BACKGROUND The present study aimed to assess the effect of crossbreeding a local breed (Segureña, S × S) with Texel as the sire line (Texel × Segureña crossbred, T × S) on productive traits and meat quality attributes. Sixty‐eight lambs (both males and females) from each genotype, weaned at about 45 days old and intensively fed with concentrates and cereal straw ad libitum until they were 72 days old, were used to assess productive traits, and ten animals from each genotype were used to assess meat quality. RESULTS The crossbreeding with Texel improves productivity, with a greater weight at birth (+1 kg) and at slaughter (+3 kg) and a greater average daily gain (+29 g). T × S lambs had a better conformation, less carcass fatness, and higher content of muscle (+45 g kg−1) as opposed to a lower fat content (−50.6 g kg−1). With regard to meat quality, crossbreeding with Texel provided a meat with a higher protein content (+4 g kg−1) and a lower oleic acid content (21% less), although the differences were very scarce from a sensory point of view, and non‐existent with respect to instrumental quality. CONCLUSION Crossbreeding could comprise a useful tool in the production of ovine meat in local breeds, such as Segureña, within the Mediterranean Area, and, consequently, a way of increasing the profitability of the farms. © 2018 Society of Chemical Industry

The aim of this study was to determine whether the prophylactic use of antibiotics in intravaginal sponges used for estrus synchronization in goats may result in the presence of inhibitors in milk and, therefore, of positive results by microbial screening tests. Ninety-eight Murciano-Granadina goats were used, divided into 7 groups of 14 animals. Intravaginal sponges were placed in 6 groups using 2 concentrations of 3 different antibiotics: doxycycline, oxytetracycline, and sulfathiazole-framycetin. The sponges of the control group were placed without antibiotics. Milk samples were collected daily until 7 d posttreatment and analyzed using 3 microbial tests. Positive samples were retested by specific receptor-binding assays to confirm the positive results. Vaginal status was evaluated by visual assessment of the external aspect of the sponges after removal. The microbial test response was not affected by either day posttreatment or dose of antibiotic used, except for oxytetracycline at the higher concentration. Moreover, no positive results were obtained using receptor-binding assays, suggesting that residues, if present in milk, did not exceed the regulatory (safety) levels established for these drugs. The occurrence of soiled sponges was higher in the control group. With respect to the dose of antibiotics used, no significant differences were found for the lower dose administered. However, a significant increase in the percentage of clean sponges was observed for the higher dose of doxycycline. We conclude that the prophylactic use of low doses of doxycycline, oxytetracycline, or sulfathiazole in intravaginal sponges used for synchronization of estrus helps to reduce clinical vaginitis in dairy goats and does not seem to be the cause of positive results in microbial inhibitor tests used to detect antibiotics in goat milk.

RESUMENSe han estudiado los rendimientos productivos (peso al nacimiento, peso al sacrificio, y ganancia media diaria), así como los parámetros de calidad de la canal (conformación, engrasamiento, índices de compacidad de la canal y de la pierna, y composición tisular) de corderos provenientes de la raza Segureña y del cruce industrial de ésta con la raza Texel. Se han observado mejoras en los animales cruzados, tanto en la productividad: mayor peso al nacimiento y al sacrificio y una mayor ganancia media diaria de peso, como en la calidad de la canal: mejor conformación, menor engrasamiento, y una mayor composición muscular en contraposición a un menor porcentaje de grasa. Los resultados obtenidos indican que el cruce entre estas dos razas podría ser una herramienta recomendable a desarrollar y utilizar en determinadas explotaciones y especificaciones de producción. Effect of crossbreeding on productive yield and carcass quality in Segureña lambs SUMMARYProductive traits (birth weight, slaughter weight, average daily gain), carcass quality traits (conformation, fatness score, carcass and leg blockness and tissue composition) in lambs from either pure Segureña breed or crossbred with Texel were studied. Improvements in the crossbred animals were observed, both in productive traits: higher birth and slaughter weights and average daily gain, and in carcass quality: bigger conformation, lower fatness score and a higher muscle composition in contrast with a lower fat percentage. The results indicate that the crossbreeding between these two breeds could be a recommended tool to develop and use in certain farms and production conditions. INTRODUCCIÓNDiversos factores, políticos, técnicos, sociales y económicos han puesto al Sector Ovino en situación de crisis en muchas zonas de Europa. Por ello, se deben buscar nuevas alternativas o reinventar las ya existentes, haciendo frente a un mercado en el que la meta debe ser la obtención de un producto de calidad. El cruce industrial, entendido como el acoplamiento de machos de razas cárnicas con hembras de razas lecheras o locales, fue una técnica muy utilizada en España entre los años 70 y 90 del siglo XX. Su principal objetivo es mejorar los índices productivos y la calidad de la canal de las razas locales, posibilitando unos mayores pesos al sacrificio (Nitter, 1974;Kempster et al., 1987;Osorio et al., 1998; Kremer et al., 2004). En este sentido, se han desarrollado numerosos trabajos de cruzamiento, especialmente con las razas llamadas Ovinos Precoces (Espejo et al., 1977;Esteban, 2003) y otras (Valls, 1980;Sierra, 1981). Hoy en día, en amplias zonas, el uso del cruce industrial ha decaído notablemente, y posiblemente más de lo técnica-mente justificable. El precio de los sementales, la mayor complejidad del manejo del rebaño al tener que mantener las razas de los progenitores en pureza o la compra NOTA BREVE