PART THREE: ANIMAL PRODUCTION

CHAPTER 9 - Fodder Production

All parts of the green tamarugo crown bear fruit equally. The fruit begins to fall in late February, continuing up to mid-April. Part of the leaves fall in July and August. An estimated 50% in weight of the fodder produced is fruit and the remaining 50 leaf litter. There is an estimated yield of 1 kg of dry matter per m² of crown projection (Lanino, 1966).

Table 13 compares the composition of tamarugo fruit and leaves in fodder value. Nutritive value is judged good despite the relatively high raw fibre content of the fruit.

Tamarugo fruit is a good feed for sheep and cattle. It contains 5% crude digestible protein and nearly 55% total digestible nutrients. The carbohydrates and proportion of fibres are adequate for ruminants, and the amount of fat is less. These findings have been confirmed with regard to sheep maintained in tamarugo forests. A forest without fruit, or with very erratic fruit production, can only maintain breeder ewes during the early stages of gestation. At the later stages, when nutritional demand is higher -- such as the last third of the pregnancy and the period of lactation -- fruit becomes the basic item in the animal's diet. A comparison between digestible nutrients in tamarugo and in alfalfa hay is given in Table 14. The composition of tamarugo fruit, seed and leaf litter is shown in Table 15 (Lamagdelaine, 1972).

Nutritive value of the tamarugo

Tamarugo produces large quantities of fruit, leaves and other products which appear to constitute an adequate diet for sheep, and possibly cattle. The estimated leaf and fruit yield is 1 kg/m² of crown projection of adult trees. This means one hectare of tamarugo could feed approximately 3.5 sheep (Latrille and García, 1968). Other estimates increase this figure to ten sheep per hectare (Instituto Forestal, 1964).

In an experiment with Early Maturing French Merino capons, Lanino (1966) found a TDN value of 23.5% (25.9% dry matter base) in a test of digestibility of dry tamarugo leaves. The digestibility of the fruit was obtained by comparison with a 60/40 leaf and fruit mixture giving a TDN value of 59.8% (61.7% dry matter base). However, this work fails to indicate either consumption levels or weights of animals. In a controlled feeding trial, the same author achieved consumption levels for sheep of 2 kg/day, with a 40/60 mixture of fruit and leaves. Average lamb weight at weaning under these conditions was only 56% that of other lambs of the same breed feeding ad libitum with their mothers in a tamarugo forest. He interpreted this as a probable indication that sheep in the tamarugo forest chose to feed on a different mix than that offered in the trial, and probably ate larger amounts.

TABLE 13: Nutritive values of samples of tamarugo and dry leaves (Lanino, 1966)

TABLE 14: Digestible nutrients of tamarugo fruit and alfalfa hay (Lamagdelaine, 1972)

TABLE 15: Average composition of various tamarugo components for cattle feed (Lamagdelaine, 1972)

* Unpublished data, analyses by González and Haardt. University of Chile, School of Veterinary Medicine, 1966.

** Lanino, 1966.

One striking characteristic of the analysis (Table 15) is the high ash content in most parts of the tamarugo, especially the dry and green leaves. Relatively small differences are also observed between whole fruit and fruit without seeds.

Latrille et al. (1971) ran two tests on digestibility and nitrogen balance, using for each test four adult Early Maturing French Merinos in metabolic confinement (Table 16). In the first trial, an acclimatization period of nine days was followed by a ten-day period of collecting feces. After the seventh day of acclimatization, common salt (NaCl) was offered to all the animals -- their only other food was tamarugo fruit and water. Constant quantities of fruit were offered during the entire feces and urine collection period, adjusted for minimum rejection. Daily individual consumption and moisture content of consumed and rejected fruit were checked.

The total output of feces and urine was collected every day during the observation period. The feces were semi-dried in a 60° C oven. The urine was collected every day, avoiding contamination by feces. ¹⁰

Table 17 shows the approximate balance of energy for which theoretical maintenance requirements were calculated. It shows that the animals maintained their live weight with the exception of animal 4 in the second trial, which lost weight at a constant rate. This is reflected in the balance between consumption and IDN requirements, which was also negative in this animal. Despite this, all the animals showed a positive balance. Likewise, the calculation of maintenance requirements produced similar trends (Latrille et al., 1971).

Table 18 compares the findings on fruit composition obtained by Lanino (1966) and González and Haardt (1966) with those of the two earlier trials.

As to total value of digestible nutrients, though that of the tamarugo fruit is rather low, this should not be taken as indicative of low nutritive value, since these values are roughly comparable with a good quality hay, such as alfalfa. Of course, there is no comparison with the nutritive value of concentrated feeds. The trials in this study did not attempt to determine maximum consumption per se, but a rather high figure was nonetheless achieved in the test of digestibility. An average consumption of 1 515 gr of dry matter for capons weighing 48.5 kg was obtained in the second trial, and an even higher figure in the first, when expressed on the basis of initial weight. So obviously voluntary consumption of the dry matter in tamarugo fruit is high, probably comparable with that of a good-quality hay (Table 19).

TABLE 16: Values for protein, crude fibre, digestible non-nitrogen extract, ether extract and total digestible nutrients based on dry matter, observed in four animals (Latrille et al., 1971)

TABLE 17: Energy balance and calculation of theoretical maintenance requirements for four sheep, expressed in corresponding units for two tests of assessment of nutritive value of tamarugo (Latrille et al., 1971)

TABLE 18: Average values of tamarugo fruit composition from two trials by Laterille et al. (1971), Lanino (1966) and González and Haardt (1966)

 * Average of 4 analyses.
** Average of 7 analyses.

TABLE 19: Estimated values for digestible dry matter, consumption dry-matter trials 1 and 2, feces output and digestibility (in %) (Latrille et al., 1971)

Other important experimental work carried out by Latrille et al. (1971) covered estimated values of digestible dry matter, feces output and digestibility (Table 19), and the nitrogen balance for both groups of animals under study (Table 20).

TABLE 20: Values of nitrogen balance corresponding to four animals, for nitrogen consumption, fecal nitrogen, nitrogen in urine (Latrille et al., 1971)

To sum up, it seems clear that: 1) tamarugo fruit, in season and not attacked by insects and other organisms, has a low concentration of nutrients compared to concentrated feed but is comparable to a good quality hay; 2) tamarugo fruit consumption seems to be high when consumed freely and compares favourably with that of other high-quality fodders; 3) the combination of both these features indicates good nutritive value for sound tamarugo fruit (Latrille and Garcia, 1968).

In conclusion, with better sheep management in these areas, superior quality wool can be obtained using these new fodder resources as the nutritional base. Moreover, considering the fibre diameter values (R) for the different seasons as a central parameter, it is found that the greatest variations in diameter are between the spring and summer wool in groups bred in March–April, and between the autumn and winter wool of sheep bred in May–June, according to Oyarzún (1967).

Angora goats

Karakul sheep

The best breeding season for sheep, based on phenotypic characteristics, was observed, as well as environmental influence on wool production (particularly diet (Oyarzún, 1967). An experiment with two breeds of sheep maintained permanently in a new tamarugo forest and bred in March–April and in May-June, led to the conclusion that the former period is best from the standpoint of wool yields. Moreover, Australian Merino was found to breed best when adapted to the conditions under which the study was conducted in terms of average fleece weight, washed yield, length of fibre, and greater uniformity of fibre diameter (Table 21).

Salt supplements

Feeding trial, Canchones, Tamarugal Pampa, April 1964

TABLE 21: Average fleece weight, washed weight, fibre length and fibre diameter observed in Australian Merino and Early Maturing French Merino, bred at two different seasons. Salar de Pintados (Oyarzún, 1967)

A comparison of these findings with Lanino (1966) on animals in confined spaces with a controlled diet, clearly shows the benefits of managing sheep in open forests with direct access to the resource. The sheep have a good quality standing fodder up to July. From this time on, the only real fodder available is the leaf letter, which Lanino (1966) found to have a very low nutritive value, much lower than that of fruit (Oyarzún, 1967).

CHAPTER 10 - Species and Breeds Tested

The following were tested:

1. Sheep: particularly Corriedale, Early Maturing French Merino, Australian Merino, Romney Marsh, Suffolk Down and Karakul.

2. Goats: Angora.

3. Cattle: Herefords and crossbreeds.

The following is a summary of the results (Cadahia, 1970).

Corriedale. A dual-purpose breed showing great adaptability, hardiness and resistance to critical food situations. Under sub-standard food conditions, lambing rates are as high as 68.3%, reaching 80% under better conditions. Weaned lambs, male and female, weigh 24.6 kg and 22.2 kg respectively. Wool yields are 4 kg for sheep and 1.5 kg for lambs.

Early Maturing French Merino. This was the first breed introduced into man-made tamarugo forests. It adapted well at first. However, its restlessness, which reaches crisis proportions during lambing, causes problems for newborn lamb management and losses due to abortion and accidents. Lambing rates in tamarugo forests range from 30 to 95%. Average lamb weight at weaning is 18.4 for males and 17.6 kg for females.

Australian Merino. This breed shows great adaptability to the environmental conditions prevailing in man-made tamarugo forests, especially during critical periods. Lambing rates average only 55%. Lamb birthweight is 17.8 kg for males and 16.6 kg for females.

Romeny Marsh. This breed has proved the least adaptable to the tamarugo ecosystem, with a lambing rate no higher than 25%.

Suffolk Down. This is one of the most promising breeds for its wide range of adaptation and for its meat-producing qualities. Lamb weights at weaning are 24.1 kg for males and 23.9 kg for females. Wool yield is 2.5 kg for sheel and 1.0 kg for lambs.

Karakul. Very good adaptability and hardiness, no reproduction problems. Lambing rate 70–90% and lamb weight at weaning 22 kg.

Angora Goat. Exceptional adaptability, high fertility (reproductive rates of 90–115% in the Refresco tamarugo forests), very hardy, but difficult to manage.

Cattle. Hereford beef cattle are now being tested for adaptation, as are crosses of Hereford with Santa Gertrudis, Galloway and other beef breeds. The results seem promising, despite loss of appetite, which would seem to point to significant mineral deficiencies.

Utilization of tamarugo forests in the Refresco property. Hereford crossbreed cattle.

Agronomist Francisco Araya with an Early Maturing, French Merino, Canchones, Tamarugal Pampa, April, 1964.

CHAPTER 11 - Stockfeeding

Lanino (1966) studied the adaptability of Early Maturing French Merino, Australian Merino and Corriedale, under conditions prevailing in the Tamarugal Pampa. The animals were put on a controlled diet, with a daily ration of 2 kg, of which 40% was tamarugo fruit and 60% leaf litter. From the 1965 observations made by Canchones, he concluded that the fruit and leaf litter which had lain on the ground for more than one year were low in nutritive value. Digestible protein made up 6.07% of the fruit, which contained a total of 59.58% digestible nutrients. For leaf litter, the figures were 1.27% protein and 23.45% digestible nutrients.

Sheep feeding in the forest produced better results as the animals had greater amounts of fruit and litter from which to choose, and could graze at will, as compared with animals subjected to a controlled diet of 2 kg/day. Lambing rates were calculated at birth as 60% for Early Maturing French Merino; they were 95% for Corriedale and 61% for Australian Merino. At weaning, the figures were 48% and 46% respectively for the breeds compared. Table 22 gives the overall results of research done on Early Maturing French Merino with three systems of feeding.

Trials by CORFO (1970) in the Tamarugal Pampa on the effect of alfalfa supplements showed that total sheep weight at weaning was greater than that of the control sheep, but that both had increased by weight per sheep at rates of 4.53% and 3.63% respectively. There were no appreciable differences in wool yields between the two treatments (Table 23).

TABLE 22: Comparison of results from Early Maturing French Merino sheep in the Tamarugal Pampa fed with leaves and fruit, alfalfa hay, and grazing freely in tamarugo forest (Lanino, 1966)

TABLE 23: Comparison of results with an alfalfa supplement trial and results from control in the Refresco property (CORFO, 1970)

Vitamin requirements

In the 1967–68 season, an experiment was made to determine effects of supplementary vitamin A treatment on two groups of sheep receiving 600 000 IU and 1 200 000 IU, and on a third, control group. The results show that animals fed exclusively with tamarugo leaf hay and fruit responded favourably to vitamin A treatment: lamb mortality was lower (Cadahia, 1970).

A study was planned in 1966–1969 to observe the interaction between such environmental factors as low relative air humidity, high daytime temperature, fodder with low moisture content, soil with abrupt micro-relief and presence of salt, and the distances that animals had to cover to reach water, in terms of flock behaviour. The animals were grouped according to the distance from their source of water (far and close). They received vitamin A supplements, as did the control group far from water. The dose of vitamin A was favourable to those animals fed exclusively on tamarugo fruit and leaves.

There was, however, no appreciable effect on lamb birth rates, but at the same time, a drop in lamb mortality rates was observed. Lamb-meat production for the group receiving vitamin A supplement was 3.2 times greater than for the control group for sheep close to their drinking water, and 1.8 times greater for the group far from their drinking water. Distance from drinking water had no effect on lamb mortality (Cadahia, 1970).

Mineral supplements

It was found that sheep fed exclusively on tamarugo fruit and leaf hay responded favourably to mineral supplements, and there was a corresponding drop in lamb mortality rates. As for the individual minerals, cobalt was probably the most important one, though the synergetic action of the mixture should not be overlooked. There was usually an increase in overall weight at weaning (Cadahia, 1970).

These findings appear to indicate, in summary:

1. A dosage of 1 000 000 IU of vitamin A per animal per year is needed. This reduces the mortality rate.

2. Mineral supplementation shows its effects in weight gain -- the most important minerals seem to be cobalt, iron and magnesium

3. Food supplements for cattle are important during the first stages of development. At the present time, mixtures of leaf litter, tamarugo fruit and alfalfa hay as a feed for calves (for three months) are being tested.

Sanitary control

The sheep are dipped before the July shearing, before diseases appear. The worst disease is anthrax, and this is prevented through vaccination. No internal parasites were found in the animals' feces over a period of several years.

Local goat herd in natural tamarugo forest, La Tirana, Tamarugal Pampa

CHAPTER 12 - Carrying Capacity

The information obtained in seven years' observation of sheep and goat behaviour in the Tamarugal Pampa forests indicates that all breeds, except Romney Marsh (Cadahia, 1970) adapt well. Given the climatic imperatives, this adaptation consists mainly of adjusting to the types and characteristics of fodder resources -- browsing on green leaves and grazing on the standing fodder, which in this case are tamarugo fruit and leaves. Forest use, by age, is summarized in Table 24.

TABLE 24: Estimated carrying capacity (sheep/ha) by age of tamarugo forest (Cadahia, 1970)

The stock should be distributed by age and general state of health, vigour, etc., in 25-hectare enclosed pastures, each containing approximately 5 000 trees. One sector is divided into two parts for better management of lambing ewes. Table 25 describes an experimental system of management with a flock of 1 000 sheep, based on the following:

1. Maintaining the flock in sectors where it can browse on green leaves and leaf hay.

2. Reserving the choice sectors for ewes in the latter third of pregnancy, lambing and lactation.

3. Concentrating lambing in one sector for the best utilization of the fruit, and more orderly management of the programme.

4. Reserving the poorer, low-yield sectors for cull animals and non-lactating ewes.

Oyarzún (1967) suggests a management scheme which he used as an experiment in a tamarugo forest (Table 26).

TABLE 25: Summary of rotational management of livestock unit on 100 hectares, or 5 500 trees

TABLE 26

GRAPH OF TAMARUGO GROWING CYCLE, SHEEP MANAGEMENT AND FEEDING DURING THE YEAR OF THE EXPERIMENT (1965–66) ***

	Treatment I: breeding March–April			Fall of fruits
	Treatment II: breeding May–June			Partial fall of leaves
	Browsing - fruits - dry leaves			Blooming
	Browsing - dry leaves	***	Author's original
		**	Lanino, pers. comm.
		*	Instituto Forestal

CHAPTER 13 - Production Potential

This is an area of conflict for strategists and planners. Rolando (1974) concludes in his study that 200 000 ha can be afforested as a first stage in areas where information about groundwater resources is available, considering 15% of the area to be occupied by roads, infrastructures, fences, and so forth. He estimates the potential carrying capacity for such an area at 2 800 000 head of sheep on an area somewhat smaller than the Province of Magallanes. Wool production could be as much as 7 400 tons. He believes that a project of this nature could be profitable, even at higher rates of interest. Secondary benefits would be the absorption of unemployment and curtailment of migration.

The Tamarugal Pampa covers an area of roughly 1 100 000 ha, of which a little over 1 200 000 ha are salt flats, rich in underground water, where tamarugo, the most important species, can develop and grow (Cadahia, 1970). The author estimates that there are some 100 000 ha distributed in the following salt flats:

As some sectors have active salt deposits and very high groundwater levels, the potential area is reduced to 800 000 ha (Cadahia, 1970). Cattle can be raised on salt flats where groundwater lies at 10–15 m and where reforestation requires an establishment period of more than one year; this represents another 25 000 ha. According to the author, a further 80 000 ha could be planted in a four-year period, in addition to the 13 100 ha reforested during 1967–1969.

Vidal (1978) reports that CORFO planted 10 875 ha on the Salar de Pintados between 1966 and 1972, in irregularly distributed plots of 100 ha. This makes it impossible to use them today, as they are surrounded by other plantations of widely varying ages and would require vast inputs for extracting water, construction of drinking troughs, fences, etc. -- an unjustified expense where small areas are concerned.

Vidal estimates the carrying capacity of a tamarugo forest from the eighth year onward at 0.5 head/ha to start with, working up to 4 head/ha when the forest is 18 years old. He agrees that the breed most suitable for these conditions is Karakul for its hardiness, feeding habits and adaptation to a high-luminosity environment. He points out that one direct benefit of large-scale sheep raising is the potential for exporting hides to Europe, and the industrial processing of some of the side products.

¹⁰ Each animal's urine production was diluted in 5 cc of H₂SO₄ and topped up to 2 000 cc with distilled water. This mixture was kept refrigerated for later analysis, and 200 cc taken from it daily. The same procedure was followed in the second trial, except that the acclimatization period was brought up to 15 days. A ten-day collection period was retained. Slightly heavier sheep were used for this trial.