Maternal and direct genetic parameters for tail length,tail lesions,and growth traits in pigs

Tail length and tail lesions are the major triggers for tail biting in pigs. Against this background, 2 datasets were analyzed to estimate genetic parameters for tail characteristics and growth traits. Dataset 1 considered measurements for trait tail length (T-LEN) and for the growth traits birth weight (BW), weaning weight (WW), postweaning weight (PWW), and average daily gain (ADG) from 9,348 piglets. Piglets were born in the period from 2015 to 2018 and kept on the university Gießen research station. Dataset 2 included 4,943 binary observations from 1,648 pigs from the birth years 2016 to 2019 for tail lesions (T-LES) as indicators for nail necrosis, tail abnormalities, or tail biting. T-LES were recorded at 30 ± 7 d after entry for rearing (T-Les-1), at 50 ± 7 d after entry for rearing (end of the rearing period, T-LES-2), and 130 ± 20 d after entry for rearing (end of fattening period, T-LES-3). Genetic statistical model evaluation for dataset 1 based on Akaike’s information criterion and likelihood ration tests suggested multiple-trait animal models considering covariances between direct and maternal genetic effects. The direct heritability for T-LEN was 0.42 (±0.03), indicating the potential for genetic selection on short tails. The maternal genetic heritability for T-LEN was 0.05 (±0.04), indicating the influence of uterine characteristics on morphological traits. The negative correlation between direct and maternal effects for T-LEN of –0.35 (±0.13), as well as the antagonistic relationships (i.e., positive direct genetic correlations in the range from 0.03 to 0.40) between T-LEN with the growth traits BW, WW, PWW, and ADG, complicate selection strategies and breeding goal definitions. The correlations between direct effects for T-LEN and maternal effects for breeding goal traits, and vice versa, were positive but associated with a quite large SE. The heritability for T-LES when considering the 3 repeated measurements was 0.23 (±0.04) from the linear (repeatability of 0.30) and 0.21 (±0.06; repeatability of 0.29) from the threshold model. The breeding value correlations between T-LES-3 with breeding values from the repeatability models were quite large (0.74 to 0.90), suggesting trait lesion recording at the end of the rearing period. To understand all genetic mechanisms in detail, ongoing studies are focusing on association analyses between T-LEN and T-LES, and the identification of tail biting from an actor’s perspective.     

Normal haematological parameters of pigs in Papua new guinea

Summary The normal haematological parameters of pure Native and Crossbred Native pigs under intensive management are listed. The values for both groups are within the wide range of normal values for conventional breeds under intensive management. The “normal” haematological values of 5-month and 11-month Village pigs are also listed. Compared with the corresponding age group of both pure Native and Crossbred Native pigs, the Village pigs had significantly lower haemoglobin, red blood cell counts and haematocrit values. The cause of the lower values in Village pigs is thought to be due to the malnutrition-parasite complex of Village pigs. The significantly higher leucocyte count of Village pigs is thought to be due to chronic pneumonia and parasitism of the Village pigs.

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Resumen Se enumeran los parámetros hematológicos normales de cerdos Nativos puros y mestizos bajo manejo intensivo. Los valores encontrados en ambos grupos caen dentro de los valores normales establecidos para razas convencionales sometidas a un manejo intensivo. Se enumeran los valores hematológicos normales de cerdos de Villorrio de 5 y 11 meses de edad. Comparando estos valores con los del grupo correspondiente de la misma edad de Nativos puros y mestizos, los cerdos de Villoriio presentaron valores bajos de hemoglobina, eritrocitos y hematocrito. La causa de estos valores bajos se cree sea debida al complejo malnutrición-parasitismo. El aumento significativo leucocitario en los cerdos de Villorrio podría tener relación con neumonías crónicas y parasitismo.

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Résumé Les paramètres hématologiques normaux de porcs indigènes et de porcs métis en élevage intensif sont passés en revue. Les valuers de ces deux groupes se situent aux environs de celles constatées pour les races classiques entretenues en élevage intensif. Les valeurs hématologiques normales des porcs villageois, agés de 5 et de 11 mois sont également précisées. Leur richesse en hémoglobine, en hématies et en hématocrite est significativement inférieure à celle constatée chez les porcs des deux autres groupes. Cette différence en moins semble être due à l'action conjuguée de la malnutrition et du parasitisme auxquels sont soumis les porcs de village alors que la plus grande richesse en leucocytes de leur sang semble résulter de la pneumonie chronique et du parasitisme qui les frappent.

     

Phenotypic and genetic variation in hematological traits of Pietrain-Meishan-F2 crossbred pigs

Hematological traits are essential parameters for veterinary practice to quantify health status of individuals and herds. A major problem with the interpretation of hematological values is their pronounced variability that is to a great extend caused by non-systematic factors. Differences in breeds and populations are providing evidence for different genotypes in this regard, although there is no information available in swine about the nature and shares of participating genes. Goal of the present paper was to evaluate the additive-genetic share of total variability of traits of the red and white blood cell count. The results are based on 139 F2-pigs of a Pietrain-Meishan-family. Medium to high heritabilities have been estimated for the numbers of neutrophiles, the mean corpuscular hemoglobin concentration and the hemoglobin content, and for the shares of basophile granulocytes, platelets and lymphocytes. No meaningful shares of additive genetic variance were obvious in the other traits. Shares of additive genetic variance of the above mentioned traits argue for the existence of favourable and unfavourable gene variants to be involved in their phenotypic variation. Isolation of these variants might improve the diagnostical use of those traits in the future and provide a measure to advance general health in the pig.     

Estimation of genetic (co)variances of Gompertz growth function parameters in pigs

The objective of this study was to estimate genetic (co)variances for the Gompertz growth function parameters, asymptotic mature weight (A), the ratio of mature weight to birthweight (B) and rate of maturation (k), using alternative modelling approaches. The data set consisted of 51 893 live weight records from 10 201 growing pigs. The growth of each pig was modelled using the Gompertz model employing either a two‐step fixed effect or mixed model approach or a one‐step mixed model approach using restricted maximum likelihood for the estimation of genetic (co)variance. Heritability estimates for the Gompertz growth function parameters, A (0.40), B (0.69) and k (0.45), were greatest for the one‐step approach, compared with the two‐step fixed effects approach, A (0.10), B (0.33) and k (0.13), and the two‐step mixed model approach, A (0.17), B (0.32) and k (0.18). Inferred genetic correlations (i.e. correlations of estimated breeding values) between growth function parameters within models ranged from ?0.78 to 0.76, and across models ranged from 0.28 to 0.73 for parameter A, 0.75 to 0.88 for parameter B and 0.09 to 0.37 for parameter k. Correlations between predicted daily sire live weights based on the Gompertz growth curve parameters’ estimated breeding values from 60 to 200 days of age between all three modelled approaches were moderately to strongly correlated (0.75 to 0.95). Results from this study provide heritability estimates for biologically interpretable parameters of pig growth through the quantification of genetic (co)variances, thereby facilitating the estimation of breeding values for inclusion in breeding objectives to aid in breeding and selection decisions.     

Some normal biochemical parameters of pigs in Papua new guinea

Summary The normal values of serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, serum lactic dehydrogenase and serum alkaline phosphatase, total protein, urea, creatinine, cholesterol, glucose, magnesium, calcium and inorganic phosphorus were measured monthly over a 12-month period from 10 “pure” Native and 10 Native x British Crossbred pigs. Except for cholesterol, no significant difference was found between the two groups. Similar estimations were made for 5-month and 11-month Village pigs in which the serum alkaline phosphatase, inorganic phosphorus, total protein, urea, creatinine and calcium were significantly lower when compared with the corresponding age group of the pure Native pigs and Crossbred pigs. These lower values are thought to be due to the effects of the malnutrition-parasite complex of Village pigs.

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Resumen Se llevaron a cabo determinaciones séricas de transaminasa glutámica oxaloacética, transaminasa glutámica pirúvica, deshidrogenasa láctica y fosfatasa alcalina. Otras determinaciones en el suero incluyeron protína total, urea, creatinina, colesterol, glucosa, magnesio, calcio y fósforo inorgánico. Las determinaciones se efectuaron mensualmente por un período de 12 meses, en 10 cerdos Nativos puros y 10 mestizos Nativos x Británicos. Exceptuando al colesterol, no se encontraron diferencias significativas en los dos grupos. Determinaciones similares se efectuaron durante períodos de 5 y 11 meses en cerdos de Villorrio, en los cuales la fosfatasa alcalina del suero, fósforo inorgánico, proteína total, urea, creatinina y calcio fueron significativamente más bajos cuando se compararon con el grupo correspondiente de la misma edad de cerdos Nativos puros y cerdos mestizos. Los valores bajos se cree sean debidos al efecto del complejo malnutrición-parasitismo en los cerdos de Villorrio.

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Résumé Les transaminases sériques glutamique—oxaloacétique et glutamique-pyruvique, la déhydrogénase lactique, la phosphatase alcaline, les protéines totales, l'urée, la créatinine, le cholestérol, le glucose, le magnésium, le calcium et le phosphore inorganique ont été mensuellement mesurés durant 12 mois chez 10 porcs indigènes purs et sur 10 métis indigène x anglais. Sauf pour le cholestérol, aucune différence significative n'a pu être mise en évidence entre ces deux groupes d'animaux. Des recherches semblables ont été conduites sur des porcs villageois de 5 et de 10 mois chez lesquels la phosphatase alcaline du sérum, le phosphore inorganique, les protéines totales, l'urée, la créatinine et le calcium ont significativement été trouvés inférieurs aux niveaux constatés avec les animaux de même age des groupes correspondants des porcs indigènes et métissés. On pense que ces valeurs inférieures peuvent résulter du complexe malnutrition-parasitisme dont souffrent les porcs villageois.

     

Genetic parameters and purebred–crossbred genetic correlations for growth,meat quality,and carcass traits in pigs

Growth, meat quality, and carcass traits are of economic importance in swine breeding. Understanding their genetic basis in purebred (PB) and commercial crossbred (CB) pigs is necessary for a successful breeding program because, although the breeding goal is to improve CB performance, phenotype collection and selection are usually carried out in PB populations housed in biosecure nucleus herds. Thus, the selection is indirect, and the accuracy of selection depends on the genetic correlation between PB and CB performance (rpc). The objectives of this study were to 1) estimate genetic parameters for growth, meat quality, and carcass traits in a PB sire line and related commercial CB pigs and 2) estimate the corresponding genetic correlations between purebred and crossbred performance (rpc). Both objectives were investigated by using pedigree information only (PBLUP) and by combining pedigree and genomic information in a single-step genomic BLUP (ssGBLUP) procedure. Growth rate showed moderate estimates of heritability for both PB and CB based on PBLUP, while estimates were higher in CB based on ssGBLUP. Heritability estimates for meat quality traits were diverse and slightly different based on PB and CB data with both methods. Carcass traits had higher heritability estimates based on PB compared with CB data based on PBLUP and slightly higher estimates for CB data based on ssGBLUP. A wide range of estimates of genetic correlations were obtained among traits within the PB and CB data. In the PB population, estimates of heritabilities and genetic correlations were similar based on PBLUP and ssGBLUP for all traits, while based on the CB data, ssGBLUP resulted in different estimates of genetic parameters with lower SEs. With some exceptions, estimates of rpc were moderate to high. The SE on the rpc estimates was generally large when based on PBLUP due to limited sample size, especially for CBs. In contrast, estimates of rpc based on ssGBLUP were not only more precise but also more consistent among pairs of traits, considering their genetic correlations within the PB and CB data. The wide range of estimates of rpc (less than 0.70 for 7 out of 13 traits) indicates that the use of CB phenotypes recorded on commercial farms, along with genomic information, for selection in the PB population has potential to increase the genetic progress of CB performance.     

Estimation of genetic parameters for farrowing traits in purebred Landrace and Large White pigs

Genetic parameters were estimated for six reproductive traits related to farrowing events in Landrace and Large White pigs; total number born (TNB), number born alive (NBA), number stillborn (NSB), total litter weight at birth (LWB), mean litter weight at birth (MWB), and gestation length (GL). We analyzed 62,534 farrowing records for 10,637 Landrace dams and 49,817 farrowing records for 8,649 Large White dams. Estimated heritabilities of TNB, NBA, NSB, LWB, MWB, and GL by single‐trait repeatability model analyses were 0.12, 0.12, 0.08, 0.18, 0.19, and 0.29, respectively, in Landrace, and 0.12, 0.10, 0.08, 0.18, 0.16, and 0.34, respectively, in Large White. Genetic correlation between NBA and NSB was unfavorable: 0.20 in Landrace and 0.33 in Large White. Genetic correlations of GL with the other five traits were weak: from ?0.18 with NSB to ?0.03 with NBA in Landrace, and from ?0.22 with NSB to ?0.07 with NBA in Large White. LWB had a highly favorable genetic correlation with NBA (0.74 in both breeds), indicating the possibility of using LWB for the genetic improvement of NBA.     

深县猪繁殖性状遗传参数的估计

应用动物个体模型和ASReml软件分析109头深县母猪繁殖性状的遗传参数,结果表明:总产仔数、产活仔数、初生窝重、断奶窝重、初生重和断奶重的遗传力分别是0.165、0.024、0.21、0.086、0.018和0.121,性状之间的遗传相关程度差别较大,遗传相关系数在-0.24~0.98之间,表型相关系数在-0.15~0.89之间。结果说明,深县猪的繁殖性能优良,产仔数高但差别大,尚需进一步探究影响繁殖性状的环境和遗传因素。     

Estimates of genetic parameters for growth traits in Kermani sheep

Birth weight (BW), weaning weight (WW), 6-month weight (W6), 9-month weight (W9) and yearling weight (YW) of Kermani lambs were used to estimate genetic parameters. The data were collected from Shahrbabak Sheep Breeding Research Station in Iran during the period of 1993-1998. The fixed effects in the model were lambing year, sex, type of birth and age of dam. Number of days between birth date and the date of obtaining measurement of each record was used as a covariate. Estimates of (co)variance components and genetic parameters were obtained by restricted maximum likelihood, using single and two-trait animal models. Based on the most appropriate fitted model, direct and maternal heritabilities of BW, WW, W6, W9 and YW were estimated to be 0.10 +/- 0.06 and 0.27 +/- 0.04, 0.22 +/- 0.09 and 0.19 +/- 0.05, 0.09 +/- 0.06 and 0.25 +/- 0.04, 0.13 +/- 0.08 and 0.18 +/- 0.05, and 0.14 +/- 0.08 and 0.14 +/- 0.06 respectively. Direct and maternal genetic correlations between the lamb weights varied between 0.66 and 0.99, and 0.11 and 0.99. The results showed that the maternal influence on lamb weights decreased with age at measurement. Ignoring maternal effects in the model caused overestimation of direct heritability. Maternal effects are significant sources of variation for growth traits and ignoring maternal effects in the model would cause inaccurate genetic evaluation of lambs.     

Energy balance and growth rate of outbred and inbred male guinea pigs

Water intake, food consumption, growth rate, and rectal temperature were measured daily for 14 days and oxygen uptake was determined weekly for 3 weeks in healthy outbred (Hartley stock) and inbred (strains 2 and 13) male guinea pigs. Body weights ranged from 300 to 465 g, and ages were approximately 6 to 10 weeks. Strain-13 guinea pigs had the lowest daily body weight gain (3.27 +/- 0.33 g), when compared with strain-2 (4.04 +/- 1.21 g) and Hartley guinea pigs (5.72 +/- 1.08 g). Outbred guinea pigs also had highest values of water intake and water/food intake ratio(s), and had significantly (P less than 0.05 and 0.01) lower oxygen uptake values than did inbred guinea pigs. The ratio of daily average body weight gain to the corresponding daily retained calories, with or without corrections of body surface area (0.05 m2), was higher in Hartley stock than in the strain-13 guinea pigs. Rectal temperatures and food consumption were similar in all guinea pigs. Data indicated that the outbred Hartley guinea pig had a faster growth rate and appeared stronger physiologically, compared with inbred strains.     

Comparison of two models to estimate genetic parameters for number of born alive in pigs

The performance of the two‐trait animal model that regards the first parity and later parities as two different traits in estimating genetic parameters for number of born alive (NBA) was examined using real and simulated data. Genetic parameters for NBA were estimated in purebred Landrace and Large White pigs using a single‐trait repeatability model (Model 1) that regards all parities as the same trait and a two‐trait animal model (Model 2) that regards the first and the later parities as different traits. For Model 2, the permanent environmental effect was fitted to only the records of the later parities. Heritability for NBA estimated using Model 1 was 0.12 for Landrace and 0.11 for Large White. Estimated heritability for NBA of the first parity and the later parities was 0.21 and 0.16, respectively, for Landrace; 0.18 and 0.16, respectively, for Large White obtained using Model 2, and higher than those in both breeds obtained using Model 1. Further results based on data simulated using the Monte Carlo method suggest that estimated additive genetic variance could be more biased using Model 2 than Model 1.     

Estimates of genetic parameters for carcass measures of body composition and growth in swine

Records for pigs included in an experiment on reciprocal recurrent selection conducted from 1956 through 1971 at the USDA Beltsville Agriculture Research Center were analyzed to obtain estimates of heritabilities and genetic correlations and to derive prediction equations for estimating weight of lean cuts (WTLC) and percentage of lean cuts of shrunk slaughter weight (LCPC). Lean cuts growth rate (LCGR) was then estimated as WTLC/age of pig at slaughter. The base population consisted of two unrelated crossbred strains. A total of 1,294 records of F1 and F2 crossbred pigs were analyzed with one barrow and one gilt from each litter. Estimates of heritabilities and genetic correlations were computed with sire components of variance and covariance from a nested analysis of variance with an assumed model of years, strain-lines within years, sire within strain-lines, dams within sires and residual. Degrees of freedom were 307 for sires in strain-lines, 270 for dams in sires and 646 for residual. Heritability (h2) estimates were .42 +/- .13, .41 +/- .13 and .27 +/- .18 for WTLC, LCPC and LCGR, respectively, and .71 +/- .16, .38 +/- .13, .31 +/- .13 and .25 +/- .15 for carcass length, average backfat thickness, longissimus muscle area and ADG in BW, respectively. These estimates were apparently the first published genetic estimates involving LCGR based on carcass data. It was recommended that prediction equations to estimate WTLC, LCPC and LCGR for use in swine testing programs be derived from current meat-type pigs.