The study was conducted to evaluate the effect of different levels of synthetic lysine (sLys) on dry matter intake (DMI), average daily weight gain (ADG), dry matter conversion ratio (DMCR), carcass characteristics and economics of productionof finisher broiler chicks. As 240 day-old broiler chicks were randomly distributed to 12 pens of 20 chicks each and assigned to four treatment rations in a completely randomized design. Six broilers (3 males and 3 females) from each replication were starved for 16 hours and slaughtered to evaluate carcass characteristics. Control diet had a lysine content of 0.9 and 0.8% of the ration, which was 0.3 and 0.2% of the ration below the recommended level. The four rations were formulated by including sLys at levels of 0, 50, 100 and 150% of the deficient amount of lysine. No sLys in the ration (T1) and rations to which 50% (T2), 100% (T3) and 150% (T4) of the deficient amount of lysine being added as sLys. No significance difference (P>0.05) was observed among treatments in total and daily DMI, metabolic energy (ME) and crude protein (CP) intakes and DMCR at all phases of the experiment. Final body weight (1665, 1672, 1707 and 1786 g (standard error of the means(SEM)=18.04)) and ADG during the entire period (33.0, 33.1, 33.9 and 35.5 g/day (SEM=0.36) for T1, T2, T3 and T4, respectively) was significantly higher (P<0.05) for birds kept on T4 diets. No significant difference (P>0.05) existed in mortality percentage among treatments. Dressed carcass weight (1407, 1426, 1461 and 1510 g (SEM=15.07)), breast weight (329, 334, 338 and 365 g (SEM=5.09)) and drumstick weight (134, 137, 135 and 150 g (SEM=2.3)for T1, T2, T3 and T4, respectively) were greater for T4 than other treatments. In conclusion, 12.5% extra addition of sLys above the level recommended by NRC to the commercial diets, as in T4, improved broiler performance and profitability. پرونده مقاله

Rapid exploratory field survey, to identify indigenous chicken ecotypes was conducted in north Gondar zone of Ethiopia. Chicken ecotypes including Necked neck, Gasgie and Gugut from Quara, Alefa and Tache Armacheho districts were identified, respectively. Morphological variations among the three study populations and nine measurable traits were evaluated. General linear model, canonical discriminate and stepwise analyses were applied for assessing variability among the study populations. Necked neck and Gasgie ecotypes were heavier and had wider linear traits than the rest, while most of the study traits for the Gugut ecotype were the lowest. The most important variables for discriminating between the three populations were shank length, keel length, wingspan and beak length with canonical discriminant functionscore of0.897, 0.752, 0.449 and0.433, respectively. The greatest distance value was between Gasgie and Necked neck ecotype while the least one was between Gugut and Necked neck. The discriminate analysis therefore classified the three populations to be distinct clusters. The morphological traits studied have proved to be useful in genetic characterization of indigenous chickens and can thus be useful in developing strategies for conservation of the genetic diversity. پرونده مقاله