Effect of founder allele survival and inbreeding depression on litter size in a closed line of Large White pigs

1998 ◽  
Vol 67 (3) ◽  
pp. 573-582 ◽  
Author(s):  
J. Rodrigáñez ◽  
M. A. Toro ◽  
M. C. Rodriguez ◽  
L. Silió

AbstractAn experimental herd of Large White pigs was established in 1931 and maintained as a closed population until 1992. The complete -pedigree (410 boars and 916 sows) has been analysed to measure along the succesive cohorts of breeding animals: thefounder representation and allele survival, the evolution ofcoancestry and inbreeding and the components of inbreeding due to each founder. Inferences about genetic and phenotypic parameters and effects of dam and litter inbreeding on litter size were obtained, using Bayesian techniques, from 2612 litter records. A significant mean reduction of 0·27 piglets born and 0·39 live born for each 10% of litter inbreeding was found but also evidence of variation among founder lineages in inbreeding depression. Alleles contributing to inbreeding depression were descendent from specific founder lineages.

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 133-134
Author(s):  
Mark Knauer ◽  
Zack Peppmeier

Abstract The objective of the study was to evaluate sow teat quality in relation to subsequent reproductive throughput. Data included one cohort of 42 Landrace × Large White second parity maternal line sows at the Tidewater Research Station (Plymouth, NC). Functional teats (FUNCTIONAL) were classified pre-farrow as acceptable (ACCEPTABLE) or substandard (SUBSTANDARD). Teats were categorized as SUBSTANDARD when teat size was ≤75% of ACCEPTABLE. At day 20 of lactation, ACCEPTABLE and SUBSTANDARD were assessed for the presence of a swollen mammary gland and piglets observed nursing SUBSTANDARD were recorded (24 piglets from 15 litters). Means for FUNCTIONAL, ACCEPTABLE and SUBSTANDARD were 15.07, 13.59 and 1.48 teats, respectively. Biological dam traits included birth weight (BWT), total number born (TNB), litter size at weaning (LSW) and piglet survival (LSW/TNB). Weaning weight (WWT) was considered a trait of the nurse dam. Means for TNB, LSW, litter BWT and litter WWT were 13.4, 10.9, 17.8 kg and 57.8 kg, respectively. Data was analyzed using a chi-square test for binary traits and linear mixed models for continuous traits. At weaning, a greater (P < 0.01) proportion of ACCEPTABLE had a functional mammary gland when compared to SUBSTANDARD (76 vs. 47%). Within litters, piglets nursing SUBSTANDARD tended (em>P = 0.09) to be 158 grams lighter at weaning in comparison to ACCEPTABLE. Yet BWT of SUBSTANDARD piglets did not differ (em>P = 0.60) from piglets nursing ACCEPTABLE. Across litters, an increase in one SUBSTANDARD tended (em>P = 0.07) to reduce litter WWT by 1.74 kilograms. An increase in one SUBSTANDARD tended (em>P < 0.07) to increase piglet survival by 3.5%. Results suggest substandard teats, identified pre-farrow, are less likely to have a functional mammary gland at weaning, impair piglet quality yet may enhance piglet survival.


1996 ◽  
Vol 1996 ◽  
pp. 18-18
Author(s):  
O.I. Southwood ◽  
S. Hoste ◽  
T.H. Short ◽  
A.J. Mileham ◽  
D. Cuthbert-Heavens

A significant relationship between the oestrogen receptor gene (ESR) and litter size has been detected in USA populations of Large White and a synthetic comprising 50% Meishan (Rothschild et al., 1995). Animals carrying two copies of the favourable allele (B) had an extra pig born per litter than those that did not have the allele. This paper reports on results observed in a UK 50% Meishan synthetic and four UK Large White lines.Litter size data from 50% Meishan synthetic (L93) full-sib females where more than one ESR genotype was segregating. Data were analysed using a mixed model with full relationships and including the fixed effects of season of farrowing, parity, ESR genotype (AA, AB or BB) and service type (AI or natural service). Heritiability and permanent environmental effects for litter size were assumed as 0.09 and 0.11, repectively. A total of 27 full-sib families were represented and included 62 sows and 139 litter records. Hypothesis testing used the option in PEST under a mixed model (Groeneveld et al., 1991).


Author(s):  
Tshepo Teele

Background: This study aimed to investigate the influences of sexual preparation on the effects of boars’ semen viability on the fertilization capacity of artificially inseminated sows. After all, boar sires more pigs than farrowed by a sow which the boar has been mated to improve reproductive parameters in response to AI. Methods: The semen viability of boars were studied during various sexual stimulations and analyzed during the study period. Sperm rich fractions were collected and separated at every level of sexual stimulation during the morning (08:30) and the afternoon (14:30) hours, respectively. Artificial insemination was performed following three levels of sexual preparations of boars (0 minutes of sexual restraint (MSR), 5 MSR and 10 MSR) before semen collection. Receptive sows were inseminated and evaluated for fertility traits using non-return rate, farrowing rate and litter size. Result: The non-return rate was recorded as a percentage of sows conceived after insemination over the total number of sows inseminated. The farrowing rate was recorded as a percentage of sows that farrows over the number of sows conceived and litter size as several live piglets per sow. Sexual desire was influenced by sexual preparations and significantly influenced the fertility of the artificially inseminated sows. This study is of practical significance to the animal breeder mainly because boars have greater influence than sows on the average litter size and live piglets. The study concludes that the use of at least 5 to 10 minutes of sexual restraint during the afternoon periods prior to semen collection and artificial insemination is found to be a practical method for optimizing sperm viability and fertility of sows in the intensive system.


2016 ◽  
Vol 20 (2) ◽  
pp. 357-361
Author(s):  
J.O. Oyedeji ◽  
G.O. Imagbenikaro

The study examined the effect of cooling on the reproductive performance of gilts using 27 Large White Experimental Gilts on a Completely Randomized Design (CRD) with 3 systems of cooling, namely Wallow Cooling (WC), Sprinkler Cooling (SC) and Zero Cooling (ZC). Gilts were weighed at the commencement of the experiment and thereafter fed ad libitum from service to farrowing. Feed intake till farrow, feed cost, gilt weight at farrow, date of farrow, litter size and weight were recorded. The feed/piglet weight, feed intake/litter, feed cost/litter and birth weight/piglet were derived. The results showed that feed intake per litter and feed per piglet weight were highest for gilts placed on WC(P< 0.05), followed by SC and least for sow placed on ZC; gilt weight before farrow was highest for sow placed on SC (69.78±0.92), followed by ZC (69.33±0.94) and least for gilts placed on WC (67.33±0.87); litter sizes of gilts placed under the WC and SC systems were similar (5.6±0.41) while that under the ZC system was comparatively smaller (5.4±0.40);while the date of farrow was lowest in the ZC system (113.8±0.32) followed by SC (114.0±0.33) and highest under the WC (114.1±0.33). However, the feed intake per litter, feed per piglet weight, litter sizes of gilts, birth weight per piglet of gilts and the average date of farrow among gilts placed on WC, SC and ZC were not statistically different at 5% level of significance. Though, there is no significant difference in the performance among gilts placed on WC, SC and ZC, temperature regulation through provision of efficient cooling system in piggery would help to increase litter size, improve feed intake per litter and reduce the average cost of feeding gilt per day in maximizing reproductive performances in pigs.Keywords: Cooling, gilts, service, farrow, piggery, litter size, piglet and birth weight


2015 ◽  
Vol 58 (2) ◽  
pp. 317-323 ◽  
Author(s):  
T. Kumchoo ◽  
S. Mekchay

Abstract. Osteopontin (OPN) gene is a secreted phosphoprotein which appears to play a key function in the conceptus implantation, placentation and maintenance of pregnancy in pigs. The objectives of this study were to verify the non-synonymous single nucleotide polymorphisms (SNPs) and their association with litter size traits in commercial Thai Large White pigs. A total of 320 Thai Large White sows were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Three SNPs at c.425G> A, c.573T> C and c.881C> T revealed amino acid exchange rates of p.110Ala> Thr, p.159Val> Ala and p.262Pro> Ser, respectively, and were then segregated. These three SNPs were significantly associated with total number born (TNB) and number born alive (NBA) traits. No polymorphisms of the two SNP markers (c.278A> G and c.452T> G) were observed in this study. Moreover, the SNPs at c.425G> A and c.573T> C were found to be in strong linkage disequilibrium. The association of OPN with litter size emphasizes the importance of porcine OPN as a candidate gene for reproductive traits in pig breeding.


2009 ◽  
Vol 52 (1) ◽  
pp. 51-64 ◽  
Author(s):  
A. Köck ◽  
B. Fürst-Waltl ◽  
R. Baumung

Abstract. In this study records of 58 925 litters of Austrian Large White and 17 846 litters of Austrian Landrace pigs were analysed. Regression models were used to determine the effects of litter, dam and sire inbreeding on total number of born, born alive and weaned piglets in Large White and Landrace. In both populations, litter and dam inbreeding showed a negative effect on all traits. Sire inbreeding had no effect in Large White, whereas a significant positive effect was observed in Landrace. On average, inbred sires with an inbreeding coefficient of 10 % had 0.45 more piglets born total and 0.43 more piglets born alive in comparison to non-inbred sires. In a further analysis the total inbreeding coefficients of the animals were divided into two parts: »new« and »old« inbreeding. »New« inbreeding was defined as the period of the first five generations. It was shown that the observed inbreeding effects were not only caused by recent inbreeding. Reproductive performance was also affected by »old« inbreeding. Finally partial inbreeding coefficients of four important ancestors in each population were calculated to investigate if inbreeding effects are similar among these ancestors. The results revealed a varation of inbreeding effects among the four ancestors. Alleles contibuting to inbreeding depression were descendent from specific ancestors.


2014 ◽  
Vol 66 (3) ◽  
pp. 1097-1103 ◽  
Author(s):  
Janne Thirstrup ◽  
Cino Pertoldi ◽  
Peter Larsen ◽  
Vivi Nielsen

Litter sizes in a cross between Brown and Black mink color types were observed through six generations. Litter size was significantly affected by yearly environmental variations. After adjusting for year effects, we found significant increases in litter size in the second and third generations (F2 and F3) after crossing. Thereafter, in the following generations, litter size dropped to a level comparable to the mean litter size of the midparent. Increased litter size in F2 compared to F1 indicated that maternal effects influenced litter size more than non-maternal effects. The heterosis was mainly caused by an increase in litter size compared to the Black parental line. This indicates that the Black line was affected by inbreeding depression prior to crossing. We also found that two-year old F1 females had significantly more offspring compared to one-year old F1 females.


2020 ◽  
Vol 50 (3) ◽  
pp. 434-441
Author(s):  
R. Klimas ◽  
A. Klimienė ◽  
W. Sobotka ◽  
W. Kozera ◽  
P. Matusevičius

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


2019 ◽  
Vol 97 (5) ◽  
pp. 1979-1986 ◽  
Author(s):  
Joaquim Casellas ◽  
Noelia Ibáñez-Escriche ◽  
Luis Varona ◽  
Juan P Rosas ◽  
Jose L Noguera

Author(s):  
P.R. Eastham ◽  
C.T. Whittemore

Weight gains can occur with substantial fat losses and therefore liveweight change is unlikely to form the basis of feeding strategies, whereas the fatness of the animal may be a more appropriate criterion. Eighty Large White x Landrace gilts were first mated at 123.5 kg ± 1.54 with a P2 of 14.5 mm ± 0.24 [Meritronics] and 12.7 mm ± 0.19 (Vetscan]. Half these gilts were fed to be fat [F] at parturition [target 20-24 mm P2) and half were fed to be thin [T] [target 10-14 mm P2). F gilts consumed more feed during pregnancy and gained more weight and backfat than T gilts [all differences between the 2 treatments were significant P˂0.001). The number of piglets born and the number of live births were not affected by feeding gilts to be fat or thin, but fat gilts produced significantly heavier piglets. After parturition, half of both F and T gilts were offered either 7 kg of food per day [H] or 3 kg per day [L] and half were sucked by litters of 5 piglets and half by litters of 10 piglets during a 28 day lactation. Piglets were not given creep feed. Fatness of the gilts at parturition, feed level during lactation and sucking litter size all significantly influenced both the absolute and the change in liveweight and backfat from farrowing to weaning. Weight and P2 changes are shown in Figures 1 and 2. The performance of the litter was also significantly affected by the fatness of the gilt at parturition and by the number of piglets sucking. Results for each treatment group are given in Table 1. Animals offered the high level of feed during lactation had a significantly shorter interval between weaning and conception. There were also positive relationships between readiness to rebreed and absolute liveweight and absolute fatness.


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