Effect of cassava (Manihot esculenta) foliage on nutrition, parasite infection and growth of lambs

International audienceThe effects of feeding wilted cassava foliage (WCF) on the growth of Martinik lambs and the parasite Haemonchus contortus (Hc) were evaluated. Thirty 6-month-old Martinik lambs (body weight: 20.3±1.6kg) were allocated to one of the three treatments. The basal diet consisted of Dichanthium spp. hay ad libitum plus cassava tuber (450g/lamb/day). In addition, depending on the experimental treatment, they received alfalfa pellets (450g/lamb/day) or WCF (650g/lamb/day) or WCF (650g/lamb/day)+PEG (25g/lamb/day). At the beginning of the trial, each lamb was inoculated with a single dose of 10,000 third-stage larvae of Hc. The mean faecal egg count decreased by 41% in lamb fed WCF relative to the lucerne control level. Egg development to third-stage larvae was reduced by 60% when excreted by lambs fed on WCF compared to those fed on lucerne. Given the results obtained with animals receiving PEG, the positive effect of WCF on the reduction of Hc parasites may be explained by the action of condensed tannins. The action of the latter on worm fertility is suspected. Due to the high fill value (ADL) relative to the lucerne diet, the consumption of WCF provides limited total energy intake (48.0g vs. 57.6g of digestible dry matter per kg of metabolic weight) and has a depressive effect on lamb growth (120.8g/d vs. 163.5g/d)

In vitro effects of Musa x paradisiaca extracts on four developmental stages of Haemonchus contortus

International audienceThis study was carried out to evaluate the in vitro effect of Musa x paradisiaca stem and leaf against the parasitic nematode of small ruminants Haemonchus contortus. Three extracts (aqueous, methanolic and/or dichloromethane) of Musa x paradisiaca stem and leaf were tested in vitro on four developmental stages of H. contortus using egg hatch assay (ERA), larval development assay (LDA), 13 migration inhibition assay (LMI) and adult worm motility assay (AWM). The highly significant (P 67% for each extract) and the negative effect of the dichloromethane extract of leaf on adult worm motility (43% of inhibition of motility after 24 h of incubation) compared to the negative controls, suggest anthelmintic properties of Musa x paradisiaca stem and leaf against H. contortus. The active principles responsible for the activity could be secondary metabolites such as terpenoid and flavonoid compounds present in the leaf and stem of the plant

In vitro effects of Cassava (Manihot esculenta) leaf extracts on four development stages of Haemonchus contortus

International audienceThree extracts (aqueous, methanolic and dichloromethane) of Manihot esculenta (Cassava) leaf were tested in vitro on four development stages of Haemonchus contortus using egg hatch assay (EHA), larval development assay (LDA), L3 migration inhibition assay (LMI) and adult worm motility assay (AWM). Compared to the negative control, significant effects (P < 0.0001) were observed for the methanolic extract of leaf against larval development (57.6% ±7.6), with a dose dependent effect. These results suggest that Cassava possess anthelmintic activity against H. contortus. The active principles responsible for the activity could be the terpenoids and condensed tannin compounds present in the leaf

Various condensed tannins from tropical plants as potential multi-purpose nutraceutic in ruminant feed

Session 9: Nutritional management of health and welfareNational audienc

Various condensed tannins from tropical plants. Potential multipurpose nutraceutics in ruminant feed

Condensed tannins (CT) are bio-reactive complex plant secondary metabolites. Protein-CT complexes could result in affection of rumen fermentation, allow availability of amino-acids and induce a gastrointestinal nematicidal action in ruminants. In this study 5 tropical plants were evaluated to provide some natural multi-active nutraceutics to animal production. The CT composition of plants was quantified and elucidated using vanillin-H2S04 assay and LC-MS analysis. CT extracts were assayed for bioactivity against the exsheathment of the nematode Haemonchus contortus, and fermentation profiles of plants (CH4 and NH3-N produced, organic matter digestibility (OMD)) were determined in vitro. Thiolysis analysis showed that CT extracts contained from 1.7 to 59 g of CT per 100g. mDP ranged from 3.3 to 15.3, PC/PD ratios from 0 to 10.7, cis/trans flavan-3-ol ratios from 1.7 to 24.7, and galloyl groups from 0 to 37.4 %. CT had a high effect (p<0.001) on nematicidal activity and fermentation profile.The complexity of composition of CT in tropical plants and their multipurpose potential for animal production were highlighted. It seems that CT chemical composition may influence bio-reactivity and neutracutical feed value

Mobilizing tropical plants as a sustainable alternative to the issue of anthelmintic resistance in small ruminants

International audienc

Comparative intake and digestion of fresh or dry grass of Digitaria decumbens consumed by Black-belly sheep.

International audienc

Impact of the post-weaning parasitism history on an experimental [i]Haemonchus contortus[/i] infection in Creole goat kids

Gastrointestinal nematode (GIN) infections have an important negative impact on smallruminant production. The selection of genotypes resistant to these parasitic infections is apromising alternative control strategy. Thus, resistance against GIN is an important componentof small ruminant breeding schemes, based on phenotypic measurements of resistancein immune mature infected animals. In this study we evaluated both the impact of thepost-weaning parasitism history on the response to an experimental Haemonchus contortusinfection of resistant and susceptible Creole kids chosen on the basis of their estimatedbreeding value, and the interaction with the kid’s genetic status. During the post-weaningperiod (from 3 months until 7 months of age) Creole kids were reared at pasture accordingto four different levels of a mixed rotational stocking system with Creole cattle: 100% (control),75% (GG75), 50% (GG50), and 25% (GG25) of the total stocking rate of the pasture. Thelevel of infection of the kids decreased significantly at 50% and 25% of the total stocking rate.After the post-weaning period at pasture, at 11 months of age kids were experimentallyinfected with H. contortus. The faecal egg counts (FEC) were significantly lower in the groupsshowing the highest FEC at pasture. This result suggests that a degree of protection againstan experimental H. contortus infection occurred during the post-weaning period and wasdependant on the level of parasitism. Interestingly, no interaction was observed betweenthis level of protection and the genetic status. In conclusion, the level of post-weaning naturalparasitism history at pasture would not influence the genetic status evaluation. Moregenerally our results suggest that it would be better to expose kids to a high level of gastrointestinalparasitism during the post-weaning period in order to increase the basal levelof resistance thereafter

Effect of heat stress on blood rheology in different pigs breeds.

International audienceThe main objectives of the present work were to test the effects of heat stress on blood rheology and to determine whether the responses can change according to the pig breeds. Thirty-six pigs from three pig's lines (n = 12 for each line) with assumed different tolerance to heat stress were compared: Large White (LW, little tolerance), Creole (CR, good tolerance) and LW × CR pigs (produced from a cross between LW and CR lines). In a first period, all pigs were exposed to a 9-d period of thermo-neutral environment (24°C; d-9 to d-1; P0). At the end of P0, six pigs from each line were slaughtered (n = 18). Then in a second period, the remaining pigs (6/breed; n = 18) were exposed to a 5-d period of heat stress (32°C; d + 1 -d + 5; P1) and thereafter slaughtered at d + 5. Rectal and skin temperatures, as well as respiratory rate, were recorded on d-1 and d + 5. At slaughter, blood was sampled for hematological and hemorheological measurements. Heat stress caused a rise of the skin temperature and respiratory rate without any changes in the rectal temperature or on the hematological and hemorheological parameters when all pigs' lines were considered. We observed a pig line effect on blood viscosity at high shear rate (375 s-1) and red blood cell deformability at 30 Pa with CR pigs having lower blood viscosity and higher red blood cell deformability than LW pigs. While the changes of blood viscosity under heat stress did not reach statistical significance in LW and CR lines, blood viscosity (at 375 s-1) increased above the temperate values in the LW × CR line. Red blood cell deformability at 30 Pa was higher in CR pigs exposed to heat stress compared to LW pigs in the same condition. In conclusion, thermal loading caused physiological stress but did not widely change the hematological and hemorheological profiles. Although some blood rheological parameters seem to vary with the pig breeds, the responses to heat stress are very similar