A new xylanase from Penicillium griseofulvum.

A new xylanase (pgxynA) from Penicillium griseofulvum A160 has been isolated and characterised using a screening method based on the ability to digest a complex substrate. The enzyme belongs to the hydrolase family 11 or G and shows an optimum pH of 5.0 and an optimum temperature of 50 degrees C. The xylanase breaks down the xylan to very small oligosaccharides. The corresponding gene (PGXYNA) was cloned and expressed in Aspergillus oryzae. A second xylanase gene with 66% identity to PGXYNA has also been isolated from P. griseofulvum A160. The recombinant pgxynA xylanase has been tested in some industrial applications. In bread making, hard rolls volume increased significantly using this enzyme. In wheat flour processing, the enzyme improved the separation of gluten from starch. In poultry, the addition of the A160 xylanase to a wheat-based diet led to an higher body weight as well as to a better feed conversion ratio.

Effect of a bacterial xylanase and/or antibiotic growth promoter on zootechnical performances of piglets fed arabinoxylan rich diets.

272 cross bred piglets (Saw (wbp x pbz) x Boar (Hamp x Pietr) were fed a basal diet rich in arabinoxylans from 29 days old to 84 days old. In the prestarter period (29 to 42 d) the basal diet was formulated with 27% wheat, 10% barley, 10% maize, 18% soybean meal and 22% milk products and the analytical content was adjusted at 13.81 MJ/kg metabolisable energy, 19.6% crude protein, 12.4% lactose, 1.38% lysine and 0.88% SAA. During the starter period (43 to 84 d) the basal diet was formulated with 53% wheat, 25% barley and 16% soybean meal and the analytical content was adjusted at 12.91 MJ/kg metabolisable energy, 16.7% crude protein, 1.09% lysine, 0.62% SAA.

Effects of methionine hydroxy analog on voluntary intake, digestibility, nitrogen balance, and chewing behavior in sheep fed grass silage.

Voluntary intake, digestibility, N balance, and chewing behavior of six 6-mo-old (young) and six 30-mo-old (mature) Texel wethers (32.6 and 83.1 kg average BW) given ad libitum access to grass silage and 100 g of top-dressed soybean meal with or without 5 g of methionine hydroxy analog (MHA) in the acid form were examined according to a two-period crossover design. Supplementation level of MHA in the acid form corresponded to .32 and .16 g of MHA/kg BW.75, respectively, in young and mature wethers. There was no effect (P greater than .10) of MHA on mean voluntary DMI. Methionine hydroxy analog supplementation increased (P less than .02) digestibility of DM, OM, and CP by young wethers but not (P greater than .18) by mature wethers. The MHA decreased eating time (P less than .03) in both young and mature wethers and intake level (P = .01) in young wethers during the first 1.5 h of access to grass silage. With MHA, both age groups increased (P less than .05) the daily number of meals and decreased (P less than .02) the mean duration of each meal. There was no effect (P greater than .06) of MHA on daily and unitary eating, ruminating, and masticating times; however, mean duration of consecutive rumination bolus cycles was longer (7.2%; P = .01) in young wethers. Young vs mature sheep ate more (53.4 vs 39.3 g of DM/[d.kg BW.75]; P less than .001) and had shorter unitary mastication times (P = .001). Results suggest that, depending on its relative level of supplementation, MHA in the acid form could act through both palatability and effects on ruminal metabolism.