Directory UMM :Data Elmu:jurnal:A:Animal Feed Science and Technology:Vol87.Issue3-4.Oct2000:
Animal Feed Science and Technology
87 (2000) 153±162
Effect of regrowth age on intake and digestion
of Digitaria decumbens consumed by
Black-belly sheep
H. ArchimeÁdea,*, M. Bovala, G. Alexandrea,
A. XandeÂa, G. Aumonta, C. Poncetb
a
Institut National de la Recherche Agronomique, Unite de Recherches Zootechniques,
Prise d'eau, 97170 Petit-bourg, Guadeloupe
b
Institut National de la Recherche Agronomique, Station de Recherches sur la Nutrition des Herbivores,
Centre de Clermont-Ferrand-Theix, Theix, 63122 Saint-Genes-Champanelle, France
Received 17 February 1999; received in revised form 9 November 1999; accepted 29 August 2000
Abstract
The intake and digestion of fresh Digitaria decumbens grass were studied following the stage of
regrowth. Six rams (mean liveweight: 40:8 0:6 kg) received successively a 14, 28, 42 and 56-day
old forage during four 4-week periods. The range of variation of crude protein and acid detergent
®bre content (g/kg) of the forages was 57±130 and 380±442, respectively. The DM intake (g/
kg W0.75) and the organic matter total tract digestibility decreased from 83 to 56 and from 0.728 to
0.628, respectively, between 14 and 56 days of regrowth. The fractional degradation rate (hÿ1) of
dry matter in the rumen, estimated by the nylon bag method, decreased curvilinearly with a mean
daily rate of 0.0010. A curvilinear relationship was recorded between the rumen turnover rate and
forage regrowth stage. The mean daily decrease (per hour per day) was 0.0005. The total nitrogen
duodenal ¯ow (g per day) decreased from 22.7 to 11.6 between 14 and 56 days. The mean
ef®ciency of microbial protein synthesis was similar with the four diets (31.8, S.E. 2.2 g microbial
nitrogen/kg organic matter apparently digested in the rumen). In conclusion, intake, digestibility
and duodenal nitrogen ¯ow are high with the 14-day D. decumbens. As a consequence, the nutritive
value of the latter is similar to the one of a good temperate grass forage. Good nutritive value of a
14-day old D. decumbens and fast maturation and ligni®cation in C4 forage before the ®rst month of
regrowth suggest the need to investigate ruminant feeding strategies with forages younger (
87 (2000) 153±162
Effect of regrowth age on intake and digestion
of Digitaria decumbens consumed by
Black-belly sheep
H. ArchimeÁdea,*, M. Bovala, G. Alexandrea,
A. XandeÂa, G. Aumonta, C. Poncetb
a
Institut National de la Recherche Agronomique, Unite de Recherches Zootechniques,
Prise d'eau, 97170 Petit-bourg, Guadeloupe
b
Institut National de la Recherche Agronomique, Station de Recherches sur la Nutrition des Herbivores,
Centre de Clermont-Ferrand-Theix, Theix, 63122 Saint-Genes-Champanelle, France
Received 17 February 1999; received in revised form 9 November 1999; accepted 29 August 2000
Abstract
The intake and digestion of fresh Digitaria decumbens grass were studied following the stage of
regrowth. Six rams (mean liveweight: 40:8 0:6 kg) received successively a 14, 28, 42 and 56-day
old forage during four 4-week periods. The range of variation of crude protein and acid detergent
®bre content (g/kg) of the forages was 57±130 and 380±442, respectively. The DM intake (g/
kg W0.75) and the organic matter total tract digestibility decreased from 83 to 56 and from 0.728 to
0.628, respectively, between 14 and 56 days of regrowth. The fractional degradation rate (hÿ1) of
dry matter in the rumen, estimated by the nylon bag method, decreased curvilinearly with a mean
daily rate of 0.0010. A curvilinear relationship was recorded between the rumen turnover rate and
forage regrowth stage. The mean daily decrease (per hour per day) was 0.0005. The total nitrogen
duodenal ¯ow (g per day) decreased from 22.7 to 11.6 between 14 and 56 days. The mean
ef®ciency of microbial protein synthesis was similar with the four diets (31.8, S.E. 2.2 g microbial
nitrogen/kg organic matter apparently digested in the rumen). In conclusion, intake, digestibility
and duodenal nitrogen ¯ow are high with the 14-day D. decumbens. As a consequence, the nutritive
value of the latter is similar to the one of a good temperate grass forage. Good nutritive value of a
14-day old D. decumbens and fast maturation and ligni®cation in C4 forage before the ®rst month of
regrowth suggest the need to investigate ruminant feeding strategies with forages younger (