No abstract

An experiment was conducted to determine the digestibility of energy and crude protein (CP) in hulled and hulless barley with the in vivo and in vitro method. Six barrows were fed six diets according to a 6 × 6 Latin square design. The six diets included 950 g kg -1 of four barleys and two mixtures. Diet A: hulled barley, c.v. Harrington I. Diet B: hulled barley, c.v. Harrington II. The origin of c.v. Harrington in diet B was different from that in diet A, and therefore referred to as c.v. Harrington II. Diet C: hulless barley, c.v. CDC Buck. Diet D: hulless barley, c.v. CDC Richard. Diet E: mixture of c.v. Harrington I and c.v. CDC Buck (50:50, wt/wt). Diet F: mixture of c.v. Harrington II and c.v. CDC Richard (50:50, wt/wt).The mixtures were created in order to establish linear regression equations between in vivo and in vitro methods. Chromic oxide was used as the digestibility marker. The barrows were fed twice daily, at 08.00 and 20.00 h. Each experimental period consisted of an 8-d adaptation period followed by a 2-d collection period of faeces. The initial and final average body weights of the barrows were 40 and 90 kg, respectively. The in vivo energy digestibilities were higher (P < 0.05) in the hulless (81.4 to 84.7%) than in the hulled barleys (76.9 to 77.6%). The digestible energy contents in the hulless barleys ranged from 14.01 to 14.60 MJ kg -1 while the contents in the hulled barleys ranged from 13.05 to 13.16 MJ kg -1 (as-fed). The average digestible CP contents in the hulled and hulless barleys were nearly similar and were 88.0 and 89.7 g kg -1 (as-fed), respectively. The in vivo energy and CP digestibilities in the barleys and their mixtures can be accurately predicted by in vitro values, as these were very high correlations between these methods for energy (r 2 = 0.93) and CP (r 2 = 0.87).

This study was carried out to investigate the growth performance and the carcass ratio of meat-type Korean Native Ducks. Four hundred twenty Korean Native Ducks' chicks were selected and divided into four treatments (7 replications/treatment, 15 birds/replication) by strains (A and B) and gender(male and female) with 2×2 fractal factors. There was no significant difference between A and B on the body weight at 2, 4, 6, and 8 weeks old (P>0.05). However, body weight of female was higher at 2 weeks old than male while that of male was higher at the 8 weeks old (P<0.01). Daily feed intake of male was higher compared to female during 6～8 weeks (P<0.05). On weekly body weight gain, there was no significant difference between strains, but gained body weight of male was higher until 2 weeks old while that of female was higher during 6～8 weeks (P<0.01). On the live body weight and carcass weight by strains and genders, B strain was higher than A strains at the 8 weeks of age (P<0.01). Carcass yield was the highest at 8 weeks of age in both strains (P<0.05). These results may provided the basic data on growth performance and carcass ratio of meat-type Korean Native Ducks.

The effects of conjugated linoleic acid (CLA) with other fatty acids on the fatty acid composition of egg yolk and on egg quality characteristics were studied in 5 groups: 1) CLA 0% (control), 2) CLA 2%, 3) CLA 2%+oleic acid (OA) 2% (CLA+OA), 4) CLA 2%+linoleic acid (LA) 2% (CLA+LA), and 5) CLA 2%+alpha-linolenic acid (LNA) 2% (CLA+LNA). Some parameters of egg quality such as shell thickness, shell strength, yolk color, yolk index, egg diameter, and Haugh units were aggravated when CLA was fed alone, but the quality was improved when CLA was combined with some other fatty acids. The egg production rate, which was decreased by feeding CLA alone, was improved by co-supplementation with LA or OA. An increase in CLA content was observed in all the dietary groups fed CLA for 2 wk. Feeding hens with CLA+LNA led to a linear increase in CLA content in the egg yolk after the fourth week of the feeding trial. Egg yolks from hens given CLA had considerably higher amounts of saturated fatty acids and lower amounts of monounsaturated fatty acids than egg yolks from the control group. The pattern of change in CLA concentration during the feeding trial was similar to the level of C18:0, which was inversely correlated with the level of C18:1. The unsaturated fatty acid co-supplementation strategy applied in this study offers insight into the mechanism of CLA accumulation in the egg yolk without apparent adverse effects on egg quality and egg production.