Bulkiness and protein treated with zinc ions in concentrates for grazing dairy cows

  • Yaminette Rodríguez Universidad de Puerto Rico, Mayaguez
  • Paul F. Randel Universidad de Puerto Rico, Mayaguez
  • Ernesto Riquelme Villagrán Universidad de Puerto Rico https://orcid.org/0000-0002-8049-4025
Keywords: Protected Protein, Zinc-Treated Protein, Supplemental Concentrates, Grazing Cows

Abstract

Conventional or high fiber concentrates, formulated with or without treated protein, were compared using 12 Holstein cows in a repeated 3 × 3 Latin square dice experiment, with periods of 21 days in a dry season. Rotational grazing was at a rate of 4.8 animals / ha in non-fertilized grass forage. As supplements, three commercial concentrates were used, with theoretical levels of 1.76 Mcal of net energy / kg and 13% of crude protein (CP) in dry matter (DM). Concentrates B and C contained protein protected against ruminal degradation by treatment with zinc ions, unlike A (control); C was bulky, but with 5.25 fat to adjust for energy value. Forage on offer was estimated at 20.2, 22.1 and 14.0 kg DM / cow-day during the three periods, with 5.68% CP and 46.0% digestibility in vitro. The molar ratios of acetate / propionate (A / P) formed in vitro were 2.29 with the forage and 1.93, 2.42 and 2.52 with three concentrates in that order. The average results obtained with treatments A, B, and C were: daily consumption of DM of concentrate 7.69, 7.61 and 7.78 kg; daily milk production corrected to 4% fat: 14.0, 13.5 and 14.2 kg; fat percentage, 3.21, 3.04 and 3.79; daily increase in live weight, 0.36, 0.46 and 0.51 kg. The bulky concentrate promoted a higher fat content in the milk, associated with a high A / P. The lack of a productive stimulus of the supplemental protected protein suggests that intestinal amino acid absorption was not limiting or that such absorption was not increased.

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Author Biography

Ernesto Riquelme Villagrán, Universidad de Puerto Rico

Catedrático Departamento de industria Pecuaria

References

NA
Published
1994-12-30
How to Cite
Rodríguez, Yaminette, Paul F. Randel, and Ernesto Riquelme Villagrán. 1994. “Bulkiness and Protein Treated With Zinc Ions in Concentrates for Grazing Dairy Cows”. Archivos Latinoamericanos De Producción Animal 2 (2), 187-96. https://ojs.alpa.uy/index.php/ojs_files/article/view/2908.
Section
Original paper