Virginia Diversified Research Corporation, Harrisonburg, VA USA. Abstract*. Histomonas meleagridis is the etiological agent that causes blackhead disease in ...
Evaluation of Medium Chain Fatty Acids Alone or with a Phytogenic on Tom Turkey Performance and Lesion Development Following Challenge with Histomonas meleagridis. N.P. Evans1, T.P. Karnezos1, R.A. Dvorak1, M. Sims2. 1PMI Nutritional Additives, Arden Hills, MN, USA, 2Virginia Diversified Research Corporation, Harrisonburg, VA USA
Abstract*
Histomonas meleagridis is the etiological agent that causes blackhead disease in turkeys. Histomonas can reside in, and is often transmitted between birds by eggs of the cecal nematode Heterakis gallinarium. Infected birds typically have reduced feed consumption and weight gain. Lesions develop in the ceca and liver and are accompanied by high mortality. With the recent withdrawal of nitarsone approval for use in food animals, few other treatment or prevention options remain. The purpose of this study was to evaluate various levels of medium chain fatty acids, with or without a phytogenic, on performance and lesion development in turkeys. In two separate studies, day-of-hatch turkeys were randomly assigned to floor pens containing fresh pine shavings. Birds were provided diets containing either medium chain fatty acids, medium chain fatty acids + phytogenic, or medium chain fatty acids at a half rate + phytogenic, and compared to control. Birds were challenged by placing infected litter in each pen at 7 days-post-hatch or by a double challenge model. Production parameters (body weights, feed conversion ratio, and mortality) and lesion scores (ceca and liver) were collected through 10 weeks. Overall, birds challenged with Histomonas meleagridis and supplemented with medium chain fatty acids + phytogenic performed similar to birds supplemented with BMD®. *Note: The above abstract has been amended from the original submission.
Study 1 Birds: 30 Nicholas Toms per 4’x8’ pen Reps: 12 pens per treatment Challenge: H. meleagridis infected litter placed in each pen at 7d Performance data: 4, 7, and 10 wk Lesion scores: 5 and 10 wk Treatment
Starter 1 (0-28d) BMD® 50 g/t MCFA 4 lb/t MCFA + Phyto 5 lb/t MCFA ½ + Phyto 3 lb/t
Study 1 Body Weights
FCR
Treatment BMD® MCFA MCFA + Phyto MCFA ½ + Phyto
Week 0-4 1.2002a 1.1758a 1.1468a 1.1810a
Week 0-7 6.2877a 6.0753a 6.0494a 6.1131a
Week 0-10 9.6474a 9.0763b 8.9861b 9.2978ab
Mortality
Starter 2 (29-42d) 50 g/t 3 lb/t 3.75 lb/t 2.5 lb/t
Grower (43-56d) 50 g/t 3 lb/t 3.75 lb/t 2.5 lb/t
Finisher (57-70d) 50 g/t 2 lb/t 2.5 lb/t 1.5 lb/t
Treatment BMD® MCFA MCFA + Phyto MCFA ½ + Phyto
Week 0-4 1.5855a 1.5277a 1.6077a 1.5233a
Week 0-7 2.0353b 2.2249a 2.0884ab 2.0370b
Week 0-10 2.2433b 2.3815a 2.3522ab 2.2703ab
Lesion Scores
Treatment BMD® MCFA MCFA + Phyto MCFA ½ + Phyto
Week 0-4 2.38a 1.19a 2.98a 3.57a
Week 0-7 5.00b 6.00ab 8.33a 8.33a
Week 0-10 7.20a 6.44a 12.50a 12.12a
Treatment BMD® MCFA MCFA + Phyto MCFA ½ + Phyto
Ceca 5wk 0.417b 0.778a 0.472b 0.657ab
Liver 5wk 0.111a 0.167a 0.306a 0.222a
Ceca 10wk 0.417ab 0.472a 0.389ab 0.250b
Liver 10wk 0.806a 0.000c 0.064b 0.369b
Treatments not connected by the same letter are significantly different (P≤0.1)
Study 2 Body Weights
Methods • • • • •
Results
FCR
Treatment Infected Ctrl BMD®
Week 0-4 Week 0-6 Week 0-8 Week 0-10 2.182a 3.378b 5.961b 9.477b 2.105a 3.504ab 6.150b 9.895a
Treatment Infected Ctrl BMD®
Week 0-4 Week 0-6 Week 0-8 Week 0-10 1.530a 2.030a 2.103a 2.395a 1.522a 1.873b 1.980b 2.240b
MCFA ½ + Phyto
2.176a
MCFA ½ + Phyto
1.505a
3.643a
6.355a
10.183a
Mortality
1.848b
1.986b
2.235b
Lesion Scores
Treatment Infected Ctrl BMD®
Week 0-4 Week 0-6 Week 0-8 Week 0-10 4.00a 4.27a 4.80a 6.97a 1.60a 2.13a 2.67a 6.67a
Treatment Infected Ctrl BMD®
Ceca 8wk Liver 8wk Ceca 10wk Liver 10wk 1.467a 1.422a 1.225a 1.225a 1.511a 1.289a 0.500b 0.750b
MCFA ½ + Phyto
1.87a
MCFA ½ + Phyto
1.444a
1.87a
3.20a
6.36a
1.267a
0.725b
0.650b
Treatments not connected by the same letter are significantly different (P≤0.05)
Study 2
• Birds: 25 Nicholas Toms per 4’x8’ pen • Reps: 15 pens per treatment • Challenge: H. meleagridis infected litter placed in each pen at 7d and 5 birds from a communally infected pen swapped into each pen at 4 wk • Performance data: 4, 6, 8, and 10 wk • Lesion scores: 8 and 10 wk Treatment
Starter 1 (0-28d) Infected Ctrl BMD® 50 g/t MCFA ½ + Phyto 3 lb/t
Starter 2 (29-42d) 50 g/t 2.5 lb/t
Grower (43-56d) 50 g/t 2.5 lb/t
Finisher (57-70d) 50 g/t 1.5 lb/t
Conclusion Study 1 • MCFA, MCFA + Phyto, and MCFA ½ + Phyto supplementation resulted in performance and lesion scores similar to BMD® supplementation. • MCFA ½ + Phyto supplementation resulted in a larger numerical improvement in body weight and FCR than MCFA or MCFA + Phyto supplementation.
Study 2 • MCFA ½ + Phyto supplementation resulted in performance and lesion scores that were significantly better than the infected control and often numerically better than BMD® supplementation.
