Multivariate Craniometrics of Wild Banteng, Bos banteng, and Five Types of Native Cattle in Eastern Asia

Yoshihiro HAYASHI, Jun-ichi OTSUKA* and Takao NISHIDA

Laboratory of Veterinary Anatomy, Faculty of Agriculture, University of Tokyo, Bunkyo-ku, Tokyo 113 * Laboratory of Veterinary Anatomy , Faculty of Agriculture, Kagoshima University, Kagoshima-shi 890

(Received January 14, 1988)

Abstract Multivariate craniometric analyses were performed using the princi- pal component analysis to clarify the relationship between wild Banteng and five types of Asian native cattle; i.e., cattle native to Bali, Madura, Aceh, Leyte, and Korea. In a principal chart constructed by the first and second components derived from 15 cranial measurements, Bali cattle showed the closest relationship to Banteng, suggesting that these cattle may be a domestic form of Banteng. This assumption was supported by the fact that the resemblance between the two was not based on the first (size) component but on the second (shape) component. The sexual differences in Bali cattle were less than those in Banteng cattle. The second principal component strongly contributed to the distinction of Banteng and Bali cattle from Leyte and Aceh cattle, which are believed to belong to zebu- type cattle. The Madura cattle had an intermediate relationship between the former two groups in the principal component chart. On the other hand, the Korean cattle believed to be one of the primigenius-type cattle, was separated from the others mainly by the first component. The discriminatory power of the analysis was considered to become higher when the components were extracted from the covariance matrix of measurements than when they were extracted from the correlation matrix. Similarly, discriminatory power was higher when 24 cranial measurements were used rather than 15. Jpn. J. Zootech. Sci., 59 (7): 660-672, 1988 Key words: craniometry, banteng, cattle, skull PCA (principal component analysis)

The Banteng, Bos banteng, inhabiting the forests of Indonesia, Malaysia, and some other areas of southeastern Asia, is believed to be an ancestor of Bali cattle which are native cattle raised on Bali Island in Indonesia4-12). In fact, Bali cattle resemble the wild Banteng in coat-color, however, there is little hard evidence for assuming this relationship between the two. In the authors' previous study, craniometric comparisons between the Banteng and three types of Indonesian native cattle (Bali, Madura, and Aceh cattle) was carried out5). Consequently, the morphological status of Bali cattle was concluded to be

Jpn. J. Zootech. Sci., 59 (7): 660-672 660 1988 Craniometry of Banteng and Asian Cattle

nearer to that of the Banteng rather than of the other two; however, this conclusion must be considered as preliminary because of the shortage of specimens of Banteng . The first aim of the present study is to further clarify the relationship between the Banteng and Bali cattle, and between these two types of cattle and several types of native cattle in eastern Asia, by using newly collected specimens. The second aim is to examine the effectiveness of multivariate analysis of craniometric measurements in attaining the objectives mentioned above. Because of the complexity and variability of living organisms, multivariate statistical methods have become an important tool in studies of variation and evolution6). In the present study , 24 cranial measurements, at most, were used for the principal component analysis, which is a popular method for discrimination of populations1).

Materials and Methods

The number and sex of the specimens are shown in Table 1. Some of the specimens from Banteng were collected and measured in the Ujung Kulon National Park of Indonesia. The remaining specimens were those stored at the Bogor Zoological Museum or Nature Conservation Office in Bogor. The specimens from different types of native cattle were collected in slaughter houses of their respective countries. The ages of specimens were determind by the status of eruption and wear of the incisor teeth. Young adults, less than four years of age , whose skulls might not have reached final proportions, were excluded from the present data so that the analysis would not be complicated by variations due to growth. The 30 cranial measurements used in this study were those defined by Duerst3) and Driesch2). Figure 1 shows the locations of these measurements . All measurements were taken with sliding or spreading calipers and were recorded to the nearest 0.1 millimeter.

Results

Table 2 shows the means and standard deviations of 15 cranial and 15 mandibular

Table 1. Number and sex of the skull samples*

* All samples were estimated to be more than 4 years old .

661 HAYASHI, OTSUKA and NISHIDA measurements for the Banteng and Bali cattle in Indonesia. In general, the measure- ments of Banteng are significantly larger than those of Bali cattle. It is also clear

Fig. 1. Measurements of the skull of Bos A: Akrokranion B: Basion Goc: Gonion caudale Gol: Gonion laterale Gov: Gonion ventrale Id: Infradentale N: Nasion P: Prosthion St: Staphylion 662 Craniometry of Banteng and Asian Cattle

that the males are larger than the females in both cattle in most of the measurements. Table 3 shows the means and standard deviations of the measurements for the Madura and Aceh cattle in Indonesia, the Leyte cattle in the Philippines, and the Korean cattle in South Korea. Of these specimens, only those from females more than four years old were of sufficient number to make statistical analyses possible. The Korean cattle were larger than both Banteng and other native cattle in most of the measurements (Tables 2 and 3). In contrast with the mean values, the standard

Table 2. Means and standard deviations of 15 cranial and 15 mandibular mea- surements for Banteng and Bali cattle in Indonesia

All dimensions are expressed in mm.

663 HAYASHI, OTSUKA and NISHIDA deviations of most measurements of Leyte cattle were greater than those of other cattle, suggesting that these cattle may be from a population with a low degree of uniformity as compared with the others. The principal component analysis was conducted using 15 cranial and 9 mandibular measurements of which item numbers were from 1 to 18, from 20 to 23 and from 27 to 28. Table 4 shows the eigenvectors of these 24 measurements classified by the first and second components. In the first component, most of eigenvectors had positive values, indicating that this component was acceptable as a size vector; however, some

Table 3. Means and standard deviations of 15 cranial and 15 mandibular measu- rements for four types of female cattle in eastern Asia

All dimensions are expressed in mm.

664 Craniometry of Banteng and Asian Cattle

of them belonging to the mandibular measurements had small or negative values , indicating that their contribution to this component was negligible . In the second component, the proportion of the skull was an important discrimi- nator, since the eigenvectors belonging to the lengths of facial of the skull (item nos . 4 and 7), basal length of the skull (no. 5), the heights of skull (nos . 14 and 15), and lengths of the mandible (nos. 16 and 17) had negative values, in contrast with most of the other measurements having positive ones. Likewise in the first component , contribution by most of the mandibular measurements to the variational pattern was negligible, because the absolute values of eigenvectors belonging to these measurements were relatively small. Figure 2 shows the principal component chart constructed by the first and second components. In the application of the principal component analysis , there are two ways for extracting the principal components: one is to extract them from a covariance matrix of measurements, another is to extract them from a correlation matrix . The components given in Fig. 3 were derived from the covariance matrix, whereas those in Fig. 4 were from the correlation matrix. Fifteen cranial measurements were used for both analyses. There was no remarkable difference between the two figures with respect to the locations of 6 ellipsoids constructed for different cattle. However, looking again at Figs. 3 and 4 and checking the discriminatory power of the analyses, it seems that the principal components derived from the covariance matrix were more effective at discrimination of the populations since there was a formation of three groups (the Leyte, Aceh, and Madura group, the Bali and Banteng group, and the Korea group) seen relatively clearer in Fig. 3; in contrast with Fig. 4 where there was an over- lapping between these groups . In Fig. 3, the first and the second principal components accounted for 64.7% and

Table 4. Eigenvectors of 15 cranial and 9 mandibular measurements in the first and second components

665 HAYASHI, OTSUKA and NISHIDA

11.6% of all the variation and the sum of both components was more than 76%. On the other hand, these two components in Fig. 4 accounted for 54.8% and 14.4% respectively, and their sum was about 69%. Thus, the variation explained by the components derived from the covariance matrix was larger than that from the correlation matrix by approximately 7%; hence, further analyses were carried out using covariance matrix. To examine the relationship between Banteng and Bali cattle in more detail, the principal component analysis was conducted using specimens from both sexes of these cattle (Fig. 5). The components were extracted from the covariance matrix of 15 cranial measurements. The first principal component accounted for 77.6% of all the variation and the second one for 9.8% thus the sum of both components was no less than 87%. As shown in Fig. 5, the distance between the two sexes was longer in the Banteng

Fig. 2. The principal component chart of the first two trans- formed variables derived from the covariance matrix of 15 cranial and 9 mandibular measurements of the females of Banteng and 5-types of native cattle in eastern Asia.

666 Craniometry of Banteng and Asian Cattle than in the Bali cattle, indicating that sexual dimorphism is larger in the Banteng than in the Bali cattle. This trend appeared not only in the size vector but also in the shape vector, since there was a slight overlap between the sexes in the Bali cattle when both of them were projected into the first (size) or second (shape) components, while there was a complete separation in the Banteng.

Discussion

The domestic cattle of the world have long been divided into two large groups13) one is made up of European humpless cattle, which are assumed to be a domestic form of Bos primigenius found throughout the forests of North Africa, Europe, and southwestern Asia until it became extinct about 162715); the other is made up of Zebu cattle which are native to India and now widely introduced to other parts of the world.

Fig. 3. The principal component chart of the first two trans- formed variables derived from the covariance matrix of 15 cranial measurements of the females of Banteng and 5 types of native cattle in eastern Asia.

667 HAYASHI, OTSUKA and NISHIDA

These cattle are frequently called "humped cattle" because of the large hump over the shoulder, and no wild cattle having this characteristic exist today. NAMIKAWA and WIDODO8), however, suggested that the Bali cattle were an important breed as a gene source of the native cattle distributed in southeastern Asia, since the X band of hemoglobin (Hb-X), which is absent in both the typical primigenius-type and zebu-type cattle, occurred frequently in the Bali cattle. In fact, in support of this suggestion, Hb-X has been found to occur often in different types of native cattle in southeastern Asia9) The Bali cattle are assumed to be a domesticated form of the wild Banteng, as mentioned in the introduction. To confirm this assumption, it is necessary to compare the wild Banteng with native cattle in southeastern Asia including Bali cattle. However, there have been few genetical comparisons made between these cattle because

Fig. 4. The principal component chart of the first two trans- formed variables derived from the correlation matrix of 15 cranial measurements of the females of Banteng and 5 types of native cattle in eastern Asia.

668

. Craniometry of Banteng and Asian Cattle of difficulties in collecting blood samples from the wild Banteng. The present study, using skull specimens of wild Banteng stored at museums or collected in the national parks, offers a new line of information on the relationship between the wild Banteng and Bali cattle, and further, between these cattle and several types of native cattle in eastern Asia. As shown in Fig. 2, the Bali cattle are located on the chart nearest to the wild Banteng. This resemblance is not based on the skull-size, but on the skull-shape ; because these two cattle completely overlap when they are projected into the axis of the second (shape) component, in contrast to a separation between the two when analyzed by the first (size) component. This result suggests that the Bali cattle may be a small form of the wild Banteng. Dwarfism is known to be a phenomenon in the process of domestication, and hence, it is not unusual that this phenomenon may have occurred in the process of domestication from the wild Banteng to the Bali cattle. On the other hand, OTSUKA et al.11) demonstrated that the Banteng and Bali cattle

Fig. 5. The principal component chart of the first two trans- formed variables derived from the covariance matrix of 15 cranial measurements of the Banteng and Bali cattle.

669 HAYASHI, OTSUKA and NISHIDA were separated from other cattle not by the second component but by the third component when 9 body measurements were used for the principal component analysis. These differences are probably due to the low explanation rate (5.3%) of the second component in their study. Out of five types of native cattle examined in this study, the Leyte and Aceh cattle are assumed to belong to the Zebu-like cattle, because of the occurrence of the B band of hemoglobin with relatively high frequencies9). Figures 3, 4 and 5 indicate that the second component may be a good discriminator between the Bali cattle and Zebu-like cattle, since this component separates the Leyte and Aceh cattle from Bali cattle. The location of Madura cattle in the charts is intermediate between the former two groups, which is in agreement with the genetical relationship between these cattle. On the other hand, the first component seems to discriminate Bali cattle and Zebu-like cattle from the Korean cattle which are assumed to be one of the primigenius-type cattle7,10,14). In the application of the principal component analysis, the components are often extracted from the correlation matrix of observations1). In fact, this method is effective to treat various characters (e.g., length, weight, and angle) at the same time. Comparative examination between Fig. 3 and 4, however, suggests that the components extracted from the covariance matrix are more effective in discrimination of the cattle populations than those extracted from the correlation matrix. The superiority of the former method is also demonstrated by the fact that 76% of all the variations are explained by the first two components derived from the covariance matrix, in contrast with 69% by those derived from the correlation matrix. In general, it is concluded that as more measurments are taken of the skull, the better will be the analysis attempting to determine the true relationships of the cattle. The discrimination of the cattle group is clearer in Fig. 2, where the analysis was conducted using 24 measurements, than in Fig. 3 and 4, where 15 measurements were made, suggesting that Fig. 2 displays the relationship between the cattle more exactly. However, phylogenic relationships between the different cattle are fundamentally expressed even when mandibular measurements are not used for analysis, since there was no essential difference between the former three charts. This makes the craniometric study of cattle easier to conduct, since it is difficult to collect mandibles in the field due to the weak connection of the median section of mandibular body. Although some information on the relationship between the Banteng and different types of Asian native cattle was derived from the present study, work on this subject is still in the preliminary stage because of the lack of specimens from typical zebu and primigenius cattle. Further studies will be required to clarify the phylogeny of Asian native cattle.

Acknowledgements

The authors wish to show their gratitute to Prof. H. MARTOJO, Dr. S.S. MANSJOER, Dr. I. K. ABDULGANI and Dr. S. SIMAMORA, Faculty of Animal Science, 670 Craniometry of Banteng and Asian Cattle

Bogor Agricultural University, Bogor, Indonesia, and to Prof. C.S. LEE of Department of Veterinary Medicine, Kyungpook National University, Daegu, Korea, for their kind arrangements and cooperations in the field work. This study was partly supported by grants for overseas scientific survey (No. 56041045 and 57043041) from the Ministry of Education, Science, and Culture of Japan.

References

1) BLACKITH, R. E. and R. A. REYMENT, Multivariate morphometrics. 146-200. Academic Press. London. 1971. 2) Driesch, A. von den, A guide to the measurement of animal bones from archaeological sites. Peabody Museum Bulletin 1. 27-57. Peabody Museum of Harvard Univ. Massachusetts. 1976. 3) DUERST, J. U., Handbuch der biologischen Arbeitsmethode. Abt. VII. 125-530. Berlin & Wien. 1926. 4) HALDER, U., Okologie und verhalten des Banteng (Bos javanicus) in Java. 1-124. Verlag Paul Parey. Hamburg & Berlin. 1976. 5) HAYASHI, Y., T. NISHIDA, K. MOCHIZUKI and J. OTSUKA, Jpn. J. Vet. Sci., 43: 901- 907. 1981. 6) JOLICOEUR, P., The wild canids (Fox, M. W. ed.) Van Nostrand Reinhold Co. New York. 1975. 7) MOCHIZUKI, T., Jpn. J. Zootech. Sci., 2: 187-239. 1927. 8) NAMIKAWA,T. and W. WIDODO, Jpn. J. Zootech. Sci., 49: 817-827. 1978. 9) NAMIKAWA,T., Z. Tierzuchtg. Zuchtgsbiol., 98: 151-159. 1981. 10) NISHIDA, T., Y. HAYASHI, C. S. LEE, Y. J. CHO, T. HASHIGUCHI and K. MOCHIZUKI, Jpn. J. Vet. Sci., 45: 537-541. 1983. 11) OTSUKA, J., T. NAMIKAWAand K. NOZAWA, Jpn. J. Zootech. Sci., 55: 174-182. 1984. 12) PAYNE, W. J. A. and D. H. L. ROLLINSON, World Anim. Rev., 7 : 13-21. 1973. 13) PHILLIPS, R. W., J. Hered., 52: 207-243. 1961. 14) YAMANE, J. and K. KATO, Zool. Mag. Jpn., 48: 705-716. 1936. 15) WALKER, E.P., Mammals of the world. 3rd ed. 1426-1430. Johns Hopkins Univ. Baltimore & London. 1975.

671 HAYASHI, OTSUKA and NISHIDA

バ ン テ ン と ア ジ ア在 来 牛5集 団 の 頭 蓋 計 測 に お け る

多 変 量 解 析

林 良博 ・大塚閏一*・ 西 田隆雄

東京大学農学部,東 京都文京区113 *鹿 児島大学農学部 ,鹿 児島市890

野 生 牛Bantengと ア ジ ア 在 来 牛5集 団(Bali牛, (2) 頭 蓋 の 形 状 の 差 異 を 示 す と 考 え ら れ る第二 主 成

Madura牛,Aceh牛,Leyte牛,韓 牛)と の 形 態 学 分 に よ っ て,Bali牛 とBantengの2者 は,ゼ ブ型 の

的 な 関 係 を 明 ら か に す る た め に,24の 頭 蓋 計 測 部 位 を 在 来牛 に属 す と考 え られ て い るAceh牛 とLeyte牛 の

用 い て 主 成 分 分 析 を 行 な っ た.そ の 結 果 は,以 下 の3点 2者 と 明 瞭 に 判 別 され た.Madura牛 は そ れ らの両 群 に 要 約 さ れ る. の 中 間 の位 置 を 占 め た.一 方.原 牛 型 の 在 来 牛 と考 え ら

(1) 第 一 お よ び 第 二 主 成 分 か ら な る 主 成 分 図 に お い て, れ て い る韓牛 は,大 き さの 要 因 を 示 す 第 一 主成 分 に よ っ Bali牛 は 在 来 牛 の な か でBantengに 最 も近 い 位 置 を て,他 の在 来 牛 お よ びBantengと 区 別 され た.

示 し た.こ の 結 果 は,Bali牛 がBantengか ら家 畜 化 (3) 主 成 分 分 析 に よ る集 団 間 の 判別 力 は,各主 成 分 を さ れ た と い う 仮 説 を 支 持 す る も の と 考 え ら れ る.ま た 頭蓋 計 測値 の相 関 行 列 か ら抽出 す るよ り も,共 分散 行 列

Bali牛 とBantengの 頭 蓋 に お け る 類 似 性 は,そ の 大 か ら抽 出 す る方 が 優 れ て い た.ま た計 測 部 位 を15箇 所

き さ で は な く,そ の 形 状 に 依 存 して い た.な おBali牛 か ら24箇 所 に増 やす こ と に よ って,判 別 力 も向上 した. の 頭 蓋 に お け る 性 差 は,Bantengの そ れ に 比 較 し て 小 日畜 会 報,59,(7):660-672,1988

さ か っ た.

日 畜 会 報,59(7):660-672 672 1988