Vetech Laboratories Inc.

(Appeared in International Poultry Production. 2006. Vol. 14, No. 5, p. 23. References added)

Combination of Vaccination and Medication in the Same Crop for the

Control of Coccidiosis in Chickens and Turkeys

Eng-Hong Lee, Ph.D., Vetech Laboratories Inc., Guelph, Ontario, Canada

Control of coccidiosis by vaccination, although started less than a decade behind anticoccidials (Dorn and Mitchell, Inc., 1952, manufacturer), did not gain wide acceptance until after the concept of uniform exposure (Lee, 1986) began to take hold. It is now the preferred method for breeders and has started to gain acceptance in egg layers and turkeys. However, general acceptance for the control of coccidiosis by vaccine in chicken broilers is still slow in coming. Complaints of secondary infection, such as necrotic enteritis despite the presence of growth promotants, are usually the main reason. Falling back on medications is the general practice for now but, with the continuous and increased problem with drug resistance, reliance solely on anticoccidials is becoming a diminishing option.

Alternate use or rotation of vaccination and medication between crops (Mathis & McDougald, 1989; Chapman, 1994) provides a viable means of temporarily stopping the problem of drug resistance by displacement of drug resistant field strains with drug sensitive strains in vaccines. A “boost” in performance after returning to medication is being used as an attractive feature of this rotation program. However, inconsistent results incurred by vaccinated flocks sometimes are sufficient to discourage the continuation of this option.

Combination of vaccination and medication in the same crop (Lee, 2001 U.S. Patent 6,306,385) is an option whose time has come. One that can be used to eliminate both the continuous problem of drug resistance and reducing the nagging problem of necrotic enteritis associated with coccidiosis vaccination. Vaccinated hatchlings were first fed with non-anticoccidial starter then around 15 days of age, at least one load of grower feed medicated with an existing anticoccidial is used to mitigate possible vaccine reactions before continuing with feeds with growth promotants only until market (Table 1). By curbing vaccine reaction, necrotic enteritis will be seriously curtailed as well. This is obvious as presented. What is not obvious is the fact that, because all vaccine strains are produced in chicks fed with plain feed, drug sensitivity to most anticoccidials in these vaccine coccidia will continue into perpetuity. This option also allows the use of a wide range of anticoccidials: from monensin, salinomycin, narasin to robenidine or as many as the coccidiosis vaccines such as IMMUCOX ^® would allow (Table 1).

This combination program should also be applicable to the control of coccidiosis in breeders, egg layers and turkeys. This option for the control of coccidiosis in commercial poultry should have its uses extended far into the future.

Table 1. Control of Coccidiosis by Vaccination/Medication Program (Jan 2004-Dec 2005)

Number placed	Sex	Number of flocks	Live (% )	Days of age	Weight kg (lbs)	Feed conversion

72,114	MIXED	4	97.57	41.00	2.20(4.84)	1.97
53,040	Pullets	3	95.63	41.60	2.20(4.84)	1.95
84,456	Cockerels	5	94.70	43.00	2.62(5.76)	1.96
123,522	Light Roasters	7	94.49	46.00	2.80(6.16)	2.07
56,304	Heavy Roasters	3	94.63	54.30	3.64(8.01)	2.06

Hatchlings were vaccinated with Immucox coccidiosis vaccine. Starter feed was medicated with growths promotants only. From day 15 on, at least one load of anticoccidial medicated feed was used. The remainder of the feed was medicated with growth promotants only. Anticoccidials used: monensin, salinomycin, narasin, or robenidine.

References:

1. Chapman, H.D. and A.B. Kacker. (1994). Sensitivity of field isolates of Eimeria from two broiler complexes to anticoccidial drugs in the chicken. Poult. Sci. 73(9):1404-8.

2. Lee, E-H. (1986). Canadian Patent 1,204,057.

3. Lee, E-H (2001). United States Patent 6,306,385.

4. Mathis, G.F. and L.R. McDougald. (1989). “Restoration of drug sensitivity on turkey farms after introduction of sensitive coccidia during controlled-exposure immunization.” In: Yvové P. (Ed). Coccidia and intestinal coccidiomorphs, INRA, Paris, France. pp. 339-343.