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Shank length is used as a tool for the determination of fertility, body weight, estimates of frame size, and the monitoring of growth and development of pullets. This study was carried out to investigate the effects of infectious bursal disease (IBD) on shank length, diameter, body weight, shank length and body weight growth curves, and mortality rate in males and females in the rearing period in broiler breeder flocks. In this study, 2 broiler breeder flocks (Ross 308 flocks) and 800 breeder chicks (both females and males) were selected for shank length and diameter assessments. All the management, nutrition, and geographical statuses were similar, except for one flock that was infected with IBD. Results of this study showed that IBD presence in the flock decreased shank length in male and female chickens compared with the control group. Shank length in male and female chickens at 20 weeks of age was 0.53 and 0.02 cm, respectively, which was less than that in the controls, but these differences were not statistically significant. Shank diameter in the diseased male and female chicks was also smaller than that in the controls, although this difference was not also significant. There were no significant differences in the body weight of both sexes at 20 weeks of age. Body weight to shank length ratio in the diseased males was higher than that in the controls, but in female chickens it was less than it was in the control group after 12 weeks. Mortality rate in diseased males was 2.26% more than that in the control group (P < 0.05) but mortality in females was not different from that in the control group. After observing clinical IBD in both male and female chicks, antibody titers against IBD virus were found to have increased compared to the control group (P < 0.0001). It could be concluded that male chickens are more sensitive to IBD than females.

An analytical solution is presented for fully developed laminar flow between vertical parallel plates filled with 2 immiscible viscous and couple stress fluids in a composite porous medium. The flow in the porous medium is modeled using the Brinkman equation. The viscous and Darcy dissipation terms are included in the energy equation. The transport properties of the fluids in both regions are assumed to be constant. The continuity conditions for the velocity, temperature, shear stress, and the heat flux at the interfaces between the couple stress permeable fluid layer and the viscous fluid layer are assumed. The influence of physical parameters on the flow, such as the couple stress parameter, porous parameter, Grashof number, viscosity ratio and conductivity ratio, are evaluated, and a set of graphical results is presented. An interesting and new approach is incorporated to analyze the flow for strong, weak, and comparable porosity conditions with the couple stress fluid parameter.

In [1] we introduced a new sequence of linear positive operators Mn to approximate unbounded continuous functions of exponential growth on [0,\infty). As this sequence is saturated with O(n-1), to accelerate the rate of convergence we applied the technique of linear combination introduced by May [3] and Rathore et al. [4] to these operators. The object of the present paper is to study the phenomena of simultaneous approximation (approximation of derivatives of functions by the corresponding order derivatives of operators) by the linear combination Mn ( . , k, x) of Mn. First, we establish a Voronovskaja-type asymptotic formula and then proceed to obtain an estimate of error in terms of modulus of continuity in simultaneous approximation by this sequence of operators.

In the present paper, we study some direct results in Lp -approximation by a linear combination of a new sequence of linear positive operators. The error in the approximation is estimated in terms of the higher order integral modulus of smoothness using some properties of the Steklov means.