INTRODUCTION
Guangdong Province is in the tropical zone of China with an annual average temperature of 19–26°C. The lowest monthly average temperature is 7–12°C and the warmest monthly temperature is 27–29°C. The amount of sunshine is 1600 to 2600 hours and accumulated temperature is 6000–9500°C. Average rainfall is 1000 to 2300 mm and non-frost days in 1986 where 346.
There are about 23,000 black and white cattle in the province, with about 12,000 (52%) on the state operated farms, about 5,000 on the collective farms (21%) and about 6,000 (26.2%) in the farmers' hands. There are about 2,000 water buffalo in milk, most of them belonging to farmers. Local water buffalo can produce about 800–1200 kg milk per year. The crossbred of local and Murrah or local and Nili-Ravi can produce about 1500–1800 kg milk and the highest can produce about 1800–2000 kg per year.
Besides selling fresh milk in the province, there are some milk processing plants. They produce yoghurt, vita milk, citrus fruit milk, condensed milk, etc.
In order to meet the people's milk demand, between 1980–1985, this province imported 3,318 black and white dairy cattle from New Zealand, Denmark, the USA, Canada and Australia. The milk productivity and management of these cattle and the original local black and white are as follows.
PRODUCTIVITY OF LOCAL AND IMPORTED DAIRY CATTLE
Adaptation to local conditions
Cattle from New Zealand are better adapted to the Guangdong Province conditions than cattle from other countries. In the first year of their importation, those cattle suffered serious heat stress. In the Chu-Cuen dairy cattle farm, among 675 cattle imported in 1985, 18.7% of them had to be slaughtered in the first year because of foot-rot, septicaemia, mastitis, pneumonia, dystocia, uterine prolapse, ruptured uterus and other diseases. In the second and third years, they had to cull only 5.8% and 1.9% of the total cows, respectively.
Milk production
From Table 1, it can be seen that the milk production of cattle from New Zealand is nearly equal to that found in their home country. The milk production of the cows from other countries, although it is increasing each year, is still lower than the production in their home countries (although higher than the New Zealand cows). The milk production has increased rapidly every year. Some of the cows produced 6000 kg of milk in a 305 day lactation and the highest one achieved 9327 kg of milk in 305 days.
| Country of origin | Lactation | No. of cattle | Average milk production kg | Average butter fat % |
|---|---|---|---|---|
| New Zealand | 1 | 541 | 2948 | 4.3 |
| 2 | 594 | 3580 | 4.3 | |
| 3 | 532 | 4003 | 4.3 | |
| 4 | 159 | 4257 | 4.3 | |
| 5 | 222 | 4187 | 4.3 | |
| USA | 1 | 482 | 3013 | 3.2–3.7 |
| 2 | 357 | 4280 | - | |
| 3 | 252 | 5405 | 4.4 | |
| Denmark | 1 | 119 | 4434 | 3.9 |
| 2 | 64 | 5123 | 4.0 | |
| Australia | 1 | 6 | 4472 | - |
| 2 | 3 | 4058 | - | |
| Guangdong black and white | 1 | 984 | 4238 | |
| 2 | 710 | 4797 | ||
| 3 | 656 | 5110 | ||
| 4 | 422 | 5146 |
Reproductive performance
Table 2 shows that the reproductive performance of imported and local cattle are not very different.
Body weight of the cattle
The birth weight is smallest in New Zealand calves and their is not much difference between the others (Table 3). The body weights of heifers are highest in the American Holsteins.
| Origin | Number of cattle | Conception rate at one heat % | Conception rate per year % |
|---|---|---|---|
| New Zealand | 1132 | 57.2 | 91.7 |
| Denmark | 499 | 56.4 | 89.8 |
| USA | 1816 | 41.5 | 81.1 |
| Guangdong black and white | 1639 | 56.9 | 86.7 |
| Origin | Birth weight | 3 months of age | 6 months of age | 12 months of age | 18 months of age |
|---|---|---|---|---|---|
| New Zealand | 31.1 | 107.8 | 154.2 | 251.5 | 316.7 |
| Denmark | 35.6 | - | 138.9 | 267.9 | 340.9 |
| USA | 35.8 | 92.2 | 185.9 | 281.6 | 415.5 |
| Guangdong black and white | 34.5 | - | - | - | 345.7 |
GUANGDONG DAIRY CATTLE MANAGEMENT
Most of the dairy cattle are fed in-doors. In order to let the cattle adapt to the tropical climate and also to give high milk production, people have paid much attention to site selection, housing construction, dairy cattle management and disease prevention and cure.
Dairy cattle farm site selection
In the selection of farm sites, they have not only to consider those items such as prevention of sickness, transportation and communications, water supply, excrement and urine management and so on, but they specially select and construct a farm on the top of a hill, where the air flow is good and the manure, after fermentation in a manure pit, can be used to irrigate grassland around the farm automatically by gravitation through irrigation canals.
Housing design
In the past, most of the cattle houses had walls with doors and windows. Now, most of the cattle houses are open and they have only a big roof made of alloy, which is good for heat radiation. In windy areas, the roof may be made of cement.
Feed and feeding
Elephant grass is most important for cattle in Guangdong province because it can produce 8,000–15,000 kg of grass per Mu (1/15 of a hectare). Some of the farms plant a small area of stylo for calves. In the winter and spring season, they supply corn and elephant grass silage, and sometimes they also supply Chinese cabbage and sweet potatoes. Some of the farms supply grass hay the whole year round. In the concentrate, corn makes up about 40–50% and by-product feed ingredients such as wheat meal and soyabean meal make up about 30–50%. They also supply sufficient amounts of minerals, salt and some necessary trace elements. Most of the dairy cattle farms feed their cattle according to the feeding standards provided by the government. Sin-Tun dairy cattle farm uses a complete diet self-feeding system and gets very good results.
Dairy cattle management
The farmers do their best to avoid heat stress and foot rot in the cattle. Some of the farms lay bricks on the ground in the yard and some of them put sand down. Most of the cows' bedding is made of cement. Some of the farms have fixed bedding, with about 20 cm depth of sand in it, and some have a carpet on the bed to make the cattle comfortable. They put a water supply in the house, as well as outside, so that water is available all the time. Most of the farms have electric fans in the milking parlour as well as in the cows bedding area. Most of the farms let the cows have a shower once or twice a day and, in hot seasons, they use the shower two or three times a day.
Many dairy cattle farms are using milking machines to milk their cows. Chu-Cuen, Kwan-Ming and Sin-Tun dairy cattle farms are using herring bone milking parlours with fully automatic milking machines and the milking time per cow is only 8 minutes. They can machine-milk 12 to 20 cows at one time and have therefore raised their labour efficiency and produce very hygienic milk.
Management of bull calves
In many countries, young calves are sold for veal during the first few days of life but in our province, because the price of milk is very high and because most of the people cannot afford very expensive veal meat, most of the bull calves are slaughtered at birth.
DAIRY CATTLE PROJECT DEVELOPMENT AND INCREASED MILK PRODUCTION
Tentative ideas
In the past 10 years, thanks to the open door policy, the income of urban and rural people has increased remarkably and personal purchasing power has been raised in our country. The demand for more and more milk supply is a great problem for us to solve.
First of all, a better plan for dairy cattle distribution needs to be made and to increase the number of milking cattle. At present, most of the big dairy cattle farms are inside Guangzhou City or very close to Guangzhou. It is easier to transport milk to the consumers but there are many problems such as feed, especially forage and roughage supply, and pollution problems. So many people think that the distribution of dairy cattle should be changed.
Those farms in the city or very close to the city should raise a limited amount of good quality, high production cows, because they have a long dairy cattle-raising history, their technicians are good and so they could make good use of high quality cows.
Those farms in rural areas should raise cows that are better adapted to the conditions. In this area, it is easier to manage forage and roughage supply and the cost of labour is lower. With the improvement in transportation, it is not a problem to send milk to the city from 100 miles away in the rural areas. This is the area to develop more dairy cattle farms in the future.
There is a need to get more milk from water buffalo. In Nanhai and Jiashe Country, there are about 2000 milking buffaloes. They produce about 2392 tons of milk per one year. Farmer who raise one buffalo for milk can earn 1200 – 1500 yen of per year. Our province has more than three million water buffaloes. If 5% to 10% are milked, it will not only provide more milk to the people but will also increase the economic income of the farmers.
From a genetic point of view, in order to raise more good quality, high production dairy cattle and have good quality bulls from those high production cows, we are trying to make use of embryo transfer techniques. In the past few years, we used Chinese-produced FSH to super-ovulate donor cows and obtained 5–6 viable embryos on average per cow. The transfer success rate of fresh or frozen embryos was about 40–50%. We are also planning to do some experiments using injection of recombinant DNA growth hormone products and try to make use to bio-technology methods to increase milk production.
