By Huang Bizhi, Wen Jikun and Liu Tianliang

 

Tropical beef industry is one of the important components in the whole beef industry, though far behind the top predominance of temperate one, still performing its prominent role that cannot be substituted. However, because of social or natural reason, productivity of tropical beef is relatively lower compared with that of the temperate. Viewing globally, the tropical beef industry has greatly developed in the last two or three decades especially the development of tropical beef industry in the southern tropical zone in the United States and the north and the northeast area in Australia, which strongly emphasizes on the tropical beef cattle breeding and correspond development with livestock and pasture.

The same as the outside of the world, in spite of the northern area being the dominance for beef industry in China, the southern beef industry in China has achieved rapid progress reflecting in its breed introduction, breeding selection and development pasture and livestock production. With the practical situation in Yunnan province, it is included some rough idea in this paper on the benefit of tropical cattle breed, livestock and pasture production. Comments and suggestions to the paper from the experts of all sorts will be appreciated.

 

1.Tropical Beef Cattle Breed

       There are varieties of tropical beef cattle breeds. Generally speaking, it mainly consists of tow major groups: traditional Zebu breed and selected breed. In terms of impact to the practical productivity, the selected breed is recommended.

1.1  Brahman

Brahman breeding, dated back to 40s of 19^th century in the United States, forms a standard breed till the late end of the century. The breed with characteristic of heat and rough forage tolerance as well as tick disease resistance is selected from the crossbreeding of four types of Indian Zebu with British breed. It is reported abroad that the progeny of temperate breed will thoroughly perform the characteristics of Brahman by introducing only a quarter of Brahman blood into the temperate breed.

In China, the crossbreeding program with Brahman started in Guangxi, Fujian and Yunnan provinces in 1980. It is shown from the actual practice that Brahman is ideally suitable for the improvement of Yellow Cattle crossbreeding in the southern tropical area in China. Concerning of the contribution of Brahman to the development of world beef industry, professor Cheng Youchun once commented that it was the success of Brahman breeding and utilization of its crossbreeding bulls that constructed the beef crossbreeding system in the southern tropical area in the United States, which not only brought the prosperity of the beef industry in the southern America but also accelerated the establishment of intensive beef crossbreeding system in the world with high efficiency.

1.2  Deriving breeds of Brahman

There are groups of breeds derived from Brahman known as Santa Gertrudis, Droughtmaster, Braford and Bragus etc., all of which are well adapted to the tropical zone. It is known that Santa Gertrudis, Braford and Bragus are formed from crossbreeding of Brahman with Short Horn, Heford and Angus containing 3/8 of Brahman blood and 5/8 of Short Horn, Heford and Angus blood respectively. The breeds perform well both characteristic of Brahman for tropical beef production and high efficiency of British cattle for beef producing. 

   Droughtmaster, known as drought tolerant beef cattle originated in Queensland, Australia, is formed from crossbreeding of Brahman with Short Horn, Heford, Devon and Red Poll containing from 3/8 to 1/2 of Brahman blood. The breed is well adapted to the environment on matter the climate of humid tropical in the bay area or dry tropical in the inner land. The breed is also with strong resistance to the ticks and tick born disease especially the babesiosis, making it an ideal breed for quality beef production. The breed is suitable to raise in the drought valley area in the southern China.

1.3 BMY crossbreeding

Suggested in the Livestock and Pasture Development Project of the Sino- Australia Technology Co-operation Program, BMY crossbreeding was set up and implemented in the Technology Development Program of Yunnan Province as the Breeding Program for New Tropical Beef Cattle Breed during the National Eighth-Five Year, Ninth-Five Year and Tenth-Five Year Rolling Development Plan n. BMY now is a transiting breed consisted 1/2 of Brahman, 1/4 of Murray Grey and 1/4 of Yunnan Yellow, which through the breeding program from more than one and half decades of the three Five Years development program has performed typical characters as following: 

    (1) Precocity. The body weight of the breed at 18 months reaches 80% of its matured body weight. It is important for the beef cattle that if it is with high body weight at early age, it will approach to the matured body weight soon, ready for mating and reproduction, making a great contribution to economy benefit and reproduction.

 (2) High Weaning Weight. The body weight gained of the breed at age of weaning, 12 months and 18 months ranks the highest among 11 combinations of the cross breeding. Body weight gain from birth to weaning reflects the lactation capability of cows. However, the body weight gain from weaning to 18 months of age generally depends on genetic performance and adaptability to the environment (in concerning of fodder supplied). In Yunnan province, the period body weight gain has to go unfortunately through dry season with frost. Therefore, the high body weight gain shows the feeding ability, adaptability to the stressed environment and capability of using rough forage of the breed.   

  (3) High Fertility. The average calving survival rate in the periods of the Eighth Five Years and the Ninth Five Years Rolling Development Program reached 84.3 and 77.9% respectively (the lower one was due to serious drought of a whole year), which was equivalent to that of local breed Yunnan Yellow under the same situation. The high fertility and survival rate is an important economic target for beef industry, embodying reliable reproductivity.

 (4) High Body Weight Gain. It is shown from the trail results implemented that, under grazing situation with a few supplementary feeding, the MBY breed performs the best among the four crossbreeding combinations in the trail. The concentrate feeding in a short term is one of important means to improve the quality of beef and increase premium in beef selling. Different genetic combination makes big difference in feedlot. High feedlot rate means high efficiency of feed utilization and conversion rate from feed to meat.

 (5) High Performance Of Tick Resistance. It is shown from natural tick infection survey and the result of tick infection trails that MBY breed is with the best tick resistance performance. The tropical area in Yunnan is the place where it is easy for babesiosis, the tick-born disease, to break out. Observed more than ten years, MBY breed has never infected with typical babesiosis, which is of great significance for tropical beef industry.

 

  The benefit of beef industry can be achieve from raw produce producing, processing and marketing, which is the same for tropical beef industry. If not concerning the last two phases, the reasonable balance between animal and forage will be the final result for the raw product producing of the industry, of which the benefit is determined by the dynamic balance and sustainable development between animal and forage with the balance as its kernel including balance of seasonally even forage supply and nutrient balance within forage as well.

 

2.1 The Balance Between Animal And Forage.

Beef industry no matter in tropical or temperate zone is largely limited by the maximum productivity of land environment for forage supply (including natural and established pasture, crop stem and concentrate feed available for beef).Therefore, the scale of the industry or number of beef cattles raised is limited in accordance with the capability of forage supplied, which is generally known as balance between animal and forage. Only with the reasonable balance can the best benefit be achieved. What can be affected by man is to try to improve the productivity of forage on the specified land as much as possible (such as establishing more pasture, forage cropping and fully using of crop stems).  

  

2.2 Seasonally Even Supply of Fora

Rainfall in tropical area is always distributed unevenly with clear difference of dry and wet season. The most rainfall in a year is focused in the wet season in which forage can be sufficiently supplied, but in dry season of the supply shortage in feeding. In Yunnan, dry season starts from November to May with only 15-20% rainfall of the total in a year, which is the critical time for beef industry in Yunnan resulting of losing body weight heavily. In this stressed situation, the rural practice for supplementary feeding relies on dried rice straw and maize stem (or aminated rice straw and maize silage etc.) while the scaled ranchs often manage to prepare quality maize silage with corns on or quality hay and control the size of animal numbers (such as culling no performing cattles out of herds) to maintain the balance between animal and forage in the critical period. The control of herds size to keep the seasonal balance between animal and forage should be recommended for the tropical beef industry.

 

2.3 Nutrition Balance Of The Forage Supplied

Problems of forage supplied for tropical beef industry exist in unbalanced nutrition, which are caused by natural selection. Natural grazing land in the tropical area is usually dominated with tall grass, which is of poor nutrient value with very low proportion in crude protein, often only 3-5%. In addition, because of the most moisture and heat energy coming in wet season, it makes a superior growth of grass to legume under the same natural environment, resulting not only the poor growth of legume but difficulty to establish legume mixed pasture in tropical area. With the poor legume component, crude protein supplied from the pasture is therefore very low. Moreover, because of the heavy rainfall in the wet season, there used to be serious run-off in the pasture causing bad situation of mineral nutrient leaching from the soil adding up another problem of mineral nutrient balance in the pasture in tropical area. The problems mentioned above can be partly solved by establishing pasture well mixed with grass and legume, usually with mixture of Brachiaria Griseb., Paspalum L,. Pueraia phaseoloides Benth. and Arachis pintoi Krap. Et Greg. Nom. Nud. Cv. Amarrillo ect., for grazing or strip sowing with grass and legume for cutting(the best) and grazing (better). Through analyzing of mineral nutrient content both in soil and pasture, the balance of mineral nutrient in forage can be maintained. If necessary, according to the basic requirement of beef cattle, the deficient of mineral nutrient can be supplemented in terms licking block etc.

20/12/2005