REPRODUCTIVE PERFORMANCE OF GILTS FROM LINES SELECTED FOR FEED UTILIZATION AND CARCASS SCORE

1972 ◽  
Vol 52 (2) ◽  
pp. 267-271
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD

Eight reproductive traits were studied on 751 gilts of 3 lines of Yorkshire pigs derived from a common population by selecting for feed utilization (line 1), carcass score (line 2), and for both traits combined (line 3) during 10 generations. Least squares means for the traits were as follows: gestation length 115.2 days; litter size at birth 9.0 pigs (total) and 8.4 pigs (alive); litter size at weaning 6.8 pigs; number of teats 13.4; and litter weight at birth, 21, and 56 days, 9.3, 32.6, and 92.6 kg, respectively. Heritability estimates were calculated for each line by half-sib correlation and intra-sire regression of offspring on dam. The pooled estimate for the above eight traits was 0.45, 0.11, 0.09, 0.15, −0.12, 0.08, 0.14, and 0.14, respectively. Line effect was highly significant for all traits except litter size at birth. Means and heritabilities for line 3 were higher than those for lines 1 and 2, which did not differ greatly from each other. Variation from year to year had significant effects only on litter weight at different ages. The within years–within line regressions of the eight traits on inbreeding were not significant. The within line phenotypic correlations between each of feed utilization and carcass score and the eight traits were generally low and nonsignificant.

2013 ◽  
Vol 42 (2) ◽  
pp. 143-147
Author(s):  
BK Saha ◽  
MB Sarker ◽  
MH Alam ◽  
ME Kabir ◽  
MR Amin ◽  
...  

The aim of this study was to know the effects of postpartum re-mating intervals on reproductive performances of does and growth of kits. Fifteen female New Zealand White crossbred rabbits were divided into three groups of equal numbers. They were re-mated within 24 hours, at 10 days and 28 days postpartum. Animals were individually caged in cells measuring 2'×2'×2'. Does were kept under natural lighting. Plastic nest boxes were supplied to does 3-4 days before parturition. They were reared up to four generation. Litter weight at birth was significantly (p<0.05) higher at 10 days postpartum than within 24 hours and at 28 days postpartum intervals. Higher growth rate was observed in 10 days postpartum group comparing to other re-mating groups. Milk yield of the dams were significantly (p<0.05) higher when dam re-mated at 10 days postpartum than those re-mated within 24 hours after parturition. Conception rate, gestation length of does, litter size at birth and weaning, litter weight at weaning, doe weight at mating, kidding, weaning and kid mortality did not differ significantly among the groups. Rabbit does re-mated at 10 days postpartum show maximum litter weight at birth, growth rate of kits and milk yield of dam.DOI: http://dx.doi.org/10.3329/bjas.v42i2.18497 Bang. J. Anim. Sci. 2013. 42 (2): 143-147


1972 ◽  
Vol 52 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD

The associations between 15 preweaning traits in pigs were studied to determine which had the most important effects on litter weights at birth and weaning. The traits were litter size at birth and weaning, number born alive, percentage survival to birth and weaning, pig and litter weights at birth and weaning, daily gain from birth to weaning, gestation length, number of teats, weights of dam at farrowing and at weaning, and the change in dam weight during lactation. Of the 105 correlations, 66 were statistically significant, though many were markedly low. Litter weights at birth and weaning were significantly and relatively highly correlated with most of the other traits, whereas number of teats was correlated only with survival rates at birth and weaning and pig birth weight. The results showed that the importance of litter size was almost twice that of pig weight in determining litter weights at birth and weaning. The results in general indicated that most of the economically important traits related to swine reproductivity are favorably associated.


1977 ◽  
Vol 57 (4) ◽  
pp. 627-634 ◽  
Author(s):  
HITOSHI MIKAMI ◽  
H. T. FREDEEN ◽  
A. P. SATHER

The regression of reproductive performance of dams and post-natal performance of progeny on inbreeding was examined for a population of replicated lines subjected to mass selection over a period of nine generations. Inbreeding advanced by 2.0–2.3% per generation. Regression coefficients per 1% increase in inbreeding, based on 817 degrees of freedom for first parity sows, were −.56 ±.23 kg for dam weight at first parturition (12 mo), −.48 ±.19 kg for dam weight change from parturition to weaning, −.013 ±.034 for litter size at birth, −.103 ±.033 for litter size at weaning and −1.36 ±.36 kg for litter weight at weaning. Regressions for post-natal traits, estimated for progeny produced by second parity dams during the final three generations (638 df) were 10.3 ± 4.0 g for birth weight, 16.8 ± 32.7 g for weaned weight, −4.53 ± 1.22 g for post-weaning daily gain, −.34 ±.16 mm for backfat,.10 ±.04 cm2 for cross-sectional area of the longissimus dorsi, and.09 ±.04% for estimated yield of trimmed retail product from the carcass.


Author(s):  
N. Savino ◽  
Z. Chusi ◽  
A. Dhali ◽  
P. Perumal

The present study was conducted to measure the reproductive attributes of Naga local pigs (Votho) in Kohima, Peren and Phek district of Nagaland. The reproductive parameters were measured through field survey and reproductive records of owner. The reproductive parameters such as age at first fertile service (AFFS), age at first farrowing (AFF), gestation length, farrowing interval, litter size at birth, litter size at weaning, litter weight at birth, litter weight at weaning, mortality rate and stillbirth rate were measured. The result revealed that there was a significant difference among the different districts of Nagaland in AFFS, AFF and litter weight at birth. Parameters such as AFFS, AFF and litter weight at birth were significantly higher and gestation length, farrowing interval, litter size at weaning, litter weight at birth, litter weight at weaning were non-significantly higher in Kohima than in Peren and Phek District. Similarly, parameters such as litter size at birth, mortality rate were non-significantly higher in Peren district and stillbirth was non- significantly higher in Phek district than other districts of Nagaland. These reproductive attributes analyses may be useful in selection of breeding stock for future parents and select the place for breeding programme for indigenous local Naga pigs.


Author(s):  
Uday Kannegundla ◽  
S. Sai Reddy ◽  
M. Gnana Prakash ◽  
M. Mahenderand ◽  
P. Amareswari

Study was conducted to evaluate the performance of Soviet Chinchilla and Californian White rabbit breeds maintained in tropical environment at rabbit research station, Hyderabad, Telangana. Data generated on total of 1364 bunnies, 701 belongings to the Soviet Chinchilla born in 122 litters and 663 bunnies of Californian White born in 124 litters during the period from 2012 to 2015 were utilized to examine the various productive performance traits. The overall least-squares mean litter size and litter weight was 5.52 ± 0.16 and 264.75 ± 7.86 at birth and 3.56 ± 0.17 and 1439.67 ± 72.55 g at weaning, respectively. The overall least-squares mean pre weaning body weights were 48.39 ± 0.48, 113.65 ± 1.38, 161.50 ± 2.03, 226.15 ± 3.47, 417.89 ± 7.53g at birth, 1, 2, 3 and 4 weeks of age and the post weaning weights at 6, 8, 10, 12, 14 and 16 weeks of age were 628.75 ± 13.02, 844.11 ± 14.81, 1040.79 ± 16.42, 1225.96 ± 17.81, 1437.57 ± 20.54 and 1636.99 ± 28.87 g, respectively. Season of birth and litter size at birth showed significant (£0.01) effect on body weights while genetic group, parity of the doe and sex of the bunny had slight effects only. The low to high heritability estimates, genetic and phenotypic correlations of body weights are the indication for improvement of body weights by appropriate breeding plans.


2021 ◽  
Vol 31 (2) ◽  
pp. 154-160
Author(s):  
O. N. Durunna ◽  
U. E. Ogundu

A total of 135 kittens from 22 kindlings were used to determine the relationship between gestation length (GL) and some preweaning litter traits alongside the weight of their 12 dams. Average daily gain at 21 days (ADG21), average litter weight at birth (ALWB), kindling to weaning viability (KWV), litter size at birth{L.SB), litter size at 21 days (LS21), litter weight at 21 days(LW21), litter weight at birth (LWAB), and still birth number (SBN) when subjected to multiple regression analysis revealed non-significant t-test value with GL. However, Average litter weight at 21 days (ALW21) was highly significant (P<0.01) suggesting that such can be used to predict GL. Weight of doe (WOD) was highly significant (P<0.01) showing that such parameter is important for predicting GL. A high R2 value was obtained indicating that the variability in GL is explained by the linearity of the preweaning litter traits and WOD. However the correlation coefficient R, (0.89) revealed a high degree of association between the preweaning litter traits in the rabbits and the weight of doe in a linear form. The F-value was significant at P<0.05 indicating that WOD and the preweaning litter traits in rabbits have significant contribution to the variation in GL. The correlations among traits were positive and significant for majority of the traits, which include live birth number (LBN), ADG21, ALW21, KWV, LS21, and LW21. However SBN had negative correlation with other traits.


2021 ◽  
Vol 29 (1) ◽  
pp. 59
Author(s):  
Yingjie Wu ◽  
Ang Zhao ◽  
Yinghe Qin

<p>In order to establish a lighting regime suitable for rabbit farms in East China, the effects of lighting schedule, intensity and colour on the reproductive performance of rabbit does were evaluated by three experiments, respectively. In experiment 1, does were exposed to different lighting schedules: 16L:8D-continuous, 16L:8D-18d (6 d before artificial insemination (AI) to 12 d post-AI), 16L:8D-6d (6 d before AI to the day of AI) and 12L:12D-continuous. In experiment 2, does were exposed to different light intensities: 40 lx, 60 lx, 80 lx and 120 lx. In experiment 3, does were exposed to different light colours: white, yellow, blue and red. For all experiments, conception rate, kindling rate and pre-weaning mortality were calculated; litter size at birth, litter weight at birth, litter size at weaning, litter weight at weaning and individual kit weight at weaning were recorded. Results showed that none of the reproductive parameters of does were affected by the application of 16L:8D-18d lighting schedule compared with the continuous 16L:8D group(<em>P</em>&gt;0.05). Moreover, rabbits does exposed to 80 lx light performed as well as those under 120 lx light in conception rate, kindling rate, litter size (total and alive) at birth and litter weight at birth (<em>P</em>&gt;0.05). Furthermore, the exposures of 60 lx and 80 lx light were beneficial for litter weight at weaning. In addition, red light had a positive effect, as it led to a larger litter size and litter weight at weaning and lower pre-weaning mortality than white light (<em>P</em>&lt;0.05). In summary, a 16L:8D photoperiod with 80 lx red light from 6 d before AI to 12 d post-AI is recommended for use in breeding of rabbit does according to our results.</p>


2007 ◽  
Vol 2007 ◽  
pp. 66-66
Author(s):  
W. Mekkawy ◽  
R. Roehe ◽  
R. M. Lewis ◽  
M. H. Davies ◽  
A. M. Van Heelsum ◽  
...  

The reproductive performance of ewes is a major factor influencing the economic success of lowland flocks. Even so reproductive traits have not often been included in sheep genetic improvement programs because of their low heritabilities compared with other performance traits like body weight and carcass merit. Litter size is one of the most important traits affecting reproductive performance. There are two important factors to be considered in the genetic analysis of litter size. First, several authors have suggested that litter size in different parities is controlled in part by different genes, and therefore should be treated as different traits. Second, ignoring the categorical nature of litter size and analysing it using a linear model does not account for its non-normal distribution. As a consequence, threshold models are likely to be more appropriate for the analysis of categorical traits (Gianola and Foulley, 1983). Therefore, the objective of the current study was to estimate the genetic parameters for litter size of Mule ewes using both repeatability and a multiple trait threshold models for repeated observations of litter size across four different parities.


1977 ◽  
Vol 17 (85) ◽  
pp. 256 ◽  
Author(s):  
K Baharin ◽  
RG Beilharz

The reproductive performance of 308 boars with total records of 9220 matings from a large commercial farm was analysed. The boars were purebred Large White, Landrace and from the newly synthesized M breed and were mated to purebred and crossbred sows of the same breeds. The M breed was derived from crossing between Large White and Landrace pigs with foundation females selected on the basis of their ability to produce large litters. Over half the total records were from matings with sows of parity 1 and parity 2. Overall production statistics were 78.8 per cent conception rate, an average total litter size of 9.3 pigs born per litter, 6.5 per cent stillbirths, an average litter weight (live piglets) at birth of 12.2 kg, average birth weight per piglet of 1.43 kg and average gestation length of 11 5 days. Most of the traits analysed showed significant effects due to parity of dams, with performance increasing from parity 1 to parity 6 to 8, after which the performance began to decline. There were significant heterosis effects (mainly maternal) on reproduction of the sows and survival performance of the litters resulting in an estimated improvement of 11 per cent in number of live pigs born, 12.4 per cent in total litter weight at birth and 35 per cent reduction in stillbirths. Heritability estimates were generally low for most traits except for boar conception rate which was moderate (0.29).


2021 ◽  
Vol 18 ◽  
pp. 61-65
Author(s):  
I. K. ODUBOTE ◽  
J. O. AKINOKUN

Fifty two litters obtained over a period of 8 months (December 1986-July 1987) from the mating of eight bucks with twenty nine does (first mating) and twenty three does (second mating) all belonging to the New Zealand White breed of rabbits were used in this analysis. Mean gestation length, number of mating to conception, litter size at birth and parturition interval were 31.6 ± 0.2 days, 1.4 ± 0.1, 5.6 ± 0.3 pups and 79.0 ± 14.5 days respectively. Litter weight at birth, 3,6 and 8 weeks of age were 230.4 ± 9.5g, 602.1 ± 35.6g, 1247.5 ± 81.5g and 1673.0 ± 112.3g respectively. Parity significantly (P <0.05) affected the number of mating to conception and litter birth weight. Litter weight at all ages were influenced (P<.01) by corresponding litter sizes at such ages. Sire neither had any effect on litter weight at all ages nor on any of the reproductive parameters studied. Litter size at birth was negatively correlation with gestation length (-0.08), number of matings to conception (-0.27) and average birth weight (-0.42). 


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