Customised ration boosts egg weight

Published: 20 May 2019

Dudley Southgate knows better than most producers the impact that the retailers' ongoing quest for Large eggs has had on the market. Dudley is a shareholder of Anglia Free Range Eggs and is part of its Agricultural Team.

"Effectively the market has been tight on Large eggs since last year which has resulted in a challenge for both packers and producers," says Dudley, who farms a total of 80,000 hens in Norfolk.

In most cases packers have responded by increasing the price paid to producers for Large eggs whilst at the same time reducing the price paid for Medium - leading to a differential of up to twenty pence a dozen in some instances.

"As a producer, I've had to respond to this challenge by maximising egg weight and we've achieved this primarily by modifying our start-lay ration," says Dudley, who sat down with his feed supplier Crown Milling to formulate a new bespoke ration. The result was the birds were fed a 'super high density' start-lay ration to 21 weeks (see specification below), enabling them to achieve that all-important bodyweight growth, after which they moved on to a more conventional early-lay diet.

Crude Protein

19.0 per cent


12.0 ME


0.5 per cent


1.0 per cent

Linoleic Acid

2.4 per cent







The flock, reared by Country Fresh Pullets on a six-week step-down to 10 hours light, continued on 10 hours when transferred to the laying farm. Light stimulation was then based on bodyweight, not age, explains Kraig Shephard, Hy-Line's Technical Advisor for the Eastern region. "Whereas our recommendation has in the past been to start lighting birds up when they were 1450 grams, usually around 18 weeks, if producers are looking for larger eggs then that should be delayed until at least 1500 grams or above.

"In the case of Dudley's flock, they had achieved an average bodyweight of 1545 grams by 18½ weeks and were then given an extra hour of light," says Kraig. "From that point they received an increase of an hour a week, whilst we closely monitored bodyweights, until the flock was on 15 hours by 23 weeks and weighing 1886 grams."

As for giving the final hour of light, taking the birds to a 16-hour day, Kraig likes to see this kept in reserve until the majority of the flock are in lay. "I like to keep that last hour up our sleeve and when we think the birds have about reached peak, we add it then and it tends to give the flock another little push and can also stimulate further feed intake."

The effect of the high-spec early diet was an average egg weight of nearly 60 grams by week 25 and by week 38, with the flock laying at 97 per cent, the average egg weight was 65 grams, meaning around 65 per cent of the eggs were in the Large and Very Large weight band.

Commenting on these impressive results, Kraig told the Ranger: "Of the flocks I've got on the ground currently, these were by far the best prepared for the onset of lay and it has paid off. With feed costs currently high and egg prices depressed, I fully understand why producers are reluctant to pay more for feed than they have to but by investing in the ration from the start, it is exactly that, an investment for the future performance of the flock. The extra cost of the improved ration worked out at a little over 6p a bird so it isn't going to take too many eggs moving from the Medium band into Large to recoup that. The time to start saving money on feed is later in lay when egg weight has been established." Dudley's flock were switched to a lower specification ration when the average egg weight reached 64 grams. "Diet changes must be geared to egg weight rather than bird age," emphasises Kraig.


Hy-Line Brown (Standard)

Flock Size

2 x 16,000


38 weeks

Hen Day Production

97 per cent

Average Egg Weight

65 grams

Average Feed Consumption

130 grams


0.5 per cent


2080 grams


87 per cent

Floor Eggs

0.44 per cent

Feather Cover














Hy-Line's nutritionist, Marcus Kenny, agrees that bodyweight is one of the most important determinants of egg size, especially early egg size. Analyses of Hy-Line Brown flocks (394 flocks) shows that those flocks with the highest early bodyweights – 1560 grams at 18 weeks versus 1470 grams – are associated with higher egg weight. The higher 18-week bodyweight flocks not only achieved a higher egg weight but also a higher number of eggs – 318 by 70 weeks as opposed to 281 in the lower bodyweight flocks.

"Feeding for egg size has to start from the beginning of lay," says Marcus. "The objective is to achieve a large egg from the onset of lay which should result in a larger egg for the remainder of the laying period. If feed intake is too low at the beginning of lay, nutrient intake will be too low to support development of large eggs. Producers should adjust the feed specification based on the bird's feed intake, aiming to achieve target nutrient intake to support egg size. Remember, birds don't eat 'percentages' they eat nutrients.

"In summary, large framed and well-conditioned birds at the start of lay will lay larger eggs. The aim is to achieve breed bodyweight standards throughout lay, aiming to meet or be above breed standards through lay. Checking bird bodyweight regularly allows the nutritionist to assess if the feed is meeting the bird's nutrient requirements. This is particularly important for birds that are still growing at the beginning of production. Bodyweights below breed standard may well be a result of an imbalanced diet and/or inadequate consumption of nutrients."