THE PHILIPPINE WATER BUFFALO

estimated breeding values of (EBVs) (from Best Linear
Unbiased Prediction of BLUP mixed models) between
body weights at the different ages were generally not
significant (P>0.05). This is because individual EBVs that
are commonly expressed as the deviations from the
population mean, were small and close to zero. The EBV
for each trait however, should be used as the main criterion
for selection, either as an EBV of an animal for one trait or
as part of a selection index composed of more that one
trait. The high phenotypic correlations are recommended
to redesign the local breeding program to allow selection
for body weights at younger ages (i.e., yearling weight).
However, more studies to determine the genetic correlations
and relative economic values of body weights at different
ages are needed to properly derive a local multiple trait
selection index for water buffaloes.
Keywords: correlations between body weights, estimated
breeding values (EBVs)
*Proceeding of the PSAS 32 nd Annual Convention, PICC,
Metro Manila, October 26-27, 1995. p. 273-283. Also in
Philippine Journal of Veterinary Animal Science,
22(1&2):33-42. Also in Abstracts of Water Buffalo
Researches in the Philippines 1981-1995 (1996) p. 1, PCC-
DA. Also in Philippine Carabao Center R & D Highlights
1994-1996 (1997) p. 2-4, PCC-DA. Also in Annotated
Bibliography on Philippine Biodiversity: Livestock and
Poultry (Agrobiodiversity) 1949-1997, Carabaos (2002) p.
357
B-12
QUANTITATIVE ANALYSIS OF KARYOTYPIC
CHARACTERISTICS IN WATER BUFFALOES
(Bubalus bubalis)*
O. L. Bondoc, Associate Professor, IAS-CA, UPLB
I.. T. Santos, Research Assistant, IAS-CA, UPLB
M. R. Rapusas, Research Assistant, IAS-CA, UPLB
B. C. Gomez, Research Assistant, IAS-CA, UPLB
Twenty-eight (28) water buffaloes at the Philippine Carabao
Center (PCC) – U. P. Los Baños, belonging to five breed
groups namely, 6 Carabao (C), 5 Murrah (M), 5 F 1 (50%M
– 50%C), 4 F 2 (50%M – 50%C) and 8 backcross or
(75%M – 25%C), were used in the karyotype analysis.
Using the modified Leukocyte Culture Technique (Bongso
and Hilmi, 1982), blood samples were cultured and
processed. Photomicrographs were taken, scanned, and
further enhanced, magnified (4 to 5 times), and printed.
Chromosome pairs were manually cut and pasted according
to their length and position of centromere to from the
photokaryotype. Modal chromosome number and
chromosome type based on centromeric location were
BREEDING AND GENETICS
compared by simple frequency analysis. Analysis of
variance by ordinary least squares methods was used to
determine significant breed differences in relative length,
centromeric index, and arm ratio of all chromosomes.
Means of karyotypic characteristics were compared
between breeds using the Duncan’s Multiple Range Test
(DMRT). Based on a total of 2,973 cells examined, the
modal chromosome number for the Carabao (C), Murrah
(M), F 1 (50%M – 50%C), F 2 (50%M – 50%C) and
backcross or (75%M – 25%C) was 48 (80.25%), 50
(69.75%), 49 (83.31%), and 50 (55.35%), respectively.
The results of the present study are consistent with the
results reported by previous workers (Songsri and
Ramirez, 1979; Bongso, et. al. 1984). No metacentric
chromosomes were found for all breed groups examined.
For Carabao and Murrah breeds, 21% of all chromosomes
were submetacentric and the remainder (79%) acrocentric.
Chromosomes of the three crossbreed groups in contrast
were 20% submetacentric and 80% acrocentric. Significant
breed differences (P