Effect of gastro-intestinal nematode infection on sheep performance: a systematic review and meta-analysis

Parasites & Vectors

Table 3 Meta-analysis of 94 trials on the estimated effect of parasitic infection on sheep performance

Production trait	Infection type	Number of trials	Ratio production infected/control	95 % C.I.	Number of trials reporting egg excretion	Mean number of eggs per gram faeces in infected animals
Weight gain	Mixed species^a	30	0.74	0.71–0.77	22	2336
Weight gain	H. contortus	20	0.79	0.71–0.87	20	4019
Weight gain	T. colubriformis	12	0.78	0.71–0.87	12	1070
Weight gain	T. circumcincta	8	0.81	0.66–0.99	4	296
Wool production	Mixed species^a	14	0.9	0.86–0.93	11	3788
Wool production	H. contortus	2	1.04	0.96–1.13	2	7585
Wool production	T. colubriformis	2	1.02	0.95–1.1	2	1359
Wool production	T. circumcincta	1	0.83	0.81–0.86	1	201
Milk yield	Mixed species^a	5	0.78	0.73–0.84	1	527

^aMain species were of the genus Haemonchus, Teladorsagia, Trichostrongylus, Cooperia and Nematodirus

ISSN: 1756-3305