02907naa a2200421 a 450000100080000000500110000800800410001902200140006002400390007410000180011324501150013126000090024650001090025552015030036465000320186765000130189965000110191265000200192365300260194365300350196965300130200465300350201765300320205265300400208465300090212465300340213365300400216765300280220765300320223565300370226765300320230465300250233670000190236170000180238070000170239870000180241577300520243310538812019-11-05       2015    bl uuuu     u00u1 u    #d  a0031-93847 a10.1016/j.physbeh.2015.04.0042DOI1 aDAMIÁN, J.P.  aReproductive and sexual behaviour development of dam or artificially reared male lambs.h[electronic resource]  c2015  aArticle history:Received date: 30 December 2014/Revised date: 27 March 2015/Accepted date: 2 April 2015.  aABSTRACT.  The objective of this study was to determine if artificially reared male lambs differ from those reared by their mothers in their reproductive development and sexual behaviour during the first breeding season and in their serum testosterone to a GnRH challenge at the end of the first breeding season. Lambs were assigned to two experimental groups: 1) artificially reared lambs, separated from their dams 24-36. h after birth (Week 0) and fed sheep milk until 10. weeks of age (group AR, n = 14); and 2) lambs reared by their dams until 10. weeks of age (group DR, n = 13). Reproductive parameters and sexual behaviour were recorded from Weeks 9 to 39. The GnRH challenge was performed on Week 40. Body weight, scrotal circumference, gonado-somatic index, testosterone concentration and sperm parameters were unaffected by group, but increased with age (P < 0.0001). Lambs reared by their mothers had greater values of gonado-somatic index on Weeks 9, 16 and 19 (P < 0.05), and tended to reach puberty earlier than AR (22.9 ± 0.7 vs. 25.1 ± 1.1. weeks, respectively, P = 0.087). Lambs reared by their mothers presented more lateral approaches and mount attempts than AR (P < 0.05), and DR lambs presented more mounts on Weeks 32 and 39 than AR (P < 0.05). Blood testosterone concentrations 3.5 and 4. h after the GnRH challenge were higher in AR than in DR lambs (P < 0.05). In conclusion mother rearing promoted sexual behaviour and reproductive performance of male lambs.   © 2015.  aCOMPORTAMIENTO REPRODUCTIVO  aCORDEROS  aOVINOS  aREPRODUCTIVIDAD  aCOMPORTAMIENTO SEXUAL  aCONCENTRACIÓN DE TESTOSTERONA  aCORDEROS  aCRIANZA ARTIFICIAL DE CORDEROS  aCRIANZA NATURAL DE CORDEROS  aDESEMPEÑO REPRODUCTIVO EN CORDEROS  aGnRH  aHABILIDAD MATERNA EN LA OVEJA  aHORMONA LIBERADORA DE GONADOTROPINA  aÍNDICE GONADOSOMÁTICO  aLACTANCIA MATERNA EN OVINOS  aMOTILIDAD DE LOS ESPERMATOZOIDES  aPUBERTAD PRECOZ EN CORDEROS  aVÍNCULO MADRE-CRÍA1 aBERACOCHEA, F.1 aHÖTZEL, M.J.1 aBANCHERO, G.1 aUNGERFELD, R.  tPhysiology and Behavior, 2015gv.147, p. 47-53.