The relationship between age at first effective service and numbers born in the gilt litter in purebred pigs

Author(s):  
J.T. Mercer

Practical use is made of an increase in the ovulation rate of gilts over the first few oestrous cycles. In large herds it may well be easier to increase the interval between entry into the herd and first service in order to improve the size of the first litter. The present study considers existing herd records, taken from the Easicare management system, in which the relationship between age at first litter and reproductive parameters in the first parity are examined. A total of 3778 gilt litters were involved, mostly Large White or Landrace, from 14 nucleus or multiplication herds. Average age at first litter ranged from 342 to 376 days across herds and total numbers born per litter from 9.03 to 11.27. Within herd variation in age at first service ranged from a standard deviation of 19 days to 40 days, that of litter size being more consistent, ranging from 2.45 to 3.21. The within herd regressions between these traits were generally small, averaging 0.007 piglets per day, and insignificant (p>0.05).

1996 ◽  
Vol 63 (1) ◽  
pp. 143-148 ◽  
Author(s):  
A. Blasco ◽  
J. Gogué ◽  
J. P. Bidanel

AbstractThe relationship between total number born (TNB), ovulation rate (CL) and prenatal survival was analysed in a French Large White population. The left ovary had a significantly (P < 0·01) higher ovulation rate (7·9) than the right ovary (6·9). Prenatal survival showed an ovum wastage of 35 or 37% depending on whether referred to total number born or number born alive. No differences between parities were found in these traits. There was a negative relationship between ovulation rate at both sides (v = −0·34). There was a negative relationship between CL and prenatal survival (r = −0·37), a low correlation between CL and TNB (i = 0·19), and a high positive correlation between prenatal survival and TNB (i = 0·82). Litter size showed a quadratic relationship with ovulation rate, and the individual variation for each class of ovulation rate was found to be high. The relationship between prenatal survival and ovulation rate was found to be linear, and a high individual variation for each class of litter size was also found. The relationships between prenatal survival and litter size were quadratic, but depended much less on individual variation.


1995 ◽  
Vol 60 (3) ◽  
pp. 471-479 ◽  
Author(s):  
G. J. Lee ◽  
M. Ritchie ◽  
M. Thomson ◽  
A. A. Macdonald ◽  
A. Blasco ◽  
...  

AbstractUterine capacity was estimated in Chinese Meishan (MS), Large White (LW) and crossbred (LW × MS) sows, using unilateral liysterectomy-ovariectomy (UHO) methods. In the first two parities, 20 sows of each genotype, whose left uterine horn and ovary had been removed in the post-pubertal period, were mated, their ovulation rate recorded by laparoscopy and allowed to farrow normally. In the third parity the mated sows were slaughtered at around 30 days of pregnancy and ovarian, uterine and embryo traits were recorded. The ovulation rate in UHO females was similar to that observed previously in intact females of the same population, MS sows producing 4·2 (s.e. 1·0) more ova at parities 1 and 2 and 7·0 (s.e. 1·9) more ova at parity 3 than LW sows. At parity 3, MS sows had 5·9 (s.e. 2·0) more viable embryos at 30 days of pregnancy than LW sows. Crossbred sows were intermediate for both ovulation rate and the number of viable embryos at 30 days. At the first two parities, litter size was higher in the MS by 1·0 (s.e. 0·8) piglets per litter than in the LW, while the crossbred sows exceeded the mid-breed mean by 1·7 (s.e. 0·7) piglets. Uterine capacity, estimated as twice the number of piglets carried to term in a single horn, was 12 foetuses in the LW, 14 in the MS and 16 in the crossbred sow. Piglets born to MS sows were 0·4 (s.e. 0·1) kg lighter than those born to LW sows, with a significantly lower (MS: LW = 0-68, P < 0·01) within-Utter standard deviation, which was found to be independent of the smaller mean weight. At parity 3, MS sows were found to have uteri of similar length with both lighter (-0·36 (s.e. 0·14) g) and shorter (-1·54 (s.e. 0·76) mm) embryos with smaller spaces (-7·8 (s.e. 2·7) cm) between embryo sites than LW sows. Within-Utter standard deviations for embryo size traits were lower in MS than in LW sows, especially for the distance between embryo sites (MS: LW = 0·45, P<0·01). The reduced variability of embryo traits in litters in MS sows was independent of their smaller litter means. Third parity litters from crossbred sows were similar to the mid-breed mean for means and variability of embryo traits but crossbred sows had significantly longer uteri (48·5 (s.e. 18·5) cm) than the mid-breed mean, being longer than either pure breed. It was concluded that differences between the pure breeds in uterine capacity may have arisen through better within-uterus organization, whereas the observed heterosis effects may result in part from physically longer uteri in crossbred sows and that uterine capacity contributes to the genotype differences in prenatal survival and prolificacy, especially in crossbred sows.


1995 ◽  
Vol 60 (2) ◽  
pp. 269-280 ◽  
Author(s):  
G. J. Lee ◽  
C. S. Haley

AbstractGrowth and survival from birth to weaning were monitored during three generations of crossbreeding between British Large White (LW) and Chinese Meishan (MS) pigs. The design allowed comparisons between sow genotypes ranging from zero to all MS genes, which were mated toLWor MS boars, to produce progeny with proportions of 0·0 to 0·5 or 0·5 to 1·0 MS genes, respectively. Crossbreeding parameters of both maternal and direct piglet performance were estimated for the first two parities using restricted maximum likelihood (REML) methods for litter traits (litter weight at birth, litter mean and within litter standard deviation of piglet weight at birth, proportion surviving to weaning, litter size and weight at weaning and litter mean piglet weight at weaning) and for traits of the piglet (birth weight, probability of survival and weaning weight). For litter traits, the estimated contribution of the additive maternal effect to the breed differences (MS-LW) was significant for litter mean piglet birth weight (–0·46 (s.e. 0·04) kg), survival to weaning (0·15 (s.e. 0·02)), litter size at weaning (1·6 (s.e. 0·16) piglets), litter weaning weight (–11·2 (s.e. 3·8) kg) and litter mean piglet weaning weight (2·54 (s.e. 0·24) kg). Adding litter size and litter mean piglet birth weight to the model removed the additive maternal contribution to the breed differences in survival, and litter size and reduced that for litter mean piglet weaning weight. The contribution of the direct additive effect to the breed difference (MS-LW) was significant for the within litter standard deviation in birth weight (0·018 (s.e. 0·006)), survival to weaning (0·12 (s.e. 0·02)) and litter size (1·12 (s.e. 0·64)) and weight (11·6 (s.e. 4·0) kg) at weaning, but not for piglet weight at birth or weaning. Fitting litter size and litter mean birth weight had comparatively little impact on the direct additive effects. There were significant maternal heterosis effects for litter weight at birth and litter size and weight at weaning, the estimated deviation of the F1 from the midpoint of the two purebreds 3·22 (s.e. 0·55) kg, 2·20 (s.e. 0·47) piglets, and 20·1 (s.e. 3·3) kg respectively, but none for survival or piglet weights. There were direct heterosis effects for litter weight and litter mean piglet weights, the estimated deviation of the Fjfrom the mid point of the two purebreds being 1·16 (s.e. 0·41) kg and 0·14 (s.e. 0·02) kg, for survival to weaning (0·04 (s.e. 0·02)) and for litter weight (11·2 (s.e. 2·5) kg) and litter mean piglet weight (0·96 (s.e. 0·17) kg) at weaning. Fitting litter size and litter mean piglet birth weight removed or reduced both maternal and direct heterosis effects. Individual piglet analyses gave similar results to analyses of the equivalent sow trait. It was concluded that in litters born to MS cows, the lower piglet survival and lower weaning weights were related to the larger litter sizes and lower piglet birth weights. For their birth weight, however, MS piglets have a greater ability to survive and thrive. The large direct and maternal heterosis effects observed for litter and mean piglet weight at weaning werepartly associated with the heavier birth weight of the crossbred piglet.


2014 ◽  
Vol 14 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Damian Knecht ◽  
Kamil Duziński

Abstract The aim of this study was to demonstrate the influence of the month of insemination on the reproductive performance of crossbred sows in moderate climates. The research material consisted of 309 primiparous and 625 multiparous (PLW×PL) sows kept on an industrial-scale farm. Analysis included 2457 litters obtained during a five-year period from 2006 to 2011. Statistically, the lowest number of piglets born alive and weaned was observed as a result of summer month insemination (July, August, September) compared to the winter months (February, March) (P≤0.01 and P≤0.05). Inseminations in the first four months of the year resulted in a higher number of piglets born alive in second and following parities (P≤0.01). Statistically significant differences in litter size due to the month of insemination were observed for sows in parities 4 and 5-11 (P≤0.01 and P≤0.05). The shortest farrowing interval was demonstrated for sows inseminated in November, the longest in January, March (P≤0.01) and April, July (P≤0.05). The results indicate that the insemination month of the sow may affect some reproductive parameters.


1979 ◽  
Vol 57 (2) ◽  
pp. 375-390 ◽  
Author(s):  
John R. Cary ◽  
Lloyd B. Keith

Reproduction was monitored during a 16-year study of snowshoe hare (Lepus americanus) populations near Rochester, Alberta. Pregnancy rate, ovulation rate, and litter size changed markedly between successive litters within the breeding season; these parameters were thus further categorized by litter in our analyses. Most reproductive components varied significantly between years; a significant '10-year' periodicity was the dominant source of this variation. The cyclic fluctuations of reproductive parameters were broadly synchronous and tended to precede the population cycle by about 3 years, thereby producing a range in potential natality annually of 7.5 to 17.9 young per female. The year-to-year variability of pregnancy rate, ovulation rate, and litter size was markedly larger in the later litters than in the early ones. Paunched weight, mean age, incidence of endoparasites, liver and spleen weights, and midwinter-to-spring weight change also possessed significant 10-year cycles; paunched weight cycled directly with the hare population, but the others cycled either directly with or counter to reproduction. We believe that the correspondence between midwinter-to-spring weight change and reproduction implicates winter nutrition as the primary cause of the cyclic variation. Onset of spring accounted for a significant amount of variability in onset of breeding, adding to that due to the periodic change.


2017 ◽  
Vol 57 (6) ◽  
pp. 1040
Author(s):  
W. H. E. J. van Wettere ◽  
M. Mitchell ◽  
D. K. Revell ◽  
P. E. Hughes

The effect of moderate restriction of pre- and peri-pubertal liveweight gain on puberty attainment and potential litter size was investigated. At 69 days of age, 48 Large White/Landrace crossbred gilts (28.3 ± 0.3 kg), were fed to attain a liveweight of 70 kg (LIGHT) or 100 kg (HEAVY) at 161 days of age (n = 24 gilts/treatment). At 161 days of age, half the gilts in each group were fed to gain liveweight at 0.5 (LOW) or 1.0 (HIGH) kg/day until puberty (n = 12 gilts/treatment). From 175 days of age, gilts received 20 min/day of full, physical boar contact. Gilts were artificially inseminated at the pubertal oestrus, with reproductive tracts collected 22 ± 0.1 days later, and the number of corpora lutea and viable embryos recorded. LIGHT-LOW gilts were older (P < 0.05) at puberty compared with LIGHT-HIGH, HEAVY-LOW and HEAVY-HIGH gilts; 207.7 ± 3.50 versus 191.7 ± 3.65, 193.1 ± 3.50 and 192.5 ± 3.65, respectively. Treatment (HIGH vs LOW) increased (P < 0.05) pubertal ovulation rate (15.2 ± 0.43 vs 13.1 ± 0.47), oestradiol at oestrus (13.4 ± 1.87 vs 9.1 ± 1.22 pg/mL) and progesterone 72 h post-oestrus (7.1 ± 0.48 vs 4.6 ± 0.50 ng/mL). Embryo number (10.8 ± 0.46) and survival (77.0 ± 3.21) were unaffected (P > 0.05) by treatment. To conclude, puberty was delayed by chronic, but not acute, dietary restriction. Although short-term, moderate increases in feed intake increased pubertal ovulation rates, embryo numbers and survival were unaffected.


1975 ◽  
Vol 20 (3) ◽  
pp. 401-406 ◽  
Author(s):  
D. J. A. Cole ◽  
M. A. Varley ◽  
P. E. Hughes

SUMMARYForty litters were weaned from their Landrace × Landrace × Large White dams at 2-day intervals to give a range of lactation lengths from 4 to 42 days. A significant (P<0·001) negative curvilinear relationship was observed between lactation length and the interval from weaning to first oestrus. This period was increased by 4·2 days with the reduction of lactation from 42 to 4 days. The relationship between lactation length and the interval from farrowing to remating was significant (P<0·001) and positively linear over the whole range of observations. A decrease of 1 day in lactation length reduced this interval by 0·91 days. Very short lactations were associated with reduced litter size at the following farrowing; sows weaned after lactation lengths between 4 and 21 days had an average litter size of 9–6 piglets born per litter in the next parity, whereas sows weaned following lactation lengths between 21 and 42 days had an average of 12·7 piglets born in the next parity (P<0·01).


1988 ◽  
Vol 60 (6) ◽  
pp. 585-590
Author(s):  
J. B. Owen ◽  
I. AP Dewi

The Cambridge breed has been developed since 1964, based on a foundation group of 54 ewes representing 11 breeds mated initially to seven Finnsheep rams. Data presented show that a high litter size(LS) has been established (mean 2.8 in 3 year old ewes) by a policy of selection coupled with minimising generation interval. Observations on ovulation rate (OR)show a large range (1—13) and are consistent with an hypothesis that OR is influenced by a major gene effect superimposed on a basal level of about 2.5 ova. The gene appears to increase ovulation by about two ova per copy and to have a frequency approaching 0.3 in the Bangor University flock. Data on the relationship of LS at birth and of lambs weaned per ewe are presented which indicate that under ideal conditions the optima for OR and LS at birth cannot exceed 5 and 3.5 respectively for mature ewes. The practical utilisation of the breed as a dam-line sire of crossbred ewes show that the Cambridge crossbreds are more precocious, more prolific, have slower growing lambs with carcasses of similar quality to the corresponding Border Leicester crosses. Overall superiority inefficiency of feed utilisation is about 20 %. Methods of genotyping sheep and utilising the major gene in practice are discussed.


2012 ◽  
Vol 57 (No. 5) ◽  
pp. 220-230 ◽  
Author(s):  
J. Wolf ◽  
M. Wolfová

The proportion of variance for service sire effect was estimated for three litter size traits (numbers of piglets born, born alive, and weaned) in Czech Large White (89 231 litters) and Czech Landrace (28 320 litters) pigs. Each trait in the first parity was considered as one trait and that trait in the second and subsequent parities was treated as a repeated trait. Consequently, three two-trait animal models were evaluated for each litter size trait: (i) the service sire effect was included and the complete relationship matrix for all the animals (service sires and sows) was taken into account; (ii) the service sire effect was included as a random effect without inclusion of the relationship matrix; (iii) the service sire effect was omitted from the model. Using the residual variance as a criterion, both models including the service sire effect were slightly better than the model without this effect. Estimates of genetic parameters were very similar for the two models including the service sire effect. The proportion of variance for service sire was in the range from 2&nbsp;to 3% (standard error approx. 0.2%) in Czech Large White and 2% (standard error approx. 0.3%) in Czech Landrace for all three litter size traits and all models. Models without service sire effect or models including service sire as a simple random effect and without inclusion of the genetic relationship matrix are recommended for genetic evaluation of litter size traits. &nbsp;


2018 ◽  
Vol 4 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Md Abdullah Al Mansur ◽  
Md Golam Shahi Alam ◽  
Pankaj Kumar Jha ◽  
Md Asaduzzaman Rimon ◽  
Nazmun Naher ◽  
...  

This study was undertaken to assess the reproductive performances of sheep at field level of Rajshahi and Mymensingh district of Bangladesh during January to December, 2016. A total of 52 farms (26 each in Rajshahi and Mymensingh) were selected for determining the reproductive parameters of ewes. Ewe lambs in Mymensingh reached puberty at significantly (P<0.03) younger age (186.9±18.4 days) than in Rajshihi (199.9±24.9 days). The average age at first pregnancy was 201.4±20.0 days in two regions. Similarly, the ewes in Mymensingh was lambing at significantly (P<0.002) early age than ewes in Rajshahi (356.0±6.8 days vs. 372.7±27.8 days). The observed duration of oestrus at Rajshahi and Mymensingh was 36.0±6.7 hrs and 36.0±7.3 hrs, respectively. The gestation length varied from 145 to 150 days. The average gestation length was 147.9±3.4 days in two regions. The gestation length was not significant (P˃0.05) in the ewes between Rajshahi and Mymensingh (148.7±3.4 and 147.1±3.2 days; respectively). The pooled over litter size was 1.6±0.2 in two regions. However, there was no significant (P>0.05) difference in litter size of ewes in Rajshahi and Mymensingh region (1.7±0.2 vs. 1.6±0.2). The pooled lambing interval was 193.9±21.7 days in two regions. Mean birth weights of lambs, weaning weight and mature weight were 1.7±0.6 vs. 1.3±0.1 kg; 8.9±2.7 vs. 6.9±1.0 kg and 24.9±7.3 vs. 19.4±2.7 kg in Rajshahi and Mymensingh, respectively. These reproductive parameters were significantly higher (P<0.001) in Rajshahi compared with in Mymensingh. The reproductive parameters are almost similar between confined and the traditional management system if the farms are well managed.Asian J. Med. Biol. Res. March 2018, 4(1): 63-68


Sign in / Sign up

Export Citation Format

Share Document