The influence of the method of preservation of forages on the digestion in dairy cows. 1. Composition of the forages and digestibility of dry matter, organic matter and nitrogen.

1. Grass from the same sward was ensiled without additive, with 14.6 g formic acid/100 g crude protein or 10.8 g formic acid and 10.6 g formaldehyde/100 g crude protein. Similar grass was dried and pelleted. Drying or ensiling with the mixture reduced solubility of N in the preserved grass but formic acid increased it, and ensiling without additive increased it even more. Apparent digestibility of N in the rumen of cows tended to decrease with decrease in solubility. Digestibility in vitro of the mixed diet given to the cows, calculated from digestibility of the separate components, agreed well with the values in vivo for diets with silages, but was high for that with dried grass. (Abstract retrieved from CAB Abstracts by CABI’s permission

A comparison of some laboratory techniques for the estimation of the digestibility of the organic matter in forage samples.

The 194 samples of forage were of 6 groups; grass or other forage dried, fresh or ensiled. Workers from 5 institutes analysed some of the samples by their usual methods, 10 methods altogether. Digestibility estimated with sheep was regressed on the other results and correlation coefficients and residual standard deviations were calculated; those were closer for groups of forages than for all forages together. The least accurate predictor of digestibility in vivo was crude fibre content, which is much used in the Netherlands. The best method for each fodder group was the method of Tilley and Terry (NAR 34, 156) as modified by Koelen, Kemmink and Dijkstra (De bepaling van de voederwaarde van ruwvoeders met behulp van de in vitroverteerbaarheid. Internal Report, Institute for Animal Feeding and Nutrition Research 'Hoorn' (1969), No. 27, available in English). It took least work but required sheep rumen fluid. For all groups together, the cell-wall constituents method of Gaillard and Nijkamp (NAR 38, 8034) was better for 54 samples but the residual standard deviation was higher than within groups; it required more labour, but not rumen fluid. (Abstract retrieved from CAB Abstracts by CABI’s permission

Ruminal behaviour of structural carbohydrates, non-structural carbohydrates and crude protein from concentrate ingredients in dairy cows.

Resultaten van een onderzoek naar afbraakeigenschappen van Neutral Detergent Fibre (NDF), zetmeel en ruw eiwit in krachtvoeringrediente