[Effect of vitamin and mineral premixes withdrawal time on growth and economic peformance of broiler chickens]

Poultry requirements for vitamins and minerals are met from two sources feed ingredients and premixes. In practical poultry nutrition, the role of feed ingredients is over looked. This experiment was conducted to evaluate the effects of the time of vitamin and mineral premixes withdrawal on growth and economic performance of broilers. Four hundred and fifty, one day-old male broiler chickens [Ross 308] were used in a completely randomized design with 6 treatments of 5 replicates. Chicks were fed on a common starter diet formulated based on corn and soybean meal, with common vitamin and mineral premix [VMP] levels [0.25% each] for the first week. Then, the treatments 1 to 6 were constructed, on the basis of withdrawal time of VMP, in a way that treatment numbers were represented the number of weeks fed on VMP supplemented diet. The results showed that VMP withdrawal from 7,14 and 21 days of age decreased daily weight gain and feed intake significantly [p<0.01], and impaired feed efficiency [p<0.01]. While VMP withdrawal from day 28 and day 35, did not influence weight gain, feed intake and feed efficiency. Relative weights of abdominal fat, bursa of fabricius and spleen, and carcass yields were not influenced by VMP withdrawal. The overall results of the present study, considering economical aspects showed that the removal of vitamin and trace mineral supplements from 7 days prior to slaughter can reduce production costs without negative consequences on growth performance of broiler chickens

[Comparison of intraobserver and interobserver reliability between the lenke and king classification systems for adolescent idiopathic scoliosis]

In spite of many advantages in Lenke classification of adolescent idiopathic scoliosis, the latest study of Richards et al showed that the King classification is better than had been reported recently and the Lenke classification system of adolescent idiopathic scoliosis is less reliable than previously reported. In this study, we performed a multi-surgeon comparison of these two classification systems. After teaching and discussing all available data of these classification systems with four spine surgeons, a pilot classification was performed. Then, they independently evaluated preoperative radiographs [standing posteroanterior, lateral, and two supine side-bending views] of 99 patients with adolescent idiopathic scoliosis. The results were determined by calculating the average percentage of intraobserver and interobserver agreement. Reliability was quantified using kappa statistics. The King classification demonstrated good intraobserver and interobserver reliability, with an intraobserver agreement of 85.8% [kappa coefficient, 0.80]. Interobserver percentage of agreement averaged 80.8% [kappa coefficient, 0.74]. The complete Lenke classification, combining curve type, lumbar modifier, and sagittal thoracic modifier, demonstrated good reliability for both intraobserver and interobserver measurements. The intraobserver percentage of agreement averaged 85.8% [kappa coefficient, 0.82]. The interobserver percentage of agreement averaged 80.8% [kappa coefficient, 0.77]. In this study, with each investigator performing the radiographic measurements, the King and Lenke classifications were almost similar [the Lenke classification had slightly better results]. Such better results might be due to more training of this complex classification system. So, because of greater coverage of idiopathic scoliosis curve and usefulness of Lenke classification system, we prefer using this classification system in our center