EGGS IN HOT WEATHER
O ptimising egg size in hot weather E
very summer the same thing happens. Hot weather hits suddenly, layer feed consumption drops, and production and egg size suffer as a result. It’s a predictable sequence of events, yet we seldom plan ahead for avoiding these consequences. It is obvious that egg size is manageable through controlling body weight, rate of maturity, and nutrition. Now is the time to plan ahead for hot weather peaking flocks to improve early egg size and optimise profitability.
The most severely affected flocks are those just coming into production when the hot weather arrives. That is a precarious time in the life of a layer anyway, because they have difficulty consuming sufficient feed to meet their nutritional demands, even in normal conditions. Adding the effect of heat stress at this time can only make it worse. What
are some actions that can be taken to better prepare young flocks to maintain production and egg size during hot weather?
The single most important factor for achieving egg weight is the pullet’s body weight maturity. This relationship, is summarised in below table.
For every 45 g heavier the average body weight at 18 weeks, egg size increased almost 0.5 grams. Of course, body weight is affected by many management factors, including disease, lighting, space allotment, and beak trimming, but the most direct influence probably comes from nutrition.
It has been demonstrated that pullet growth is most responsive to protein in roughly the first half of the growing period and to energy in the later half. We have learned that energy intake can be the most restrictive nutrient limiting growth. With today’s feed efficient varieties, we sometimes need to encourage consumption during growing by keeping house temperatures a little cooler, running feeders more often, and allowing more space per bird. Also, higher density diets, especially energy, will allow the pullets to consume adequate energy and other nutrients on a lower