Otal, J., Martı´nez, M., Quiles, A., Hevia, M. L. and Ramı´rez, A. 2010. Effect of litter size and sex on the birth weight of newborn kids and in the behaviour of primiparous goats before, during and after the parturition. Can. J. Anim. Sci. 90: 483Á490. The objective of this study was to determine the effect of litter size (46 single birth and 32 double birth) and sex (44 male and 66 female) of newborn kids on the puerperal behaviour of primiparous MurcianoÁGranadina goats (N 078). The highest frequencies were grunting, with 124.99166.5, and butting conspecific, with 7.098.7. Frequencies of the remaining variables considered (standing, kicking, moving head and neck, licking their back and pawing the earth) were lower than 3.0. The majority of variables were significantly greater for single births than for twin births (PB0.01). Goats that gave birth to twins spent more time lying down, and less time walking than those that gave birth to one kid (10.196.7 min vs. 6.897.0 min, PB 0.05 and 2.991.1 min vs. 6.095.5 min, P B0.01, respectively). Parturition was longer and birth weight heavier for singleton than twin-born kids (64.5915.7 min vs. 41.9910.7 min and 2.990.2 kg vs. 2.390.1 kg, respectively). In conclusion, primiparous goats showed objective signs of discomfort that were more evident for singleton than twin birth kids.Key words: Behaviour, goat, Murciano-Granadina breed, parturition Otal, J., Martı´nez, M., Quiles, A., Hevia, M. L. et Ramı´rez, A. 2010. Effet de la taille de la litie`re et le sexe sur le poids des chevreaux et dans le comportement chez les che`vres primipares avant, pendent et apre`s la mise bas. Can. J. Anim. Sci. 90: 483Á490. L'objectif de cette e´tude e´tait de de´terminer l'effet de la taille de la litie`re (46 de naissance unique et 32 de naissance double) et le sexe (44 maˆles et 66 femelles) des chevreaux nouveau-ne´s sur le comportement puerpe´ral de che`vres Murciano-Granadina primipares (N 078). Les variables qui pre´sentaient les plus hautes fre´quences ont e´te´grognements, avec 124.99166.5, et coup de teˆte a`conge´ne`res, 7.098.7. Les fre´quences des autres variables conside´re´es (debout, ruer, de´placement de la teˆte et le cou, le´cher leur dos et gratter la terre) ont e´te´infe´rieures a`3.0. La majorite´des variables e´taient significativement plus e´leve´s pour les naissances uniques que pour les naissances doubles (P B0,01). Les che`vres de mise bas double passe´plus de temps couche´, et moins de temps en marchant que celles de mise bas simple (10.196.7 min vs. 6.897.0 min, P B0.05 et 2.991.1 min vs. 6.095.5 min PB0.01, respectivement). Le poids corporel et la dure´e de la mise bas e´taient plus e´leve´s dans la mise bas unique que dans les premier jumele´(64.5915.7 min vs. 41.9910.7 min land 2.990.2 kg vs. 2.390.1 kg, respectivement). In conclusion, les che`vres primipares a montre´des signes objectifs d'agitation qui ont e´te´plus e´vident pour la mise basse simple que pour les doubles.