Genetics of the interval from weaning to estrus in first-litter sows: correlated responses.

Napel, J. ten; Meuwissen, T.H.E.; Johnson, R. K.; Brascamp, E.W.

doi:10.2527/1998.764937x

Cited by 15 publications

(7 citation statements)

References 17 publications

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“…Selection for decreased A100 will also favorably decrease the interval from weaning to first service. This is contrary to results of ten Johnson (1997) andten Napel et al (1998), which suggested that selection for increased daily gain and reduced BF would increase the probability of a long WTS interval. They found no correlation to the interval from weaning to first service treated as a continuous trait, and they also questioned the accuracy of using WTS on a continuous scale.…”

Section: Discussioncontrasting

confidence: 98%

Genetic correlations between reproduction and production traits in swine1

Holm

Bakken

Klemetsdal

et al. 2004

Journal of Animal Science

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Genetic correlations between reproduction and production traits were estimated in swine. Reproduction traits investigated were age at first service (AFS), number of live-born piglets in the first litter (NBA1), interval from weaning to first service after first litter (WTS1), number of live-born piglets in the second litter (NBA2), and interval from weaning to first service after the second litter (WTS2). Females generating the data were Norwegian Landrace born in nucleus herds between 1990 and 2000, and the number of records ranged from 13,792 to 56,932. Genetic correlations were estimated among the main production traits in the breeding goal: adjusted age at 100 kg live weight (A100), percentage of lean meat content (LMC), individual feed consumption from 25 to 100 kg (FC), and bacon side quality (BSQ). Average adjusted backfat thickness (BF) was included as a production trait. The A100 and BF traits were recorded on gilts on-farm with 190,454 records, whereas LMC, BSQ, and FC were recorded on-station with the number of records ranging from 12,487 to 12,992. Analyses were carried out with a multivariate animal model using average information restricted maximum likelihood procedures by first running each reproduction trait with A100 and BF, followed by each reproduction trait with LMC, BSQ, and FC. Average heritabilities for reproduction traits were as follows: AFS (0.38), NBA1 (0.11), WTS1 (0.06), NBA2 (0.12), and WTS2 (0.03); and for production traits: A100 (0.30), BF (0.44), FC (0.22), LMC (0.58), and BSQ (0.23). The highest genetic correlation was estimated between A100 and AFS (r(g)= 0.68), also resulting in a positive genetic correlation between FC and AFS. Growth (A100) was negatively (i.e., unfavorably) genetically correlated to NBA1 and NBA2 (r(g) = 0.60 and rg = 0.42 respectively), and so the genetic correlation to FC also became unfavorable (r(g)= 0.23 and r(g) = 0.20). Single-trait selection for enhanced LMC would also affect NBA1 and NBA2 unfavorably (r(g)= -0.12 and r(g)= -0.24). Correlations between BF at 100 kg live weight and reproduction traits were close to zero; however, a low genetic correlation between BF and WTS1 was obtained (r(g)= -0.12), indicating that selection toward reduced BF at 100 kg live weight may have an unfavorable impact on WTS1.

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Section: Discussioncontrasting

confidence: 98%

Genetic correlations between reproduction and production traits in swine1

Holm

Bakken

Klemetsdal

et al. 2004

Journal of Animal Science

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“…Estimates between these traits reported by ten Napel et al (1998) were close to zero, −0.09 and 0.08, respectively. The genetic correlation between BC and PREGNANT was positive but with large PSD (r g = 0.18, PSD = 0.27).…”

Section: Correlationsmentioning

confidence: 59%

“…same population at 0.14 (Lundgren et al, 2012). In a study by ten Napel et al (1998), body condition at weaning was measured by trained technicians using a similar scale as in the present study. The heritability was estimated at 0.33.…”

Section: Heritabilitiesmentioning

confidence: 97%

Genetic parameters for feed intake, litter weight, body condition and rebreeding success in primiparous Norwegian Landrace sows

Lundgren

Fikse

Grandinson

et al. 2014

Animal

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The aim of this study was to estimate genetic parameters for feed intake recorded as farmers' perception of young sows' appetite for the first 3 weeks of lactation (APP) and feed intake recorded for one day in the 3rd week of lactation (FEED), litter weight (LW) at 3 weeks, sow body condition at weaning (BC) and the following five reproduction traits: weaning-to-service interval of 1 to 7 days (WSI7), weaning-to-service interval of 1 to 50 days (WSI50), delayed service or not (DELAYED), pregnant on first service or not (PREGNANT) and litter size in 2nd parity (NBT2). The analyses included data on 4606 Norwegian Landrace 1st-parity sows and their litters. The Gibbs sampling method was used. The traits DELAYED and PREGNANT were analysed as threshold traits and APP, FEED, LW, BC, WSI7, WSI50 and NBT2 were analysed as linear traits. The heritability estimates for APP and FEED were low (<0.1), whereas the estimates for DELAYED and PREGNANT were rather high (0.4 and 0.3). The heritability estimate for BC was 0.2. The genetic correlations confirmed the complexity of breeding for sow performance; selection for heavy 1st litters may lead to lower body condition at weaning, which in turn leads to lower reproductive performance and smaller litters in 2nd parity. Selection for higher sow feed intake would improve body condition, but the simple way of measuring feed intake tested in this study (APP and FEED) cannot be recommended because of the low heritability obtained for these traits.

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“…In adjusting litter size for previous WCI, we are assuming that the effect is mainly environmental. The genetic correlation between WCI and litter size is reported to be small (Adamec and Johnson, 1997;Ten Napel et al, 1998). If WCI has an important genetic correlation with litter size, then the correct procedure would be to use a multivariate model to produce EBV for both litter size and WCI.…”

Section: Resultsmentioning

confidence: 99%

Accounting for lactation length and weaning-to-conception interval in genetic evaluations for litter size in swine.

Marois

Brisbane

Laforest

2000

Journal of Animal Science

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Effects of lactation length and weaning-to-conception interval on the subsequent litter size of purebred sows were estimated using an animal model. Data on 2,847 Landrace sows with 7,125 litters born between January 1989 and May 1997 and on 1,234 Yorkshire sows with 2,999 litters born between January 1990 and May 1997 were obtained from two Canadian selection herds. Sows having a lactation of less than 14 d (MMEW) were usually not mated until their second estrus, whereas sows weaned after at least 14 d of lactation (later weaning) were usually mated on their first estrus. Litter size included both number of pigs born alive and those stillborn. Linear, quadratic, and logarithmic effects of lactation length were tested. The effect of weaning-to-conception interval on litter size was modeled using an approach based on threshold variables and an approach using segmented polynomials. Results indicated linear and logarithmic effects of lactation length on subsequent litter size for Yorkshire and Landrace breeds, respectively. Litter size decreased as weaning-to-conception interval increased up to 7 and 10 d for Yorkshire and Landrace, respectively, then increased with further increases in weaning-to-conception interval up to 35 and 30 d for the two breeds, and then remained constant. The MMEW sows did not have lower subsequent litter sizes than later-weaned sows because the negative effect of a shorter lactation was offset by the positive effect of a longer weaning-to-conception interval. However, average time spent open per parity was longer for MMEW sows than for later-weaned sows. Both lactation length and weaning-to-conception interval should be considered in models for the genetic evaluation of litter size in purebred swine. Segmented polynomials can be used to predict litter size as a continuous function of weaning-to-conception interval or to derive weaning-to-conception interval adjustment factors for litter size.

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Genetics of the interval from weaning to estrus in first-litter sows: correlated responses.

Cited by 15 publications

References 17 publications

Genetic correlations between reproduction and production traits in swine1

Genetic correlations between reproduction and production traits in swine1

Genetic parameters for feed intake, litter weight, body condition and rebreeding success in primiparous Norwegian Landrace sows

Accounting for lactation length and weaning-to-conception interval in genetic evaluations for litter size in swine.

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