrients but tended to reduce the incidence of diarrhoea from 21 to 41 days of age (P<0·1). Oat hulls inclusion reduced FI and ADG in diets based on maize but had the opposite effect in diets based on rice, indicating that piglets might have a minimum requirement for dietary fibre. It is concluded that cooked rice is an ingredient of choice in pre-starter diets for weanling pigs. Also, the inclusion of moderate levels of fibre as oat hulls reduces the incidence of diarrhoea and might improve productive performance in low fibre diets.

Two hundred and forty pigs of 56 ± 3 days of age were used to investigate the effects of sex (barrows; gilts), boar sire (DD, Danish Duroc; ND × LW, Dutch Duroc × Large White ; P × LW, Pietrain × Large White) and slaughter age (160; 175 days) on performance and carcass and meat quality. Treatments were arranged factorially (2 × 3 × 2) and there were four replicates (five pigs per replicate) per treatment. The female line was Landrace × Large White in all cases. Barrows had greater daily food intake (P <0·001) and average daily gain (P <0·01) and had poorer food conversion ratio (P <0·001) than gilts. Carcasses from castrates were fatter and had a lower yield of trimmed lean cuts than carcasses from females (P <0·001). Longissimus muscle from barrows had more intramuscular fat and higher a* value than muscle from gilts (P <0·05). Pigs from DD sire line grew faster (P <0·05) and had a better food conversion ratio (P <0·001) than pigs from the other two lines. Dressing proportion and backfat thickness were greatest for P × LW sired pigs (P <0·01) and proportion of trimmed lean cuts was greater for DD and P × LW than for ND × LW sired pigs (P <0·01). Longissimus muscle from DD sired pigs had less protein (P <0·01) and more intramuscular fat (P <0·001) than muscle from the remaining lines. Longissimus muscle from P × LW line had more intense colour than muscle from DD and ND × LW lines (P <0·01). Pigs slaughtered at 175 days had poorer food conversion ratio (P <0·01) and less trimmed primal cut proportion (P <0·001) than pigs slaughtered at 160 days. Also, increasing the age at slaughter increased intramuscular fat content (P <0·01), a* value (P <0·001) and colour intensity of the muscle (P <0·01). Danish Duroc boars are a good alternative to ND × LW or P × LW boars for production of heavy pigs whether the crossbreds are sacrificed at 160 or 175 days. Also, an increase in age at slaughter impairs growth efficiency and yield of lean cuts but improves some aspects of meat quality, which might be of interest in the production of heavy pigs destined for the dry-cured product industry.

We studied the influence of enzyme supplementation (ES) of the diet and heat processing (HP) of barley on digestive traits and productive performance of broilers from 1 to 42 d of age. There were 6 diets arranged factorially with 2 doses (0 and 500 ppm) of a fungal enzyme complex with beta-glucanase and xylanase activity and 3 HP of barley (raw, micronized, and expanded). In addition, a control diet based on raw corn without ES was also included from 1 to 21 d of age. Enzymes reduced intestinal viscosity (IV) at all ages (P < or = 0.001) and water intake at 21 d of age (P < or = 0.01) and increased DM of the ileal contents at 28 d (P < or = 0.001). Also, ES increased total tract apparent retention of nutrients and BW gain and feed conversion ratio from 1 to 42 d of age (P < or = 0.001). Heat processing of barley increased IV at 7 and at 28 d of age, and DM of ileal contents (P < or = 0.05) at 28 d of age. In addition, HP improved feed intake (P < or = 0.01) and BW gain (P < or = 0.001) from 1 to 7 d of age, but the effects disappeared after 21 d of age. From 1 to 7 d of age, chicks fed micronized barley had higher IV, gained less weight, and had poorer feed conversion ratio than chicks fed expanded barley (P < or = 0.05). It is concluded that barley with enzymes can substitute for all of the corn in diets fed to broilers from 1 to 21 d of age. Enzymes improved digestive traits, retention of nutrients, and broiler performance from 1 to 42 d of age, and HP of barley improved performance from 1 to 7 d of age. The effects of HP of barley on broiler performance were more evident with expansion than with micronization.