The recent completion of the swine genome sequencing project and development of a high density porcine SNP array has made genome-wide association (GWA) studies feasible in pigs.
Using Illumina's ...PorcineSNP60 BeadChip, we performed a pilot GWA study in 820 commercial female pigs phenotyped for backfat, loin muscle area, body conformation in addition to feet and leg (FL) structural soundness traits. A total of 51,385 SNPs were jointly fitted using Bayesian techniques as random effects in a mixture model that assumed a known large proportion (99.5%) of SNPs had zero effect. SNP annotations were implemented through the Sus scrofa Build 9 available from pig Ensembl. We discovered a number of candidate chromosomal regions, and some of them corresponded to QTL regions previously reported. We not only have identified some well-known candidate genes for the traits of interest, such as MC4R (for backfat) and IGF2 (for loin muscle area), but also obtained novel promising genes, including CHCHD3 (for backfat), BMP2 (for loin muscle area, body size and several FL structure traits), and some HOXA family genes (for overall leg action). The candidate regions responsible for body conformation and FL structure soundness did not overlap greatly which implied that these traits were controlled by different genes. Functional clustering analyses classified the genes into categories related to bone and cartilage development, muscle growth and development or the insulin pathway suggesting the traits are regulated by common pathways or gene networks that exert roles at different spatial and temporal stages.
This study is one of the earliest GWA reports on important quantitative traits in pigs, and the findings will contribute to the further biological function analysis of the identified candidate genes and potential utilization of them in marker assisted selection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Piglets are susceptible to hypothermia because they lack hair and energy reserves, have a large surface area to body weight ratio, and have poor body thermostability. Different heat sources are used ...on farm, but it is not known how long it takes half a litter to locate it and lie down. The objectives of this study were to determine 1) how long it took for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last-born pig and, 2) how long this cohort of piglets laid on- or under the heat source. A total of 12 sows were enrolled in the study (parity 1 = 4; 3 = 2; 4 = 2; 5 = 2; and 7 = 2). The stall containing one sow and her litter was the experimental unit. Two treatments were compared: 1) Baby Pig Heat Mat-Single 48 (MAT) and 2) Poly Heat Lamp (LAMP). Temperature was 32°C for both heat source treatments. Sow and litter video recordings occurred continually over a 24-h period on the day of farrowing. Two measures were determined 1) how long it took for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last-born pig (h:min), and 2) how long this cohort of piglets laid on- or under the heat source (min:sec). Lying was defined as either sternal or lateral recumbency with ≥ 75% of the piglet's body touching the heat mat or inside the lamp heat circle. Production records were used to verify farrowing date, total number of piglets born, and born alive. No cross fostering occurred during this study. All data will be presented descriptively. On average, sows assigned to the LAMP treatment took ~2 ½-h to farrow, and for sows assigned to the MAT ~3 ½-h, respectively. Piglets took between ~5-h (LAMP) and ~9-h (MAT) for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last piglet. Cohort of piglets laid on- or under the heat source as follows, LAMP piglets spent ~29 mins lying and for MAT piglets ~42 mins, respectively. Average pre-weaning mortality was 11% (LAMP) and 18% (MAT). The MAT heat source used less energy than the LAMP (16 vs. 63 kWh) over the study duration. To the authors' knowledge, this is the first published study using a continuous sampling method to precisely examine a new measure (time needed for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last-born piglet) and to determine how long this cohort of piglets laid on- or under the heat source. Our findings show an immense range in locating and lying under- or on the heat source. Therefore, we suggest that caretakers should assist all piglets to locate the heat source after farrowing is complete to improve piglet livability.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The objective of the study was to investigate the possibility of utilizing an early litter size trait as an indirect selection trait for longevity and to estimate genetic parameters between sow ...stayability and litter size at different parities using a linear-threshold model for longevity in Thai Large White (LW) and Landrace (LR) populations.
The data included litter size at first, second, and third parities (NBA1, NBA2, and NBA3) and sow stayability from first to fourth farrowings (STAY14). The data was obtained from 10,794 LR and 9,475 LW sows. Genetic parameters were estimated using the multipletrait animal model. A linear-threshold model was used in which NBA1, NBA2, and NBA3 were continuous traits, while STAY14 was considered a binary trait.
Heritabilities for litter size were low and ranged from 0.01 to 0.06 for both LR and LW breeds. Similarly, heritabilities for stayability were low for both breeds. Genetic associations between litter size and stayability ranged from 0.43 to 0.65 for LR populations and 0.12 to 0.55 for LW populations. The genetic correlation between NBA1 and STAY14 was moderate and in a favorable direction for both LR and LW breeds (0.65 and 0.55, respectively).
A linear-threshold model could be utilized to analyze litter size and sow stayability traits. Furthermore, selection for litter size at first parity, which was the genetic trait correlated with longevity, is possible when one attempts to improve lifetime productivity in Thai swine populations.
Abstract
Sow longevity is a key productivity indicator trait that has real economic and welfare importance for commercial swine farms globally. The average parity at culling is 3.8 parities. Reports ...indicate that it takes 3 to 4 parities before a sow “pays for herself.” Research groups around the world have reported heritabilities estimates for sow longevity traits ranging from 0.05 to 0.35. Estimate differences result from the animal population under evaluation, the trait being evaluated, and the methodology employed to obtain the genetic parameter estimate. Because sow longevity is measured at the end of the sow’s productive life, indicator traits like age at first farrowing, leg conformation, and other traits are utilized in gilt selection programs. The genetic correlations between sow longevity and lifetime production traits range have been reported to range from 0.64 to 0.94, suggesting that selection will improve sow longevity. Genetic markers have been identified that affect both sow longevity and other indicator traits. Selection to improved sow longevity still requires phenotypes. Future technologies, e.g. CT scans, digital images, and automated disease detection, will provide additional phenotypes. Continued hardware, software, and molecular developments will improve selection accuracy for sow longevity traits and related traits. Research is needed to evaluate the impact that non-additive genetic effects have on sow longevity and other fitness-related traits. Sow longevity seems to be an ideal trait to employ genomic selection in order to make more rapid trait improvements because it is measured late in life, it is sex-limited, and the trait is not directly measured on nucleus animals. In conclusion, sow longevity and related traits have sufficient heritability and variation to improve through traditional and genomic enhanced selection methods. Selection programs employing effective genomic selection programs will be more effective in improving sow longevity trait and related traits and ultimately economical return.
Sow longevity is a key productivity indicator trait that has real economic and welfare importance for commercial swine farms globally. The average parity at culling is 3.8 parities. Reports indicate ...that it takes 3 to 4 parities before a sow “pays for herself.” Research groups around the world have reported heritabilities estimates for sow longevity traits ranging from 0.05 to 0.35. Estimate differences result from the animal population under evaluation, the trait being evaluated, and the methodology employed to obtain the genetic parameter estimate. Because sow longevity is measured at the end of the sow’s productive life, indicator traits like age at first farrowing, leg conformation, and other traits are utilized in gilt selection programs. The genetic correlations between sow longevity and lifetime production traits range have been reported to range from 0.64 to 0.94, suggesting that selection will improve sow longevity. Genetic markers have been identified that affect both sow longevity and other indicator traits. Selection to improved sow longevity still requires phenotypes. Future technologies, e.g. CT scans, digital images, and automated disease detection, will provide additional phenotypes. Continued hardware, software, and molecular developments will improve selection accuracy for sow longevity traits and related traits. Research is needed to evaluate the impact that non-additive genetic effects have on sow longevity and other fitness-related traits. Sow longevity seems to be an ideal trait to employ genomic selection in order to make more rapid trait improvements because it is measured late in life, it is sex-limited, and the trait is not directly measured on nucleus animals. In conclusion, sow longevity and related traits have sufficient heritability and variation to improve through traditional and genomic enhanced selection methods. Selection programs employing effective genomic selection programs will be more effective in improving sow longevity trait and related traits and ultimately economical return.
The objective of this study was to estimate genetic parameters for age at first farrowing (AFF), length of productive life (LPL), lifetime number of piglets born alive (LNBA), lifetime number of ...piglets weaned (LNW), lifetime wean to first service interval (LW2S), and lifetime pig efficiency (LTP365) from commercial Thai Landrace and Large White populations. Data from 12,843 Landrace (LR) and 14,757 Large White (LW) sows in a Thai commercial pork production system were utilized in this study. The genetic parameters for each trait were estimated using the average information restricted maximum likelihood algorithm where a multivariate animal model was implemented. Heritability estimates for AFF and LPL were low for LR (0.11 and 0.02, respectively) and LW (0.19 and 0.07, respectively). Heritability estimates for lifetime traits ranged from 0.01 to 0.05 for LR and 0.04 to 0.09 for LW. The genetic correlation between LPL with LNBA, LNW, LW2S and LTP365 were positive for LR (0.39 to 0.90) and LW (0.59 to 0.94). Favourable genetic correlations were observed between AFF and LPL for LR (− 0.14) and LW (− 0.14). The phenotypic correlations between LPL and lifetime traits ranged from 0.64 to 0.92 for LR and 0.61 to 0.91 for LW. Favourable phenotypic correlation between AFF and lifetime production traits was observed in the present study. The estimated heritability for the length of productive life and lifetime traits was relatively lowly heritable; length of productive life is genetically associated with lifetime traits. These findings indicate that sow lifetime productivity could be improved using selection on LPL and AFF without antagonism. Thus, improving sow lifetime productivity in the commercial pork production system, AFF and LPL should be included in a maternal line genetic evaluation programme.
The objective of this study was to validate standing and locomotion lameness scoring, mechanical nociceptive threshold testing, and behavioral profile tools for the diagnosis of naturally occurring ...lameness etiologies in pigs. A total of 55 crossbred gilts and sows obtained from a commercial farm were enrolled in the study; with sound pigs classified as controls (8) and the remainder as lame due to integumentary (20), musculoskeletal (15), and combinations of integumentary and musculoskeletal (12) etiologies. Standing and locomotion lameness, mechanical nociceptive threshold (MNT) test, pig-human interventions, and latency to complete an obstacle course were evaluated. Standing and locomotion lameness scoring systems, MNT, and pig behavior (latency) were capable of discriminating between animals with mild organic lameness and animals that were sound and may have utility on the farm for staff to use to identify and manage lame animals. In rare instances, the tools used here were able to discriminate between broad categories of lameness etiology.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
In the United States swine industry, preweaning mortality represents the highest mortality rate of any production phase, nearly half attributed to crushing. The overarching aim of this study was to ...determine if enrichment ropes would entice neonatal piglets away from the sow and reduce preweaning mortality. Rope enrichments were provided to 161 piglets from 26 sows after farrowing. Ropes were dipped in sunflower oil (
= 7), semiochemical (
= 8), or milky cheese (
= 11). Piglet purposeful rope investigations, weight gain, and mortality were recorded. On Day 2, 75% of piglets touched the enrichment at least once, and frequency ranged from 1 to 21 investigations across all treatments. Frequency (
= 0.20) and duration (
= 0.21) of investigations were not affected by treatment. Preweaning litter average weight gain did not differ between treatments (
= 0.71). MC (milky cheese) piglets had the lowest percent mortality when the enrichment ropes were present (Days 2 to 5,
= 0.01), and SC (semiochemical) piglets had the lowest percent mortality after the enrichment ropes were removed (Days 6 to weaning,
< 0.0001). This proof-of-concept study highlights the potential value of neonatal piglet environmental enrichment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The objectives of this study were to explore the usefulness of blood-based traits as indicators of health and performance in beef cattle at weaning and identify the genetic basis underlying the ...different blood parameters obtained from complete blood counts (CBCs). Disease costs represent one of the main factors determining profitability in animal production. Previous research has observed associations between blood cell counts and an animal’s health status in some species. CBC were recorded from approximately 570 Angus based, crossbred beef calves at weaning born between 2015 and 2016 and raised on toxic or novel tall fescue. The calves (
N
= ∼600) were genotyped at a density of 50k SNPs and the genotypes (
N
= 1160) were imputed to a density of 270k SNPs. Genetic parameters were estimated for 15 blood and 4 production. Finally, with the objective of identifying the genetic basis underlying the different blood-based traits, genome-wide association studies (GWAS) were performed for all traits. Heritability estimates ranged from 0.11 to 0.60, and generally weak phenotypic correlations and strong genetic correlations were observed among blood-based traits only. Genome-wide association study identified ninety-one 1-Mb windows that accounted for 0.5% or more of the estimated genetic variance for at least 1 trait with 21 windows overlapping across two or more traits (explaining more than 0.5% of estimated genetic variance for two or more traits). Five candidate genes have been identified in the most interesting overlapping regions related to blood-based traits. Overall, this study represents one of the first efforts represented in scientific literature to identify the genetic basis of blood cell traits in beef cattle. The results presented in this study allow us to conclude that: (1) blood-based traits have weak phenotypic correlations but strong genetic correlations among themselves. (2) Blood-based traits have moderate to high heritability. (3) There is evidence of an important overlap of genetic control among similar blood-based traits which will allow for their use in improvement programs in beef cattle.
Abattoir-level digital image measurement and assessments recorded during the harvest process could contribute to better estimates of the economic value of each animal and could be used as animal ...health and well-being assessment tools to provide information/feedback for commercial pork producers. This study evaluated the association between live animal infrared images and nonedible trim loss from cull sows. Eighty sow carcasses selected from cull sows normally presented at a Midwest cull sow abattoir were evaluated. A thermal image and corresponding trim losses were collected from each sow.Regions of interest, referred to as hotspots, were isolated from the thermal images of individual sows. The relationships between the thermal hotspots, trim loss weight, and trim loss percentage from each carcass were evaluated using Pearson correlation coefficients, stepwise regression, and prediction equations. The most predictive model included covariates for the number of hotspots, live identification category, hotspot location, and explanatory continuous covariates for pixels with elevated temperature. Live animal defect classification and hotspot location categories significantly contributed to variation in percent trim. This suggests that visually identifying defects like abscesses, poor condition, mammary infection, or a combination on live cull sows is associated with trim losses from their carcass.
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