Nitrogen fertilization, regrowth age, and altitude directly alter the nutritional quality and fatty acid profile of kikuyu grass in the Colombian high-altitude Andean tropics, according to a study published on the institutional repository of the Universidad Nacional de Colombia.
The study mapped how canopy vertical stratification and plant maturity reshape forage composition across dairy production systems. Researchers evaluated structural variables, crude protein, fiber fractions, and lipid profiles across different foliar strata and vegetative organs.
Young leaves located in the upper canopy strata showed higher crude protein, in vitro dry matter digestibility, and polyunsaturated fatty acid content, particularly alpha-linolenic acid. In contrast, stems and lower strata accumulated higher fiber contents and palmitic acid. Foliar position along the stolon emerged as a stronger predictor of nutritional quality than chronological regrowth age.
Harvest age controlled nutritional quality, biomass production, and fatty acid profiles in polyphytic pastures. Nitrogen fertilization primarily drove crude protein content shifts without significantly modifying fatty acid composition. Altitude also shaped lipid content, with intermediate elevations yielding higher proportions of unsaturated fatty acids.
| Forage Component | Upper Canopy Strata | Lower Strata / Stems |
|---|---|---|
| Crude Protein (CP) | Higher | Lower |
| Digestibility (IVDMD) | Higher | Lower |
| Fatty Acid Profile | Alpha-linolenic acid (PUFA) | Palmitic acid (C16:0) |
Palmitic acid remained the predominant fatty acid across the altitudinal gradient, a factor researchers linked to storage conditions and polyunsaturated fatty acid oxidation.
- Universidad Nacional de Colombia Institutional Repository: Efecto de la fertilización nitrogenada, la madurez y la altitud sobre la calidad nutricional y el perfil de ácidos grasos del pasto kikuyo (Cenchrus clandestinus) y praderas polifíticas en el trópico altoandino colombiano.
