Developmental changes in testicular interstitium in the Najdi Ram Lambs.

This experiment was designed to study the relationship between growth rate and sexual development in Najdi ram lambs. Forty-five Najdi ram lambs were used in nine age groups (1-9th month age), keeping 5 lambs in each group. Results show that mean testis size and scrotal circumference increased at a constant rate, reaching a maximum value of 392.

Laying hen behavior 2. Cage type preference and heterophil to lymphocyte ratios.

Studies were conducted to determine hen preference for and stress response to cage type. By using a plywood (1.25 cm) test apparatus with open- and solid-sided compartments and a plexiglass divider at the entrance for controlling passage, birds (n = 20) were evaluated as to their choice of compartment after training and acclimation.

Effect of induced molting in laying hens on production and immune parameters.

A total of 600 commercial strain (DeKalb) Single Comb White Leghorn hens, 80 wk of age, were used in this study to determine the effects of different induced molting programs on production and immune parameters. The hens were randomly divided into four treatment groups (three experimental and one control) of 150 hens each. The hens in the first treatment group were fed a layer ration containing 20,000 ppm of zinc for 5 d, and received a reduced photoperiod of 8 h/d for 5 d (Zn group).