GENETIC ANALYSIS OF PRODUCTIVE AND REPRODUCTIVE PERFORMANCE IN CROSSBRED PIGS
Loading...
Date
2010-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA
Abstract
ABSTRACT:
Data on 1662 pigs belonging to 50 and 75% Large White Yorkshire
(LWY)-desi crossbreds maintained at All India Coordinated Research Project on
Pigs, Tirupati born during 2005 to 2010 were utilizd to study the influenct of
genetic and non-gcnctic factors on reproductive traits, litter traits, body weights,
body measurements and avcrage daily gains. Prediction equations were
developed to cstirnatc body weights based on body meanmments. Genetic
parameters were estimated for various traits.
The overall least squares means for AFS, AFF, FL GP and SP were
329.05 * 2.90, 440.42 * 2.80, 171.15 ~t 2.97, 111.28 zt 0.26 and 283.87 * 3.00
days respectively. The effects of pcriod and stason only were significant on
reproductive baits.
The overall kast quarts mean LSB, LSW and LWB and LWW were
7.59 * 0.17, 6.94 0.16 piglets and 8.40 + 0.18 and 66.92 * 1.42 kg,
respectively. The effects of pcriod and parity were significant (Pg.O1) on
majority of the litter traits.
The overall least squares mcan body weights were 1.13 * 0.02, 2.13 It
0.01, 3.19 * 0.02, 4.29 * 0.02, 5.41 It 0.03, 6.48 0.03, 7.55 * 0.04, 8.72 * 0.05
and 9.97 * 0.06 kg at birth, 1, 2, 3, 4, 5, 6, 7 and 8 wks of age, respectively.
Genetic group, period, parity and litter size pup affected all pre weaning body
weights highly significantly except for the non-significant effect of stason on
body weight at birth. Scxual dimorphism in favour of males was evident from 1
to 6 weeks of age. Body weights of piglets born in rainy and winter seasons and
those from smaller litters recorded significantly higher body weights.
The overall least squares means for BL, HW. HG and PG varied from
22.68 to 50.58, 16.91 to 36.65, 23.27 to 47.43, 19.03 to 42.19 cm from bid to 8
weeks of age. The effect of litter size group was significant on all the biomctrical
measurements at various ages. Season also influenced body measurements at
birth, 2 and 8 weeks of age significantly where as at other ages it influmced one
(or) more traits but not all. Parity e f f i was significant on all the body
measurements at 4 and 6 weeks of age. Sexual dimorphism was evident on all
the body measurements at birth only. Significant effect of genetic group was
observed only on heart girth and paunch girth at birth and 2 woeks of age,
respectively.
The overall least squares mean ADG during 0 to 2, 2 to 4, 4 to 6, 6 to 8
and birth to 8 weeks wm 0.150 + 0.001, 0.160 f 0.001, 0.150 * 0.002, 0.170 *
0.002 and 0.160 * 0.001 kg, respectively. Pigs from smaller litters recorded
significantly higher ADGs.
Heritability of gestation period in 75% LWY group was 0.08 * 0.38 while
that of litter traits ranged hm 0.14 + 0.35 to 0.32 + 0.48 among the genetic
groups. Heritability estimates varied from 0.19 + 0.09 to 0.97 * 0.22 for body
weights and from 0.13 * 0.08 to 0.80 f 0.17 for ADGs. Heritability estimates
among body measurements were medium to high.
The genetic, phenotypic and environmental correlations among gestation
period and litter traits ranged hm -0.76 to 029, -0.24 to 0.01 and -0.22 to 0.35,
while those among litter baits wm all positive and high.
Genetic, phenotypic and environmental correlations among body weights
were positive and medium to high. Phenotypic comlations among body weights
were all positive. Comlations among ADGs were very low without any
consistent trend.
Phenotypic correlations among body measurements ranged from - 0.0 1 to
0.9 1 and among body weights and measurements, it ranged from -0.03 to 0.86.
Prediction equations were developed to predict body weight at birth 2, 4, 6 and 8
weeks of age based on cOrnSponding measurements on each genetic group. The
R~ values varied from 69.1 to 81.7 percent among the genetic groups. Multiple
regression equations developed at 2 and 8 weeks of age were found to be most
efficient of all.
Description
Keywords
null