Effectiveness of near-infrared spectroscopy to predict the chemical composition of feces and total-tract apparent nutrients digestibility estimated with uNDF or AIA in lactating buffaloes' feces

A Guerra; M Simoni; V Longobardi; A Goi; G Mantovani; T Danese; G Neglia; M De Marchi; F Righi

doi:10.3168/jds.2023-24511

Effectiveness of near-infrared spectroscopy to predict the chemical composition of feces and total-tract apparent nutrients digestibility estimated with uNDF or AIA in lactating buffaloes' feces

J Dairy Sci. 2024 Mar 28:S0022-0302(24)00634-9. doi: 10.3168/jds.2023-24511. Online ahead of print.

Authors

A Guerra¹, M Simoni², V Longobardi³, A Goi¹, G Mantovani⁴, T Danese⁴, G Neglia³, M De Marchi¹, F Righi⁴

Affiliations

¹ Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Italy.
² Department of Veterinary Medicine, University of Parma, Strada del Taglio, 10, 43126, Italy. Electronic address: marica.simoni@unipr.it.
³ Department of Veterinary Medicine and Animal Production, Federico II University, Via Federico Delpino 1, 80137 Naples, Italy.
⁴ Department of Veterinary Medicine, University of Parma, Strada del Taglio, 10, 43126, Italy.

PMID: 38554826
DOI: 10.3168/jds.2023-24511

Abstract

Following a comparison of nutrient total-tract digestibility estimates in lactating buffaloes using single-point undigestible NDF (uNDF) or acid-insoluble ash (AIA) as internal markers, the potential of fecal near-infrared spectroscopy (NIRS) to provide calibration equations for the assessment of the chemical composition of feces and nutrient total-tract digestibility estimated with internal markers was explored. Chemical analyses were performed on 147 fecal samples from lactating buffaloes reared in 5 farms in central Italy (Naples). Each farm fed a silage-based total mixed ration (TMR) to the buffaloes, which was sampled in the 2 d before the fecal collection. The TMR and individual fecal samples were collected and analyzed for dry matter (DM), organic matter (OM), ash, AIA, ether extract (EE), starch, fiber fractions (aNDFom, aNDF, ADFom, ADF, hemicellulose, cellulose, ADL, uNDF), N, CP and CP bound to aNDF (NDICP) and to ADF (ADICP). The uNDF content was determined through a 240-h in vitro fermentation and employed, together with AIA as markers to estimate the total-tract apparent digestibility (ttaDe) and total-tract digestibility (ttDe) of DM, OM, ash, N, CP, EE, aNDFom, aNDF, NDIP, ADFom and ADF, ADIN, ADL, hemicellulose, cellulose, starch, non-fibrous carbohydrates (NFC) and fraction B3 of N. No correlation was found between DM and OM digestibility estimated with AIA and uNDF as internal markers. Weak correlations were detected for all the other nutients digestibilities while strong correlations were observed for EE, ADFom, HC, NDIN, ADIN, NB3, NFC and starch.Inizio modulo The sample set (n = 147) was divided in a calibration set (n = 111) and a validation set (n = 36) to "train" and "validate" the fecal NIRS curve through an external validation process. An estimation usable for preliminary or initial evaluation was obtained for N, CP and aNDF fecal content. An excellent prediction was obtained for ttADINDe (R² = 0.90) when estimated with uNDF as internal marker. The NIRS technology was not able to accurately predict all the other traits and the estimated nutrient digestibility of lactating buffalo diets from fecal spectra.

Keywords: Fecal NIRS spectra; buffaloes; markers; undigested neutral detergent fiber.

© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).