Guatemalan Research: Making Poultry Profitable

Oscar García researches the effects of corn flour supplementation in poultry feed on the health and production of chickens. Results are recorded.

 

When the Benson Institute realized that some small- and medium-scale chicken producers in rural Guatemala were substituting corn flour for chicken feed to cut costs, it feared this practice would backfire by producing smaller, less healthy chickens. The Benson Institute sponsored a study by Oscar García to find the effects of this practice on poultry production. His results were surprising.

García demonstrates proper poultry care to farmers.

Humans have been eating chickens for thousands of years. But chickens of long ago would be surprised to see how their posterity live today. Now, chickens are bred and genetically engineered, given scientifically formulated feeds, and raised together in enormous quantities.

Systematic chicken production techniques were introduced in Guatemala in the 1960s. Chicken has been a dietary boon there, where nutritious and affordable food is scarce. Chicken is high in protein, a macro nutrient commonly deficient in the diets of an alarming number of Guatemalan children. A 1991 survey indicated that Guatemalans eat an average of one-half ounce of chicken per day (7.25 kg per year), more than any other meat consumed there, and chicken production and consumption continues to increase (Calderón, 1997). The increase has come because chicken costs less than other meats, is easy to produce, and results in rapid returns for producers.

However, the cost of feeding chickens has become a great concern for poultry producers. Commercial chicken feeds have been developed that satisfy a chicken’s nutritional needs while producing a high-quality product for consumers. These feeds contain meat sub products, calcium, and vitamin supplements combined with grains in specific amounts. Many of these raw materials are in short supply in Guatemala, and feed constitutes an ever-increasing percentage of the production cost for chicken producers (Castello, 1995).

As feed prices continue to rise, chicken production is no longer viable for some producers and is rejected for more profitable work. Other producers supplement the more expensive commercial chicken feed with a cheaper alternative such as corn flour. Corn already composes up to 60 percent of commercial feeds, and adding more changes the percentage of protein in the diet. This could result in smaller, less healthy chickens, and profits could actually decrease.

Oscar's favorite chicken

The Ezra Taft Benson Agriculture and Food Institute, which promotes improved agricultural practices,was aware of this dilemma. To get accurate information on which to base proposed solutions, the Benson Institute turned to Oscar García, a native of Guatemala, and a member of the Institute office staff in 1997. He had studied animal science at CUNORI, a satellite campus of the University of San Carlos but had not yet completed his thesis, a graduation requirement for every student.

Sponsoring García to do a thesis about the effect of the substitution of corn flour on the diets of chicken would benefit both parties: García could complete his thesis for graduation and the Institute would gain information to solve a problem. This situation is familiar to the Benson Institute, which regularly sponsors student research as an integral part of its method.

García hypothesized that a partial substitution of corn flour for commercial feed would negatively affect chicken growth and the palatability of the meat, resulting in an overall decrease in profits. He wrote, “My objective is to find a way to reduce the cost of feeding chickens without negatively affecting their size, nutritional value, or appeal to consumers.” García tested the effect of substitution of different periods and amounts of corn flour on chicken production. He analyzed the areas each level of substitution might change, including cost, chicken size, and market value.

García conducted his research with chickens at CUNORI’s experimental farm. A total of 300 chickens were divided into 10 groups, and each group was assigned a different diet. Two-day-old Arbor Acres breed chicks were purchased and divided into groups at the age of seven days.

García conducts his research.

The first variable in the diet was the amount of substitution of corn flour. The control group was given commercial feed only. Three experimental groups were given a mix containing commercial feed with 15 percent corn flour, three groups had 30 percent corn flour, and the three groups 45 percent corn flour. At each substitution level, there were three substitution periods. The substitution for one group at each level began during the fifth week of development and continued until slaughter. The other two groups at each level began receiving the substituted diet during the sixth and seventh weeks of life, and this continued until slaughter. All the chickens were killed at the end of the seventh week (the approximate age at which chickens are normally slaughtered).

A summary of the data collected during the experiment is listed in Table 1. Each group’s feed bin was weighed at the beginning and ending of each week to determine the total “feed consumed” by each bird. After the seventh week, the chickens were denied access to food for six hours, weighed for the determination of “live weight at slaughter,” and killed. The “feed conversion” was found by dividing the total amount of feed consumed per chicken by the average live weight at slaughter.

The first variable noticeably affected by the differing diets was the live weight at slaughter. Although there were not large differences between groups, a trend of higher weight was associated with shorter periods and lower percentages of substitution (see Figure 1). The main exception to this was the group that had a 15 percent substituted diet beginning in the seventh week. The group had a higher average live weight at slaughter than the control group.

This same trend occurred with feed conversions. Since feed conversion is the amount of feed consumed by a chicken for a certain gain in weight, lower feed conversions are better. Groups with shorter substitution periods and rates showed better feed conversions. The same group that had the highest live weight at slaughter, the group that received 15 percent substitution during the seventh week, had the best feed conversion.

García feeds chickens as part of his study.

That another group outperformed the control group surprised García, leading him to believe that substitution rates at or below 15 percent may be beneficial to chickens. Before reaching a final conclusion, however, García prepared the chickens that were fed substituted feed and carried out a sensory test of the appearance, smell, and taste. A panel of 10 people evaluated chicken from different groups with respect to the control. They found no sensory difference in the various preparations of the chicken.

Finally, a comparative financial analysis was made of the production costs and profits that corresponded to each group. In general, high rates of feed substitution are cheaper but result in slightly lower total return. García used a method suggested by CIMMYT, the international corn and wheat improvement center, to evaluate the rate of marginal return for each group. He found that the best return again corresponded to the group that had 15 percent substitution beginning the seventh week, demonstrating another benefit of this feeding practice.

García concluded that substitution of corn flour in the chicken’s diet prior to the seventh week negatively affects feed conversion and has no positive effect on the financial aspect of chicken production. But a low rate of substitution (15 percent) in the seventh week improves feed conversion and provides greater financial benefits.

Based on the combined results of the different areas of his study, García suggests that producers use a slightly substituted diet beginning in the seventh week. When García finished his thesis in February 1999, he taught the residents of three rural communities about what he had learned. As the Benson Institute supports research and its diffusion to villagers, it advances the progress of both students and rural producers.

Works Cited

Calderon, C. 1997, Efecto de la substitución de proteína de harina de soya. Guatemala City: Universidad de San Carlos de Guatemala, 25:32

Castello, J. A. 1995. Producción de carne de pollo. Barcelona: Real Escuela de Avicultura, 273:85.