In situ dry matter, protein and neutral detergent fibre degradation kinetics of Cholistan Desert grasses
Global climate change is evident and poses serious threats to the sustainability of traditional rangeland livestock production systems. This study tested the feeding potential of perennial grasses of Cholistan Desert for various species of ruminants at different physiological stages. Eight common and nutritionally important grass species (Cenchrus ciliaris, Stipagrostis plumose, Panicum antidotale, Cymbopogon jwarancusa, Cenchrus pennisitiformis, Lasiurus scindicus, Ochthochloa compressa and Vetiveria zizanioides) were investigated for in situ degradation parameters according to Nordic feed evaluation system (NorFor) standards. The collected, dried and milled grass samples were incubated for 0, 4, 8, 16, 24, and 48 hours to determine dry matter and crude protein biodegradation and additionally for 96 and 168 hours for neutral detergent fibre degradation in the rumens of lactating Nili-Ravi buffalo and Cholistan Desert cows and heifers (two from each species and from each physiological stage). All of these grass species influenced the dry matter, crude protein and neutral detergent fibre degradation fractions significantly. The overall effective degradability of dry matter for asymptotic extent of degradation did not differ. However, the potentially degradable but insoluble fraction and rate of degradation were influenced significantly by the species of the animals. All the proximate parametric characteristics of perennial desert grasses were within the nutrient range for typical ruminant diets except for crude protein. It was concluded that rumen availability of grasses was highly influenced by grass species. However, these grasses are equally nutritionally important for various species of ruminants for example buffalo versus cattle at different physiological stages and heifers versus lactating animals.
Keywords: buffalo, Cenchrus ciliaris, desert cows, desert forage, feeding value