Research: Feed Additives for Antibiotic-Free Broiler Production

The results of research on feed additives for Antibiotic-Free (ABF) broiler production were presented last year previously. The purpose of this article is to provide an update on subsequent research conducted on feed additives for ABF broiler production.

There are several types of products available to help producers meet production and profitability goals without the use of feed-grade antibiotics. These products include direct-fed microbials (DFM), prebiotics, essential oils, and enzymes. A combination of these different feed additive types are used in Wenger Feed’s ABF broiler programs.

The research previously reported was conducted in the Wenger Feed’s Broiler Research House to evaluate the effect of additives on the performance of broilers fed an ABF feed program. The results of this experiment (Table 1) demonstrate the benefits of different feed additive combinations in ABF broiler feed programs on growth rate and feed conversion. No feed additives were included in the finisher phase, so the potential benefit of using feed additives during this phase could not be evaluated.

Subsequently, an experiment was conducted to evaluate the potential benefit of including feed additives in the finisher phase. In this experiment, 36,000 broilers (5 pens of 7,200 birds/pen) were housed in the Wenger Feed’s Broiler Research House and fed one of two dietary treatments. Treatment 1 was a feeding program containing a DFM and prebiotic in the starter phase, a plant extract and a prebiotic in the grower phase, and no additives in the finisher phase. Treatment 2 was the same as Treatment 1, except the additives used in the grower phase were also added in the finisher phase.

No benefit of including the additives in the finisher phase was apparent on overall performance (Table 2). Numerically, growth rate and feed conversion improved during the finisher period when feed additives were used, but the difference was not statistically significant (P > 0.10). This lack of response on overall performance may have been associated with timing of typical health challenges, which typically occur in the starter and grower phases. In fact, livability during the finisher period was greater than 99.5% suggesting no real challenges during this period.

A third experiment was conducted at the Penn State Poultry Unit to compare different additive combinations in ABF broiler programs and to evaluate the potential benefit of adding Yucca schidigera and Quillaja saponaria to ABF broiler feed programs. Yucca schidigera and Quillaja saponaria contain saponins and polyphenolics, which demonstrate anti-inflammatory properties. Previous research has indicated the addition of both Yucca schidigera + Quillaja saponaria can improve feed conversion.

In this experiment, 1,728 day-old broilers were assigned to one of four dietary treatments. Treatment 1 was a standard ABF broiler feed program containing a prebiotic and DFM in the starter and grower period (PB1+DFM1). Treatment 2 was a standard ABF broiler feed program containing a different prebiotic and DFM combination (PB2+DFM2). Treatment 3 was the same as Treatment 1 with the addition of a product containing a combination of Yucca schidigera and Quillaja saponaria (PB1+DFM1+YQ). Treatment 4 was the same as Treatment 2 with the addition of the YQ (PB2+DFM2+YQ). Birds were housed 36 birds per pen and processed at 42 days of age.

Growth rate, feed conversion and livability (Table 3) were not different between treatments (P > 0.05). However, breast meat yield was greater (P < 0.05) for birds fed diets containing PB1 + DFM1 compared to diets containing PB2 + DFM2. The YQ combination had no effect on bird performance.

Again, in this experiment, no feed additives were used in the finisher period. A fourth experiment was then conducted at the Penn State Poultry Unit to evaluate the benefit of feeding an ABF broiler program with a DFM/prebiotic combination with or without YQ product fed during the starter and grower phase only or throughout the entire feeding program.

1,728 one-day-old broilers were assigned to one of four dietary treatments. Treatment 1 was a standard ABF broiler feed program containing a DFM and prebiotic in the starter and grower period (P+D).

Treatment 2 was the same as Treatment 1 with the addition of a product containing a combination of Yucca schidigera and Quillaja saponaria (P+D+YQ). Treatment 3 was the same as Treatment 1 but fed the entire feeding period. Treatment 4 was the same as Treatment 2 but fed the entire feeding period. Birds were housed 36 birds per pen and were processed at 42 days of age.

The results of this experiment are presented in Table 4. There were no differences (P>0.05) in final body weight, feed conversion, or livability between treatments. The addition of the feed additives in the finisher period (Treatments 3 and 4) provided no improvement in bird performance (P>0.05).

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