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Animals : an open access journal from MDPI2023; 13(16); 2624; doi: 10.3390/ani13162624

Protein Evaluation of Feedstuffs for Horses.

Abstract: The German Society of Nutrition Physiology has proposed a new protein evaluation system for horse feeds to estimate pre-cecally digestible crude protein (pcdCP) and amino acids (pcdAA) from chemical properties. A total of 71 feeds for horses were chemically tested and evaluated according to the new protein evaluation system. A feeding trial with eight horses tested whether differences in estimated pcdAA and neutral detergent soluble CP (NDSCP) in the diet were reflected by post-prandial (ppr) kinetics of plasma lysine (Lys) by feeding a complementary feed (control = CTRL) with 1.02 g Lys/100 kg body weight (BW) as well as three diets with 3.02 g Lys/100 kg BW, as follows: (i) CTRL with synthetic AA (CTRL + synAA); (ii) CTRL with soybean meal (CTRL + SBM); and (iii) lucerne pellets (LUC). In comparison to CTRL, the areas of curves (s) of ppr plasma Lys differed: CTRL < CTRL + SBM ( < 0.01) < CTRL + synAA ( < 0.05). For 71 feeds, the estimated pcdCP was correlated with the CP content ( < 0.001), NDSCP ( < 0.001), and ash-free neutral detergent fiber ( < 0.001). A mean neutral detergent insoluble CP content of at least 3-5% can be assumed in horse feed. It is speculated that the predicted availability of Lys from LUC seems to be underestimated by the new protein evaluating system. The influence of chewing and microbiota in vivo needs to be considered in horses.
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Publication Date: 2023-08-14 PubMed ID: 37627415PubMed Central: PMC10451164DOI: 10.3390/ani13162624Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The study proposes a new way to assess the protein content of horse feed and examines how variations in certain aspects, including digestible crude protein and amino acids, can be reflected in the horse’s metabolism. The study indicates that this new method of assessing protein content may underestimate the availability of a particular amino acid – lysine – in one specific type of horse feed, suggesting that certain factors, such as the horse’s chewing habits and gut microbiota, need more consideration in the evaluation.

Research Methodology and Findings

  • The German Society of Nutrition Physiology proposed a new protein evaluation system for assessing the amounts of digestible crude protein (pcdCP) and amino acids (pcdAA) in horse feed based on their chemical properties.
  • 71 horse feeds were tested and evaluated in line with this new system.
  • A feeding trial involving eight horses aimed at understanding if the differences in estimated pcdAA and another type of protein, neutral detergent soluble crude protein (NDSCP), get reflected in the horse’s metabolism after eating. This was tested by looking at the levels of an amino acid called lysine (Lys) in the horse’s blood after eating.
  • For this, a basic feed (control diet – CTRL) containing 1.02 g of lysine per 100 kg of horse’s body weight was used. The same feed was also tested with the addition of synthetic amino acids (CTRL+synAA), soybean meal (CTRL+SBM), and lucerne pellets (LUC) – all containing 3.02 g of lysine per 100 kg of horse’s body weight.
  • The study found significant differences in the lysine levels in the horse’s blood after eating these different diets. The study observed the lowest blood lysine levels after eating the control diet and the highest levels after eating the diet with added synthetic amino acids.
  • The research also found that in the 71 feeds tested, the estimated digestible crude protein (pcdCP) was correlated with total crude protein content, levels of NDSCP, and the content of ash-free neutral detergent fiber.

Studying the Protein Composition of Horse Feed

  • An important finding was that horse feeds generally contain 3-5% of a particular type of protein that the horse cannot digest (neutral detergent insoluble crude protein).
  • The researchers speculated that their new protein evaluation system might be underestimating the availability of lysine when lucerne pellets are used in the feed. Lucerne pellets are a common ingredient in horse feed and lysine is a key amino acid that horses need for proper growth and maintenance.
  • The researchers suggest that further improvements can be made to their evaluation system by considering individual horse factors such as chewing habits and the bacteria present in the gut (microbiota). These factors may significantly influence how much of the protein in the feed the horse can actually digest and use.

Cite This Article

APA
Bockisch F, Taubert J, Coenen M, Vervuert I. (2023). Protein Evaluation of Feedstuffs for Horses. Animals (Basel), 13(16), 2624. https://doi.org/10.3390/ani13162624

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 13
Issue: 16
PII: 2624

Researcher Affiliations

Bockisch, Franziska
  • Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 9, 04103 Leipzig, Germany.
Taubert, Johannes
  • Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 9, 04103 Leipzig, Germany.
Coenen, Manfred
  • Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 9, 04103 Leipzig, Germany.
Vervuert, Ingrid
  • Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 9, 04103 Leipzig, Germany.

Conflict of Interest Statement

The authors declare that they have no competing interests.

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Citations

This article has been cited 2 times.
  1. Kranenburg LC, Reinke KS, van den Broek J, Zaal EA, van den Boom R, van Doorn DA. Free Plasma Amino Acid Concentrations in Horses Fed Different Dosing Regimens of Hydrolysed Collagen. Animals (Basel) 2025 Nov 3;15(21).
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  2. Li Y, Zhou H, Yu J, Dong B, Li H, Zhang C, Zhang G, Guo C. Dietary protein sources in concentrate supplementation influence growth performance by manipulating gut microbiota and serum metabolites in suckling Donkey foals. Anim Microbiome 2025 Aug 26;7(1):91.
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