title: The effects of a ration change from a total mixed ration to pasture on health and production of dairy cows.
abstract: In pasture-based dairy production systems, dairy cows often receive a silage- and concentrate-based ration [total mixed ration (TMR)] during wintertime and are gradually introduced to fresh herbage in spring. The present study aimed to investigate how the transition to this new nutritional situation influenced different production and health indicators. A 10-wk trial was performed in spring 2014, including 60 dairy cows of the German Holstein breed (166±23 d in milk, 23.5±3.7 kg of milk/d; means ± SD). The cows were divided into a pasture and a confinement group (PG and CG, respectively). The CG stayed on a TMR-based diet (35% corn silage, 35% grass silage, 30% concentrate; DM basis), whereas the PG was gradually transitioned from a TMR- to a pasture-based ration (wk 1=TMR-only, wk 2=3 h/d on pasture, wk 3 and 4=12 h/d on pasture, wk 5-10=pasture-only). A continuous grazing system was implemented on a ryegrass dominated pasture and temperature humidity indices were assessed based on continuous recording of temperature and humidity indoors as well as outdoors. Dry matter intake (DMI) from TMR, milk production, body weight (BW), and body condition score decreased as soon as the PG had partial access to pasture. Milk production and BW decreased even further in the first week on a full grazing ration, but thereafter BW increased again and milk production stabilized. The DMI estimation using the n-alkane method in wk 7 and 9 revealed an increase in DMI from pasture between the 2 time points and indicates an adaptation of grazing behavior and metabolism over several weeks. Increased serum β-hydroxybutyrate and fatty acids concentrations at several time points, as well as a continuous body condition score decrease during the whole course of the trial, indicate an energy deficit in the PG. A significant correlation between serum glucose concentrations and the temperature humidity indices was observed. An increase in serum and milk urea concentrations as well as an increase in the urine total N to creatinine ratio occurred in the PG. To assess possible negative effects of the ration change on metabolic and liver health, different clinical chemistry variables and complete blood counts were assessed. No biologically relevant changes were observed for serum albumin, total protein, cholesterol, aspartate transaminase, γ-glutamyltransferase, and glutamate dehydrogenase concentrations, as well as for white and red blood cell counts.
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schären
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Jostmeier
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Ruesink
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Hüther
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Frahm
authors.affiliation: Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 4, 06120 Halle (Saale), Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bulang
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany. Electronic address: Ulrich.Meyer@fli.bund.de.
authors.forename: U
authors.initials: U
authors.lastname: Meyer
authors.affiliation: Clinic for Cattle, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Rehage
authors.affiliation: Department of Crop Sciences, Grassland Science, Georg-August University Göttingen, Von-Siebold-Str. 8, 37077 Göttingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Isselstein
authors.affiliation: Department of Physiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, 30173 Hannover, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Breves
authors.affiliation: Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Brunswick, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Dänicke
mesh_terms: D020155:3-Hydroxybutyric Acid; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition; D001835:Body Weight; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D002149:Energy Intake; D005227:Fatty Acids / Q000097:blood; D005260:Female; D006304:Health Status; D007774:Lactation / Q000502:physiology*; D008129:Lolium; D008892:Milk; D006109:Poaceae; D012621:Seasons; D012820:Silage; D003313:Zea mays; D005723:gamma-Glutamyltransferase
chemical_list: D005227:Fatty Acids; D005723:gamma-Glutamyltransferase; D020155:3-Hydroxybutyric Acid
keywords: confinement; health; pasture; ration change