The genetics of broiler breeders change constantly as the poultry industry continues to shift the direction towards more processed products to meet the increasing demand of consumers for these products.
Breeds with the potential to achieve higher breast meat yield through efficient use of feed, now occupy the majority of the US market.
The genetic improvements during the last 50 years have not been unimportant for anything. In fact, the improvement of the carcass yield, up to six times higher in the chickens of 2001, fed with a diet of 2001, compared to the chickens of 1957, fed a diet of 1957, was between 85 and 90 percent to genetics and only between 10 and 15 percent to nutritional changes (Havenstein et al., 2003).
However, efficient growth and high meat yield in broiler chickens means that broiler breeders are highly demanded. Unfortunately, efficient broiler growth and reproductive health in the broiler are features that are negatively associated in production (Siegel and Dunnington, 1985).
As a consequence, efficient management of a flock of broiler breeders is a compromise. Continuous genetic improvements in feed efficiency, rapid growth and high breast meat performance in broilers require constant changes in the management and feeding of heavy broilers to prevent overweight of birds and associated negative impacts in the amount of eggs, fertility and reproductive performance.
Weight gain must be limited throughout the broiler’s life through the control of food intake to minimize reproductive problems in the adult bird (Richards et al., 2010). This supposes that the managers and breeders of heavy breeders are presented what is known with the “paradox of the heavy reproductive” (Decuypere et al., 2006); that it is the difficult task of managing a breeding bird so that it maintains all the important production characteristics for broilers through strict control of food intake and weight gain to avoid egg production depleted and a low reproductive efficiency.
The goal is fertile eggs
The main objective of the management of breeders is the production of eggs. Ultimately, the eggs determine the number of fattening chicks for each hen housed. But the only good egg of a breeder is one that is fertilized (McDaniel, 2011). The one that is not is not more than a simple table egg that has little value for the breeding manager.
If the figures for egg production or mating activity are low, it is likely that the number of chicks per hen housed is less than desired. Although it is true that the integrators are in the business to sell chicken meat and not eggs, first you need to have fertile eggs to be able to have fattening chicks and, finally, chicken meat to sell.
Getting a fertile egg is harder than it looks. The external factors that can affect egg production are several. The age of the bird, flock management practices and specific food ingredients, formulations and portions can affect the oviduct, the egg itself and the quality of the semen. One by one, they affect egg production figures and reproductive efficiency.
The understanding of the ovarian function of the hen and its interaction with nutritional status, age and genetic breed are fundamental for the production of fertile eggs with a high probability of fertilization (Renema et al., 2008).
The interaction between the nutritional and reproductive attributes is complex and is continually changing due to the genetic advances that are still being made (Renema et al., 2007). The management of modern breeding stock has been complicated because these birds do not adequately regulate food intake during the growth and development phases.
This increases the difficulty associated with achieving optimum body weight and composition to support the efficiency in the production of eggs and chicks in the hen (Richards et al., 2010).
To help poultry farmers deal with the landscape of genetic change, primary breeders serve as a guide to target food levels, diet compositions and body weights that best suit each genetic race. The key to maximizing egg production is simply to provide enough food at the right times.
Too much or too little amount in the intake will result in decreased egg production. In general, flocks of breeders with better performance are close to the recommendations established by the primary breeders in terms of body weight, photostimulation, composition of the diet and amount of food.
breeding management, poultry farming, the poultry siteEating of food
Breeders need a minimum total nutrient intake prior to photostimulation to maintain subsequent egg production and fertility during the production cycle (Walsh and Brake, 1997). The same can happen in breeding males to maintain reproductive performance (de Reviers and Seigneurin, 1990).
Although several factors affect egg production and mating activity, nutrient intake is certainly at the top of the list. Also important is the underlying relationship between energy status and physiological processes that need energy, such as maintenance, growth and reproduction (Richards, 2010). It includes a strict control of the amount of food both during breeding and during reproduction in the management of breeders to limit the gain of body weight and reduce the incidence of overweight birds.
However, even with controlled feeding programs it is still very easy to feed the breeders more. Therefore, regular monitoring and recording of body weights as well as uniformity are fundamental tools, especially during the period between 15 weeks of age and photostimulation.