Breeder nutrition and management. Influence on flock performance

The uniformity in the size of birds is achieved mainly during the first 8 weeks. From 16 weeks on, uniformity in muscle development (fleshing) and fat deposits become more significant in achieving good sexual uniformity. Figure 1 illustrates an example of the correlation between uniformity and egg weight for Cobb 500 FF (fast feather) hens.

• The average uniformity is 88.2%, with a spread of +/- 10%.
• This means that the chicks should show > 80% uniformity at hatch, which is very acceptable.
• At 25 weeks, eggs weighing more than 50 g reach a uniformity> 80%, and this stabilizes at approximately 89%.

Normally there is a positive correlation between the total amount of feed consumed and the body condition of the females at the end of rearing – 21 weeks of age. This directly influences chick viability, at least during the first 6-8 hatches.

Chick feed conversion and growth can be improved simply by selecting broodstock that show better fleshing and a correct proportion of body fat, which is critical at the time of the first lighting stimulation, with the following objectives:

• Good sexual timing in females
• High peak and persistence of production
• High hatch rate, quality and vitality of chicks from an early age
• Reduction of mortality at the beginning of production

It’s not easy to get the correct amount of total body fat just by measuring abdominal fat. After 12 weeks of age, females should acquire age-appropriate conditioning, expressed through the level of muscle development and the degree of accumulation of pelvic fat.

A lower feed intake during rearing can produce very negative results in productivity. Overly restricting feed for example, results in an incorrect body condition in females when stimulating them lightly, which is a catastrophic error.

Evaluate the condition of the females (fleshing)

• 16, 19 and 21 weeks of age: evaluate the conditioning (fleshing) of the females.
• 19 and 21 weeks: assess pelvic fat stores.
• 25, 30 and 40 weeks: assess the level of abdominal fat stored to more accurately calculate reductions in feed consumption.
• > 50 females at the aforementioned ages should be examined to assess and weigh abdominal fat and count the number of follicles> 2 cm in diameter.

It is extremely important to have fat storage.

The age at which the breeders will start production must be determined (23-24 or 25 weeks of age) – We must develop a feeding program that guarantees that at the time of light stimulation, more than 95% of the females have a muscular development of grade 3-4 (scale from 1 to 5 see Table 1), and more than 90% of the females must have sufficient pelvic fat.

Figure 2 shows data from 36 females at 25 weeks with an average abdominal fat of 2%, which is considered adequate as an energy reserve. There is a tendency to have a greater number of follicles in birds with a higher percentage of fat.

Figure 3 shows the performance of the flock up to 60 weeks with the body weight curve in females and males, the weights of the eggs and the amounts of feed supplied.

Females would be losing body fat up to 40 weeks of age (Figure 4), and then begin to accumulate fat again if feed intake is maintained or if feed reductions occur slowly.

Females mobilize energy reserves from fat stores to meet their energy requirements. It is critical to start the production cycle with sufficient fat storage, but without confusing a sufficient amount of storage at the start of the lighting program with excess body weight.

A higher body weight is not necessarily equivalent to a higher amount of fat reserve. If the energy reserves at the beginning and during the peak of production are low, the feeding amount must be reduced more slowly. Fat reserves are essential to obtain a good performance of the breeders and a very good chick quality via the transfer of nutrients through the egg yolk.

The deterioration of the quality of the shell indirectly affects the quality of the chicks. Vaccination programs should prevent diseases such as Newcastle disease , infectious bronchitis or avian influenza, which affect the external quality of the egg. Consider the following:

• Simplify the program as much as possible.
• Give vaccines correctly.
• Distribute vaccinations to achieve a good immune response.
• Vaccinations induce stress in the feeding program, diverting the necessary nutrients for the development of the females.
• Vaccinate with inactivated vaccines in the groin to reduce stress.
• Implement an immune system surveillance program.
• Periodically review the vaccination program and implement any necessary modifications.

• Protect the shell against diseases that affect its integrity.
• Avoid ingredients that affect hatch and shell quality.
• For crumbs, use fine-grained limestone.
• Use > 50% coarse limestone rock (2-3 mm).
• Supplement with coarse calcium particles in the afternoons on the litter, particularly from 10 weeks before a substantial deterioration in the quality of the shell takes place.

The management of fertile eggs should keep the main objective to achieve a shell of optimal structure and cleanliness.

• Disinfect fertile eggs immediately after collection to avoid bacterial contamination.
• Implement a program to reduce floor eggs to <1% due to a 10% lower hatch rate and higher bacterial load.
• Correct distribution of equipment and correct conditioning and percentage of pelvic fat so that females are inclined to use the nests more.
• Maintain optimal litter quality so that nests are kept clean.

For the chicks to have excellent viability and achieve good body weight in the first week of life, it is essential that they be of excellent quality. The latter will depend on uniform breeders with correct conditioning and sufficient fat reserves at the time of light stimulation. This will be a sign that there has been a good incorporation of nutrients that will eventually be transferred to the fertile egg and will ultimately contribute to the vitality and productivity of the newborn chicks.