Levels of testosterone, progesterone and oestradiol in pregnant-lactating does in relation to aggression during group housing

[EN] The neuroendocrine regulation of rabbit maternal behaviour has been explored in detail. However, little is yet known about the hormonal regulation of aggression in concurrently pregnant-lactating does, a reproductive condition that prevails during group housing of rabbits on farms. Therefore, in this study we determined the relation between a) the levels of progesterone, testosterone, and oestradiol during lactation; b) the anogenital distance at artificial insemination; and c) the timing of grouping with the intensity of agonistic behaviour, published previously. We performed four consecutive trials, where three groups of eight does each were artificially inseminated on day 10 postpartum (pp) and grouped on either day 12, 18 or 22 pp. Using Dipetalogaster maxima, a reduviid blood-sucking bug, we collected blood samples during the pregnant-lactating phase (days 13, 15, 17, 19, 21, 23 pp) on one or two randomly chosen does per treatment group. Testosterone levels varied little across the pregnant-lactating phase, agreeing with results from pregnant-only rabbits, while progesterone levels increased from day 3 (=13 dpp) to day 7 (=17 dpp) and remained unchanged until day 13 (=23 dpp) of pregnancy. All oestradiol concentrations fell below the limit of detection. Overall, all concentrations were slightly lower in comparison to rabbit studies with pregnantonly does. The agonistic behaviour was not related to the respective hormonal concentrations at grouping. In conclusion, the time point of grouping does after artificial insemination (AI) in the semi-group housing system only had a weak influence on aggression and the hormonal profile did not indicate an optimum time for grouping.Federal Food Safety and Veterinary Office (BLV, Project No. 2.18.04)Braconnier, M.; González-Mariscal, G.; Wauters, J.; Gebhardt-Henrich, SG. (2021). Levels of testosterone, progesterone and oestradiol in pregnant-lactating does in relation to aggression during group housing. World Rabbit Science. 29(4):247-261. https://doi.org/10.4995/wrs.2021.14897OJS247261294Aguilar-Roblero R., González-Mariscal G. 2020. Behavioral, neuroendocrine and physiological indicators of the circadian biology of male and female rabbits. Eur. J. Neurosci., 51: 429-453. https://doi.org/10.1111/ejn.14265Albert D.J., Jonik R.H., Walsh M.L. 1990. Hormone-Dependent Aggression in Female Rats: Testosterone Implants Attenuate the Decline in Aggression Following Ovariectomy I. Physiol. Behav., 47, 659-664. https://doi.org/10.1016/0031-9384(90)90074-EAndrist C.A., Bigler L.M., Würbel H., Roth B.A. 2012. Effects of group stability on aggression, stress and injuries in breeding rabbits. Appl. Anim. Behav. Sci., 142: 182-188. https://doi.org/10.1016/j.applanim.2012.10.017Andrist C.A., van den Borne B.H.P., Bigler L.M., Buchwalder T., Roth B.A. 2013. Epidemiologic survey in Swiss group-housed breeding rabbits: Extent of lesions and potential risk factors. Prev. Vet. Med., 108: 218-224. https://doi.org/10.1016/j.prevetmed.2012.07.015Arias-Álvarez M., García-García R.M., Torres-Rovira L., González- Bulnes A., Rebollar P.G., Lorenzo P.L. 2010. Influence of hormonal and nonhormonal estrus synchronization methods on follicular and oocyte quality in primiparous lactating does at early postpartum period. Theriogenology, 73: 26-35. https://doi.org/10.1016/j.theriogenology.2009.07.017Bánszegi O., Altbäcker V., Bilkó Á. 2009. Intrauterine position influences anatomy and behavior in domestic rabbits. Physiol. Behav., 98: 258-262. https://doi.org/10.1016/j.physbeh.2009.05.016Bánszegi O., Szenczi P., Dombay K., Bilkó Á., Altbäcker V. 2012. Anogenital distance as a predictor of attractiveness, litter size and sex ratio of rabbit does. Physiol. Behav., 105: 1226-1230. https://doi.org/10.1016/j.physbeh.2012.01.002Beehner J.C., Phillips-Conroy J.E., Whitten P.L. 2005. Female testosterone, dominance rank, and aggression in an Ethiopian population of hybrid baboons. Am. J. Primatol., 67, 101-119. https://doi.org/10.1002/ajp.20172Bill J., Rauterberg S., Herbrandt S., Ligges U., Kemper N., Fels M., Agonistic behavior and social hierarchy in female domestic rabbits kept in semi-groups. J. Vet. Behav., 38: 21-31. https://doi.org/10.1016/j.jveb.2020.03.004Braconnier M., Gómez Y., Gebhardt-Henrich S.G. 2020. Different regrouping schedules in semi group-housed rabbit does: Effects on agonistic behaviour, stress and lesions. Appl. Anim. Behav. Sci., 228: 105024. https://doi.org/10.1016/j.applanim.2020.105024BTS. 2019. https://www.blw.admin.ch/blw/de/home/instrumente/direktzahlungen/produktionssystembeitraege/tierwohlbeitraege.html.Buijs S., Maertens L., Hermans K., Vangeyte J., André F., Tuyttens M. 2015. Behaviour, wounds, weight loss and adrenal weight of rabbit does as affected by semigroup housing. Appl. Anim. Behav. Sci., 172: 44-51. https://doi.org/10.1016/j.applanim.2015.09.003Buijs S., Vangeyte J., Tuyttens F.A.M. 2016. Effects of communal rearing and group size on breeding rabbits' post-grouping behaviour and its relation to anogenital distance. Appl. Anim. Behav. Sci., 182: 53-60. https://doi.org/10.1016/j.applanim.2016.06.005Carnaby K., Painer J., Söderberg A., Gavier-Widèn D., Göritz F., Dehnhard M., Jewgenow K. 2012. Histological and endocrine characterization of the annual luteal activity in Eurasian Lynx (Lynx lynx). Reproduction, 10.1530 / REP-12-0166 144: 477-483. https://doi.org/10.1530/REP-12-0166Chu L.R., Garner J.P., Mench J.A., 2004. A behavioral comparison of New Zealand White rabbits (Oryctolagus cuniculus) housed individually or in pairs in conventional laboratory cages. Appl. Anim. Behav. Sci., 85: 121-139. https://doi.org/10.1016/j.applanim.2003.09.011Dal Bosco A., Mugnai C., Martino M., Szendrő Z., Mattioli S., Cambiotti V., Cartoni Mancinelli A., Moscati L., Castellini C. 2019. Housing Rabbit Does in a Combi System with Removable Walls: Effect on Behaviour and Reproductive Performance. Animals, 9: 528-528. https://doi.org/10.3390/ani9080528Davis E.S., Marler C.A. 2003. The progesterone challenge: steroid hormone changes following a simulated territorial intrusion in female Peromyscus californicus. Horm. Behav., Special Issue on Aggressive and Violent Behavior, 44: 185-198. https://doi.org/10.1016/S0018-506X(03)00128-4Dehnhard M., Naidenko S., Frank A., Braun B., Göritz F., Jewgenow K. 2008. Non-invasive Monitoring of Hormones: A Tool to Improve Reproduction in Captive Breeding of the Eurasian Lynx. Reprod. Domest. Anim., 43: 74-82. https://doi.org/10.1111/j.1439-0531.2008.01145.xDenenberg V.H., Sawin P.B., Frommer G.P., Ross S. 1958. Genetic, physiological and behavioral background of reproduction in the rabbit: IV. An analysis of maternal behavior at successive parturitions. Behaviour 13: 131-142. https://doi.org/10.1163/156853958X00073Drickamer L.C. 1996. Intra-uterine position and anogenital distance in house mice: consequences under field conditions. Anim. Behav., 51: 925-934. https://doi.org/10.1006/anbe.1996.0096Dušek A., Bartoš L. 2012. Variation in Ano-Genital Distance in Spontaneously Cycling Female Mice. Reprod. Domest. Anim., 47: 984-987. https://doi.org/10.1111/j.1439-0531.2012.02003.xFortun L., Prunier A., Lebas F. 1993. Effects of lactation on fetal survival and development in rabbit does mated shortly after parturition. J. Anim. Sci., 71: 1882-1886. https://doi.org/10.2527/1993.7171882xGobikrushanth M., Bruinjé T.C., Colazo M.G., Butler S.T., Ambrose D.J. 2017. Characterization of anogenital distance and its relationship to fertility in lactating Holstein cows. J. Dairy Sci., 100: 9815-9823. https://doi.org/10.3168/jds.2017-13033González-Mariscal G., Díaz-Sánchez V., Melo A.I., Beyer C., Rosenblatt J.S. 1994. Maternal behavior in New Zealand white rabbits: Quantification of somatic events, motor patterns, and steroid plasma levels. Physiol. Behav., 55: 1081-1089. https://doi.org/10.1016/0031-9384(94)90391-3González-Mariscal G., Jiménez P., Beyer C., Rosenblatt J.S. 2003. Androgens stimulate specific aspects of maternal nestbuilding and reduce food intake in rabbits. Horm. Behav., 43: 312-317. https://doi.org/10.1016/S0018-506X(02)00046-6González-Mariscal G., Gallegos J.A., Sierra-Ramirez A., Flores J.G. 2009. Impact of concurrent pregnancy and lactation on maternal nest- building, estradiol and progesterone concentrations in rabbits. World Rabbit Sci., 17: 145-152. https://doi.org/10.4995/wrs.2009.654González-Mariscal G., Lemus A.C., Vega-González A., Aguilar-Roblero A. 2013a. Litter size determines circadian periodicity of nursing in rabbits. Chronobiol. Int., 30: 711-718. https://doi.org/10.3109/07420528.2013.784769González-Mariscal G., Toribio A., Gallegos-Huicochea J.A., Serrano-Meneses M.A. 2013b. The characteristics of suckling stimulation determine the daily duration of motheryoung contact and milk output in rabbits. Dev. Psychobiol. 55: 809-817. https://doi.org/10.1002/dev.21071González-Mariscal G., Gallegos J.A. 2014. The maintenance and termination of maternal behavior in rabbits: Involvement of suckling and progesterone. Physiol. Behav., 124: 72-76. https://doi.org/10.1016/j.physbeh.2013.10.031González-Mariscal G., Caba M., Martínez-Gómez M., Bautista A., Hudson R. 2016. Mothers and offspring: The rabbit as a model system in the study of mammalian maternal behavior and sibling interactions. Horm. Behav., 77: 30-41. https://doi.org/10.1016/j.yhbeh.2015.05.011González-Mariscal G., Sisto Burt A., Nowak R. 2017. Behavioral and neuroendocrine indicators of well-being in farm and laboratory mammals. Pfaff D. & Joëlls M., eds. "Hormones, Brain and Behavior" 3a ed. Elsevier, 454-485. https://doi.org/10.1016/B978-0-12-803592-4.00017-1Graf S., Bigler L., Failing K., Würbel H., Buchwalder T. 2011. Regrouping rabbit does in a familiar or novel pen: Effects on agonistic behaviour, injuries and core body temperature. Appl. Anim. Behav. Sci., 135: 121-127. https://doi.org/10.1016/j.applanim.2011.10.009Hein D.J. 2019. Labordiagnostik bei Kleinsäugern: Präanalytik und tierartspezifische Befundung. Schlütersche. Hein J. 2014. Blutentnahme und Venenverweilkatheter beim Kaninchen. kleintier konkret 17: 23-25. https://doi.org/10.1055/s-0034-1384446Hoffman K.L., Martínez-Alvarez E., Rueda-Morales R.I. 2009. The inhibition of female rabbit sexual behavior by progesterone: Progesterone receptor-dependent and-independent effects. Horm. Behav., 55: 84-92. https://doi.org/10.1016/j.yhbeh.2008.08.011Holst D. von, Hutzelmeyer H., Kaetzke P., Khaschei M., Rödel H.G. 2002. Social rank, fecundity and lifetime reproductive success in wild European rabbits (Oryctolagus cuniculus). Behav. Ecol. Sociobiol., 51, 245-254. https://doi.org/10.1007/s00265-001-0427-1Hudson R., Shaal B., Bilkó Á., Altbäcker V. 1996. Just three minutes a day: The behaviour of young rabbits viewed in the context of limited maternal care. In Proc.: 6th World Rabbit Congress, July 1996, Toulouse, France, 2: 395-403.Hudson R., Shaal B., Martínez-Gómez M., Distel H. 2000. Mother-young relations in the European rabbit: physiological and behavioural locks and keys. World Rabbit Science 8: 85-90. https://doi.org/10.4995/wrs.2000.424Kosowska B., Strzała T., Moska M., Ratajszczak R., Dobosz T. 2015. Cytogenetic Examination of South American Tapirs, Tapirus Terrestris (Perissodactyla, Tapiridae), from the Wroclaw Zoological Garden. Vestnik Zoologii, 49: 529-536.Lebas F., Coudert P.,. de Rochambeau H.,. Thebault R.G. 1997. The rabbit - Husbandry, health and production. FAO Animal Production and Health Series No. 21.Maertens L., Rommers J., Jacquet M. 2011. Le logement des lapins en parcs, une alternative pour les cages classiques dans un système "duo"? [Combi-park housing of females, an alternative for the classical cages when using the "duo" management system?]. 14èmes Journées de la Recherche Cunicole, 85-88.Mann M.A., Svare B. 1982. Factors influencing pregnancy induced aggression in mice. Behav. Neural Biol., 36: 242-258. https://doi.org/10.1016/S0163-1047(82)90867-6Mann M.A., Konen C., Svare B. 1984. The role of progesterone in pregnancy-induced aggression in mice. Horm. Behav., 18: 140-160. https://doi.org/10.1016/0018-506X(84)90039-4Markvardsen S.N., Kjelgaard-Hansen M., Ritz C., SØrensen D.B. 2012. Less invasive blood sampling in the animal laboratory: Clinical chemistry and haematology of blood obtained by the triatominae bug Dipetalogaster maximus. Lab. Anim., 46: 136-141. https://doi.org/10.1258/la.2011.011063Mira-Escolano M.P., Mendiola J., Mínguez-Alarcón L., Melgarejo M., Cutillas-Tolín A., Roca M., López-Espín J.J., Noguera-Velasco J.A., Torres-Cantero A.M. 2014. Longer anogenital distance is associated with higher testosterone levels in women: a cross-sectional study. BJOG, 121: 1359-1364. https://doi.org/10.1111/1471-0528.12627Mugnai C., Dal Bosco A., Castellini C. 2009. Effect of different rearing systems and pre-kindling handling on behaviour and performance of rabbit does. Appl. Anim. Behav. Sci., 118: 91-100. https://doi.org/10.1016/j.applanim.2009.02.007Nielsen S.S., Alvarez J., Bicout D.J., Calistri P., Depner K., Drewe J.A., Garin-bastuji B., Luis J., Rojas G., Michel V., Angel M., Chueca M., Roberts H.C., Sihvonen L.H., Spoolder H., Stahl K., Calvo A.V., Viltrop A., Buijs S., Edwards S., Candiani D., Mosbach-schulz O. 2020. Health and welfare of rabbits farmed in different production systems, EFSA J., 18: 1-96. https://doi.org/10.2903/j.efsa.2020.5944O'Malley B. 2005. Rabbits. In: O'Malley B. (Ed.), Clinical Anatomy and Physiology of Exotic Species. Elsevier, New York, pp. 173-195. https://doi.org/10.1016/B978-070202782-6.50011-9Palanza P., Parmigiani S., Vom Saal F.S. 1995. Urine marking and maternal aggression of wild female mice in relation to anogenital distance at birth. Physiol. Behav., 58: 827-835. https://doi.org/10.1016/0031-9384(95)00107-TPalka Y.S., Sawyer C.H. 1966. The effects of hypothalamic implants of ovarian steroids on oestrous behaviour in rabbits. J. Physiol., 185: 251-269. https://doi.org/10.1113/jphysiol.1966.sp007986R Core Team, 2019., A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/Rödel H.G., Monclús R., von Holst D. 2006. Behavioral styles in European rabbits: Social interactions and responses to experimental stressors. Physiol. Behav., 89: 180-188. https://doi.org/10.1016/j.physbeh.2006.05.042Rödel H.G., Starkloff A., Bautista A., Friedrich A.C., Von Holst D. 2008. Infanticide and maternal offspring defence in European rabbits under natural breeding conditions. Ethology, 114: 22-31. https://doi.org/10.1111/j.1439-0310.2007.01447.xRommers J.M., Gunnink H., Klop A., De Jong I.C. 2011. Dynamics in aggressive behaviour of rabbit does in a group housing system: a descriptive study. In: 17th International Symposium on Housing and Diseases of Rabbits, Fur Providing Animals and Pet Animals, May 11-12. Celle, Germany, pp. 75-85.Rommers J.M., Reuvekamp B.J.F., Gunnink H., de Jong I.C. 2014. Effect of hiding places, straw and territory on aggression in group-housed rabbit does. Appl. Anim. Behav. Sci., 157: 117-126. https://doi.org/10.1016/j.applanim.2014.05.011Schönbrodt F.D., Perugini M. 2013. At what sample size do correlations stabilize? J. Res. Pers., 47: 609-612. https://doi.org/10.1016/j.jrp.2013.05.009Shargal D., Shore L., Roteri N., Terkel A., Zorovsky Y., Shemesh M., Steinberger Y. 2008. Fecal testosterone is elevated in high ranking female ibexes (Capra nubiana) and associated with increased aggression and a preponderance of male offspring. Theriogenology 69: 673-680. https://doi.org/10.1016/j.theriogenology.2007.11.017Simpson E.R. 2002. Aromatization of androgens in women: current concepts and findings. Fertil. Steril., 77: 6-10. https://doi.org/10.1016/S0015-0282(02)02984-9Squire L.R. 2009. Encyclopedia of Neuroscience, Volume 1. Academic Press. https://doi.org/10.1093/acprof:oso/9780195380101.003.0001Stadler A., Meiser C.K., Schaub G. a. 2011. "Living Syringes": use of Haematophagous Bugs as Blood Samplers from Small and Wild Animals. Nature Helps... 243-272. https://doi.org/10.1007/978-3-642-19382-8Szendrő Z., McNitt J.I., Matics Z., Mikó A., Gerencsér Z. 2016. Alternative and enriched housing systems for breeding does: A review. World Rabbit Sci., 24: 1-14. https://doi.org/10.4995/wrs.2016.3801Takahashi, Kayo, Hosoya T., Onoe K., Takashima T., Tanaka M., Ishii A., Nakatomi Y., Tazawa S., Takahashi, Kazuhiro, Doi H., Wada Y., Watanabe Y. 2018. Association between aromatase in human brains and personality traits. Sci. Rep., 8: 1-9. https://doi.org/10.1038/s41598-018-35065-4Theau-Clément M., Poujardien B., Bellereaud J. 1990. Influence des traitements lumineux, modes de reproduction et états physiologiques sur la productivité de lapines multipares. In: 5èmes Journées de La Recherche Cunicole, Dec 1990, Paris, France.Thomsen R., Voigt C.C. 2006. Non-invasive blood sampling from primates using laboratory-bred blood-sucking bugs (Dipetalogaster maximus; Reduviidae, Heteroptera). Primates, 47: 397-400. https://doi.org/10.1007/s10329-006-0194-8Trainor B.C., Bird I.M., Marler C.A. 2004. Opposing hormonal mechanisms of aggression revealed through short-lived testosterone manipulations and multiple winning experiences. Horm. Behav., 45: 115-121. https://doi.org/10.1016/j.yhbeh.2003.09.006Trainor B.C., Kyomen H.H., Marler C.A. 2006. Estrogenic encounters: How interactions between aromatase and the environment modulate aggression. Front. Neuroendocrinol., 27: 170-179. https://doi.org/10.1016/j.yfrne.2005.11.001Ubilla E., Rebollar P.G. 1995. Influence of the postpartum day on plasma estradiol-17 β levels, sexual behaviour, and conception rate, in artificially inseminated lactating rabbits. Anim. Reprod. Sci., 38: 337-344. https://doi.org/10.1016/0378-4320(94)01366-TVoigt C.C., Von Helversen O., Michener R.H., Kunz T.H. 2003. Validation of a Non-Invasive Blood-Sampling Technique for Doubly-Labelled Water Experiments. J. Exp. Zool. A Comp. Exp. Biol., 296: 87-97. https://doi.org/10.1002/jez.a.10121Voigt C.C., Faßbender M., Dehnhard M., Wibbelt G., Jewgenow K., Hofer H., Schaub G.A. 2004. Validation of a minimally invasive blood-sampling technique for the analysis of hormones in domestic rabbits, Oryctolagus cuniculus (Lagomorpha). Gen. Comp. Endocrinol., 135: 100-107. https://doi.org/10.1016/j.ygcen.2003.08.005Voigt C.C., Peschel U., Wibbelt G., Frölich K. 2006. An Alternative, Less Invasive Blood Sample Collection Technique for Serologic Studies Utilizing Triatomine Bugs (Heteroptera; Insecta). J. Wildl. Dis., 42: 466-469. https://doi.org/10.7589/0090-3558-42.2.466von Engelhard N., Kappeler P.M., Heistermann M. 2000. Androgen levels and female social dominance in Lemur catta. In Proc.: R. Soc. Lond. B, 267: 1533-1539. https://doi.org/10.1098/rspb.2000.1175Vos A.C., Müller T., Neubert L., Voigt C.C. 2010. Validation of a Less Invasive Blood Sampling Technique in Rabies Serology Using Reduviid Bugs (Triatominae, Hemiptera). J. Zoo. Wildl. Med., 41: 63-68. https://doi.org/10.1638/2009-0103.1Wingfield J.C., Hegner R.E., Dufty, Alfred M., Ball G.F. 1990. The "Challenge Hypothesis": Theoretical Implications for Patterns of Testosterone Secretion, Mating Systems, and Breeding Strategies. Am. Nat., 136: 829-846. https://doi.org/10.1086/285134Zomeño C., Birolo M., Zu A., Xiccato G., Trocino A. 2017. Aggressiveness in group-housed rabbit does: Influence of group size and pen characteristics. Appl. Anim. Behav. Sci., 194: 79-85. https://doi.org/10.1016/j.applanim.2017.05.016Zomeño C., Birolo M., Gratta F., Zuffellato A., Xiccato G., Trocino A. 2018. Effects of group housing system, pen floor type, and lactation management on performance and behaviour in rabbit does. Appl. Anim. Behav. Sci., 203: 55-63. https://doi.org/10.1016/j.applanim.2018.03.00

Effects of on-farm hatching on short term stress indicators, weight gain, and cognitive ability in layer chicks

Layer chicks are usually transported early in life, experiencing immediate post-hatch food and water deprivation and various transport-related stressors with potentially negative long-term consequences for learning, cognition and welfare. In contrast, as chicks are only temporarily exposed to these stressors, the experienced stress could be sub-chronic which may improve cognitive flexibility. The aim of this exploratory study was therefore to investigate the acute and long-term effects of on-farm hatching (OFH) compared to conventional hatching. Dekalb White layer chicks were subjected to either OFH (n = 47) with ad libitum access to feed and water or temporary post-hatch resource deprivation and eight hour transport (RDT; n = 42). Physical and behavioural measures were collected to examine short-term effects of the treatment procedures. To determine longer term effects, treatment differences in learning and cognitive flexibility were assessed in a Y-maze using several paradigms (reversal, attentional-shift, extinction) between 4 and 12 weeks of age (WOA). Compared to OFH chicks, RDT had: greater corticosterone levels after transport (F1,19 =8.15, p = 0.01, RDT (16.24 ± 1.20 ng/mL) vs. OFH (8.13 ± 1.20 ng/mL) and post-recovery (F1,19 =4.93, p = 0.04; RDT (11.69 ± 1.35 ng/mL) vs. OFH (5.31 ± 1.37)), and lower body mass after resource deprivation and transport (F2258 =9.7, p < 0.001, RDT (33.14 ± 0.33 g) vs. OFH (37.62 ± 0.28 g)). Performance of activity behaviours (foraging, drinking, resting, wing-assisted running) after transport exhibited treatment by time interactions. Additionally, a tendency for OFH being heavier than RDT chicks was observed up to 11 WOA. The majority of birds learned the initial association in the Y-maze between a reward and location (77% of n = 19 RDT and n = 29 OFH chicks) or light stimulus (91% of n = 12 RDT and n = 11 OFH chicks). Subsequently, a number of chicks reached the learning criterion in the location reversal (24% of n = 13 RDT and n = 24 OFH chicks) and the light-to-location attentional-shift (47% of n = 11 RDT and n = 10 OFH chicks), and most of these chicks succeeded in the following extinction paradigm (80% of n = 3 RDT and n = 7 OFH chicks). No treatment effects were detected in any phase of cognitive testing. In conclusion, treatment affected behaviour and health parameters suggesting RDT animals were recovering from resource deprivation and transport. Continued treatment differences in body mass throughout rearing demonstrated long term effects as well although no effects on initial learning and cognitive flexibility were identified. Future work is needed to determine what mechanisms are responsible for the observed health and behavioural differences

Intra-individual variation of hen movements is associated with later keel bone fractures in a quasi-commercial aviary.

Measuring intra- and inter-individual variation in movement can bring important insights into the fundamental ecology of animals and their welfare. Although previous studies identified consistent differences in movements of laying hens within commercial aviaries, the level of consistency was not quantified, limiting our capacity to understand the importance of individual movements for welfare. We aimed to quantify the scope of intra- and inter-individual differences in movements of commercial laying hens and examined their associations with indicators of welfare at the end of production. We quantified individual differences in one composite daily movement score for 80 hens over 54 days post-transfer to a quasi-commercial aviary. Results showed consistent inter-individual differences in movement averages, explaining 44% of the variation, as well as individual variation in predictability and temporal plasticity (at the population-level, hens increased their movements for 39 days). Hens that were more predictable in their daily movements had more severe keel bone fractures at the end of production while we found no such correlation between daily movement averages (individual intercept) and welfare indicators. Our findings highlight the importance of inter-individual difference in intra-individual variation of movements to improve poultry welfare

Effect of different management protocols for grouping does on aggression and dominance hierarchies

The study aimed at evaluating different management protocols of grouping does in regard to aggressive interactions and the establishment of a hierarchy under commercial conditions. Fifty-seven multiparous rabbit does of the Hycole hybrid maternal line were randomly distributed into three different management protocols (MP) for a total of 5 consecutive trials: MP12 with grouping 12 days after parturition, MP18 after 18 days and MP22 after 22 days. Video recordings were made during the first 24 h after grouping and after 6 and 10 days, and used to score aggressive interactions of the animals with exception of treatment 3 where day 10 was omitted because it was after the weaning of the kits. For MP12 and MP18 the frequency of different categories of aggressive interactions were significantly higher on the day of grouping than afterwards, with a strong decrease on day 6 (P < 0.02), but almost no change was found between days 6 and 10. This was especially true for biting, with a high frequency of occurrence just after grouping and a subsequent decrease on day 6 under all management schedules (P = 0.005). The change in the number of aggressive interactions between 6 and 10 days after grouping was not significantly different between MPs. However, the time point of 6 days after grouping seemed to be fundamental in reducing the number of aggressive events. Although a longer separation for 18 and 22 days after parturition did not reduce the total number of aggressive interactions, MP18 and MP22 showed more mild aggressive interactions with respect to MP12 on the day of regrouping. Moreover, when comparing MPs concerning the development of hierarchy, hierarchies appeared very stable independently of the length of grouping (P < 0.01)

The influence of human interaction on guinea pigs: behavioral and thermographic changes during animal-assisted therapy

Guinea pigs are often involved in animal-assisted therapy (AAT) but there is little knowledge about the effects of human contact on guinea pigs involved in AAT. The aim of this study was to investigate effects of availability of a retreat, presence of conspecifics, prior experience with AAT, and human interaction on indicators of welfare in guinea pigs involved in AAT. Guinea pigs of both sexes and different ages (n=20) were assigned to a randomized, controlled within-subject trial with repeated measurements. Each guinea pig was tested in four settings: (I) therapy with retreat possibility with conspecifics, (II) therapy with retreat possibility without conspecifics, (III) therapy without retreat possibility, and (IV) setting without human interaction. We measured changes in eye temperature, as a proxy to infer stress levels, at 5-s intervals with a thermographic camera. All sessions were video recorded and the guinea pigs' behavior was coded using continuous recording and focal animal sampling. For the statistical analysis we used generalized linear mixed models, with therapy setting as a fixed effect and individual guinea pig as a random effect. We observed a temperature increase relative to baseline in settings (I) therapy with retreat with conspecifics present and (III) therapy without retreat. The percentage of time a guinea pig was petted was positively correlated with a rise in the eye temperature independent of the setting. Time spent eating was reduced in all therapy settings (I-III) compared to the setting without HAI (human animal interaction) (IV). In the setting with retreat (I), guinea pigs showed more active behaviors such as locomotive behavior or startling compared to the setting without retreat (III) and the setting without HAI (IV). When no retreat was available (III), they showed more passive behaviors, such as standing still or freezing compared to therapy with retreat (I). Based on our results we identified the behaviors "reduced eating", "increased startle" and "increased freezing" as indicators of an increased stress level. Petting the guinea pigs was correlated with a rise in the eye temperature and might be a factor which can cause stress. Our results support the suggestion that guinea pigs involved in AAT should have a retreat possibility, should have access to conspecifics, and should be given time to adapt to a new setting. In this way, stress might be reduced

High resolution parallel sequencing reveals multistrain Campylobacter in broiler chicken flocks testing 'negative' by conventional culture methods: implications for control of Campylobacter infection.

Contaminated chicken meat is a major source of human Campylobacteriosis and rates of infection remain high, despite efforts to limit the colonisation of broiler (meat) chicken flocks on farms. Using conventional testing methods of culture or qPCR, Campylobacter is typically detected amongst broiler flocks from 3 wk of age, leading to the assumption that infection is introduced horizontally into chicken rearing houses at this time. In this study, we use parallel sequencing of a fragment of the Campylobacter outer membrane protein, encoded by the porA gene, to test for presence of Campylobacter DNA amongst fresh fecal samples collected from broiler flocks aged 23 to 28 d. Campylobacter DNA was detected in all of the 290 samples tested using the porA target, and in 48% of samples using 16S bacterial profiling, irrespective of whether or not Campylobacter could be detected using conventional qPCR thresholds. A single porAf2 variant was predominant among flocks that would be determined to be Campylobacter 'positive' by conventional means, but a diverse pattern was seen among flocks that were Campylobacter 'negative'. The ability to routinely detect low levels of Campylobacter amongst broiler flocks at a much earlier age than would conventionally be identified requires a re-examination of how and when biosecurity measures are best applied for live birds. In addition, it may be useful to investigate why single Campylobacter variants proliferate in some broiler flocks and not others

Ranging Behaviour of Commercial Free-Range Broiler Chickens 1: Factors Related to Flock Variability

Little is known about the ranging behaviour of chickens. Understanding ranging behaviour is required to improve management and shed and range design to ensure optimal ranging opportunities. Using Radio Frequency Identification technology, we tracked 300 individual broiler chickens in each of four mixed sex ROSS 308 flocks on one commercial farm across two seasons. Ranging behaviour was tracked from the first day of range access (21 days of age) until 35 days of age in winter and 44 days of age in summer. Range use was higher than previously reported from scan sampling studies. More chickens accessed the range in summer (81%) than winter (32%; p p

Ranging Behaviour of Commercial Free-Range Broiler Chickens 2: Individual Variation

Little is known about broiler chicken ranging behaviour. Previous studies have monitored ranging behaviour at flock level but whether individual ranging behaviour varies within a flock is unknown. Using Radio Frequency Identification technology, we tracked 1200 individual ROSS 308 broiler chickens across four mixed sex flocks in two seasons on one commercial farm. Ranging behaviour was tracked from first day of range access (21 days of age) until 35 days of age in winter flocks and 44 days of age in summer flocks. We identified groups of chickens that differed in frequency of range visits: chickens that never accessed the range (13 to 67% of tagged chickens), low ranging chickens (15 to 44% of tagged chickens) that accounted for