Three experiments were conducted to evaluate the impacts of removing antibiotic
growth promoters (AGP) on broiler performance and yield and to evaluate alternative
products as potential replacements. In experiment one, approximately 552,000 broilers
were reared in four solid-wall, tunnel ventilated houses that were divided into two
paired-house facilities, each assigned one of two dietary treatments. The treated group
received basal diets containing salinomycin (SAL), roxarsone (ROX) and AGP, while
the control group received the same diets without ROX and AGP. Removal of ROX and
AGP had no affect on average body weight and feed efficiency, while livability was
significantly affected negatively by the removal of ROX and AGP. Tender, wing, drum
and percentage of total white meat showed significant improvements in yield during the
study, while all other parts were not affected by removal of ROX and AGP.
In experiment two, an investigation was conducted to evaluate the effects on
performance from feeding Bacillus subtilis spores (Gallipro®, Chr Hansen A/S,
Denmark), as a direct-fed microbial additive, to commercial broiler chickens. Birds were divided among two paired-house facilities. The treatment group received basal diets
supplemented with B. subtilis spores, while the control group was fed the same basal
diets containing an AGP. Feed conversion ratio was significantly lower for the treatment
group, while average body weight, coccidiosis lesion scores, and footpad scores were not
affected by the treatments.
In experiment three, 6,000 broiler chickens were equally divided among four
treatment groups and reared to 49 d to determine the effectiveness mannan
oligosaccharides (MOS, Bio-Mos®, Alltech, Nicholasville, Kentucky, USA) as an
alternative for an AGP program and MOS plus Natustat™ (NAT, Alltech, Nicholasville,
Kentucky, USA) as an alternative to an enteric health program (AGP+anticoccidial
drug). Average body weight for the control (CON) and antibiotic (ANT) groups was
significantly different from the MOS+NAT group, but not the MOS group. Carcass front
half, carcass hind half, frame and skin yields were improved for all treatments when
compared to the MOS+NAT group. Conversely, percent total white meat yield was
improved with the inclusion of MOS when compared to the ANT group.
The findings of this research suggest that the removal of AGP from the diets of
commercial broiler chickens does not affect the performance and yield of the birds over
a one year production period. Furthermore, B. subtilis spores and mannan
oligosaccharides provide acceptable alternatives to an AGP program.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-3235 |
| Date | 15 May 2009 |
| Creators | Bray, Joey Lynn |
| Contributors | Carey, John B. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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