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Polyethylene glycol as an indigestible marker to estimate fecal output in dairy cows.
Ahvenjärvi, S; Nyholm, L; Nousiainen, J; Mäntysaari, E A; Lidauer, M.
Afiliación
  • Ahvenjärvi S; Milk Production Department, Natural Resources Institute Finland (Luke), FI-31600 Jokioinen, Finland. Electronic address: seppo.ahvenjarvi@luke.fi.
  • Nyholm L; Valio Oy, PO Box 10, FI-00039 Helsinki, Finland.
  • Nousiainen J; Valio Oy, PO Box 10, FI-00039 Helsinki, Finland.
  • Mäntysaari EA; Animal Genetics Department, Natural Resources Institute Finland (Luke), FI-31600 Jokioinen, Finland.
  • Lidauer M; Animal Genetics Department, Natural Resources Institute Finland (Luke), FI-31600 Jokioinen, Finland.
J Dairy Sci ; 101(5): 4245-4258, 2018 May.
Article en En | MEDLINE | ID: mdl-29501343
ABSTRACT
The objective of this study was to evaluate the accuracy of fecal output measurements using polyethylene glycol (PEG) as an external marker determined by near-infrared reflectance spectroscopy. In addition, the accuracy of dry matter intake predictions based on fecal output and digestibility estimated using an internal marker [indigestible neutral detergent fiber (iNDF)] was assessed. The experiment was conducted using 6 lactating dairy cows fed 2 different diets. Polyethylene glycol was administered twice daily into the rumen and the diurnal pattern of fecal concentrations and recovery in feces were determined. To evaluate the effects of alternative marker administration and sampling schemes on fecal output estimates, the passage kinetics of PEG in the digestive tract of dairy cows was determined and used for simulation models. The results indicate that PEG was completely recovered in feces and, thus, fecal output was accurately estimated using PEG. Good agreement between measured and predicted dry matter intake (standard error of prediction = 0.86 kg/d, R2 = 0.81) indicates good potential to determine feed intake using PEG in combination with iNDF. The precision of cow-specific digestibility estimates based on iNDF was unsatisfactory, but for a group of cows iNDF provided an accurate estimate of dry matter digestibility. The current study indicated that, to overcome inherent day-to-day variation in feed intake and fecal output, the minimum of 4 fecal spot samples should be collected over 4 d. Preferably, these samples should be distributed evenly over the 12-h marker administration interval to compensate for the circadian variation in fecal PEG concentrations.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Polietilenglicoles / Bovinos / Heces Tipo de estudio: Prognostic_studies Límite: Animals Idioma: En Revista: J Dairy Sci Año: 2018 Tipo del documento: Article

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Polietilenglicoles / Bovinos / Heces Tipo de estudio: Prognostic_studies Límite: Animals Idioma: En Revista: J Dairy Sci Año: 2018 Tipo del documento: Article