Dry matter digestibility

Animal Nutrition. Sulfur in the diets of mminant animals is beneficial to the animals growth (see Eeedsand FEED ADDITIVES). Sulfur increases feed intake, cellulose and dry matter digestion, and the synthesis of microbial protein. This results in increased meat, milk, and wool production (43). The special uses for sulfur in agriculture demonstrate a significant and continuing need for increased use of sulfur (44). 

Singh [18] 1992 9.02 In vitro gas production and dry matter digestibility coefficients... 

Schwartz, C.C. and G.J. Nagy. 1974. Pesticide effects on in vitro dry matter digestion in deer. Jour. Wildl. Manage. 38 531-534. 

Fig. 4.3. Typical graph for correcting measured sample dry matter digestibility (DMD) values in proportion to deviation of low and high standards from their declared values.

Jones, D.I.H. and Hayward, M.V. (1973) A cellulase digestion technique for predicting the dry matter digestibility of forages. Journal of the Science of Food and Agriculture 24, 1419-1426. 

Petit, H.V., Tremblay, G.F., Tremblay, E., and Nadeau, P. 2002. Ruminal biohydrogenation of fatty acids, protein degradability, and dry matter digestibility of flaxseed treated with different sugar and heat combinations. Can. J. Anim. Sci. 82, 241-250. 

Forage Dry Matter % Digestible Nutrients % Digestible Protein % Crude Fiber %... 

Figure I. Effect of NaOH pretreatment on the percentage of dry matter digestion in vitro with rumen micro-organisms (49)...

Figure 1. Showing the relationship of dry matter digestibility to adjusted feed intake (lb. per day) at two levels of milk production. Adjustments were proportional to weight below 66.7% dry matter digested and weight raised to the 0.51 power above 66.7% digested. Milk production expressed as pounds equivalent of 4% fat corrected milk (FCM). (Reference 13)...

The relatively high dry matter digestion coefficients, Table V, emphasize the fact that tests rations were essentially concentrate except for the inclusions of oyster shell and sawdust. The conventional digestibility trial data and the in vitro data rank the rations in a similar order. No adequate explanation can be given for the low coefficient for the basal by the nylon bag technique. Although the small sample in vivo and the... 

Cellulose digestibility declined with the additions of sawdust, Table VI. This was expected since extensive nylon bag digestibility data for various waste wood materials including oak sawdust revealed apparent dry matter digestion coefficients below 20, usually less than 5, Table VII. 

Table 1 In vitro dry matter digestibility (IVDMD), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and ethanol production of leaf and stem tissues of 12-week-old bermudagrass (Cynodon sp.), mature napiergrass (Pennisetum purpureum) and giant reed (Arundo donax) grown at Tifton, GA. 2004.

Calculated as per Undersander et al. [8] except for in vitro dry matter digestibility adjustment Calculated as per Undersander et al. [8] using ADF and NDF. 

For example, if an animal is given 10 g of chromic oxide per day and the concentration of indicator in the faeces is 4 g/kg DM, then faeces output would be calculated as 10/4 = 2.5 kg DM/day. If food intake is known, then dry matter digestibility could be calculated as (dry matter intake — faecal DM output)/DM intake. Alternatively, if DM digestibility is known, then dry matter intake could be calculated as faecal DM output/DM digestibility. The n-alkane technique is very useful in this context. As plants contain mainly odd-chain n-alkanes in their waxy cuticle, even-chain (C32) n-alkanes can be used as an external indicator to determine faecal output. At the same time, the odd-chain n-alkanes (C35) can be used to estimate diet digestibility. Dry matter intake can then be estimated in group-fed or grazing animals. 

Fig. 10.1 Laboratory methods for estimating the dry matter digestibility of forages, (a) Incubation in rumen liquor followed by digestion with pepsin, (b) Digestion with pepsin followed by digestion with cellulase.

Forages such as the cereal straws, in which the cellulose is mixed or bound with a high proportion of lignin, may be treated chemically to separate the two components. The treatment processes and their effects are described in detail in Chapter 20. The chemicals used are mainly alkalis (sodium and ammonium hydroxides), and they improve the dry matter digestibility of cereal straws quite dramatically, from 0.4 to 0.5-0.7. 

There is general acceptance of dry matter, digestible organic matter and ammonia nitrogen as the major determinants of silage dry matter intake, and it behoves the silage maker to optimise fermentation and to minimise secondary fermentation, clostridial activity and aerobic deterioration if satisfactory intakes of the product are to be achieved. 

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