Data variables in 'SSA Feeds'

Data sources

Data variables

Energy values

References

Data sources

The information on nutritional data of livestock feeds made available through 'SSA Feeds' was generated at the Animal Nutrition/Analytical Services Laboratories of the International Livestock Centre for Africa (ILCA) and the International Livestock Research Institute (ILRI) in Addis Ababa, Ethiopia. The laboratory analyses were performed as described by Osuji et al. (1993) and Ogubai and Sereke (1997). The initial data set used in this software is the same used by Anindo et al. (1994). However, this data set was modified extensively to exclude duplicate entries and extreme cases of outliers. All feeds were classified into nine 'Feed types' as described in Help. Plant names were identified, whenever possible, using the checklist of names given by Terrell et al. (1986). The initial data set is frequently revised and new data is added. Therefore the nutritive values obtained through this software may differ substantially from those provided by Anindo et al. (1994).

Data variables

'SSA Feeds' provides data on the following nutritional variables:

1. Dry matter is on dried basis. This is not the DM of the feed, but the DM of the feed sample after drying and grinding. Users need to know the DM of the feeds as they are used in the farm.
2. AAS = Atomic Absorption Spectrophotometry.
3. FIA = Flow Injection Analysis.
4. PPM = Parts Per Million.

Energy values

Digestible Energy (DE) was calculated following a modification of the equation used by NRC (2001). NRC (2001) estimated DE using data on true digestibility of the various feed fractions and their concentration of energy. Since this information was not available in the database, DE was calculated as:

DE = 0.01 OM (IVOMD + 12.9) 4.4 – 0.3

where:

• OM is % of organic matter. For feeds for which data on IVDMD was available but OM was unknown, the latter was assumed to be 90% of the DM
• IVOMD was assumed to be the same as IVDMD
• 12.9 represents the endogenous losses of energy in feces (van Soest 1982)
• 4.4 is the average concentration of energy (Mcal/kg) in the digested OM (NRC 2000, 2001)
• –0.3 is intercept from NRC (2001).

Values of ME, NEm, NEg and NEl were calculated from DE following NRC (2000, 2001) as follows:

ME = 0.82 DE

NEm = 1.37 ME – 0.138 ME² + 0.0105 ME³– 1.12

NEg = 1.42 ME – 0.174 ME² + 0.0122 ME³– 1.65

NEl = 0.703 ME – 0.19

IVDMD values that led to EM values lower than 1.75 Mcal/kg DM or higher than 3.0 Mcal/kg DM were excluded from the database.

For NEl, no adjustments for level of intake were used (NRC 2001), as milking cows in sub-Saharan Africa are rarely fed at levels above 1.5 times maintenance (Jenet 2004; Osuji et al. 2005).

References

Anindo DO, Said AN and Lahlou-Kassi A. 1994. Chemical composition and nutritive value of feedstuffs for ruminant livestock in sub-Saharan Africa. ILCA (International Livestock Centre for Africa), Addis Ababa, Ethiopia. 539 pp.

Harris LH. 1970. Nutrition research techniques for domestic and wild animals. Volume 1. Animal Science Department, Utah State University, Logan, Utah, USA. 86 pp.

Jenet A. 2004. Long-term and carry over effects of feeding level performance and energy partitioning of Boran (Bos indicus) and Boran × Holstein dairy cattle. PhD thesis. Swiss Federal Institute of Technology, Zurich, Switzerland. 105 pp.

NRC (National Research Council). 1996. Nutrient requirements of beef cattle. Seventh revised edition. NRC, National Academic Press, Washington, DC, USA. 242 pp.

NRC (National Research Council). 2000. Nutrient requirements of beef cattle. Update 2000. NRC, National Academic Press, Washington, DC, USA. 232 pp.

NRC (National Research Council). 2001. Nutrient requirements of dairy cattle. Seventh revised edition. NRC, National Academic Press, Washington, DC, USA. 381 pp.

Ogubai M and Sereke BS. 1997. Analytical methods for feeds, animal excrements and animal tissues. Nutrition Laboratory, ILRI (International Livestock Research Institute), Addis Ababa, Ethiopia. 90 pp.

Osuji PO, Nsahlai IV and Khalili H. 1993. Feed evaluation. ILCA Manual. ILCA (International Livestock Centre for Africa), Addis Ababa, Ethiopia.

Osuji PO, Saarisalo EM, Tegegne A and Umunna NN. 2005. Undernutrition of dairy cattle in smallholder production systems in East Africa. In: Ayantunde AA, Fernández-Rivera S and McCrabb G (eds), Coping with feed scarcity in smallholder livestock systems in developing countries. Animal Sciences Group, UR, Wageningen, the Netherlands; University of Reading, Reading, UK; Swiss Federal Institute of Technology, Zurich, Switzerland; and ILRI (International Livestock Research Institute), Nairobi, Kenya. pp. 97–120.

Terrell EE, Hill SR, Wiersema JH and Rice WR. 1986. A checklist of names for 3000 vascular plants of economic importance. Agriculture Handbook 505. US Department of Agriculture, USA. 244 pp.

van Soest PJ. 2002. Nutritional ecology of the ruminant. O&B Books, Corvallis, Oregon, USA. 374 pp.

van Soest PJ and Robertson JB. 1985. Analysis of forages and fibrous feeds. A laboratory manual for animal science 613. Cornell University, Ithaca, New York, USA. 202 pp.

Caution: It has recently come to light that the Metabolizable Energy values in the SSA Feeds database appear to be higher than expected. These values were predicted from IVDMD values and the method of prediction is currently under investigation. In the meantime please exercise caution in the use of the ME data. Alan Duncan 1/7/09 

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