Editor's note: This article is an excerpt from the Cobb Breeder Management Guide and additional articles will follow. The Guide was designed to highlight critical factors that are most likely to influence flock performance. The management recommendations discussed were developed specifically for Cobb products. The recommendations are intended as a reference and supplement to your own flock management skills so that you can apply your knowledge and judgement to obtain consistently good results with the Cobb family of products. To read or download the complete Guide or to view Cobb's other management guides, click here.

There will be occasions when flocks are not on the bodyweight target. Any corrective actions should be done with long term rather than short term goals. Adjustments to the growth rate of the flock must ensure that the females will still achieve the necessary body condition and weight gains to allow them to not only sexually mature but also maximize peak production and persist for the life of the flock. 

Adjustments in feed allocations take several days to be realized as change in flock weight. Prevent frequent feed change that creates a jagged growth curve. The following examples illustrate the way in which corrective action should be taken in four different situations:

Flock weight off target at 5 weeks

Problem - Birds 100 g (0.22 lb) or less under weight.

Action - Redraw target bodyweight to gradually achieve standard target by 63 days (9 weeks) of age.

Problem - Birds are more than 100 g (0.22 lb) under weight.

Action - Redraw target bodyweight to gradually achieve standard target by 84 days (12 weeks) of age.

Problem - Birds are over weight by less than 100 g (0.25 lb).

Action - Redraw target bodyweight to gradually achieve standard target by 8 weeks of age.

Problem - Birds are over weight by more than 100 g (0.25 lb).

Action - Redraw target bodyweight to gradually achieve standard target by 70 days (10 weeks) of age.

Flock weight off target at 10 weeks

Problem - Birds are 100 g (0.22 lb) under weight.

Action - Redraw target bodyweight to gradually achieve standard target by 16 weeks of age.

Problem - Birds are over weight 100 g (0.22 lb).

Action - Redraw target bodyweight parallel to standard target weights through 21 weeks. Bodyweight should return to standard by 25 weeks of age.

Flock weight off target at 15 weeks

Problem - Birds are 100 g (0.22 lb) under weight.

Action - Redraw target bodyweight to gradually achieve standard target by 133 to 140 days (19 to 20 weeks) of age.

Problem - Birds are over weight 100 g (0.25 lb).

Action - Redraw target bodyweight parallel to standard targets weights through 22 weeks.

Flock weight off target at 20 weeks

Problem - Birds are 100 g (0.22 lb) under weight.

Action - Delay photo stimulation by 1 week. Redraw target bodyweight parallel to standard target until 5 % daily production, there after bodyweight will progress in response to feed increases for production.

Problem - Birds are over weight 100 g (0.25 lb).

Action - Redraw target bodyweight parallel to standard target weights throughout.

To read or download the complete Cobb Breeder Management Guide or to view Cobb's other management guides, click here.