Effects of the inclusion of soluble fibre in diets for fattening lambs on feed intake, digestibility, animal performance and carcass characteristics

Thirty-six Merino lambs (8 to 9 wk of age, and 15.3 ± 0.13 kg of initial BW) 1 were used to evaluate the effects of the inclusion of 120 g sugar beet pulp (replacing 2 barley) and of the addition of 20 g sodium bicarbonate per kg concentrate on feed 3 intake, digestibility, animal performance and carcass characteristics in fattening lambs. 4 Animals were housed individually and fed barley straw and the corresponding 5 experimental concentrate feed ad líbitum (basal diet comprised of (g/kg) barely (500), 6 maize (230), soybean meal (190), molasses (50) and vit-min premix (30)). Faeces were 7 collected for 5 days to estimate digestibility. Lambs were slaughtered when they 8 reached 25 kg body weight. Carcass was chilled at 4oC for 24 h, some carcass 9 dimensions were calculated, the left carcass was jointed into commercial cuts and 10 shoulder tissue composition determined. Sugar beet pulp decreased dry matter intake 11 (P<0.05) and average daily gain (P<0.001), increasing feed to gain ratio (P<0.001), 12 whereas sodium bicarbonate increased neutral detergent fibre digestibility (P<0.05) and 13 average daily gain, reducing feed to gain ratio (P<0.05). Carcass characteristics were 14 not affected (P>0.05) by either sodium bicarbonate or sugar beet pulp. Replacing barley 15 with 120 g sugar beet pulp/kg concentrate caused a decrease in dry matter intake and 16 average daily gain, resulting in an increase in feed to gain ratio, with no detrimental 17 effect on carcass characteristics. The addition of 20 g sodium bicarbonate/kg 18 concentrate improved intake and animal performance without affecting carcass 19 characteristics. Inclusion of sugar beet pulp as a replacement for barley in high20 concentrate diets for fattening lambs did not produce performance responses similar to 21 those observed by adding a buffering salt. 22