MASS SELECTION IN A PIG POPULATION. 2. THE EFFECTS OF INBREEDING WITHIN THE SELECTED POPULATIONS

1977 ◽  
Vol 57 (4) ◽  
pp. 627-634 ◽  
Author(s):  
HITOSHI MIKAMI ◽  
H. T. FREDEEN ◽  
A. P. SATHER
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Degrees Of Freedom ◽  
Regression Coefficients ◽  
Longissimus Dorsi ◽  
Mass Selection ◽  
Cross Sectional ◽  
Litter Weight ◽  
Daily Gain ◽  
Size At Birth

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.

scholarly journals Phenotypic relationships between gestation length and preweaning litter traits in rabbits.

2021 ◽  
Vol 31 (2) ◽  
pp. 154-160
Author(s):  
O. N. Durunna ◽  
U. E. Ogundu
Keyword(s):  
Litter Size ◽  
Average Daily Gain ◽  
Gestation Length ◽  
Litter Weight ◽  
Litter Traits ◽  
Degree Of Association ◽  
High Degree ◽  
The Relationship ◽  
Daily Gain ◽  
Size At Birth

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.

scholarly journals Effect of lighting schedule, intensity, and colour on reproductive performance of rabbit does

2021 ◽  
Vol 29 (1) ◽  
pp. 59
Author(s):  
Yingjie Wu ◽  
Ang Zhao ◽  
Yinghe Qin
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
White Light ◽  
Artificial Insemination ◽  
Red Light ◽  
Conception Rate ◽  
Reproductive Parameters ◽  
Litter Weight ◽  
Positive Effect ◽  
Size At Birth

<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>

scholarly journals Effect of re-mating intervals on growth and reproductive performance of rabbits

2013 ◽  
Vol 42 (2) ◽  
pp. 143-147
Author(s):  
BK Saha ◽  
MB Sarker ◽  
MH Alam ◽  
ME Kabir ◽  
MR Amin ◽  
...  
Keyword(s):  
Growth Rate ◽  
New Zealand ◽  
Litter Size ◽  
Milk Yield ◽  
Reproductive Performance ◽  
Gestation Length ◽  
Natural Lighting ◽  
Litter Weight ◽  
Nest Boxes ◽  
Size At Birth

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

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
Keyword(s):  
Least Squares ◽  
Litter Size ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Feed Utilization ◽  
Gestation Length ◽  
Litter Weight ◽  
Yorkshire Pigs ◽  
Score Line ◽  
Size At Birth

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.

THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: REPRODUCTIVE PERFORMANCE

1988 ◽  
Vol 68 (1) ◽  
pp. 69-81 ◽  
Author(s):  
MOHAMED H. FAHMY ◽  
JACQUES J. DUFOUR
Keyword(s):  
Body Weight ◽  
Mortality Rate ◽  
Key Words ◽  
Litter Size ◽  
Reproductive Performance ◽  
Conception Rate ◽  
Ovulation Rate ◽  
Genetic Groups ◽  
Linear Regressions ◽  
Size At Birth

Reproductive performance and body weight were studied on 361 ewes, representing Finnsheep (F), DLS (a population of 1/2 Dorset, 1/4 Leicester, 1/4 Suffolk) and seven combinations ranging from 1/8 to 7/8 Finnsheep breeding. Conception rate in yearlings was 61.5% for DLS compared to 89.0% for F with the crosses being intermediate. Conception rate in older ewes was similar in the different genetic groups (avg. 94%). Ovulation rate and litter size at birth of DLS ewes were 1.72 and 1.44 lambs, which was less than half those of F ewes (3.51 and 2.86 lambs, respectively). Both traits increased progressively with an increase in F breeding in crosses and with advances in age. DLS ewes weaned 1.22 lambs compared to 2.03 lambs for F ewes and 1.84 lambs for 4/8 F ewes. The heaviest litters at weaning (31.7 kg) were raised by 4/8 F ewes, followed by 7/8 F (30.8 kg) while those raised by DLS ewes weighed 23.0 kg and F ewes 29.1 kg. Percentage of ova lost per ewe mated averaged 24% and ranged between 18% (DLS and 1/8 F) and 29% (6/8 F). About 3.6% of lambs were born dead and a further 13.8% died before weaning. Preweaning mortality rate was highest in F (22.9%) and lowest in 3/8 F (9.4%). Average kilograms of lambs weaned per ewe exposed was highest in 4/8 F (27.6 kg) followed by F (26.0 kg), whereas that of DLS was the lowest at 18.1 kg. The 4/8 F cross showed 25% heterosis in kg of lambs weaned per ewe exposed and 52.5% increase over DLS. Significant positive linear regressions were calculated for ovulation rate, litter size and preweaning mortality rate on proportion of Finnsheep breeding in crosses. The relation was quadratic for percent ova lost and lamb mortality at weaning. Yearling DLS females weighted 36 kg compared to 44 kg for F yearlings. However, at 5 yr of age DLS ewes weighed 62 kg, 5 kg heavier than F ewes. The heaviest ewes at all ages were the 4/8 F (45 kg at 1 yr, 65 kg at 5 yr). Key words: Reproduction, DLS sheep, Finnsheep, crossbreeding, heterosis, repeatabilities

scholarly journals Effect of parity on reproductive performance sows of different breeds

2020 ◽  
Vol 50 (3) ◽  
pp. 434-441
Author(s):  
R. Klimas ◽  
A. Klimienė ◽  
W. Sobotka ◽  
W. Kozera ◽  
P. Matusevičius
Keyword(s):  
Survival Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Weaned Piglets ◽  
Large White ◽  
Litter Weight ◽  
Piglet Survival

The aim of this study was to determine the effect of parity on reproductive performance by sows of different breeds. The sows were raised on three farms, and had seven or more litters of not fewer than seven piglets. A total of 1511 litters from various parities of Lithuanian White (N =721), Large White (N = 162) and Landrace (N = 628) sows were contained in the data that were used in this study. Multiparous sows had larger litters than primiparous sows. Piglet survival rate declined from parity 7. An increase in litter size was observed until parity 5 in Large White and until parity 6 in improved Lithuanian White (P <0.05). In comparison with parity 1, Landrace sows up to parity 5 showed not only increased prolificacy, but also increased number and litter weight of piglets at 21 days old, and the number and litter weight of weaned piglets (P <0.01). The current findings indicate that sows of these breeds can be used effectively in breeding herds until parity 5 and parity 6.Keywords: Landrace, Large White, Lithuanian White, litter size

Effect of remating interval and diet on the performance of female rabbits and their litters

1993 ◽  
Vol 56 (3) ◽  
pp. 399-405 ◽  
Author(s):  
C. Cervera ◽  
J. Fernandez-Carmona ◽  
P. Viudes ◽  
E. Blas
Keyword(s):  
Factorial Design ◽  
Energy Intake ◽  
Litter Size ◽  
Intensive Treatment ◽  
The Other ◽  
Interactive Effects ◽  
Energy Concentration ◽  
Lactation Performance ◽  
Litter Weight ◽  
Size At Birth

AbstractIn an experiment of factorial design, female rabbits were given four diets, containing 13·0, 11·4, 10·4 and 9·7 kJ digestible energy (DE) per g and subjected to two remating intervals (R) of 1 to 2 days (intensive) or 9 days (semi-intensive) from parturition. The experiment lasted for 2 years during which 352 does produced a total of 1254 litters. The only major differences due to diet were that the diet with the highest energy concentration, and which contained 35 g/kg added fat, promoted a significantly higher energy intake in lactation (111 v. an average of 94 MJ DE) than the other diets, and thereby increased litter weight at weaning at 28 days (3·48 v. 2·99 kg). Diet and R showed no major interactive effects. The intensive treatment significantly reduced parturition interval (46 v. 52 days) and increased the output of weaned rabbits per doe per year (35 v. 29). As actual R was more variable than the theoretical R imposed by the treatments, further analyses were made by dividing the does into four groups according to the actual R. In these analyses, the effects of R on current and subsequent lactation performance were assessed separately. The main difference between the groups was that litter size increased significantly with R (e.g. litter size at birth in subsequent parities was 8·0, 9·2, 9·7 and 9·0 for mean intervals of 2, 10, 16 and 37 days). However, the same pattern of differences occurred in the current parity, indicating that it was litter size that affected R, rather than the reverse (i.e. does with small litters conceived earlier than those with larger litters).

Breeding Australian crossbred ewes with Arabian fat-tailed rams for intensive lamb production

1996 ◽  
Vol 36 (1) ◽  
pp. 31
Author(s):  
RC Malik ◽  
MA Razzaque ◽  
S Abbas ◽  
T Al-Mutawa ◽  
N Al-Khozam
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Reproductive Performance ◽  
Average Daily Gain ◽  
Survival Rates ◽  
Intensive Management ◽  
Season Of Birth ◽  
Genetic Groups ◽  
Sources Of Variation ◽  
Daily Gain

The reproductive performance under intensive management of Border Leicester x Merino (BLM), Dorset x Merino (DM), and Suffolk x Merino (SM) ewes imported from Australia, and local fat-tailed Naeemi (N) ewes mated to N rams was studied. Progeny performance for birth and weaning weights, average daily gain (ADG) and preweaning survival was also evaluated. BLM ewes showed the highest reproductive performance. They produced and weaned (at 8 weeks) significantly more lambs (P<0.05) than any of the other ewe genotypes. The reproductive performance of the BLM, N, DM and SM ewes, mated twice, 8 months apart, was 127, 85, 91 and 85 respectively for percentage of lambs born to ewes joined, 109, 72, 77 and 70 respectively for percentage of lambs weaned to ewes joined, and 17.8, 13.5, 12.1 and 11.6 kg respectively of lamb weaned per ewe joined over the period of 13 months from the first joining until last lambs weaned. The effect of season on ewe reproduction was significant. Birth weight was not influenced by genotype or season but did change significantly with litter size. Genetic group, litter size, season of birth and birth weight were significant sources of variation in the ADG and weaning weight of the lamb. N x BLM lambs were weaned at significantly heavier weights than lambs of the remaining 3 groups. Season of birth and birth weight also significantly affected preweaning lamb survival. About 86% of the lambs born alive were weaned with little difference between genetic groups in survival rates.

A note on the effect of white-flowered peas on sow reproductive performance

1993 ◽  
Vol 56 (1) ◽  
pp. 155-158
Author(s):  
R. B. Ogle ◽  
K. Annér
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Live Weight ◽  
Soya Bean ◽  
Weight Gains ◽  
Bean Meal ◽  
Piglet Mortality ◽  
Natal Mortality ◽  
Soya Bean Meal ◽  
Size At Birth

The effect on sow reproductive performance of including 100 g white-flowered peas (Pisum sativum hortense, cv. Vreta and Lotta) per kg, replacing barley, wheat and soya-bean meal in gestation and lactation diets, was studied over four parities using 24 pairs of crossbred littermate sows. Net sow weight gains and changes in backfat thickness over the complete reproductive cycle were similar for both treatments. Piglet live-weight gains and mean litter size at birth were not influenced by treatment, although litter size at weaning was 0·5 pigs higher (P > 0·05) for the control sows, due to higher post-natal mortality rate in the litters from the sows given the pea diets. It can be concluded that inclusion of white-flowered peas at a rate of 100 g/kg had no adverse effect on reproductive performance, with the exception of slightly higher post-natal piglet mortality.

INTERRELATIONS BETWEEN SOME REPRODUCTIVE TRAITS IN SWINE

1972 ◽  
Vol 52 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. H. FAHMY ◽  
C. S. BERNARD
Keyword(s):  
Litter Size ◽  
Survival Rates ◽  
Reproductive Traits ◽  
The Other ◽  
Gestation Length ◽  
Percentage Survival ◽  
Weaning Pig ◽  
Highly Correlated ◽  
Daily Gain ◽  
Size At Birth

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.

Sign in / Sign up

Export Citation Format

Share Document