Nutritive value of silages

In each case, ensilage has resulted in an increase in gross energy, but this is smaller for the prewilted and additive-treated materials. 

The energy requirements of ruminant animals and the energy values of foods are currently expressed in the UK in terms of metabolisable energy (see Chapters 11 and 12). 

Faecal losses of energy when silages are consumed by animals usually lie between 25 and 35 per cent and are mainly dependent upon the nature of the source material. The effects of the ensiling process on energy losses in the faeces are generally 

The most comprehensive studies involving energy losses as methane were those carried out at the Rowett Research Institute (see Further reading). For 48 silages, mean energy loss as methane was 7.7 per cent of the gross energy, with a standard deviation of 0.71. 

After Barber eta/. 990 Animal Feed Science and Technology 28 115-28. 

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Hellamaki, M. (1992) Estimation of the nutritive value of silage using NIR digestibility. In Murray, I. and Cowe, I.A. (eds) Making Light Work Advances in Near Infrared Spectroscopy. VCH, Weinheim, Germany, pp. 264-268. 

The proximate analyses, mineral composition, digestibility coefficients and nutritive values of brassicas, by-products, grains, grasses, hays, legumes, oil cakes, root crops, seeds and silages are given in MAFF/ADAS (1971) Nutrient Allowances and Composition of Feedingstuffs for Ruminants (Advisory Paper No. 11). 

September and mid-October so seeds of selected families can be sent to a winter nursery for generation advancement. Finally, after each season of silage evaluation, the ability to predict the nutritive value of the germplasm under development is upgraded by including new NIRS spectral samples and corresponding laboratory evaluations in the calibration database. 

Silage films are used primarily to preserve silage and maize. They maintain the nutritional value of the contents and inhibit undesirable fermentation processes. Traditional silage films can be mono- or co-extruded, range from 100 to 200 p,m, and are normally pigmented (black or white). In the case of bale wrapping for round or square bales, films are normally very thin (10-25 p,m), applied in multiple layers and pigmented (mainly black or white). 

Table 19.6 Composition and nutritive value of grass silages inoculated with lactic acid bacteria compared with an untreated control...

Cammell, S.B., J.D. Sutton, D.E. Beever, D.J. Humphries, and R.H. Phipps, 2000. The effect of crop maturity on the nutritional value of maize silage for lactating dairy cows. 1. Energy and nitrogen utilization. Anim. Sc. 71,381-390. 

In Europe, formic acid is applied on fresh hay or other silage to promote the fermentation of lactic acid and to suppress the formation of butyric acid it also allows fermentation to occur quickly, and at a lower temperature, reducing the loss of nutritional value. Formic acid arrests certain decay processes and causes the feed to retain its nutritive value longer, and so it is widely used to preserve winter feed for cattle. In the poultry industry, it is sometimes added to feed to kill E. coli bacteria. Formic acid is also used in the production of textiles and leather because of its acidic nature. It is also used as a coagulant in the production of rubber. 

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