When discussing milk and lactation in general, two aspects must be taken into account. The first is the amount of milk produced per day and per lactation period. The other aspect, which is as important, is the type of milk produced. Animals living in cold areas or in the sea need a different quality of milk from those living in hot areas; this applies also to fast-growing animals as compared with slow-growing animals (Yagil & Etzion, 1980).
This section will deal with the lactation, milking and amount of milk produced.
The mainstay of the desert nomad’s food is camels’ milk, which is consumed fresh or when just soured (Mares, 1954, Gast et al.1969). Data on the actual amount of milk produced by camels are not very accurate for judging the milk-giving capabilities of camels.
Calves must be allowed to drink; therefore, the herder and his family must share with the calf the milk produced by the herd. How much the calf drinks certainly varies with its size, age, and health. The amount of grazing and water available to the camel will also determine the amount suckled, and the total produced.
The camel, like the cow, has a four-quartered udder. It is firmly suspended from the abdomen, without deep cuts (Sharma, 1963) (Photo 4). There are four teats, each having two orifices.
The two-humped Bactrian camel is used mostly as a working animal (Dong Wei, 1979). The lactation period is 14–16 months, and the amount of daily milk production averages 5 kg per animal; although some animals can give as much as 15–20 kg per day. Normally, only about 2 kg are milked; the rest is suckled by the calf.
Milking capabilities of the Bactrian, the dromedary, and the hybrid of these two types of camels were examined (Kheraskov, 1955, 1961, 1965; Lakosa & Shokin, 1964; Dzhumagulov, 1976). The dromedary gave more milk than the Bactrian or the hybrids (Table 2). The hybrid – Kazakh – gave more milk than the hybrid Turmein. The lactation period was 18 months. Most of the milk was produced in the first seven months of lactation, from spring, throughout summer, until Autumn. This was correlated with the availability of fodder. Grazing in Winter is difficult, because of snow. The second lactation yield was far greater than the first, and in each following lactation more milk is produced. The estimated milk yield between the third and sixth months of lactation was 879– 1 572 kg (Kulaeva, 1979). Slightly more milk was received from the back-quarter, 56.4 percent to 43.6 percent from the forward-quarters. From the sixth month of pregnancy the amount of milk declined.
With good stall feeding the same amounts of milk were received as with grazing animals. This would be of great importance if a steady and balanced diet could be supplied to the animals throughout the year.
When the animals are hand-milked the milker stands on one leg and balances the milking bowl on his bent left leg. The left hand holds the bowl, while the camel is milked with the right hand. Another method is to tie the bowl around the milker’s neck so it hangs low enough to be held while the camel is being milked. Camels have successfully been machine milked. Liners of 18.56 mm diameter and 56 mm length are recommended for the Bactrian and liners of 20.6 mm diameter and 90 mm length are recommended for the dromedary (Baimukanov. 1974). The animals were gradually changed from hand to machine milking in the presence of their calves. The cell-count of milk of hand-milked camels was lower than that of machine-milked camels (Kospakov, 1976).
In the vast dry areas between the Caspian Sea and the Balkash Lake the camel is, and can be, of great nutritional importance. In Kazakstan, milk and milk products account for up to 90 percent of the daily staple diet. The camel is the most important provider of milk. Thirty-seven percent of all milk comes from the camel; 30 percent from sheep; 23 percent from the Yak and only 10 percent from cows.
New World Camels
Little is known about the milk production of these members of the camel family. The alpaca, when kept on good pasture, can produce up to 0.5 kg of milk daily (Novoa, 1970).
Horn of Africa
In the Horn of Africa, milking of camels is not only an act of work, but has become an integral part of the local culture and heritage. Only boys, unmarried women or ritually clean men are allowed to milk the animals (Hartley, 1979). No treatment of the milk is allowed. The milk is either consumed fresh or when just soured. In some tribes the herdboys subsist on camel milk alone. They drink water only after the camels are watered. Two teats are left for the calf, while the other two are milked-out for the tent dwellers. These latter two teats are tied up with soft bark fibres. The colostrum is not drunk, but is either given to the calf although it is thought to be bad for the young camel (Field, 1979), or spilled onto the ground. This certainly represents a bad practice since the colostrum contains large amounts of absorbable antibodies.
The camels are milked twice a day; before dawn and at night. The average milk production is about 1 800 kg, i.e.: 9 kg per day.
Weaning is carried out when the calves are 9–11 months old. A leather band with protruding thorns is placed on the calf’s head in such a way that the dam is pricked every time the calf attempts to suckle; the dan thus quickly moves away.
In North Kenya the camels produce far more milk than the local cows. The Sakuye camel produces an average of 4 kg milk daily with a maximum of 12 kg. The cow produces 0.5–1.5 kg per day. Camels lactate for about a year. In areas with only one rainy season lactation finishes at the end of the dry season; this is thought to be caused by the shortage of feed during this period.
In areas of northern Kenya, where the nomads subsist almost entirely on camel milk, there are two rainy period. Field (1979a and 1979b) reported lactation studies lasting three lactations. The duration of lactation was 47–67 weeks. Lactation ended 4–8 weeks following conception. Daily milk production reached 21 kg in the first week, declining to 4.8 kg in the 16th week of lactation. There was an average daily milk yield of 13 kg for the first 10 weeks (1.8–50.2 kg) and 3 kg for the remainder of the lactation. Total production averaged 1 897 kg per animal. In the lactation studies the lowest milk yields were those given by camels without calves. These animals also had much shorter lactation periods, even though they were milked 5–7 times a day. Four milkings per day yielded more milk than twice a day milkings: seven liters compared with six (Evans and Powys, 1979; Shalash, 1979).
The camel is known to be capable of producing large quantities of milk under extensive and intensive management (Knoess, 1979). Knoess rightly stresses the fact that as the camels are not intensively milked, but some milk is left for their calves, the exact amount is difficult to assess. Milk trials in the Awash Valley of Ethiopia were carried out for six days in various stages of lactation (Knoess, 1976). As suckling stimulus is an integral part of milk production (Yagil et al., 1975), it is obvious that in the short period of hand-milking the maximum milk producing capabilities were not fully exploited. Even so, eight liters in two milkings, or 2 470 kg over 305 days were obtained. The daily average for twice-a-day milking was estimated at 7 kg. These animals grazed on irrigated pastures. Under rainfed conditions, 13 kg per day can be milked (Knoess, 1979). It was found that some days the camels were milked 6–8 times a day, while other days they were not milked at all. This certainly would make the milk supply lower than if the animals were milked regularly each day. In the dry season the milk yield was about half that of the rainy season. This could be due to the lack of feed or to advanced stages of pregnancy (Lakosa, 1964).
The lactation period is between 8–18 months (Mares, 1954a). The length of lactation depends on when the lactating dam is remated. The average daily yield in milk is 5 kg with a total yield of 1 950 kg. The amount of milk drunk by the calf is regulated by tying up one or more teats (Mares, 1954a). The amount the calf is allowed is determined by its needs and the milking capacity of the mother. Camels are milked twice a day; just after sunrise and at least two hours after sunset. Calves run with their mothers but are penned separately at night. From the age of six weeks they graze. When calves have finished suckling the amount left for consumption by the tent dwellers can vary from 1 to 4 kg (Epstein, 1970).
If a calf dies, the dam dries up if milking is not stimulated (Mares, 1954a). For this a foster calf or conditioning of the mother is necessary. Often arranging for the dam to see the skin of her dead calf is enough to stimulate let-down of milk. Fostering is done in three ways: (1) The foster calf is covered with the skin of the dead calf and allowed to suckle until the milk is flowing and the dam can be hand-milked. (2) The calf is tied down in front of the foster-mother, a rope being tied from the calf to the mother’s muzzle. (3) The nostrils, ears or anus of the foster-mother are compressed with a special clamp. When the clamp is released, and the pain thus removed, the calf is presented for suckling. This is usually anough for the dam to allow the foster-calf to suckle.
In all cases the calf drinks from its own mother as well as from the foster-mother.
The nomads of the Ahaggar in the Sahara depend on milk to given them a balanced diet (Gast et al., 1969). They have a saying “water is the soul; milk is life”, and hungry people say “I’ve lost the taste of milk”. Of course the camel is only one of the providers of milk. Goats, sheep and cows supply milk and milk products. The lactating camel produces 4–5 kg/day, on good pasture, for the first three months. A good milker can even provide up to 10 kg a day. When the udders are full the animals are milked three times a day, otherwise their swaying teats hinder their walking. After the third month of lactation the yield averages about 2 kg per day. The bad milkers dry off very quickly. It is therefore accepted that one camel is necessary to provide the requirements of one family. The camel herders’ only source of food is camel milk.
The camels are tied down during the night and the camels’ udders are covered with nets to prevent the young from suckling. The first milking takes place before dawn. The young calves are allowed to suckle for about one or two minutes. This is time for the milk to let-down. The calves are pulled away and the dam then milked for the tent dwellers. At twilight the camels are returned to the camp, and milked again after allowing the calves to suckle for a few minutes.
The geographical distribution of camels (dromedaries) in India, is in the States of Gujorat, Haryana, Maharashtra, Madhya, Pradesh, Punjab, Rajasthan and U.P. (Rao et al., 1970). The females calve for the first time at the age of 4 years. They lactate for 8–18 months. The amount of milk for the calf, and the amount that is milked, is regulated by tying up the teats to prevent the calf from suckling. The camels are milked twice a day. The daily milk production is between 2.5–6 kg, but often 15 kg per day is milked. Lactation yields range from 2 000 kg (Gohl, 1979) to 2 700–3 600 kg (Rao et al., 1970) under good feeding conditions, to about 1 360 kg, when feed supplies are poor (Yasin and Wahid, 1957).
The Arabian camel is found mainly in West Pakistan (Yasin & Wahid, 1957). Length of the lactation varies from 270–540 days; daily milk yields of 15 to 40 litres were recorded (Knoess, 1977). The total milk yield ranges from 1 350–3 600 kg. The lower milk yields were found in the areas where feed supplies are poor and under desert conditions. When the camels were well fed, there was an average milk yield of 10–15 kg per day (Yasin and Wahid, 1957). As much as 22 kg a day were obtained from some camels. In the areas with poor feeding the daily average was 4 kg. The heavy Pakistani camels produced up to 35 kg per day (Knoess, 1979). The desert camels gave more milk than the animals getting poor feed. These animals were milked twice daily.
With good feeding a daily milk production of 10–15 kg was obtained (Shalash, 1979) giving a yield of approximately 3 000–4 000 kg per lactation. Daily yields of 22 kg have been recorded. Where feeding was precarious the daily production was only 4 kg, with a total production of 1 500 kg. These later data are similar to those presented by El-Bahay, 1962.
No actual recordings of milking have been made. Estimates of milk production range from 7 to 15 kg daily. Lactation periods vary from 9–18 months. In order to establish the total amount of milk produced by the lactating camel, the milk yield was measured indirectly (Yagil & Etzion, 1980). This method is based on firts marking the calves’ blood with radioactive water. The calves were not allowed access to any drinking water as this would have made milk determinations impossible. The mothers were allowed drinking water only once a week for an hour, from the beginning of spring until the end of summer. The results show that there was a slight increase in milk yields as lactation progressed (5.7 to 6.2 kg). No decline was found when the animals were dehydrated. These data do not give the full potential of the camel as, in fact, what was measured was the calves’ need for water. The calves ate the same feed as their mothers. They started eating within the first month of birth. Not withstanding this fact, it is quite clear that the feed demand of the calf is fairly large. In addition, research was carried out using the same diet throughout the year to eliminate nutritional factors affecting quantity and quality of milk. The natural grazing available to camels changes from winter to spring and in the summer the changes are even more drastic, in quantity and quality. With a decline in quantity the calves would tend to take more from their mothers than when the feeding is plentiful.
The milk production of camels in general was reviewed. Only in the USSR and in Saudi Arabia were any attempts made to milk camels by machine (Baimukanov, 1974). In the main the same milking methods are still in use as were probably used for the first domesticated camels. Milk is still shared with the calf (Photo 4) and many superstitions and ritual customs accompany the milking of camels. The dromedary gives more milk than the Bactrian. The milk yield of dromedaries does not vary so greatly between the various countries; the maximum daily milk yields are relatively large; and the lenght of lactation varies greatly, not only between countries, but also within a country. It is clear that status of feed and water will determine the amounts of milk for human consumption. Improving the feed is of prime importance in planning for better husbandry. Intensive farming will also allow for better husbandry and for easier implementation of selective breeding for high milk production. These aspects will be discussed in detail in other sections.
A most interesting phenomenon was discovered when research was carried out on intestinal lactase concentrations in various ethnic groups in Saudi Arabia (Cook & Al-Torki, 1975). Adult Arabs were found to have the highest lactase levels. This was supposed to demonstrate a selective advantage associated with the fluid and caloric value of camel milk and indicate the importance of camel milk for the survival of desert nomads.