Big Gains for Small Birds

Research, field trials show coccidiosis vaccination pays "even for lightweight birds

Broussard: "Reactions are not as severe as industry once believed.'

To be vaccinated for coccidiosis or not to be vaccinated: For broilers raised to lighter weights, that is the question.

Why wouldn't producers want to vaccinate birds 4.2 lbs and less?

One old school of thought suggests that vaccinating birds marketed at light weights against coccidiosis results in performance loss. That's because vaccination introduces live coccidial oocysts to the chickens "a process that produces a reaction and subsequent intestinal disruption.

With vaccinated birds managed in a 40- to 42-day or even shorter production cycle, decreased feed intake and weight gain setbacks could be intensified, and perhaps never overcome.

New Evidence

Fortunately, a new school is evolving to empower small bird producers with tools for vaccination program success.

"We're learning that vaccination reactions are not as severe as industry once believed," says Dr. Charles Broussard, a technical service veterinarian with Schering-Plough Animal Health. "There are now data to show that growth rate following vaccination is not as suppressed as originally anticipated, especially when optimum management procedures are in place and feed digestibility is increased."

According to a recent study conducted by Southern Poultry Research, Inc. (SPR), Athens, Ga., the impact on overall performance is temporary and vaccinated birds do catch up or experience what nutritionists call "compensatory gain."

In the SPR study, the vaccine Coccivac-B was administered at hatching to a group of 960 chicks in a spray cabinet. Starting at day 1, another nonvaccinated group of 960 was fed salinomycin in starter and grower feeds, according to SPR president Dr. Greg Mathis. Commencing on day 14, individual weights and feed consumption were evaluated weekly for all birds in both groups.

At day 14, average feed conversion and live weights were similar in the vaccine and salinomycin groups, Mathis reports. By day 21, the vaccinated group trailed behind the nonvaccinated group. However, after 21 days, the vaccinated birds recovered and began to gain. About day 28, performance declined in birds receiving the anticoccidial due to the presence of subclinical coccidiosis. Under normal management conditions, this is a typical occurrence when this ionophore is used, Mathis notes.

"We found that the differences between treatments quickly diminish as the vaccinated birds recovered and the salinomycin birds were slightly affected," Mathis says. "By day 35, performance in both groups was essentially the same, and remained so throughout the remainder of the study."

Diet Management for Small Birds

For vaccinated birds raised to 4 lbs at 38 days, poultry nutritionists generally recommend the following diet:

Day 1 through day 15: Starter ration with 21% protein and 1,425 calories per lb of feed.

Day 16 through day 29: Grower ration with 19.2% protein and 1,450 to 1,460 calories per lb of feed.

Day 30 through day 38: Finisher ration with 17% protein and 1,480 to 1,490 calories per lb of feed.

A leading poultry nutritionist from the United States shares the following advice and insights on feeding vaccinated birds to lighter weights. (The consultant's name is being withheld upon request.)

- Provide a well-balanced, high-quality starter feed for lighter weight birds being vaccinated.

- Be sure to keep birds eating during the grower period. Don't change management, feed or anything that would cause the birds to eat less.

- Introduce the finishing ration 1 to 2 days after the secondary coccidiosis infection subsides.

- At day 30, vaccinated birds will generally be 0.15 lb to 0.20 lb lighter than normal because of the vaccine challenge. Considering birds have 0.10 lb average daily gain over the life of the 40-day flock, determine what bird weight is at 30 days, then calculate how much growth is needed to have a finisher feed that meets the average daily gain goal.

- From day 30 to day 40, birds need to consume 102% to 103% of their normal daily feed intake.

- Expect to spend an extra $3 to $4 per ton on ingredients for the finishing ration to get the push needed to have birds ready at 40 days or less.

- If desired market weights are not achieved after the initial processing of vaccinated birds, it may be necessary to reformulate the finisher feed with increased nutrient density. This reformulation should increase compensatory gain, resulting in better market weights

No Room for Error

In order to optimize results with a vaccination program for birds raised to lighter weights, it is critical that producers follow all the manufacturer's recommended management procedures, says Dr. Linnea Newman, a consulting poultry veternarian based in North River, N.Y.

"Move these birds into the full house in 12 days or less, preferably 7 days," Newman advises. "Increased stocking density can intensify the side effects associated with a live coccidial vaccine."

Specifically, these side effects include oocyst and moisture accumulation in the litter. Heavy oocyst accumulation and high moisture can increase vaccination reaction, which is undesirable in birds destined for lighter processing weights.

"Best results will be achieved during warm weather, when good ventilation and early movement to full house will be part of the 'normal' management program," Newman points out.

Be sure to maintain at least 4 inches of a highly absorbent litter, such as wood shavings or rice hulls, Newman adds. Maintaining proper ventilation is also critical.

"If you follow these guidelines, the birds' reaction to vaccination will be minimal, allowing flocks to achieve weight and feed conversion comparable to ionophore programs even when flocks are processed at 40 days or less," Newman says.

Brazil Experience

While approximately 70% of the 3 billion broilers produced in Brazil each year are raised for 42 to 49 days, or to weights of 4.4 lbs to 7.04 lbs (2.2 kg to 3.2 kg), a significant number are processed at lighter weights.

For starters, some Brazilian poultry companies raise females for 34 days to 3.3 lbs (1.5 kg) for export to Middle Eastern countries. Customers in that part of the world purchase whole chickens for individual consumption.

In some parts of Brazil, birds are processed at 28 to 30 days of age when they weigh 3.2 lbs to 3.4 lbs (1.45 kg to 1.55 kg).

There is also a special market in that country for even smaller birds. About 5 million annually are processed under 3 lbs (1.36 kg). Routinely found on the menus of Italian restaurants in Brazil, they are known by a special name - "galeto" in Portuguese "which means "little chicken." The principal Brazilian producer of these birds is a company called Minuano, and the firm markets galeto under the trademark "Minu."

About 50% of Brazilian birds raised to 3.3 lbs (1.5 kg.) and smaller, or some 2.5 million birds per year, are vaccinated for coccidiosis, according to Dr. Vilson Simon, director of AviSui, the poultry and swine division at Coopers Brazil, a Schering-Plough Animal Health subsidiary.

"I've never seen any outbreaks of coccidiosis in these smaller vaccinated birds," Simon reports.

Proper nutrition is the key to making it work, Simon says. "We have developed a special ration for vaccinated birds that includes increased amounts of protein, vitamins A and E, and other micronutrients. This diet helps keep weight gain on target during the first 3 weeks of age when vaccine reactions peak, reducing concerns about compensatory gain at the end of the feeding period," he explains.

"If you practice good flock management but offer these small birds a poor meal, it's likely you'll get poor results," Simon emphasizes.

Positive Results in U.S.

In September 2000, an independent U.S. poultry company reported its experiences with small bird vaccination at a special CocciForum Symposium in Colorado. According to the firm's presentation, chickens raised to 4.2 lbs in 41 days exhibited no loss of performance based on weight, feed conversion and settlement cost for the first 2 weeks on live vaccine compared to the 2 previous weeks on the standard coccidiostat program.

For a copy of the CocciForum/Durango proceedings, which includes the U.S. company's coccidiosis vaccine experience and other related information, send your name and address toS chering-Plough Animal Health. Fax: 908-629-3206 [email protected]