In recent years, the commercial broiler breeder industry has reported problems of male aggression towards females [Millman, S.T., 1999. An investigation into extreme aggressiveness of broiler breeder males. Unpublished PhD Thesis, University of Guelph]. Although this aggression is shown by the males and is apparently a defect in their behaviour [Millman, S.T., Duncan, I.J.H., 2000. Strain diffe...

This experiment was one part of a larger study investigating problems of aggression towards females by male broiler breeder fowl. To investigate causal mechanisms, we were interested in determining (1) if feed-restriction during rearing affects behaviour towards females at sexual maturity and (2) if aggressiveness towards females is correlated with general levels of aggressiveness. We compared ...

Fertility reduction due to sub-fertile males is a major concern in breeder flocks. Phenotypic traits of broiler breeder males and their relationships with fertility can be used as reliable indicators for identification and removal of sub-fertile males from the breeder flocks. This study was conducted to investigate semen traits (semen volume, sperm motility, sperm viability and sperm count) and...

Two experiments were conducted to evaluate the effects of male broiler breeder feed intake on broiler progeny performance. In experiment 1, a low cumulative nutrition program supplied 29,580 kcal of ME and 1,470 g of CP, whereas a high cumulative nutrition program supplied 33,500 kcal of ME and 1,730 g of CP to photostimulation at 21 wk of age. Two diets (HiDiet and LoDiet) were formulated, and...

The aim of the present study was to evaluate the effect of zinc as feed additive on some the blood plasma traits of males and females of broiler breeder chickens. A total 132 (96 females and 36 males) of Cobb 500 broiler breeder chickens, 45 weeks old were used in this study. These birds were randomly distributed into four dietary treatment groups with three replicates each. Each treatment grou...

Recent trends occurring in broiler primary breeding companies are described. The structure and operation of broiler primary breeder companies are described from pedigree elite populations, through great-grandparent and grandparent generations, down to the parent stock. The relatively low value of fertility and hatchability, compared with yield and feed efficiency as selection traits, is assesse...

Effect of photoperiod on age and BW at attainment of mature semen production was examined in males of lines selected for high (HL) and low (LL) threshold BW at onset of lay, and in males of a commercial Cornish male line (MC), a commercial broiler breeder female line cross (BX), and a commercial layer cross (LX). Photoperiod treatments were: I, increasing natural spring light; and D, steadily d...

Fertility is one of the most important parameters in breeder farms and cockerels play an outstanding role in fertility of eggs in broiler breeder units. Todays, supplementation of feed-additives such as organic selenium is used to increase fertility. The aim of this study was to evaluate the effects of different levels of Nano-Selenium (Nano-Se) on expression of molecular markers of spermatogon...

Reports on the influence of dietary crude protein on male broiler breeder fertility are not consistent, and therefore an experiment was conducted to determine the effect of three isoenergetic diets containing 10.5%, 12.6% and 15% crude protein, respectively, on Ross broiler breeder male fertility from 26 to 41 weeks of age. Feed allocation was the same for each treatment, and was done according...