Dry matter digestibility of grazed sainfoin and tall fescue, and estimation of soil intake, in the organic pastured growing rabbits : first results.
Digestibilité de la matière sèche d'une pâture de sainfoin ou de fétuque, et estimation de l'ingestion de sol, par le lapin en croissance élevé en cages mobiles sur prairie - Premiers résultats.
Résumé
The development of organic rabbits production at pasture is
limited by lacks in technical references, particularly about real grazed forage intake and digestibility. Moreover,
to measure digestion at pasture we must know the intake of soil (minerals), the latter could eventually contain
some pollutants. Therefore, after weaning (43 d) 30 growing rabbits have been allotted in two groups and housed
in movable cages on two types of pasture: one with 70% of sainfoin (Onobrychis viciifolia) and the other with
100% tall fescue (Festuca arundinacea). Each cage contained 3 animals, with a shelter of 0.4 m² and a pasture
surface of 1.2 m² and was moved every day A pelleted commercial feed was distributed daily at a level of 60
g/rabbit, and was totally consumed. Daily grass intake was calculated by difference between offered and residual
grass (cut over 3 cm). The in situ digestibility of the forage + pellets mixture was estimated after total collection
of faeces left on the soil for 2 x 4 days. Soil intake has been estimated with an internal marker (acid insoluble
ash), from its concentrations in soil, pasture, feed and faeces, as well as dry matter digestibility (DMd). The
DMd of pelleted feed, both vegetation types and their mixtures were also determined with metabolism cages (as
a control). The DMd of tall fescue varied from 37 to 43% respectively for a measure at pasture or in indoor,
whereas the DMd of sainfoin varied only by 1 unit (65.5 to 66.6 resp.). The rabbit's growth was 25% higher on
the "sainfoin" pasture, while the total DM intake (pellets+grass) was similar to that of the group "fescue" (55 vs
56 g/j/lap.), but the protein intake was 25% higher for the "sainfoin" group. Soil intake was lower (P<0.05) on
tall fescue meadow (1.3% of total DM intake or 1.9 g/d) in comparison to sainfoin (3.0% of total DM intake or
4.2 g/d). The smaller soil intake on pasture of tall fescue could be due to the better soil cover by grass forming a
buffer between animals and soil, in comparison to the sparser sainfoin cover.
Digestibilité de la matière sèche d'une pâture de sainfoin ou de fétuque, et estimation de l'ingestion de sol, par le lapin en croissance élevé en cages mobiles sur prairie-Premiers résultats. Résumé-Le développement de la cuniculture biologique (label AB) ou plus généralement avec accès à une prairie est limité par le manque de références techniques, notamment sur l'ingestion de végétaux pâturés et sur leur digestibilité. De plus, pour mesurer la digestion il faut connaître l'ingestion de sol (minéraux), ce dernier pouvant éventuellement contenir des contaminants environnementaux. Ainsi, 2 groupes de 15 lapins sevrés (43 j.) ont été logés en cages-mobiles (3 par cage, 0,4 m² pâturage/j/lapin). 5 cages ont été placées sur une prairie de fétuque élevée (Festuca arundinacea), 5 autres sur une prairie majoritairement (70%) composée de sainfoin (Onobrychis viciifolia). Chaque jour, les cages ont été déplacées et 60 g/lapin d'aliment complet granulé distribués (absence de refus). L'ingestion de fourrages verts a été estimée comme la différence entre l'offre et le refus mesurés hebdomadairement et par cage. La digestibilité in situ du mélange fourrage + aliment granulé a été estimée après collecte totale de fèces laissées au sol pendant 2 périodes de 4 jours. L'ingestion de sol a été estimée par dosage des cendres insolubles dans le sol, les fourrages, l'aliment granulé et les fèces. La digestibilité de l'aliment complet granulé, des deux types de fourrages et du mélange a été mesuré en parallèle en cages hors-sol. La digestibilité de la matière sèche (dMS) de la fétuque variait de 37 à 43% respectivement pour une mesure au pâturage ou hors-sol; tandis que la dMS du sainfoin variait seulement de 1pt (65,5 et 66,5% respectivement). La croissance des lapins est 50% supérieure sur la pâture de sainfoin, alors que l'ingestion totale de MS (granulé+herbe) est similaire à celle du groupe "fétuque" (55 à 56 g/j/lap.), mais l'ingéré protéique est 25% supérieure pour le groupe "sainfoin". L'ingestion de sol a été inférieure (P<0,05) sur la pâture de fétuque (1,3% de la MS ingérée ou 4,6g/j) comparée à celle de sainfoin (3,0% de la MS ou 12,5g/j). La plus faible ingestion de sol sur le pâturage de fétuque peut être due à la plus grande couverture du sol par cette graminée qui permet une zone tampon entre les animaux et le sol, comparé à la couverture plus éparse du sainfoin. Abstract-Dry matter digestibility of grazed sainfoin and tall fescue, and estimation of soil intake, in the organic pastured growing rabbits : first results. The development of organic rabbits production at pasture is limited by lacks in technical references, particularly about real grazed forage intake and digestibility. Moreover, to measure digestion at pasture we must know the intake of soil (minerals), the latter could eventually contain some pollutants. Therefore, after weaning (43 d) 30 growing rabbits have been allotted in two groups and housed in movable cages on two types of pasture: one with 70% of sainfoin (Onobrychis viciifolia) and the other with 100% tall fescue (Festuca arundinacea). Each cage contained 3 animals, with a shelter of 0.4 m² and a pasture surface of 1.2 m² and was moved every day A pelleted commercial feed was distributed daily at a level of 60 g/rabbit, and was totally consumed. Daily grass intake was calculated by difference between offered and residual grass (cut over 3 cm). The in situ digestibility of the forage + pellets mixture was estimated after total collection of faeces left on the soil for 2 x 4 days. Soil intake has been estimated with an internal marker (acid insoluble ash), from its concentrations in soil, pasture, feed and faeces, as well as dry matter digestibility (DMd). The DMd of pelleted feed, both vegetation types and their mixtures were also determined with metabolism cages (as a control). The DMd of tall fescue varied from 37 to 43% respectively for a measure at pasture or in indoor, whereas the DMd of sainfoin varied only by 1 unit (65.5 to 66.6 resp.). The rabbit's growth was 25% higher on the "sainfoin" pasture, while the total DM intake (pellets+grass) was similar to that of the group "fescue" (55 vs 56 g/j/lap.), but the protein intake was 25% higher for the "sainfoin" group. Soil intake was lower (P<0.05) on tall fescue meadow (1.3% of total DM intake or 1.9 g/d) in comparison to sainfoin (3.0% of total DM intake or 4.2 g/d). The smaller soil intake on pasture of tall fescue could be due to the better soil cover by grass forming a buffer between animals and soil, in comparison to the sparser sainfoin cover.
Domaines
Sciences agricoles| Origine | Fichiers produits par l'(les) auteur(s) |
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