Artificial insemination in Payoya goats: factors affecting fertility Francisco Arrebola A , Olga González B , Rafael Torres B and José-Alfonso Abecia C,D A IFAPA Hinojosa del Duque, Córdoba, Spain. B Asociación Nacional Criadores Cabra Payoya, Algodonales, Cádiz, Spain. C Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain. D Corresponding author. Email: alf@unizar.es Abstract. The present study was conducted to determine the effect of different factors on pregnancy rate after artificial insemination (AI) with refrigerated and frozen semen in Payoya goats reared under commercial farm conditions. A total of 820 goats, belonging to 10 farms, was used. The total number of studied inseminations was 1384 over a 4-year period. Factors considered in the study were year, farm, month of AI, age of the goat at AI, dose of progestagen, eCG dose, buck, type of semen (refrigerated or frozen), technician, number of goats to be inseminated (group size), incidences at AI (problems, no problems, trans-cervical insemination), distance from semen collection to farm, number of previous kidding, kidding–AI interval, and milk production. The variable studied was fertility, expressed as successful kidding. Mean fertility was 59%. Six (farm, age, group size, transcervical AI, number of kidding and milk production) of the 15 factors studied presented a significant (P < 0.05) effect on fertility after AI. Our results demonstrated that it is difficult to control all the critical aspects of AI programs at the farm level. These factors should be controlled and the variations that could compromise the chance of being pregnant must be known by technicians. The good fertility results obtained during the non-breeding season emphasise the implementation of this technique so as to improve the competitiveness of the dairy Payoya breed flocks. Additional keywords: age, farm, milk production, semen. Received 10 April 2013, accepted 17 June 2013, published online 17 July 2013 Introduction No reproductive technology has contributed in such a degree to the genetic improvement of livestock as has artificial insemination (AI). Although AI is a technique that has already been used for years in goats, especially in countries such as France, it has not been fully transferred into rustic goat breeds reared in grazing extensive farming systems. Payoya goat breed is located at the south-western Spain, in the Andalucía region, and is fundamentally linked to mountainous terrain and areas of high natural value. It is listed as an endangered breed, with ~9500 heads having been surveyed (González 2003). The large weight of this breed (70–90 kg in adult bucks and 50–65 kg in adult does) and its highly seasonal milk production (440 kg/goat) may necessitate an adjustment of the hormonal oestrous synchronisation protocols, the dose of eCG and the time elapsed from pessary removal to AI. Standard AI protocols used in other goat breeds under intensive farming systems (Saanen, Alpine or Murciano-Granadina) have failed in this breed. An AI program was implemented in 2005 in Payoya goats, so as to optimise the selection scheme and control kidding dates. This technique is an essential tool in developing goat-breeding programs as its use makes the genetic evaluation of the sire and the diffusion of genetic improvement more efficient, as well as helps control the parturition dates, so as to satisfy market demands. Insemination is usually carried out by the transcervical pathway, and semen is deposited in the entry of the cervix or hardly ever after the cervix, into the uterus (Nunes and Salgueiro 2011). Hormonal treatments are required to carry out fixed-time AI, so as to avoid the need for oestrous detection and to synchronise oestrus in a group of goats. Thus, more goats can be inseminated in less time, and insemination and births can be scheduled, increasing the number of kids from AI at the beginning of the kidding season and achieving better utilisation of human resources (Nunes and Salgueiro 2011). Several factors have been reported to affect AI success in goats, such as nutrition, breeding season, environmental conditions, parity, breed, farm, depth of semen deposition, extenders composition or hormonal treatments (Mellado et al. 2004, 2006; Salvador et al. 2005; Nunes and Salgueiro 2011). The present study was conducted to clarify the effect of different factors on pregnancy rate after AI with refrigerated and frozen semen in Payoya goats reared under commercial farm conditions. Materials and methods Animals and farms Animals were synchronised in oestrus and inseminated on farm, following procedures approved by the ‘Dairy Goat Health Management Guide’ of the Ministry of Agriculture, Food and CSIRO PUBLISHING Animal Production Science, 2014, 54, 356–362 http://dx.doi.org/10.1071/AN13138 Journal compilation Ó CSIRO 2014 www.publish.csiro.au/journals/an