Cobb Breeder Control Information: Strategies for grading breeders

Editor’s notice: This newsletter is an excerpt from the Cobb Breeder Control Information and further articles will observe. The Information used to be designed to spotlight crucial components which can be possibly to steer flock efficiency. The control suggestions mentioned had been evolved particularly for Cobb merchandise. The suggestions are meant as a reference and complement for your personal flock control talents in an effort to observe your wisdom and judgement to acquire constantly just right effects with the Cobb circle of relatives of goods. To learn or obtain the entire Information or to view Cobb’s different control guides, click on right here.

You will need to to have the flock at the right kind weight and uniformity by way of 4 weeks with a most of five % above or under the usual. Proper weights and prime uniformity at 4 weeks of age will save you critical feed restrictions or expanding feed quantities all through the upkeep length. 

The most important software to fortify uniformity is grading. Grading is the method of sorting person birds into classes in keeping with body weight (tremendous gentle, gentle, reasonable, heavy) in order that birds inside respective classes can also be controlled again to plain. Sorting birds into classes can also be finished after taking person weights and calculating uniformity, CV and usual deviations.

Carry out a 100 % weighing and grading when the flock is 7 to fourteen days outdated. This permits the birds to be grouped by way of weights and feed intake, which controls festival for feed from an excessively early age. The following 100 % flock gradings will have to happen at 4, 8 and 12 weeks of age or when uniformity is under 65 %. Birds will have to be categorised in heavy, medium and light-weight in comparison to the typical weight. Don’t prolong grading ages or the benefit got within the first grading will be lowered. 

It can be useful to guage the result of grading carried out at an previous age, for instance, at 3, 7 and 11 weeks of age. It’s transparent that if gradings are carried out early, it’s imaginable to acquire and handle uniformity equivalent to or more than 80 %. In some areas, the price of exertions prohibits more than one gradings. In those markets, if only one grading can also be finished, the most efficient age is between 21 and 28 days of age. Appearing a grading at this age will supply extra time to proper any uniformity problems.

Without reference to the selection of gradings finished in rearing, it is rather essential to have the fundamental control standards proper together with: sufficient feeder house, rapid feed distribution (at the hours of darkness), just right hen distribution over the entire space, consistent feed will increase on a weekly foundation and sufficient ingesting water to be had with the right kind water drive. Men observe the similar grading thought as women folk and, generally, will have to be 5 % upper in uniformity than the women folk. Men constitute simplest 10 % of the flock however are liable for 50 % of the offspring.

The common minimal uniformity in rearing will have to be above 70 % (± 10 % variation of the imply) from 3 to twenty weeks. This uniformity will have to be maintained somewhat consistent or will have to building up in opposition to the tip of the rearing length. Uniformity under 70 % signifies there are feed consumption problems and the flock isn’t uniform. Being provide at feeding is likely one of the maximum essential occasions of the day. It’s then that mistakes can also be recognized, and quick changes can also be made in order that the flock continues to develop uniformly.

Automated grading machines

There are a number of fashions available on the market. A bigger fashion is to be had and is appropriate for firms with flocks of greater than 300,000. This device can vaccinate pullets however isn’t simple to transport. By contrast, different smaller fashions are readily cell and built of stainless-steel for simple cleansing. Those smaller fashions are restricted to grading chicks and birds as much as 20 weeks of age. Generally, grading with machines is advisable for two gradings at 3 to 4 and 10 to twelve weeks of age, to handle reasonable uniformity in rearing smartly above 75%. 

Benefits of automated grading come with:

• May also be quicker than hand grading and generally calls for much less staff
• Capability in keeping with fashions can grade from 1500 to 3000 birds consistent with hour
• Types birds with actual weight levels and no errors with counting birds which can be looked after into teams (a primary factor of hand grading)

If additional information is wanted, touch your Cobb consultant to get data on the newest trends.

Weighing and grading by way of hand

Virtual placing scales are to be had for grading by way of hand. Many virtual scales can document and retailer weights to the closest gram, calculate a mean weight, and show histograms of the load distributions. 

The cutoff values for sorting the flock into teams can also be programed to make weighing and sorting quicker and more uncomplicated. In spite of everything, virtual scales too can rely the selection of birds that had been weighed and the overall selection of birds in each and every team can also be displayed at the scale. You will need to notice that, if the selection of birds in each and every team isn’t correct, then the feed allocations can’t be as it should be calculated.

Grading process

Cobb recommends sorting birds into 3 teams: heavy, reasonable, and light-weight. Relying on uniformity and CV, a 4th team (tremendous gentle) can be utilized.

Some homes have mounted pens or walls, and in those homes, no less than one pen will have to be left empty at placement for the sorting procedure. You will need to needless to say if birds are moved to an empty pen all through sorting to switch one of the crucial clutter from the used pen to the unused pen to facilitate the biking of the coccidia vaccine. If mounted pen or walls are getting used, the dimensions of the pen will have to be used to calculate the utmost selection of birds consistent with pen in keeping with flooring, feeder and drinker house. Likewise, for adjustable pens and walls, alter the dimensions of those spaces in keeping with flooring, feeder, and drinker house required for each and every hen. If flooring, drinker and feeder house isn’t adjusted to fulfill hen necessities inside the pens, sorting birds can in fact reason extra issues! 

Stocking density is essential for welfare and uniformity causes. If pen density ranges are too prime, uniformity can diminish. In some settings the place exertions is quickly to be had, more than one small pens can also be ready. On this case, it is suggested that the selection of birds consistent with pen now not exceed 1,000 birds with 600 to 800 birds consistent with pen being preferrred. In homes with 8,000 to ten,000 birds, small pens aren’t sensible. Every pen will have to have an unbiased feeding device. If this isn’t imaginable, supplementary feeders can be used to regulate the feed allocations to each and every pen.

Grading and sorting procedure

1. Previous to grading, a portion the flock (3 to five %) will have to be weighed. (It’s endorsed to gather a pattern weight despite the fact that automated scales are getting used). Resolve the typical, usual deviation and CV or uniformity (additional reference). There are two techniques to resolve the sorting weights:
   1. Use usual deviation as a cutoff. On this approach, 68 % of the flock might be positioned within the reasonable class, and the sunshine team (- 1 SD) will include 16 % of the flock. The remainder 16 % of the flock might be + 1 SD and belong to the heavy team. As an example, if there are 3,000 birds in a flock, 2000 can be reasonable weight, whilst 500 can be gentle and 500 can be heavy. This way works with all flocks however can also be very efficient for flocks with deficient uniformity. Generally, underneath just right control prerequisites and with out gradings the uniformity might be round 70 to 72 %. Subsequently, operating with +/- 1 SD might be extra herbal for flock uniformity.
   2. The use of a plus or minus 10 % calculation will also be used to grade and kind birds into teams consistent with the desk (under).
2. After the cutoff price has been calculated. Every hen will have to be weighed and looked after into the right kind team (see diagram under). Virtual scales can be used to program cutoff values for each and every team to make sorting quicker and more uncomplicated. The scales too can rely the selection of birds being looked after into each and every team.
3. If hand weighing, re-weigh a pattern of birds from each and every pen after sorting. Calculate reasonable body weight, the difference (CV), and uniformity. Use this information to resolve changes to feed allocations to carry the body weight again to the objective. It is usually a just right follow to recount the birds consistent with pen to make sure the right kind selection of birds get the right kind feed allocation after grading. Fallacious hen numbers consistent with pen are thought to be one of the most main mistakes noticed with hand weighing.
See also  Blowflies can unfold HPAI to business poultry



Flock control after grading

Calculate feed allocations for each and every team in keeping with selection of birds and reasonable body weight to carry body weight again on course (see body weight correction curves in bankruptcy 8).

• Feed allocations will have to by no means be decreased!
• Any will increase in feed quantities will have to be finished conservatively. Take into account, that it is probably not vital to extend feed quantities as festival for feed might be decreased after sorting the flock.
• Proceed tracking bodyweights with weekly weighing.



Festival for feed is at all times provide all the way through the birds’ lives. As famous, weight grading at an early age complements control of feed intake by way of keeping apart the flock into particular weight classes and feeding again to plain body weight. Inside looked after teams, it is not uncommon to look uniformity above 90 % after grading. Then again, quickly after grading, be expecting uniformity to say no to an ordinary stage of 70 to 72 % as pecking (social) order and feed festival turn out to be re-established inside looked after pens. 

If after the primary sorting, uniformity of the inhabitants throughout all pens drops to 65 % or under, an extra sorting and grading will have to be carried out. As well as, resolve why the uniformity continues to lower. Generally feed control problems are concerned. A crop take a look at too can lend a hand resolve deficient uniformity reasons. Some manufacturers carry out more than one grading and sortings all through rearing as a part of a normal protocol. For next grading and sortings, observe the similar protocol as described.

To learn or obtain the entire Cobb Breeder Control Information or to view Cobb’s different control guides, click on right here.