Table A.1. Intake coefficients for different cattle classes.
|
Animal class
|
Intake coefficients a |
|
|
1 |
2 |
|
|
1. Calves under 2 months |
0 |
0 |
|
2. Calves 3 to 5 months |
0.0305 |
0.0305 |
|
3. Calves 6 to 18 months |
Interpolation between class 2 and class 4 |
|
|
4. Mature dry, non-pregnant females and mature males (reference class) |
0.0575 |
0.1067 |
|
5. Pregnant females (last 3 months of pregnancy) |
0.0615 |
0.1142 |
|
6. Lactating cows |
0.0661 |
0.1228 |
a Intake coefficients in columns 1 and 2 refer to equations (3.1) and (3.2) respectively. See Section 3.2 for estimation procedure and qualifications of different animal classes.
Table A.2. Milk yield potential by cow age groups a.
|
Cow age (years) |
Fraction of maximum milk yield |
|
2 |
0.70 |
|
3 |
0.85 |
|
4 |
0.93 |
|
5 |
1.00 |
|
6 |
1.00 |
|
7 |
1.00 |
|
8 |
1.00 |
|
9 |
0.98 |
|
10 |
0.93 |
|
11 |
0.83 |
|
12+ |
0.70 |
a Assumes the age effect on lactation yield is the same for both breeds.
Table A.3. Fraction of total lactation yield produced each month by month of lactation.
|
Month of lactation
|
Fraction of total lactation yield produced each month |
|
|
Tswana |
Simmental × Tswana |
|
|
1 |
0.165 |
0.140 |
|
2 |
0.165 |
0.140 |
|
3 |
0.148 |
0.129 |
|
4 |
0.130 |
0.118 |
|
5 |
0.113 |
0.107 |
|
6 |
0.096 |
0.096 |
|
7 |
0.078 |
0.084 |
|
8 |
0.061 |
0.073 |
|
9 |
0.044 |
0.062 |
|
10 |
- a |
0.051 |
|
Total |
1.000 |
1.000 |
a The lactation length of Tswana cows is assumed to be 1 month less than in Simmental × Tswanas.
Table A.4. Expected annual calving rates by age and corresponding monthly probabilities of conceptions a.
|
Cow age (years)
|
Tswana |
Simmental x Tswana |
||
|
Expected annual calving rate(%) |
Expected monthly probability of conception (%) |
Expected annual calving rate (%) |
Expected monthly probability of conception (%) |
|
|
2 |
80.0 |
41.5 |
88.0 |
50.7 |
|
3 |
80.0 |
41.5 |
88.0 |
50.7 |
|
4 |
89.0 |
52.1 |
94.7 |
62.5 |
|
5 |
92.0 |
56.9 |
97.0 |
68.9 |
|
6 |
92.0 |
56.9 |
97.0 |
68.9 |
|
7 |
92.0 |
56.9 |
97.0 |
68.9 |
|
8 |
92.0 |
56.9 |
97.0 |
68.9 |
|
9 |
91.2 |
55.4 |
96.4 |
67.0 |
|
10 |
89.0 |
52.1 |
94.7 |
62.5 |
|
11 |
85.2 |
47.1 |
91.9 |
56.9 |
|
12+ |
80.0 |
41.5 |
88.0 |
50.7 |
a Calving rates and conception rates are assumed equal. Expected values are for animals of normal liveweight. The expected monthly probabilities of conception have been computed assuming a 3-month breeding season.
Table A.5. Numbers and liveweights of cows in herds used to initialize each simulation.
|
Cow age (years)
|
No. of females in age groups
|
Liveweight/head of individuals in age group (kg) |
|
|
Tswana |
Simmental × Tswana |
||
|
<1 |
12 |
200 |
210 |
|
1 |
8 |
320 |
330 |
|
2 |
8 |
415 |
425 |
|
3 |
7 |
470 |
485 |
|
4 |
5 |
470 |
485 |
|
5 |
5 |
470 |
485 |
|
6 |
4 |
470 |
485 |
|
7 |
4 |
470 |
485 |
|
8 |
4 |
470 |
485 |
|
9 |
3 |
470 |
485 |
|
Total |
60 |
|
|
Table A.6. Random sequences of year types used in all simulation runs a.
|
Year in simulated time
|
Replication number |
|||||||||
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
|
|
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
1 |
|
2 |
3 |
2 |
4 |
5 |
3 |
1 |
2 |
4 |
3 |
3 |
|
3 |
3 |
3 |
4 |
2 |
4 |
4 |
3 |
3 |
3 |
3 |
|
4 |
2 |
2 |
2 |
3 |
2 |
5 |
5 |
2 |
2 |
3 |
|
5 |
2 |
4 |
4 |
3 |
2 |
3 |
2 |
3 |
1 |
4 |
|
6 |
1 |
3 |
3 |
3 |
3 |
3 |
3 |
4 |
2 |
2 |
|
7 |
4 |
3 |
2 |
2 |
2 |
4 |
3 |
2 |
3 |
1 |
|
8 |
2 |
3 |
1 |
3 |
3 |
4 |
2 |
3 |
2 |
2 |
|
9 |
3 |
4 |
3 |
5 |
3 |
4 |
1 |
3 |
2 |
4 |
|
10 |
2 |
1 |
3 |
2 |
4 |
3 |
5 |
3 |
4 |
3 |
|
11 |
1 |
4 |
2 |
4 |
2 |
2 |
2 |
1 |
2 |
2 |
|
12 |
1 |
2 |
3 |
3 |
2 |
4 |
3 |
5 |
2 |
2 |
|
13 |
1 |
4 |
3 |
4 |
3 |
2 |
1 |
2 |
2 |
1 |
|
14 |
2 |
4 |
3 |
1 |
2 |
4 |
1 |
3 |
3 |
4 |
|
15 |
2 |
3 |
2 |
3 |
3 |
4 |
3 |
3 |
3 |
2 |
|
|
Year type |
|||||||||
|
1 |
|
2 |
|
3 |
|
4 |
|
5 |
|
|
|
Overall frequency of occurence (%) |
16.7 |
|
28.7 |
|
33.3 |
|
17.3 |
|
4.0 |
|
a Year type codes are as follows (see Table 1): 1 = good; 2 = above average; 3 = average; 4 = below average; 5 = poor.
Table A.7. Simulated average total herd size and breeding herd sizes over the 15-year period for various supplementation levels and milk offtake rates.
|
Milk offtake rate (%)
|
Genotype
|
Supplementation level (kg/head/d) |
|||||
|
0.0 |
0.5 |
1.5 |
2.5 |
5.0 |
7.5 |
||
|
Average total herd size |
|||||||
|
0
|
T |
122.1 |
125.5 |
126.6 |
127.6 |
126.0 |
124.8 |
|
ST |
120.4 |
126.6 |
130.9 |
131.6 |
131.5 |
130.5 |
|
|
20
|
T |
118.8 |
124.1 |
126.6 |
127.0 |
124.5 |
123.9 |
|
ST |
122.2 |
119.8 |
127.8 |
130.4 |
131.6 |
131.5 |
|
|
40
|
T |
114.5 |
120.3 |
124.1 |
124.7 |
123.7 |
122.7 |
|
ST |
118.1 |
118.0 |
125.1 |
128.8 |
131.5 |
130.7 |
|
|
60
|
T |
100.4 |
106.3 |
108.6 |
111.3 |
112.2 |
111.7 |
|
ST |
107.3 |
114.4 |
119.8 |
125.7 |
127.6 |
128.4 |
|
|
|
|
Average breeding herd size (number of cows) |
|||||
|
0
|
T |
39.45 |
40.17 |
40.22 |
40.27 |
40.07 |
40.01 |
|
ST |
37.60 |
39.28 |
40.15 |
40.26 |
40.26 |
40.07 |
|
|
20
|
T |
38.40 |
39.92 |
40.34 |
40.21 |
39.57 |
39.96 |
|
ST |
38.68 |
37.51 |
39.90 |
40.23 |
40.17 |
40.29 |
|
|
40
|
T |
37.60 |
39.43 |
39.97 |
40.18 |
39.78 |
40.02 |
|
ST |
37.71 |
37.06 |
38.75 |
40.05 |
40.21 |
40.11 |
|
|
60
|
T |
37.19 |
38.41 |
38.63 |
39.46 |
39.61 |
39.47 |
|
ST |
35.48 |
37.50 |
38.17 |
39.93 |
39.97 |
40.10 |
|
Table A.8. Simulated average monthly supplement utilization for Simmental × Tswana cows fed 5 kg/head/d of supplements and milked at 40% offtake rate.
|
Month |
Monthly supplement utilization by head (kg) |
Monthly supplement utilization (% of annual use) |
|
January |
1898 |
5.3 |
|
February |
5667 |
15.7 |
|
March |
5645 |
15.7 |
|
April |
5638 |
15.6 |
|
May |
5619 |
15.6 |
|
June |
1906 |
5.3 |
|
July |
531 |
1.5 |
|
August |
- |
- |
|
September |
- |
- |
|
October |
3764 |
10.4 |
|
November |
5147 |
14.3 |
|
December |
226 |
0.6 |
|
Total |
36041a |
100.0 |
a Total usage as per corresponding element of Table 10.
THE CONSULTATIVE GROUP ON INTERNATIONAL AGRICULTURAL RESEARCH
The International Livestock Centre for Africa (ILCA) is one of the 13 international agricultural research centres funded by the Consultative Group on International Agricultural Research (CGIAR). The 13 centres, located mostly within the tropics, have been set up by the CGIAR over the last decade to provide long-term support for agricultural development in the Third World. Their names, locations and research responsibilities are as follows:
The consultative group on international agricultural research
Centro Internacional de Agricultura Tropical (CIAT), Colombia: cassava, field beans, rice and tropical pastures.
Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT), Mexico: maize and wheat.
Centro Internacional de la Papa (CIP), Peru: potato.
International Centre for Agricultural Research in the Dry Areas (ICARDA), Lebanon: farming systems, cereals, food legumes (broad bean, lentil, chickpea), and forage crops.
International Board for Plant Genetic Resources (IBPGR), Italy.
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), India: chickpea, pigeon pea, pearl millet, sorghum, groundnut, and farming systems.
International Livestock Centre for Africa (ILCA), Ethiopia: African livestock production.
International Rice Research Institute (IRRI), the Philippines: rice.
International Institute of Tropical Agriculture (IITA), Nigeria: farming systems, maize, rice, roots and tubers (sweet potatoes, cassava, yams), and food legumes (cowpea, lima bean, soybean).
International Laboratory for Research on Animal Disease (ILRAD), Kenya: trypanosomiasis and theileriosis of cattle.
West Africa Rice Development Association (WARDA), Liberia: rice.
International Service for National Agricultural Research (ISNAR), the Netherlands.
International Food Policy Research Institute (IFPRI), USA: analysis of world food problems.
ILCA RESEARCH PUBLICATIONS
Research Reports
1. Trends and prospects for livestock and crop production in tropical Africa, by C. de Montgolfier-Kouévi and A. Vlavonou. 1983.
2. Cattle herd dynamics: An integer and stochastic model for evaluating production alternatives, by Panos A. Konandreas and Frank M. Anderson. 1982.
3. Evaluation of the productivities of Djallonke sheep and N'Dama cattle at the Centre de Recherches Zootechniques, Kolda, Senegal, by A. Fall, M. Diop, J. Sandford, Y.J. Wissocq, J. Durkin and J.C.M. Trail. 1982.
4. Research on farm and livestock productivity in the central Ethiopian highlands: Initial results, by G. Gryseels and F.M. Anderson. 1983.
5. Systems research in the arid zones of Mali: Initial results, eds P.N. de Leeuw, R.T. Wilson and C. de Haan. 1983.
6. The water resource in tropical Africa and its exploitation, by G.A. Classen, K.A. Edwards and E.H.J. Schroten. 1983.
7. Livestock water needs in pastoral Africa in relation to climate and forage, by J.M. King. 1983.
8. Organisation and management of water supplies in pastoral Africa, by S.G. Sandford. 1983.
9. Economics and planning of water supplies in pastoral Africa, by D.G. Browne. 1983.
International Livestock Centre for Africa
P.O. Box 5689
Addis Ababa, Ethiopia
Printed by ILCA, Addis Ababa, Ethiopia
