TY - JOUR

T1 - The impact of natural helminth infections and supplementary protein on growth performance of free-range chickens on smallholder farms in El Sauce, Nicaragua

AU - Skallerup, Per

AU - Luna, Luz A

AU - Johansen, Maria V

AU - Kyvsgaard, Niels C

PY - 2005/7/12

Y1 - 2005/7/12

N2 - Three on-farm studies were conducted in Nicaragua during three consecutive years (1999-2001) to assess the impact of natural helminth infections on growth performance of free-range chickens aged 3-4 months. On all participating farms, half of the chickens were treated regularly with anthelmintics (Trifen avicola - a combined formulation of piperazine, phenothiazine and dichlorophen - or albendazole) to express the growth potential of non-infected birds, whereas the other half served as non-treated controls. In 1999, treated chickens had a 39% higher weight gain compared to the control group 6 weeks after the first treatment on 15 farms. In 2000 and 2001, treated chickens had similar weight gain as the control group 10 weeks after the first treatment on 7 farms and 12 farms, respectively. The main reason for the very-different weight gain figures seems to be the weather conditions. In 1999, the study site experienced a rainy season with precipitation far above average, whereas in 2000 and 2001 the rainy seasons had precipitations far below average. Based on these findings, routine use of anthelmintics in the study area would only be recommended in wet years when production losses due to helminth infections seem to be pronounced. In 2001, the study set-up included an assessment of the effect of protein supplementation (soybean) on growth on six farms. Supplemented chickens (treated and non-treated with anthelmintics) had 17% higher weight gain than non-supplemented. Protein supplementation affected neither worm burdens nor faecal egg counts for any of the studied helminths. The post-mortem examinations showed that Trifen reduced burdens of Ascaridia galli, Heterakis gallinarum, and cestodes (efficacies of 100, 100 and 67%, respectively). Albendazole reduced burdens of H. gallinarum (efficacy of 100%). Efficacies against other helminths were difficult to assess due to low worm burdens. Chickens treated with albendazole had lower Ascaridia and Heterakis faecal egg counts than non-treated chickens.

AB - Three on-farm studies were conducted in Nicaragua during three consecutive years (1999-2001) to assess the impact of natural helminth infections on growth performance of free-range chickens aged 3-4 months. On all participating farms, half of the chickens were treated regularly with anthelmintics (Trifen avicola - a combined formulation of piperazine, phenothiazine and dichlorophen - or albendazole) to express the growth potential of non-infected birds, whereas the other half served as non-treated controls. In 1999, treated chickens had a 39% higher weight gain compared to the control group 6 weeks after the first treatment on 15 farms. In 2000 and 2001, treated chickens had similar weight gain as the control group 10 weeks after the first treatment on 7 farms and 12 farms, respectively. The main reason for the very-different weight gain figures seems to be the weather conditions. In 1999, the study site experienced a rainy season with precipitation far above average, whereas in 2000 and 2001 the rainy seasons had precipitations far below average. Based on these findings, routine use of anthelmintics in the study area would only be recommended in wet years when production losses due to helminth infections seem to be pronounced. In 2001, the study set-up included an assessment of the effect of protein supplementation (soybean) on growth on six farms. Supplemented chickens (treated and non-treated with anthelmintics) had 17% higher weight gain than non-supplemented. Protein supplementation affected neither worm burdens nor faecal egg counts for any of the studied helminths. The post-mortem examinations showed that Trifen reduced burdens of Ascaridia galli, Heterakis gallinarum, and cestodes (efficacies of 100, 100 and 67%, respectively). Albendazole reduced burdens of H. gallinarum (efficacy of 100%). Efficacies against other helminths were difficult to assess due to low worm burdens. Chickens treated with albendazole had lower Ascaridia and Heterakis faecal egg counts than non-treated chickens.

KW - Animals

KW - Anthelmintics

KW - Body Weight

KW - Chickens

KW - Dietary Proteins

KW - Feces

KW - Female

KW - Helminthiasis, Animal

KW - Helminths

KW - Male

KW - Nicaragua

KW - Parasite Egg Count

KW - Poultry Diseases

KW - Sorghum

KW - Statistics, Nonparametric

U2 - 10.1016/j.prevetmed.2005.02.003

DO - 10.1016/j.prevetmed.2005.02.003

M3 - Journal article

C2 - 15907572

VL - 69

SP - 229

EP - 244

JO - Preventive Veterinary Medicine

JF - Preventive Veterinary Medicine

SN - 0167-5877

IS - 3-4

ER -