RESUMO
Small ruminants are very affected by gastrointestinal nematode (GIN) parasitism worldwide. The improvement of the host protective response and the reduction of the probability of contact between hosts and parasites appear as very promising strategies. The objective of this study was to evaluate the effect of a combination of two components of these two strategies on natural GIN infection and production performances of Creole goat kids: dietary supplementation and a rotational mixed grazing system. One hundred and twenty weaned Creole kids and six Creole heifers were divided into four experimental batches: Splus (supplemented) vs. Szero (non-supplemented) × Mixed grazing (kids associated with heifers) vs. Control (kids alone), and grazing plots of forage grasses were balanced for live weight (LW) in both species. The feed intake, blood, and parasitological parameters and production performances between 3 and 11 months of age were monitored. The fecal egg count (FEC) was significantly lower and the packed cell volume (PCV) significantly higher in the Mixed grazing groups. No effect of supplementation was observed for FEC. In contrast, PCV, body condition score, and live weight were significantly higher in supplemented animals whatever the groups. Mixed grazing system and supplementation had significant effects on the slaughter parameters (P < 0.05), but there was no significant interaction. Our results suggested that the advantage driven either by mixed grazing or dietary supplementation on kids' performances would be equivalent, and the combination of both would improve the animal performances.
RESUMO
In the tropics one of the major constraints to goat production is infection by gastrointestinal nematodes (GIN). One promising alternative to chemotherapy is the improvement of host nutrition. The aim of this study was to assess the effects of infection and supplementation on packed cell volume (PCV), average daily gain (ADG) and carcass quality in growing Creole kids. Sixty male goats were reared indoors following a 2 × 3 factorial design: two experimental infection levels, (infected (I) and non-infected (NI)) and three diets D (G, kids were fed exclusively with tropical forages; B, kids were supplemented with dried and crushed banana and C, kids were supplemented with commercial pellets). Faecal egg counts did not vary among I groups (on average 2,200 ω/g). The PCV and ADG were improved (P < 0.001) for NI vs. I animals. There was a D effect (P < 0.001) and no I × D interaction was observed. There was no significant effect of GIN on the main carcass data, except the weights of liver, white offal and abdominal fat, which increased slightly in I compared with NI goats (P < 0.05). All carcass data increased significantly with the addition of supplement in the diet (P < 0.001), except for carcass-cut proportions. Meat physical parameters were degraded when I kids received low N diets (B or G) with higher lightness and water loss than in the C groups. Given that GIN affect the animal's N metabolism it is recommended to avoid the use of unbalanced diet such as those banana-based. Further research is necessary to assess the nutrition × parasitism interactions on physiological features and carcass quality of Creole goats.