title: Changes in rumen microbiota composition and in situ degradation kinetics during the dry period and early lactation as affected by rate of increase of concentrate allowance.
abstract: Changes in rumen microbiota and in situ degradation kinetics were studied in 12 rumen-cannulated Holstein Friesian dairy cows during the dry period and early lactation. The effect of a rapid (RAP) or gradual (GRAD) postpartum (pp) rate of increase of concentrate allowance was also investigated. Cows were fed for ad libitum intake and had free access to a mixed ration consisting of chopped wheat straw (dry period only), grass silage, corn silage, and soybean meal. Treatment consisted of either a rapid (1.0 kg of dry matter/d; n = 6) or gradual (0.25 kg of dry matter/d; n = 6) increase of concentrate allowance (up to 10.9 kg of dry matter/d), starting at 4 d pp. In whole rumen contents, bacterial community composition was assessed using samples from 50, 30, and 10 d antepartum (ap), and 3, 9, 16, 30, 44, 60, and 80 d pp, and protozoal and archaeal community composition using samples from 10 d ap, and 16 and 44 d pp. Intake of fermentable organic matter, starch, and sugar was temporarily greater in RAP than GRAD at 16 d pp. Bacterial community richness was higher during the dry period than during the lactation. A rapid increase in concentrate allowance decreased bacterial community richness at 9 and 16 d pp compared with a gradual increase in concentrate allowance, whereas from 30 d pp onward richness of RAP and GRAD was similar. In general, the relative abundances of Bacteroidales and Aeromonadales were greater, and those of Clostridiales, Fibrobacterales, and Spirochaetales were smaller, during the lactation compared with the dry period. An interaction between treatment and sampling day was observed for some bacterial community members, and most of the protozoal and archaeal community members. Transition to lactation increased the relative abundance of Epidinium and Entodinium, but reduced the relative abundance of Ostracodinium. Archaea from genus Methanobrevibacter dominated during both the dry period and lactation. However, during lactation the abundance of the methylotrophic Methanomassiliicoccaceae and Methanosphaera increased. The in situ degradation of organic matter, neutral detergent fiber, starch, and crude protein was neither affected by treatment nor by transition from the dry period to lactation. Results show that the composition of the rumen microbiota can change quickly from the dry period to the lactation period, in particular with a rapid increase in fermentable substrate supply postpartum, but this was not associated with changes in rumen degradation kinetics.
authors.affiliation: Animal Nutrition Group, Wageningen University and Research, PO Box 338, 6700 AH Wageningen, the Netherlands. Electronic address: kasper.dieho@wur.nl.
authors.forename: K
authors.initials: K
authors.lastname: Dieho
authors.affiliation: Laboratory of Microbiology, Wageningen University and Research, PO Box 8033, 6700 EJ Wageningen, the Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: van den Bogert
authors.affiliation: Grasslands Research Centre, AgResearch Limited, Palmerston North 4442, New Zealand.
authors.forename: G
authors.initials: G
authors.lastname: Henderson
authors.affiliation: Animal Nutrition, Wageningen Livestock Research, Wageningen University and Research, PO Box 338, 6700 AH Wageningen, the Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Bannink
authors.affiliation: Laboratory of Microbiology, Wageningen University and Research, PO Box 8033, 6700 EJ Wageningen, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Ramiro-Garcia
authors.affiliation: Laboratory of Microbiology, Wageningen University and Research, PO Box 8033, 6700 EJ Wageningen, the Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Smidt
authors.affiliation: Animal Nutrition Group, Wageningen University and Research, PO Box 338, 6700 AH Wageningen, the Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Dijkstra
mesh_terms: D000818:Animals; D002417:Cattle; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000187:drug effects; D005260:Female; D007700:Kinetics; D007774:Lactation / Q000187:drug effects; D064307:Microbiota; D008892:Milk / Q000737:chemistry*; D012417:Rumen / Q000378:metabolism*; D012820:Silage; D003313:Zea mays
keywords: dairy cattle; rumen adaptation; rumen microbiome or microbiota; transition period