Numerous studies have examined the interactions between
protein nutrition and the response to nematode parasitism in sheep, but very few in goats. Compared with other ruminants, goats are less resistant to
nematode infection. In addition, in dairy goats, high producing animals have been shown to be less resistant and less resilient to
infection compared to low producing ones. The objective of the present study was to examine the consequences of
protein supplementation on both resistance and resilience of dairy goats to nematode trickle
infection, taking into account the initial level of milk production of the animals. During a 14-week period, 40 milking goats received a high
protein (HP) diet supplying 130% of the
protein requirements, and 38 goats were fed a intermediate
protein (IP) diet (120% of the
protein requirements). In addition, half of each group was given a weekly trickle
infection with Trichostrongylus colubriformis larvae, the other part of the flock remained non-infected. Faecal egg counts (FEC), eosinophil counts and pathophysiological data (
urea,
albumin and
inorganic phosphate concentrations in the serum) were measured twice a month. Milk production data (milk yield,
protein and fat contents) were also recorded every 15 days. The results showed that FECs were lower (p < 0.05) and eosinophil counts higher (p < 0.05) in the animals receiving the HP diet suggesting that resistance was enhanced by
protein supplementation. Meanwhile, milk parameters (related to resilience) were not affected by the level of
protein in the diet when considering the whole groups. In contrast, in the high producing goats, the milk production and milk composition parameters were improved with the HP diet. To conclude, we have seen that the expression of both resistance and resilience did not appear when the coverage of the
protein requirements was insufficient. Because the milk production is dependent on the
protein supply, we suggest that there is a competition in the use of the
protein between the development of resistance and the milk production.