Biometeorology as it Relates to Cattle Breeding for Beef in Tropical Australia

B r. uet. J . (1974), 130, 413

BIOMETEOROLOGY AS IT RELATES TO CATTLE BREEDING FOR BEEF IN TROPICAL AUSTRALIA By D. F.

DOWLING

D epartment of Animal Husbandry, University of Queensland, St. Lucia, Q. 4067, Australia

Biometeorology 'is concerned with the organic effects of environmental stresses preventing optimal production. Climate is usually regarded as the primary factor in determining the systems for beef production because more cattle (and humans) die because of climate (flood, fire, famine, wind, earthquake, etc.) than any other single cause. By "climate" is m eant a summary of the weather, averaged over each month or season of the year. The term "weather" is used to denote the changes which occur at any place from hour to hour or day to day. "Weather" includes the appearance of the sky, the occurrence of rain, hail, sleet, or snow, the presence offog or mist, the direction and speed of the wind, the temperature and humidity of the atmosphere. Certainly, climate presents the dominating problem in tropical Northern Australia in low cost beefproduction. For instance, in the clear tropical atmosphere in Northern Australia, the radiant heat load absorbed in one day in an area only 200 metres square would be equivalent to the energy of the early nuclear bomb. Hence not only must cattle be adapted, but they must have the potential to sweat so as to be able to thrive and be productive grazing in the heat of summer. Yet Bas indicus qualities are required not so much for heat tolerance as for tick and parasite resistance. The infusion of desirable characters from, for example Sahiwal (pure Bas indicus), Charolais (carcass type), and Chianina (tropical beef) appear essential to make the cattle more productive and economical. Beca use of this much of the investment in the beef industry may turn to the more favourable temperate climatic areas in the South until the problems of an intrinsically biometeorological nature are better understood. Then again the vegetation is an integrator and expression of the total environment which influences the productivity of cattle. The effect of weather factors on the incidences of parasites and diseases which may suppress beef production, though more difficult to identify precisely, is easy to see. Thus the study of the effect of climate and weather and its overall bioclimatic influences on the living organism is the science of biometeorology (Dowling, 1964, 1970, 1972). In the long term effect the application of this science is basic to the use of the tropics for cattle, because beef production depends on a positive approach to the maintenance of health and the prevention of disease. It is unrealistic to think of health as a characteristic or state of the organism per se. Health is a process of animal environment interaction and must be defined and measured in terms of adaptive capacity of the animal. Health then is not the absence of all disease but

BRITISH VETERINARY JOURNAL,

130 ,

5

the ability (of the animal ) to function effectively within a given environment in its all embracing sense. Because the environment keeps changing, good health is a process of continuous adaptation. Thus adaptation is the ability of the cattle to react homeostatically. In the experiments to be described in this paper, it is measured by the capacity of the animal, not only to survive in an environment, but also to perform optimally, i.e. the adaptive characters have a genetic basis but may be expressed within their physiological limits in a total environment. Hence the author's hypothesis, that positive genetic selection and environmental control, inherent in the management and movement of calves and cattle, should be the basis of veterinary skill in minimizing disease and optimizing production. The purpose of this paper is to highlight the need for the application of available knowledge in cattle breeding (for example Kelley, 1959; Cole, 1970; Laing, 1970; Hammond, 1971) and for biometeorological research as it relates to low cost production for beef in the tropics of Australia, because the contribution that cattle can make to this country is immense. PRODUCTIVITY OF EXISTING BREEDS OF C ATTLE IN THE TROPICS

Growth Effect of high temperature. Details of results of earlier experiments have been reported (Dowling, 1956). A high correlation has been found between rate of gain and adaptability or efficiency in Bos taurus beef (Shorthorn) bulls in a tropical Northern Australian environment (Fig. I). 1200

Rainsby

(Natural pasture only)

Beef bulls 2 years old

1100

~IOOO

700

Fig.

I.

Selected group --- Control group

The growth of bulls at two years of age illustrates that the effect of selection with a breed of Bos taurus cattle within a hot tropical environment can be significant.

Bulls selected on weight for age were compared at two years of age with controls. The animals were of the same age (within six weeks) and were run together throughout life in the tropical environment, i.e. the same pretest treatment. The above experiment is presented to demonstrate the bioclimatic influence on growth and how- effective, but limited, controlled selection can be. Also it is

BIOMETEOROLOGY

shown to highlight the material difficulty of experimenting with cattle. Twenty animals only were in each group in this simple comparison test of controlled mating under extremely hot conditions to determine the productivity of the existing cattle. Australia is a very hot dry continent. The area of Australia restricted to beef cattle production only or presently unsuitable for agriculture is shown in Fig. 2. The irregularity or lack of rainfall, high potential evaporation and extreme solar radiation due to clear atmospheric conditions are evident. 1=*====1 8 ee f

··' ... D

co ttl e

Desert

. DESERT (uninhabited )

Fig.

2.

Map of Australia to show the area of the tropics restricted to beef cattle only, owing intrinsically to problems of a biometeorological nature.

Carcass The measure of the characters of real economic interest are the carcass parameters in relation to liveweight gain (Dowling, 1960). Simple relationships of length of cannon bone and carcass weight and negative effect of fat thickness were significant. Our present "beef" breed animal would be twice as fat as is economical (Charles, 1968). Stress on hardiness may not be so great in future with better control of cattle but Chianina infusions may improve carcass and strengthen survival. Health Healthy cattle were heat tolerant and productive in the intensely hot, shadeless tropical area (Dowling, 1956). Cattle at the equable subtropical improved pastures environment were subjected to the tick which is the primary problem of beef production in the North (Alexander & Burns, 1956). Cattle in a temperate environment made record gains on the spring pastures but pasture dormancy in the winter set them back (Robinson & Cameron, 1960). In the tropics and subtropics, cattle from the drier parasite-free areas were reputed to be unable to

BRITISH VETERINARY JOURNAL, 130, 5

adapt to the "humidity" of the coastal areas: However, many experiments performed by the author and students with cattle exposed continuously in unsheltered yards or paddocks demonstrated little significance in the results of direct effects of climate in a subtropical region. On the other hand, the effect of parasites could be devastating. Treated cattle performed well even on zero grazing in unshaded yards, but untreated cattle did badly even when fed grain_mixture on pasture.

Fertility The basis of all beef production systems in an efficient system of reproduction. Fertility is the real test of adaptability. Dowling (1956) reported results when bulls were pastured with the females for six to weight weeks. Only the dams which were diagnosed pregnant three months later were retained. The dams were tested free of brucellosis, tuberculosis, vibriosis, and monitored constantly for health. Liveweight was recorded monthly. The average pregnancy rate of 82·9 per cent was recorded over two generations of selection from a group of 120 females. (Details of materials were described by Dowling, 1951.) Under the uncontrolled conditions, fertility and calf wastage is critically low (Chester, 1952; Churchward, 1952; Rose, 1952, 1966; Andrews, 1967; Baker, 1967; Dpnaldson, Ritson & Copeman, 1967; Sutherland, 1967). IMPROVEMENT OF EXISTING BREEDS IN THE TROPICS

Ease oj calving Even healthy cattle have a low prolificacy and a long generation interval so that improving their productivity genetically is important. Cows must calve r()gularly with minimal assistance. Similarly cows are culled for calving difficulties to prevent consequent lower fertility. Besides culling against any evidence of difficult calving, it is necessary to select for genetic factors associated with ease of calving and productivity. This type of husbandry is the best form of medicine. The transport problems associated with drastic environmental changes are highlighted in Fig. 3. Crossbreeding per se is not necessarily the answer unless use is 'm ade of selected animals for the hybrid vigour desired, when crossbreeding, to infuse added carcass quality with ease of calving. Ease of calving is 'enhanced automatically when infusing Bos indicus to offset climatically induced stresses and ticks, because of the small size of the Bos indicus calf. The heavier the calf the higher the probability of difficult calving. However, there may be definite sire effects (associated with the shape of the calf) and dam effects (due to differences in shape and size of pelvic dimensions and physiological adaptation) . Difficult calvings are related to subsequent lower fertility records. Effect oj crossing (Bos indicus X Bos taurus) on growth and carcass Improved growth rate is associated with increased mature size. Fig. 4 demonstrates the successful use of a crosS 'bred (FIX F 1) ; there is no genetic reason to expect unfavourable results from crossbred bulls-even with crossbred dams. The use of the Charolais as a terminal' sire is illustrated in Fig. 5.

PLATE I 1.000

... OUASAH

o SHORTHORN 800

600

_ 400

""'"

>-

::t

(!)

~2oo w

~ ...J

1964

April

Apr!

1965

1966

1967

THE ''qUASAH '' TEST Fig. 4 . D emonstrates th e improvement of the selec ted F 2 Sahiwal Shor thorn (na m ed " Quasah" ) stra in.

INflUENCE OF THE CHAROLAIS ON GROWTH o CHAROlAIS I .... SAHIWAl I D BOS TAURUS

QQ QQ QQ

600 500 4lI0 300 200

Mar 1970

Apr

May

Jun.

Jul.

Au~

Sell.

Ott

Noy.

Dec.

Jan. 1971

feb.

Mar

Fig. 5. Shows that an infusion of Bas indicus makes b etter performan ce a nd th e use of a terminal Bas europa infusion results in fur ther gains. Dowling, Br. vet . } . ( 1974), 130, 5

BIOMETEOROLOGY MEAT EXPORTS ( SOO Mll1l0D@)

:1lW;(lt70)

Fig. 3. Illustrates diagramatically the problem of breeding cattle in a harsh tropical environment for a home market a thousand miles and more to the South. (Reproduced by permission from Dowling, 1970.) DISCUSSION

The results described identify the need to infuse "carcass" and Bas indicus characters if the producer is concerned with profits for beef. Provided selection was imposed, the advantages of Bas indicus hybridization were confirmed. The experiments reported above also showed that Bas taurus species, in a much hotter tropical, but tick-free area, out-performed the Bas indicus and their crosses in a more favourable but tick-infested environment. This demonstrated dramatically that other factors were more critical than heat tolerance per se. Extrapolation from other animals to cattle must be viewed with caution (because of the skin and hair responses which enable Bas taurus cattle to live at a temperature range of -40 °C to 40 °C) . In this case, the environment influences phase of skin function and follicle and gland action which consequently modify the effect of the environment. Obviously, cattle with the ability to adapt to stresses, e.g. ticks and disease, yet able to utilize efficiently the benefits of the environment and better management, were needed (Dowling, 1960, 1970). "Carcass" type animals (Edwards et at., 1966) to maximize muscle and minimize fat were required to infuse optimally with Bas indicus hybrid dams (Dowling, 1970, 1971 ). The significance of putting more effort into the evaluation and development of strains, and individuals, to incorporate desirable characters to improve the existing cattle, and to save years of costly selection, emerges from the above experiments. Dramatic action is now indicated to make our cattle function for beef within the biometeorologicallimits set in Northern Australia. Historically, no cattle were indigenous to Australia. The Shorthorn came directly from the U.K. The remarkable fact is that less than twenty years ago

BRITISH VETERII ARY JOURNAL, 130, 5

this was the only breed that was scattered throughout the U.K. In the past decade they have phased out, decisively; they have become almost a zoological curiosity in the temperate climate where they originated. In Australia, Bas taurus cattle still remain intact in a tropical climate where survival is still accepted to be the basis of the system. Cattlemen generally, though, are absorbing an increasing economic awareness of new characters for the job ahead in the production of animal protein (Kesteven, 1967; J asiorowski, 1972). Thus, evaluation of the new exotic cattle to be used to improve our cattle is now essential to make up leeway, especially as the beef industry is expanding and may well be the key to Australia's prosperity. In other words, initiative in the veterinary profession is required as never before to get in genetic resources, with care and discrimination. Transfer of ova may be considered (Dowling, 1949; Rowson, 197 I ). An initial decision based on surveys and observations may be necessary to select the quality terminal sire deemed desirable in each particular case to assist the cattlemen to make the decisions, e.g. Chianina in the tropics. Evaluation of chosen bulls for freedom from genetic defects, even though for crossbreeding, is critical for the future appraisal of cattle. The smaller, high fertile Bos indicus hybrid dam, e.g. Sahiwal X Angus, Hereford, Shorthorn, may be more efficient. Biometeorology is very old as a concept but new ~.J the interdisciplinary science or medicine in relation to cattle production. Though a Herculean task, the application of the discipline, veterinary biometeorology, to cattle breeding for beef will be necessary to achieve the objectives of profitable beef production. Incidentally Hercules' fifth task was to cleanse the enormous and incredibly filthy Augean horse stables by temporarily diverting a stream of water. Should we not turn a stream of intelligence, imagination and effort to infuse our cattle in the North with traits suitable for beef production in this climate? If we adopt biometeorological concepts we could be quite as successful as the mythical hero. Only by being in the stream of research can we understand or hope to apply knowledge to make cattle perform profitability. Thus the climate of research for progress in veterinary science may well depend on such a discipline approach, on an interdisciplinary basis, to spearhead advances, penetrate new fields, to obtain the information to help solve the problems relating to the utilization of difficult agricultural areas in Northern Australia for the production of beef at low cost. Biometeorology, as it relates to cattle breeding for beef, creates the environment for establishing a sound basis for breeding cattle. REFEREN C ES

ALEXANDER, G . 1. & BURNS, M. A. ( 1956). Qd. agric. J. 82, 505. ANDREWS, L. G. (1967 ) . Aust. vet. J. 43, 490. BAKER, A. A. (1967). AllSt. vet. J. 43, 547· CHARLES, D. D. (1968) . Aust. vet. J. 44, 223· CHESTER, R. D. (1952 ) . Aust. vet. J. 28, 273. CHURCHWARD, R . E. ( 1952 ) . Aust. vet. J. 41, 352. COLE, V. G. ( 1970). Beif Production Guide. Sydney : Graziers' Association of N.S.W. DONALDSON, L. E., RITSON, ]. B. & COPEMAN, D. B. ( 1967). Allst. vet. J. 43, I. DOWLING, D. F . (1949) · J. agric. Sci. 39, 374· DOWLING, D. F. (1951 ). Proc. S ection L, ANZAAS Conference, Brisbane 1951. DOWLING, D. F. (1956) . Aust. vet. J. 32, 246.

BIOMETEOROLOGY DOWLING, D. F. (1960) . Proc. Aust. Soc. animo Prod. 3, 184. DOWLING, D. F. ( 1964). Proc. Section L, ANZAAS Conference, Canberra 1964. DOWLING, D. F. ( 1970). Proc. Aust. Soc. animo Prod. 8, 86. DOWLING, D . F . ( 1971 ). Proc Section 16, ANZAAS Confi;;',lce, Brisbane 1971. DOWLING, D. F . (1972). Progress in Biometeorology, Section B . Progress in Animal B iometeorology ed. W. S. Tromp. Amsterdam: Swets & Zeitlinger. EDWARDS, j., JOBST, D., HODGES, j., LEYBURN, M., O'CONNOR, L. K. , MACDONALD, A ., SMITH, G. F. & WOOD, P. (1966). The Charolais Report. Thames Ditton, Surrey : U.K. Milk Marketing Board. HAMMOND, j. (1971 ). Hammonds' Farm Animals. 4th edn. London: Arnold. jASIOROWSKI, H. A. (1972) . Wld Anim. Rev. I, 2. KELLEY, R. B. (1959). Native and Adapted Cattle. Sydney: Angus and Robertson. KESTEVEN, K. V. L. (1967). World Animal Protein. Rome: F.A.O.Publication. LAING, J. A. ( 1970). Fertility and Infertility in the Domestic Animal London: Bailliere, Tindall & Cassell. ROBINSON, T . j. & CAMERON, N. G. (1960). Aust. J. agric. R es. II, lIOI. ROSE, A. L. (1952). Aust. vet. J. 28, 288. ROSE, A. L. (1966). Aust. vet. J. 42, 91. ROWSON, L. E. A. (1971). Nature, Lond. 233, 379. SUTHERLAND, D. N. (1967). Wld Rev. animo Prod. 3, 32.

(Accepted for publication 3 I July 1973)