Female chickens from eight different genetic stocks, ranging from 13 to 21 months of age, and exhibiting various levels of egg production were studied. Plasma samples were collected between 1700 and 2200 hr to determine basal circulating levels of progesterone (P4) and 17 beta-estradiol (E2) by radioimmunoassay. Linear regression analysis was used to describe the relation between mean hormone levels (E2, P4, and E2/P4) and mean egg production from these groups, and correlation coefficients were used to evaluate the general usefulness of these hormone parameters for estimating egg production within a group or flock of hens. Of the three hormone parameters evaluated, basal circulating E2/P4 was found to be the best estimator of egg productivity.

A co-precipitated concentrate of soybean and peanut proteins, prepared from flours along with two soy concentrates, a peanut concentrate and a soy-peanut concentrate blend, were texturized by twinscrew extrusion followed by rheological, functional and ultrastructural analysis of the textured products. Optimal feed moisture varied among the different feed materials and corresponded to final product moisture. Compared to the other textured products, the textured co-precipitated concentrate exhibited increased rehydration capacity, decreased peak force and work, moderate expansion and a unique ultrastructure. Product ultrastructure was determined to correspond with rheological and functional characteristics of the extrudates. Co-precipitation of soybean and peanut proteins resulted in a feed material with modified extrusion performance.

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