Tropical America, despite its large ecological diversity, can be divided into two broad zones: the lowlands (<1000m asl) and the highlands (>1000m). The Andean mountain range divides the lowlands bordering the Atlantic Ocean in the east and those bordering the Pacific Ocean in the west. Two major dairy production systems have evolved: dual-purpose cattle enterprises in the lowlands, mainly of large and medium scale, and the smaller scale crop-livestock systems in the highlands. Generally, land is privately owned, feeds are derived mainly from sown pastures, and a large proportion of the milk and dairy products are marketed.
The evolution of the production systems in the lowlands has involved intensification from pure beef to dual-purpose beef-milk and eventually to milk-beef (Berry, 1985; Wadsworth, 1992). Changes were most prominent in the tropical lowlands large-scale enterprises predominate. The gradual shift followed progressive steps (see Box), the outcomes of which are quantified in terms of land use and beef and milk output per ha in Table 1.14.
|
Intensification of cattle production systems in Latin America 1. From beef to milk production · From indigenous stock (Zebu, Criollo) to upgrading with dairy breeds · Reducing calf weaning age · From opportunistic short term milking to exploiting the entire lactation. · From use of milk for household needs and limited cheese production to maximising daily sales of liquid milk · Increased proportion of cows; sales restricted to weaned calves and culled cows · Simultaneous specialization of beef enterprises into outgrowing and fattening 2. Intensification of feeding systems · Shift from natural pasture to sown grasses and grass/legume mixtures, leading to higher stocking rates |
Dual-purpose systems
In the large-scale dual-purpose systems, crossbred (mostly Holstein Friesian (HF) or Brown Swiss x zebu) cows are milked by hand and managed in pasture-based systems. Generally male calves are sold when weaned. Holmann et al. (1990) documented examples of these systems in the humid (rainfall 2900 mm) and dry lowlands (rainfall 1300 mm) of Venezuela:
· Farm size 285-950 ha; cows: 180-380 head· Stocking rates, cows ha-1: humid 0.70; dry 0.50
· Age of first calving: 30 months; calving rate: 0.73
· Milk yield:
> 50% HF, 3500 kg cow yr-1; 2.1 t ha-1
< 50% HF, 2650 kg cow yr-1 1.6 t ha-1· Income from milk about 75% of total
· Kg milk/kg conc. feed: humid 15; dry 5.5.
In terms of intensity of milk production, the ranches in Venezuela resemble the dual-purpose system in the SE of Mexico (Table 1.14), but in Venezuela, calving rates and milk yields were higher, the scale of operation much larger and stocking rates lower. Although the proportion of income from milk sales was similar, the outgrowing of male stock was less common in Mexico. These dual-purpose systems benefit from the ability to shift the emphasis of production between beef and milk, a flexibility reflected in incomes from milk ranging from 25% of 75% of the total (Wadsworth, 1992). Specialised beef production systems can be found side by side with dual purpose systems, as observed in the SE of Mexico where beef systems were in the majority (Anderson et al, 1992).
Table 1.14 Variables of beef, dual-purpose (DP) and dairy systems in Costa Rica and Mexico
|
|
Beef-1 |
DP1 |
DP2 |
Dairy1 |
|
Farm size, ha |
74 |
43 |
28 |
35 |
|
LSU ha-1 |
0.95 |
1.62 |
1.21 |
2.01 |
|
Milk, kg cow-1 yr -1 |
220 |
560 |
1715 |
3490 |
|
Milk, t ha-1 yr-1 |
0.10 |
0.46 |
1.26 |
3.48 |
|
Beef, kg LW ha-1 yr-1 |
70 |
133 |
142 |
124 |
|
Milk income3, % |
32 |
53 |
75 |
95 |
1 Data for Costa Rica (Wadsworth, 1992); LSU = one cow
2 Intensive DP system in Yucatan (Mexico), from Anderson et al., 1992
3 Based on a live weigh/milk price ratio of 3:1.
Intensive milk production
Intensive (or specialized) dairy systems of all scales occur in tropical America; the medium-scale dairy farms presented in Table 1.14 practice high stocking rates and achieve high milk yields per cow and per ha. Large-scale specialized dairy enterprises in the Venezuelan highlands manage pure Holstein cows yielding annually 5800 kg milk, with income from milk sales reaching 93% (de Jong, 1996). Feed comprised 77% of total costs, two third of which for purchased feed. Output of milk per ha was 12.2 t, higher than equivalent systems in Costa Rica (Table 1.14), in part due to the effects of the contrasting highland and lowland environments on the performance of pure Holstein cows (Holmann et al., 1990).
In Costa Rica, intensive small-scale dairy farms in the lowland zone with high rainfall rely on planted pastures (Brachiaria, Cynodon) and high stocking rates (Table 1.15). Holmann et al (1995) reported that between their establishment in 1979-80 up to 1990, performance declined due to invasion of unpalatable low yielding grasses, exacerbated by low fertiliser inputs (Table 1.15). Combined with low levels of concentrate feeding, this led to a decline in milk yields and net incomes. Attempts to expand farm sizes and diversify back into beef production did not stem the loss of income, illustrating the importance of skilled management for efficient and profitable dairy production, especially in intensive systems.
In common with East Africa and South Asia, small-scale intensive crop-dairy systems have developed in the sub-tropical highlands (1200-2700 m) of Central and South America where rainfall varies between 1600 to 2800 mm and falls 7 to 12 mo of the year. Many of the soils are volcanic and fertile, and coffee is a major cash crop (Quiroz et al., 1997). As human population densities are, as yet, lower than in parts of East Africa, the systems are still largely pasture-based, often in rotation with vegetables and potatoes, while diversification into fruits and flowers for exports has been developing rapidly in recent years. Intensification has led to combining grazing and stall-feeding of planted forage (e.g. Napier and King grass), supplemented with molasses, other sugar crop by-products, green bananas, plantain pseudo-stems and brewer's grains. These locally available by-products are gradually replacing more expensive commercial feeds. Pure Holstein-Friesian cattle predominate, producing an average of 16 kg of milk d-1 (range: 5-27 kg) and fed concentrates at rates of 1 to 10 kg d-1. Liquid milk and cheese are the main marketed products: cheese making has increased particularly in more distant regions of the highlands of Ecuador and Colombia (de Jong, 1996).
Table 1.15 Changes in the performance of smallholder dairy farms at two sites in the lowlands of Costa Rica, 1980 to 1990
|
|
Rio Frio |
Somafluca | ||
|
|
1980 |
1990 |
1980 |
1990 |
|
Farm size, ha |
10.6 |
17.6 |
10.1 |
12.8 |
|
% pasture |
91 |
91 |
99 |
83 |
|
Stocking rate, AU ha-1 |
1.9 |
1.9 |
2.5 |
2.6 |
|
Total herd, AU. |
18.3 |
31.3 |
23.4 |
31.2 |
|
Cows, head |
15.6 |
21.6 |
19.6 |
19.7 |
|
Pasture degradation, % |
10 |
94 |
0 |
46 |
|
Fertilisers N, kg farm-1 yr-1 |
31 |
15 |
390 |
160 |
|
Supplements, kg cow-1 d-1 |
2.0 |
1.6 |
0.8 |
1.6 |
|
Milk, kg cow-1 d-1 |
7.4 |
6.4 |
8.6 |
7.6 |
|
Milk, t ha-1 yr-1 |
3.43 |
2.41 |
4.71 |
4.38 |
|
Net income, $ ha-1 yr-1 |
1044 |
440 |
1472 |
939 |
Source: Holmann et al (1995)
These intensive highland systems, which extend into the Andean eco-region, take advantage of the favourable agro-ecology for milk production (Quiroz et al., 1997). As elsewhere in the tropics, these smallholdings demonstrate the high productivity possible in crop-dairy systems that exploit the important complementarities between crops and livestock consistent with the risk-aversive strategies of resource-poor households world-wide. The pasture-based dual-purpose systems of Latin America are another strategy by which risks are reduced, and these diversified systems contrast with the specialized, generally large-scale, intensive dairy farms found in the region.
