Katelyn Humphreys | ALES Graduate Seminar

A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Katelyn Humphreys. This seminar is open to the general public to attend.
Thesis Topic: Implications of altering maternal feed availability and feeding system on offspring performance

MSc with Dr. Martin Zuidhof.

Seminar Abstract:

In the pursuit of increasing the efficiency of hatching egg production the poultry industry may have inadvertently decreased the growth potential of the broiler. Research has found that matching the offspring feeding environment to the maternal feeding environment has beneficial effects on the final offspring BW. This project consisted of 2 experiments, each used offspring from 2 maternal treatments (MT), 2 sexes and 3 feeding treatments. In experiment 1, the MT were Ross 708 broiler breeder hens raised on standard breeder-recommended target BW (SBW), or 121% of SBW (HBW). In experiment 2, the MT was Cobb grandparent breeder hens fed using a conventional (CON) or a precision feeding system (PF). Both broiler trials were organized in a 2 x 2 x 3 factorial arrangement of treatments with 2 MT treatments, 2 sexes, and 3 feeding treatments. Broilers from experiment 1 were housed in cages and fed using conventional feeding methods. Broiler from experiment 2 were housed in floor pens and fed using precision feeding techniques. Broilers from both experiments were fed ad libitum until d 28. From 29 to 42 d of age, they were provided feed ad libitum (AL), or at 80 or 60% of AL. At 28, 35 and 42 d of age, carcass yield was determined after dissection. Blood was also collected for hormone analysis. The circulating levels of T₄ were 11.7% higher in HBW offspring than in SBW offspring, suggesting that the metabolic system of the bird was trying to stimulate growth in an attempt to reach the birds growth potential because T₄ is known to be associated with increased growth. Offspring BW for trial 1 was 4.0% higher in the HBW offspring compared to the SBW offspring. There were no MT effects on BW in experiment 2. These led us to conclude that raising broiler breeder target BW could have a positive effect on the performance of their offspring by increasing final BW.