Abstract
The effect of four diets on the performance of Dorper lambs that were artificially mix-infected with 1000 infective larvae (L3) of Haemonchus contortus and 1000 L3 of Trichostrongylus colubriformis every three days for 12 weeks was evaluated. For each diet, one infected group (n = 7) and one control group (n = 4) were set up. The four diets contained the following proportions of hay (H) and concentrate (C): Diet 1 - 100%H; Diet 2 - 75%H:25%C; Diet 3 - 50%H:50%C; Diet 4 - 25%H:75. All the infected groups showed decreases in mean packed cell volume (PCV) and total plasma protein, especially the Diet 1-infected, which was also the group with the highest fecal egg count. The diets and infection had significant effects (P < 0.05) on daily body weight gain (DBWG), cold carcass weight and daily food consumption. The control and infected groups had mean DBWG (in kg), respectively, of 0.048 and 0.025 with Diet 1; 0.082 and 0.067 with Diet 2; 0.188 and 0.189 with Diet 3; and 0.303 and 0.221 with Diet 4. In conclusion, the infection affected the productive performance regardless of the diet; however, with increased metabolizable protein and energy, the risk of occurrence of anemia and hypoproteinemia diminished.
Highlights
Haemonchus contortus and Trichostrongylus colubriformis are the gastrointestinal nematodes (GINs) with the highest prevalence and infection intensity in sheep in Brazil (Wilmsen et al, 2014; Almeida et al, 2018a)
The proportions of H. contortus and T. colubriformis infective larvae produced in fecal cultures were, respectively, the following: 76% and 24% in Diet 1; 63% and 37% in Diet 2; 49% and 51% in Diet 3; and 36% and 64% in Diet 4
We evaluated simultaneous infections with the most important species of nematodes that infect sheep, H. contortus and T. colubriformis
Summary
Haemonchus contortus and Trichostrongylus colubriformis are the gastrointestinal nematodes (GINs) with the highest prevalence and infection intensity in sheep in Brazil (Wilmsen et al, 2014; Almeida et al, 2018a). They cause high losses due to reduced performance, mortality and costs of treatments. The costs and consequences resulting from the development of the immune response, as well as pathological changes caused by parasitism, can compromise productivity This is so during the process of acquisition of immunity in young sheep (Greer, 2008; Cardia et al, 2011). An estimate through meta-analysis indicated that the performance of sheep that are infected with nematodes is only 85% of the performance of uninfected individuals, with regard to weight gain (Mavrot et al, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
