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1.
J Dairy Sci ; 107(8): 5942-5961, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38490545

RESUMO

The weaning and separation phase remains one of the biggest challenges for cow-calf contact systems, but a gradual process that better mimics the naturally occurring reduction in milk intake has not yet been scientifically investigated. Therefore, the aim of our study was to compare behavioral and physiological indicators of distress in 3-mo-old dam-reared dairy calves (with previous full-time cow-calf contact) weaned and separated either via gradual reduction of contact time with the dam (GR; 1 wk of half-day contact, 1 wk of morning contact, and 1 wk of fence-line contact before complete separation, n = 18) or via 2-step weaning using a nose flap (NF, 2 wk of access to the dam with a nose flap, 1 wk of fence-line contact before complete separation, n = 18). Behavior was recorded 1 wk before (or for lying 3 wk before) weaning start and during the 3 wk weaning and separation period with direct observations on 4 d/wk or via accelerometers (locomotor play, lying behavior). Blood and fecal samples were taken twice per week from weaning start until 3 wk after weaning start. Calves were weighed weekly. Statistical analysis was conducted using (generalized) linear mixed models. Over the whole weaning and separation phase, NF calves showed a stronger decrease in the number of lying bouts, amount of locomotor play, and ADG, as well as a higher increase in TMR feeding time compared with GR calves, whereas GR calves vocalized more often and showed more searching behavior than NF calves. Also, the neutrophil:lymphocyte ratio of NF calves was elevated on d 3 after insertion of the nose flaps compared with baseline, but showed no change for GR calves on any sampling day. Overall, results point toward a favorable effect of a gradual weaning strategy on reduction of weaning and separation distress in dam-reared dairy calves, but the method requires further improvement from the protocol used in our study.


Assuntos
Desmame , Animais , Bovinos , Comportamento Animal , Feminino
2.
Anim Cogn ; 26(5): 1623-1633, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37410341

RESUMO

Learning by observing others (i.e. social learning) is an important mechanism to reduce the costs of individual learning. Social learning can occur between conspecifics but also heterospecifics. Domestication processes might have changed the animals' sensitivity to human social cues and recent research indicates that domesticated species are particularly good in learning socially from humans. Llamas (Lama glama) are an interesting model species for that purpose. Llamas were bred as pack animals, which requires close contact and cooperative behaviour towards humans. We investigated whether llamas learn socially from trained conspecifics and humans in a spatial detour task. Subjects were required to detour metal hurdles arranged in a V-shape to reach a food reward. Llamas were more successful in solving the task after both a human and a conspecific demonstrated the task compared to a control condition with no demonstrator. Individual differences in behaviour (i.e. food motivation and distraction) further affected the success rate. Animals did not necessarily use the same route as the demonstrators, thus, indicating that they adopted a more general detour behaviour. These results suggest that llamas can extract information from conspecific and heterospecific demonstrations; hence, broadening our knowledge of domesticated species that are sensitive to human social behaviour.


Assuntos
Camelídeos Americanos , Aprendizado Social , Humanos , Animais , Aprendizagem , Comportamento Social , Sinais (Psicologia)
3.
J Dairy Sci ; 106(3): 2124-2136, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36631319

RESUMO

Measurement of fecal cortisol metabolites (FGCM) is a well-established, noninvasive method to assess stress in adult dairy cattle. However, this procedure has not yet been validated for unweaned dairy calves, and it can be expected that the milk proportion of the diet may influence the resulting FGCM concentrations. The aim of this study was therefore to assess whether a peak in FGCM concentrations in response to a stressor can be measured in unweaned dairy calves on a largely milk-based diet. If so, further objectives were to examine whether maximum FGCM concentrations, as well as the time lag until they are reached, are comparable to the values in the same calves on a solid-based diet after weaning. For this study, 5 German Holstein calves of about 3 mo of age (93 to 102 d preweaning) were exposed to a 45 min transport stressor once before and once after weaning, which was 3 wk apart. All voided fecal samples were collected for 24 h after termination of the transport. Fecal cortisol metabolites were analyzed with an 11-oxoetiocholanolone enzyme immunoassay and changes in FGCM concentrations relative to the individual baseline (FGCMrel) were calculated. Results showed a clear peak in FGCM concentrations on both diet types. The peak FGCMrel concentrations tended to be higher when the calves were on the preweaning diet (at peak: +233 ± 25% increase relative to baseline) in comparison to the postweaning diet (+124 ± 23%). Considering the whole 24 h sampling period, the FGCMrel concentrations for all calves were significantly higher on the preweaning diet than on the postweaning diet. There was also a numerical difference in the delay between occurrence of the stressor and appearance of the peak FGCMrel concentrations in feces, as the time lag was 1.5 ± 1.2 h longer when the calves were on the preweaning diet compared with the postweaning diet. In conclusion, our results suggest that FGCM concentrations are a useful stress marker for unweaned dairy calves in the same way they are for older cattle, but that FGCMrel concentrations tend to be higher in unweaned than in weaned calves and are thus not directly comparable.


Assuntos
Ração Animal , Hidrocortisona , Animais , Bovinos , Peso Corporal , Projetos Piloto , Hidrocortisona/metabolismo , Ração Animal/análise , Dieta/veterinária , Fezes , Leite/metabolismo , Desmame
4.
J Environ Manage ; 289: 112523, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33839605

RESUMO

Agricultural livestock production ranks among the most environmental impactful industry sectors at the global level, and within the livestock sector, beef production accounts for a large proportion of environmental damage. Beef production in Alpine mountain regions, such as in South Tyrol (Italy), is a small, but increasing agricultural sector. Thus, the aim of this study was to examine the environmental impact of different organic and conventional beef production systems in South Tyrol and to compare their environmental impact and effect on biodiversity under Alpine production conditions. Live cycle assessment (LCA) approach was used and 1 kg of live weight (LW) was chosen as functional unit (FU). Global warming potential (GWP, kg CO2-eq), acidification potential (AP, g SO2-eq), eutrophication potential (EP, g PO4-eq), non-renewable energy use (NRE, MJ-eq), land occupation (LO, m2 organic land/year) and biodiversity damage potential (BDP) expressed in potential disappeared fraction (PDF) were investigated. The study involved 18 beef cattle farms in the South Tyrolean region: Conventional calf-fattening farms (CCF = 6), organic suckler cow farms (SCF = 6), and conventional heifer/ox fattening farms (HOF = 6). The CCF system showed a higher environmental impact compared to SCF and HOF systems for all impact categories (P < 0.05). Between the organic and the conventional system (SCF and HOF), no significant differences (P > 0.05) were found for most of the considered impact categories (means ± SEM per FU): GWP: 19.8 vs 17.1 ± 4.2 kg CO2-eq, AP: 11.4 vs 9.3 ± 4.7 g SO2-eq, EP: 4.1 vs 2.8 ± 1.2, NRE: 21.9 vs 13.8 ± 7 MJ-eq, SCF and HOF respectively. Only for LO (70.8 vs 44.1 ± 17.7 m2 organic/y, P < 0.01, SCF and HOF respectively) and the effect on BDP (-1.93 vs -0.85 ± 0.35, PDF, P < 0.01, SCF and HOF respectively) differences between organic and conventional production methods could be revealed. The study showed that beef cattle husbandry in the Alpine area has a satisfactory environmental performance. In particular, the systems studied showed a positive impact in terms of biodiversity.


Assuntos
Agricultura , Eutrofização , Animais , Biodiversidade , Bovinos , Fazendas , Feminino , Itália
5.
J Dairy Res ; 87(S1): 138-143, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33213592

RESUMO

The study reported in this research communication aimed to assess the influence of maternal contact on calves' activity, fearfulness, and social competence. Calves were either dam-reared for their first 14 d of age (Maternal Contact, n = 12) or were separated from their dams within 12 h after birth (Motherless, n = 12). Calves of both treatments and the dams of Maternal Contact calves were group-housed and suckling was prevented with udder nets. The general activity (lying, locomotion, swapping between lying and standing) was measured using pedometers in eight Maternal Contact and eight Motherless calves within a 24-d period. Since general activity might be affected by calves' age or the separation of Maternal Contact calves from the dams the 24-d period was additionally divided into two groups (period A: 3rd-13th day of age, period B: 14th-27th day of age). Emotionality and social competence were assessed in the open field, novel object, and confrontation test with an unknown cow at 14, 21, and 28 d of age, respectively. Mann-Whitney-U-tests were performed for statistical analysis. Locomotion was greater in Motherless calves than Maternal Contact calves during the 24-d period (A + B combined, P < 0.001) and period B (14th to 27th day of age, P < 0.001). There was no treatment difference in duration of lying or in the amount of swapping in any of the periods. After a Bonferroni correction, which we used due to the exploratory character of the study, there were no treatment differences in behaviours indicating emotionality. Compared to Motherless calves, Maternal Contact calves showed increased vigilance (P < 0.01) during the confrontation test. The results of this study indicate that mother-reared calves likely searched less for social contact and developed greater social skills than calves that were separated from their mothers soon after birth.


Assuntos
Animais Recém-Nascidos/psicologia , Comportamento Animal/fisiologia , Bovinos/fisiologia , Comportamento Materno/fisiologia , Comportamento Social , Bem-Estar do Animal , Animais , Animais Recém-Nascidos/fisiologia , Indústria de Laticínios/métodos , Feminino , Abrigo para Animais , Hidrocortisona/análise , Atividade Motora/fisiologia , Saliva/química , Desmame
6.
J Hered ; 108(4): 361-368, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28444202

RESUMO

Horse breeders rely heavily on pedigrees for identification of ancestry in breeding stock. Inaccurate pedigrees may erroneously assign individuals to false lineages or breed memberships resulting in wrong estimates of inbreeding and coancestry. Moreover, discrepancies in pedigree records can lead breeders seeking to limit inbreeding into making misguided breeding decisions. Genome-wide SNPs provide a quantitative tool to aid in the resolution of lineage assignments and the calculation of genomic measures of relatedness. The aim of this project was to pilot a comparison between pedigree and genomic relatedness and inbreeding measures in a herd of 36 pedigreed Egyptian Arabian horses genotyped using the Equine SNP70 platform (Geneseek, Inc.). Moreover, we sought to estimate the minimum number of markers sufficient for genomic inbreeding calculations. Pedigree inbreeding values were moderately correlated with genomic inbreeding values (r = 0.406), whereas genomic relationships and pedigree relationships have a high correlation (r = 0.77). Although first degree relationships were successfully reconstructed, more distant relationships were difficult to resolve. Multi-dimensional scaling and clustering analysis agreed with within-herd pedigree information. In comparing the herd to a reference sample of United States, Polish, and Egyptian Arabian horses, the herd's historically recorded Egyptian lineage was successfully recovered. We conclude that genomic estimates of inbreeding and relationships are superior to their pedigree counterparts. They can be thus utilized in conservation of valuable lines of livestock, and in breeds at risk for loss of genomic diversity. We also postulate a minimum of 2000 markers in linkage equilibrium to be used for inbreeding estimation.


Assuntos
Genética Populacional , Cavalos/genética , Endogamia , Animais , Cruzamento , Análise por Conglomerados , Feminino , Genômica , Genótipo , Homozigoto , Masculino , Linhagem , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
7.
Sci Rep ; 14(1): 22886, 2024 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-39358404

RESUMO

The article reports a meta-analysis of 58 peer-reviewed studies investigating on dorsoventral hyperflexion of the neck in horses, a practice under substantial public and scientific scrutiny for the past two decades. The following databases were last searched on 28.05.2023: CAB, Google Scholar, Web of Science, NAL/Agricola, PubMed and ScienceDirect. After evaluating the conclusions of each study, we performed statistical analyses to establish a consensus on welfare and performance (performance marks, kinematics and musculoskeletal) outcomes in horses performing with a hyperflexed head and neck posture (HNP). The analysis revealed that a significant majority of the articles (75% of n = 36; Z = 3.00; P>|Z|=0.0027) expressed concerns about the welfare of horses working in this posture. Parameters such as dressage training level, prior experience, duration, and method of achieving the hyperflexed posture did not influence welfare concern conclusions significantly (P > 0.1). Therefore, it appears that the practice impairs welfare regardless of how it is imposed. A concurrent assessment of the weight of evidence for performance benefits showed inconclusive results: approximately one-quarter of the studies showed benefits and one-quarter detrimental effects, while the largest proportion (44%) showed no significant effect on performance. On balance, it appears that the costs associated with hyperflexed HNPs exceed potential benefits.


Assuntos
Pescoço , Postura , Cavalos/fisiologia , Animais , Pescoço/fisiologia , Postura/fisiologia , Fenômenos Biomecânicos , Bem-Estar do Animal
8.
Front Psychol ; 13: 954472, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35936272

RESUMO

Self-control, defined as the ability to forgo immediate satisfaction in favor of better pay-offs in the future, has been extensively studied, revealing enormous variation between and within species. Horses are interesting in this regard because as a grazing species they are expected to show low self-control whereas its social complexity might be linked to high self-control abilities. Additionally, self-control may be a key factor in training and/or coping with potentially stressful husbandry conditions. We assessed horses' self-control abilities in a simplified delay of gratification test that can be easily implemented in a farm setting. In Experiment 1, we gave horses (N = 52) the choice between an immediately available low-quality reward and a delayed high-quality reward that could only be obtained if the horse refrained from consuming the immediate reward. Different experimenters (N = 30) that underwent prior training in the procedures, tested horses in two test phases either with their eyes visible or invisible (sunglasses). Twenty horses waited up to the maximum delay stage of 60 s while all horses performed worse in the second test phase. In Experiment 2, we improved the test procedure (i.e., one experimenter, refined criterion for success), and tested 30 additional horses in a quality and quantity condition (one reward vs. delayed bigger reward). Two horses successfully waited for 60 s (quality: N = 1, quantity: N = 1). Horses tolerated higher delays, if they were first tested in the quantity condition. Furthermore, horses that were fed hay ad libitum, instead of in a restricted manner, reached higher delays. Coping behaviors (e.g., looking away, head movements, pawing, and increasing distance to reward) facilitated waiting success and horses were able to anticipate the upcoming delay duration as indicated by non-random distributions of giving-up times. We found no correlations between owner-assessed traits (e.g., trainability and patience) and individual performance in the test. These results suggest that horses are able to exert self-control in a delay of gratification paradigm similar to other domesticated species. Our simplified paradigm could be used to gather large scale data, e.g., to investigate the role of self-control in trainability or success in equestrian sports.

9.
Front Vet Sci ; 9: 789260, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36187838

RESUMO

The present study aimed to assess an agreement between established and novel methods to determine laterality and to identify the distribution of laterality in warmbloods and Thoroughbreds. Nine different methods to investigate a horses' laterality outside a riding context and during riding were compared across two groups of horses (sample A: 67 warmblood- type horses, sample B: 61 Thoroughbreds). Agreement between any two methods was assessed by calculating Cohen's kappa with McNemar's test or Bowker's Test of Symmetry, and the deviation from equal distributions was assessed with chi2-tests. Continuous variables such as rein tension parameters were analyzed using ANOVA or linear mixed models. Generally, laterality test results obtained outside a riding context did not agree with laterality during riding or among each other (Bonferroni corrected p > 0.0018). However, the rider's assessment of her/his horse's laterality allowed conclusions on rein tension symmetry (p = 0.003), and it also agreed substantially with the lateral displacement of the hindquarters (p = 0.0003), a method that was newly developed in the present study. The majority of warmbloods had their hindquarters displaced to the right (73.1%, X2 = 14.3; p < 0.0001). The pattern of lateral displacement of the hindquarters was similar in the Thoroughbred sample (right: 60.7%, left: 39.3%), but did not deviate significantly from an equal distribution (X2 = 2.8; p > 0.05). Laterality seems to be manifested in different ways, which generally are not related to each other. Attention should be paid to the desired information when selecting methods for the assessment of laterality. Horses' laterality has an impact on the magnitude and symmetry of rein tension. Matching horses and riders according to their laterality might be beneficial for the stability of rein tension and thus improve training.

10.
PLoS One ; 13(12): e0204211, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30592711

RESUMO

Changes in husbandry systems as well as consumers' increasing demands for animal welfare lead to increasing importance of traits such as handleability and aggressiveness in pigs. However, before using such novel traits for selection decisions, information on genetic parameters for these traits for the specific population is required. Therefore, weight gain and behaviour-related traits were recorded in 1004 pigs (814 Pietrain x German Landrace crossbred, 190 German Landrace purebred) at different ages. Behaviour indicators and tests were assessed and conducted, respectively under commercial farm conditions and included scoring of skin lesions (twice) and behaviour during backtests (twice), injections (once), handling (twice) and weighing (three times). Since behaviour scores often exhibit suboptimal statistical properties for parametric analyses, variance components were estimated using an animal model assuming a normal (Gaussian, GA; all traits) and additionally a binary distribution of variables (BI; using a logit-link function for all behaviour traits). Heritabilities for behavioural traits ranged from 0.02 ± 0.04 (finishing pig handling test; BI) to 0.36 ± 0.08 (backtest 2; GA) suggesting that some of the traits are potentially useful for genetic selection (e.g. finishing pig weighing test: h2 (GA) = 0.20 ± 0.07). Only minor differences were observed for results from binary and Gaussian analyses of the same traits suggesting that either approach might yield valid results. However, four-fold cross-validation using correlations between breeding values of a sub-set of animals for the sample trait finishing pig weighing score indicated slight superiority of the logit model (r = 0.85 ± 0.04 vs. r = 0.77 ± 0.03). Generally, only weak to moderate associations were found between behavioural reactions to the same test at different ages (rp ≤ 0.11 for weighing at different ages; rp = 0.30 but rg (GA) = 0.84 ± 0.11 for the backtests) as well as between reactions to different tests. Therefore, for inclusion of behaviour traits into breeding programmes, and considering high labour input required for some tests such as the backtest, it is recommended to assess behaviour during situations that are relevant and identical to practical conditions, while the use of indicator traits generally does not appear to be a very promising alternative.


Assuntos
Modelos Genéticos , Característica Quantitativa Herdável , Seleção Artificial , Suínos/genética , Animais , Feminino , Masculino , Distribuição Normal
11.
Physiol Behav ; 141: 164-71, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25624109

RESUMO

In beef cows, docility is important for animal welfare reasons, the farmer's and veterinarian's safety as well as for economic reasons. The hormone testosterone is often mentioned in the context with aggressions and docility. The present study tested the hypothesis that higher testosterone levels in beef cows are associated with more aggressive behavior and lower docility during behavior tests. German Simmental (beef) (n=21) and Charolais heifers (n=20) were subjected with one repetition to a chute test as well as a separation and restraint test. Heart rate, thermal images of the eye, saliva cortisol as well as saliva testosterone were collected along with behavioral parameters during the tests. For all physiological and most of the behavioral parameters significant breed differences were detected. Charolais heifers (0.10 ± 0.01 ng/ml saliva) had considerably higher testosterone levels compared with Simmental heifers (0.04 ± 0.01 ng/ml; P=0.0001). Interestingly, the Charolais heifers expressed a higher docility, so across breeds higher levels of testosterone are associated with higher docility. However, all the parameters presumably linked to stress (heart rate, eye temperature, cortisol levels) generally showed stronger correlations to behavior traits than testosterone (e.g., trait "time in corner" - testosterone: r=0.25 vs. cortisol: r=-0.43 (Fisher's r-to-z: P=0.0985); eye temperature: r=-0.65; (P=0.0005); heart rate: r=-0.60 (P=0.003)). Eye temperature correlated with both heart rate (r=0.68) and cortisol levels (r=0.62; both P<0.0001). Therefore, eye temperature more so than testosterone appears to be a suitable indicator of stress, and as such also an, albeit incomplete, indicator of docility in cattle.


Assuntos
Agressão/fisiologia , Comportamento Animal/fisiologia , Hidrocortisona/análise , Temperamento/fisiologia , Testosterona/análise , Animais , Bovinos , Feminino , Masculino , Saliva/química
12.
Physiol Behav ; 139: 361-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25446230

RESUMO

The objectives of the present study were to evaluate the suitability of potential biomarkers for maternal ability in cattle, and in addition to test the hypothesis that dairy cows have a less pronounced motherliness than beef cows. Therefore, maternal behavior of 20 Simmental beef-type (S) and 20 German Black Pied (dairy-type) Cattle (BP) was assessed on the 2nd and again on the 3rd day of the calf's life. Measurements included the frequency of interactions between cow and calf, the cow's willingness to defend her calf, the overall maternal behavior, saliva cortisol, saliva oxytocin, heart rate, and thermal images of the eye (ET). Mixed model analysis revealed that BP had significantly (P<0.05) higher oxytocin (88.6±9.2 vs. 62.8±9.2 pg/ml saliva) and cortisol (1.3±0.1 vs. 1.0±0.1 ng/ml saliva) levels, but lower heart rates (80.0±2.0 vs. 95.8±2.0bpm) than S cows. Simmental (beef) cows showed more defensive behavior (3.5±0.2 vs. 2.7±0.2 scores), but fewer total interactions between cow and calf (8.1±1.4 vs. 13.8±1.4), compared to BP (dairy). However, with the exception of heart rate and overall maternal behavior, breed differences tended to diminish from the 2nd to the 3rd day of the calf's life. Repeatabilities ranged from 9±23% (ET) to 77±7% (maternal behavior measured on a visual analogue scale), and correlations between physiological parameters and behavior differed between breeds and were generally at a low level. In conclusion, beef cows do not seem to be per se more maternal compared to dairy cows, and the assessed parameters are of limited use as biomarkers for maternal behavior.


Assuntos
Bovinos/fisiologia , Comportamento Materno/fisiologia , Animais , Biomarcadores/metabolismo , Temperatura Corporal/fisiologia , Frequência Cardíaca/fisiologia , Hidrocortisona/metabolismo , Fenômenos Fisiológicos Oculares , Ocitocina/metabolismo , Reprodutibilidade dos Testes , Saliva/metabolismo , Especificidade da Espécie , Termografia
13.
PLoS One ; 9(1): e87285, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24489890

RESUMO

Rideability, i.e. the ease and comfort with which a horse can be ridden, is considered to be one of the most important traits in riding horses. However, at present rideability is evaluated rather subjectively in breeding horse performance tests. The aim of the present study was to evaluate the role horse behaviour as well as degree and quality of rein tension might play in judges' evaluation of horses' rideability. Mares (n=33) and stallions (n=13) from two different mare- and one stallion-testing station were observed twice during their performance test dressage training. During these rides, rein tension was measured continuously, and frequency of behaviour patterns such as head-tossing, tail swishing, and snorting was recorded. Rein tension parameters showed reasonable repeatabilities within horse-rider pairs (e.g. mean rein tension: r(2)=0.61 ± 0.11; variance of rein tension: r(2)=0.52 ± 0.14). Regression analysis revealed that a larger proportion of variance in rideability scores could be explained by maximum (17%), mean (16%) and variance (15%) of rein tension compared to horses' or riders' behavioural parameters (tail-swishing: 5% and rider's use of hands: 5%, respectively). According to mixed model analysis, rideability scores dropped (all P<0.05) with increasing mean, maximum and variability in rein tension (e.g. -0.37 ± 0.14 scores per additional 10 Newton in mean tension). However, mean rein tension differed between testing stations (P<0.0001) ranging between 9.1 ± 1.6 N in one station and 21.7 ± 1.3 N in another station. These results indicate that quantity and consistency of rein tension is either directly or indirectly an important factor for judges to derive rideability scores. Given the importance of rein tension parameters to both rider comfort and horse welfare, potentially, measurements of rein tension along with behaviour observations assessing the quality of rein contact (e.g. distinguishing a light contact from attempts to evade contact) might be used to make the assessment of rideability more impartial.


Assuntos
Comportamento Animal , Manobra Psicológica , Cavalos/psicologia , Animais , Estudos de Avaliação como Assunto , Feminino , Masculino , Recreação , Reprodutibilidade dos Testes
14.
J Anim Sci ; 91(12): 5557-64, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24158365

RESUMO

Mixing of unfamiliar pigs is a standard management procedure in commercial pig production and is often associated with a period of intense and physically damaging aggression. Aggression is considered a problem for animal welfare and production. The objective of the present paper was to investigate the genetic background of aggressive behavior traits at mixing of unfamiliar gilts under 2 different housing conditions. Therefore, a total of 543 purebred Pietrain gilts, from 2 nucleus farms (farm A: n = 302; farm B: n = 241) of 1 breeding company, were tested at an average age of 214 d (SD 12.2 d) for aggressive behavior by 1 observer. Observations included the frequencies of aggressive attack and reciprocal fighting during mixing with unfamiliar gilts. On farm A 41% of the gilts were purebred Pietrains, whereas 59% were purebred Landrace or Duroc gilts. On the farm B 42% of the gilts were purebred Pietrains, and 58% purebred Large White gilts. The average size of the newly mixed groups of gilts was 28 animals on farm A and 18 animals on farm B. The Pietrain gilts from the 2 herds were genetically closely linked. They were the offspring of 96 sires, with 64% of these sires having tested progeny in both farms. There were clear differences in the housing of the animals between the 2 farms. The test pen on farm A had a solid concrete floor littered with wooden shavings and was equipped with a dry feeder. On farm B there was a partly slatted floor, and the gilts were fed by an electronic sow feeder. Mean space allowance was 2.6 m(2)/gilt on farm A and 3.9 m(2)/gilt on farm B. Although large interindividual differences existed, gilts from farm B performed numerically more aggressive attack (mean 1.12, SD 1.42 vs. mean 0.71, SD 1.20) and reciprocal fighting (mean 0.78, SD 0.98 vs. mean 0.44, SD 0.82) when compared with gilts from farm A. The heritabilities and additive genetic variances for behavioral traits were estimated with a linear animal model and were on a low level in farm A (h(2) = 0.11, SE = 0.07, and σ(2)a = 0.12 for aggressive attack and h(2) = 0.04, SE = 0.07, and σ(2)a = 0.02 for reciprocal fighting) and on a moderate level in farm B (h(2) = 0.29, SE = 0.13, and σ(2)a = 0.44 for aggressive attack and h(2) = 0.33, SE = 0.12, and σ(2)a = 0.27 for reciprocal fighting). For both aggressive attack and reciprocal fighting, genetic correlation of the same trait between farm A and farm B was 1.0. Therefore, aggressive behavior does not seem to be influenced by genotype × environment interactions. Under these circumstances aggressions in group housing can be reduced by genetic selection against aggressive behavior. Therewith, the welfare and health of sows will ultimately increase.


Assuntos
Agressão/fisiologia , Genótipo , Abrigo para Animais , Suínos/genética , Suínos/fisiologia , Animais , Feminino
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