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    AFS The World s best tropical dairy breed

    Home page/ AFS Story / Heat Stress/ Performance/ Breeding/ Management/ Feeding/

    Technical Papers/News of Tropical Dairying/ Contacts/

    AFS(THE AUSTRALIAN FRIESIAN SAHIWAL)

    Australia's Tropical Dairy Breed

    Dr G.I. Alexander

    Queensland Department of Primary Industries

    GPO Box 46,Brisbane Queensland 4001 Australia

    (Presented by Dr M.L. Tierney to

    Ag China 86 Conference, Guangzhou CHINA)

    Introduction

    In the early 1960's a need was seen for a breed of dairy cattle which was tick resistant and would formthe basis of the dairy industry in Queensland in future years.

    Queensland is situated in the tropical and sub-tropical northern area of Australia, and the cattle tick(Boophilus microplus) is endemic throughout most of the dairying areas of Queensland. In the 1960's it

    was generally considered that there was a real possibility of chemical control of the cattle tick breakingdown completely.

    In the early 1950's Bos indicus genes had been introduced into Bos taurus beef cattle in Queenslandthrough, mainly, the introduction of Brahman cattle into the European breeds which had, themselves,been introduced many years earlier. The majorBos taurusbeef breeds were the Hereford, Shorthorn andAngus. The infusion ofBos indicusgenes was-seen to be a way of controlling cattle tick.

    The principal dairy breeds in Queensland in the early 1960's were the Jersey, Illawarra, Holstein-

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    Friesian, Ayrshire and Guernsey allBos taurusbreeds with relatively little natural resistance to the cattltick.

    In 1952, a small number of Sahiwal cattle had been introduced into Australia from Pakistan . As thSahiwal was recognised as the best of the dairy-typeBos indicus cattle a decision was taken in 1960 tdevelop a dairy breed based on approximately 50%Bos taurus genes and 50% Sahiwal genes. In 1965 iwas decided that theBos taurus component of the new breed should be the Holstein-Friesian. Thus, th

    Australian Friesian Sahiwal (AFS) Breed Development Programme was put in place.

    By the mid 1970's it was seen that the complete breakdown of the chemical control of ticks was fairlremote. However, a number of tropical countries, particularly in the South-East Asian region, werstarting to develop dairy industries. The local breeds of cattle were generally found to have very lolevels of milk production, while Bos taurus cattle of European breeding found difficulty in coping witthe tropical conditions and their production suffered markedly.

    Thus, the emphasis of the AFS Breed Development Programme changed to that of developing a breed odairy cattle that could perform well under tropical conditions, and to the development of genetiimprovement programmes within this new breed.

    This paper will discuss the development of the AFS breed, the production levels that have been achievedthe genetic improvement programmes that are in place, and the methods that can be used to incorporatthe AFS in developing dairying industries.

    Development of the AFS breed

    The first matings in the AFS programme took place in 1961 when Sahiwal bulls were mated to HolsteinFriesian, Illawarra and Jersey heifers.

    Early in the development programme, as a result of the emphasis in the Queensland dairy industr

    switching from the Jersey to the Holstein-Friesian - due to the latter's higher levels of milk production - iwas decided to concentrate on the Holstein-Friesian to supply theBos tauruscomponent of the breed.

    Limited data from tropical areas suggested that under most tropical conditions, a 50-50 mix of BoindicusandBos taurus genes would give optimum levels of both milk production and reproduction.

    As a result, it was decided that the breed should be based on a combination of 50% Holstein-Friesian an50% Sahiwal.

    The decision to base the breed on a 50-50 mix has subsequently been justified by a number of studiethat have looked at various levels of Bos taurus and Bos indicus gene contents at various locationthroughout the tropics.

    Reason (1986) has summarised the studies that have been done to date.

    (a) Milk production per lactation

    While most of the crossbreeding programmes reported here were designed on the premise of being sitspecific, results from these experiments lead to the general conclusion that 50% Bos indicus and 50Bos taurusgives close to the optimum milk production performance. A summary of a range of studies ipresented in Table 1.

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    (1) Syrstad (1985)

    (2) Sharma et al. (1982)

    (3) Amble and Jain (1967)

    (4) Sivasupramaaian et al. (1983)

    Madalena (1981)

    The results in Table 4 show the superiority of the 50% Bos taurusand 50%Bos indicusgenotype in thecombination of milk production and reproductive performance characteristics. This index gives a directmeasure of the efficiency of milk production by combining milk yield and length of intercalvinginterval. It can also provide a measure of economic value by including return per litre of milk in thecalculation. In the data reported by Syrstad (1985), a 50% Bos taurus cow produced more than twice themilk per day of intercalving interval than a 100%Bos taurusanimal.

    AFS Breeding Programme

    In the early stages of the AFS breeding programme Sahiwal bulls were mated to Holstein-Friesian cowsto produce Fl (First cross) animals which were subsequently tested for both milk production and tickresistance.

    Both Alexander et al. (1984), with the AFS, and Hayman (1973) with the Australian Milking Zebu havereported that large numbers of Fl animals had to be culled from the programme due to a failure to letdown milk under machine milking conditions in the absence of the calf. Hayman reported a culling rateof 59% with the AMZ Fl animals, which were based on Jerseys crossed with either Sahiwal or Sindhisires.

    Alexander et al. (1984) reported that the culling rate of AFS Fl animals between 1977 and 1983 was60% for heifers not milking at 120 days. There were large differences in the culling rates of daughters ofdifferent Sahiwal sires with the rate varying from 28% to 85% for the daughters of the different sires.

    Reason et al. (1979) reported that the culling rate due to the failure to achieve lactation persistency insecond generation heifers was markedly reduced (mean of 28%) even though female progeny of failedFl heifers were retained in the breeding programme. This indicates that sire Selection plays an importantrole in eliminating this trait and that response is rapid (Stohoe and Waldron 1982). In later generationsthe "failure to milk" syndrome has virtually been eliminated.

    F2 and later generations were produced by inter-se matings to ensure that a genotype of approximately50% Sahiwal and 50% Holstein-Friesian was maintained in subsequent generations.

    Evaluation of F2, and Subsequent Generation Bulls

    Alexander et al. (1985) have described the bull proving programme which was commenced is 1976 inthe AFS breed.

    Between 1976 and 1984 young bulls were selected for testing from the progeny of mating the sons ofhigh producing cows to cows of similar high production. All bulls tested have been of F2 or latergeneration.

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    The matings were carried out either in Research Station or cooperating farmers' herds. Bull calves wercollected at between 1 and 6 months of age and transported to the Department's Artificial BreedinCentre at Wacol, Queensland.

    Up to ten bulls had been assembled at Wacol for each progeny test group. They were fed a standarration to 15-18 months of age and growth rate was measured. At that age semen production and ticresistance was evaluated.

    Tick resistance is known to have a high heritability, ranging from 40% in animals with a lowBos indicucontent (Hewitson, 1968, Wharton et al. 1970), to almost 80% in animals with greater than 50% Botauruscontent (Seifert, 1971).

    Bulls in the 1976 and 1977 test groups were tick tested by ranking them on their tick burdens resultinfrom natural paddock infestation. These rankings were based on a minimum of three counts.

    Selection for the 1978 and subsequent groups was based on a method of evaluating tick resistance tartificial infestations with 20 000 tick larvae (Utech et al. 1978). After infestation, the resulting engorgefemales (4.5-8.0 mm diameter) were counted on each of the 18th to 22nd days following infestation.

    A minimum resistance standard of 98% larval mortality was set (Reason and Clark, 1979) and a mealevel of 99.1% was achieved (Alexander et al. 1984).

    The bulls were not screened for heat resistance as all progeny have been evaluated in Queensland or th

    Northern Territory under natural conditions of high temperatures (> 30oC during at least the summemonths).

    Semen from the progeny test bulls was used to inseminate either AFS or Bostaurus(mainly HolsteinFriesian) cows or heifers. The resulting heifers had their milk and fat production recorded on a monthlbasis at least du