Genetic Analyses of Growth, Carcass and Meat Quality Traits in Maternal Lines of Rabbits and Their Diallel Cross/ Análisis Genético de Caracteres de Crecimiento, Matadero y Calidad de Carne en Lineas Maternales de Conejo y en su Cruzamiento Dialélico

El gazapo engordado en explotaciones comerciales proviene de un cruzamiento a tres vías, y por tanto su madre (cruce de dos líneas maternales) aporta el 50% de sus genes y es necesario estudiar los caracteres de crecimiento y consumo de pienso de estos gazapos. Por otro lado, existen gran cantidad de estudios que demuestran que la carne de conejo es una carne con poca grasa, poco colesterol y un elevado contenido en proteina, por lo que se debe estudiar estas características se pueden ver afectadas estas como consecuencia de la mejora genética.Mínguez Balaguer, C. (2014). Genetic Analyses of Growth, Carcass and Meat Quality Traits in Maternal Lines of Rabbits and Their Diallel Cross/ Análisis Genético de Caracteres de Crecimiento, Matadero y Calidad de Carne en Lineas Maternales de Conejo y en su Cruzamiento Dialélico [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37981TESI

COMPARACION DE CUATRO LÍNEAS MATERNALES DE CONEJO EN CARACTERES DE CRECIMIENTO

El objetivo de este trabajo fue comparar los caracteres de crecimiento (peso al destete, peso al sacrificio y ganancia media diaria) en cuatro líneas maternales de conejo (A, V, H y LP), fundadas bajo diferentes criterios, pero seleccionadas todas ellas por tamaño de camada al destete. Para la inferencia se utilizó una aproximación Bayesiana. En análisis se realizó en el origen de las líneas (datos desde junio de 1980 hasta noviembre de 2010) usando, el todo el conjunto de datos y un modelo que incluía los valores aditivos, y durante el periodo desde marzo de 1997 hasta agosto 1998 para las líneas A, V y H (corte 1) y desde diciembre 2009 hasta noviembre de 2010 (corte 2) para las líneas A, V y LP, usando, únicamente, los datos de los periodos correspondientes y con un modelo sin efectos aditivos. Los resultados se pueden resumir en: Las correlaciones genéticas entre el tamaño de camada al destete y los caracteres de crecimiento fueron positivas pero bajas. En el origen, se observaron diferencias para los caracteres de crecimiento entre las diferentes líneas. Entre las líneas H y LP, el contraste no se realizó porque solamente compartieron dos años-estación. En la fundación, los resultados mostraron que las líneas más pesadas fueron la H y la LP. Estas diferencias podrían deberse a los diferentes criterios y procesos utilizados para la fundación de las líneas. En el corte 1, la línea más pesada fue la línea H. Para el corte 2, la línea más pesada resultó la línea LP. En los cortes 1 y 2, las diferencias observadas (calculadas con los datos de estos periodos) y las diferencias esperadas (calculadas con el modelo y el conjunto de datos completos) fueron muy similares para todas las líneas y todos los caracteres. Esta semejanza se puede considerar como un indicador de la validez de los modelos utilizados. En la actualidad, las diferencias en los caracteres de crecimiento entre las líneas han disminuido con respecto al origen, porque a lo largo del proceso de selección por tamaño de camada al destete, los caracteres de crecimiento han mejorado genéticamente.Mínguez Balaguer, C. (2011). COMPARACION DE CUATRO LÍNEAS MATERNALES DE CONEJO EN CARACTERES DE CRECIMIENTO. http://hdl.handle.net/10251/15929Archivo delegad

Effect of equine chorionic gonadotropin on pregnancy rate in Brown Swiss cows under high altitude conditions

The objective of the present study was to evaluate the administration of Equine Chorionic Gonadotropin (eCG) in a protocol of fixed-time artificial insemination (FTAI) to increase the pregnancy rate in cows subjected to high altitude conditions. These conditions could generate a syndrome of right-sided heart failure and, as consequence, animals trend to have a low body score condition with a decrease in fertility. The research was conducted with 84 lactating cows (Brown Swiss) randomly into two groups with a body condition score between 2.5 and 3.5, allocated at 3100 m above sea level. In the FTAI protocol, 400 IU of eCG was administered (n = 42) or not (n = 42) at progesterone intravaginal device removal. A significant improvement in pregnancy rate was found with eCG treatment in those cows with low body condition score (BCS of 2.5, scale 1–5), while no effect was found in those cows with higher BCS (i.e. 3.0 and 3.5). In conclusion, the addition of 400 IU of eCG in an FTAI in cows under high altitude conditions and low body conditions can improve the fertility.Veterinari

Effects of mannan oligosaccharide dietary supplementation on mortality, growth performance and carcass traits in meat Guinea pigs

The effects of mannan oligosaccharide (MOS) as a dietary supplement on growth performance, carcass traits and mortality in meat guinea pigs were compared to a commonly used antimicrobial growth promoter (AGP, Zn-Bacitracin). The four experimental treatments were as follow: Control group (no additives); MOS 1 (1.5 g kg−1); MOS 2 (2 g kg−1) and AGP (0.1 g kg−1). The guinea pigs were housed in 40 floor pens containing a deep litter of woodchips (n = 100 animals in each trial; 10 animals per pen). Guinea pigs were all weaned on day 28 and their body weight was measured weekly. All animals were slaughtered at the end of fattening period (day 77) and carcass traits were evaluated. Significant differences against the control group were observed for traits studied (P < 0.05). Between MOS groups and AGP no significant differences were observed. In conclusion, the use of MOS could be a suitable replacement for antibiotic growth promoter to raise guinea pigs.Veterinari

Evaluation of Non-Contact Device to Measure Body Temperature in Sheep

Non-contact devices have been used in the measurement of body temperature in livestock production as a tool for testing disease in different species. However, there are few studies about the variation and correlations in body temperature between rectal temperature (RT) and non-contact devices such as non-contact infrared thermometers (NCIT) and thermal imaging/infrared thermography (IRT). The objective of this work was to evaluate the accuracy of non-contact devices to measure the body temperature in sheep, considering six body regions and the possibility of implementing these systems in herd management. The experiment was carried out at the experimental farm of the Catholic University of Valencia, located in the municipality of Massanassa in July of 2021, with 72 dry manchega ewes, and we compared the rectal temperature with two types of non-contact infrared devices for the assessment of body temperature in healthy sheep. Except for the temperature taken by NCIT at the muzzle, the correlation between RT vs. NCIT or IRT showed a low significance or was difficult to use for practical flock management purposes. In addition, the variability between devices was high, which implies that measurements should be interpreted with caution in warm climates and open pens, such as most sheep farms in the Spanish Mediterranean area. The use of infrared cameras devices to assess body temperature may have a promising future, but in order to be widely applied as a routine management method on farms, the system needs to become cheaper, simpler in terms of measurements and quicker in terms of analyzing results.Veterinari

Genetic analysis of meat quality traits in maternal lines of rabbit and their diallel cross

[EN] Young rabbits, the dams of which came from a full diallel cross among four maternal lines (A, V, H and LP) and the sires from a single paternal line (It), that produce sixteen genetic groups, was carried out to evaluate the genetic groups and to estimate the crossbreeding genetic parameters of meat quality. The meat quality traits were recorded by NIRS from a sample of 285 longissimus lumborum muscles. Crossbreeding parameters were estimated according to Dickerson model. No differences in protein were found. The line A had significant differences with V line for intramuscular fat, and fatty acids groups. Significant differences for these traits appeared between the crossbred AH and VV (in favor of AH). As conclusion, the significant contrasts between genetic types for chemical composition of the meat are mainly consequence of direct-maternal genetic effects, having grandmaternal and maternal heterosis effects a less relevant role.This work was supported by the Spanish project AGL2011-30170-C02-01 from the Spanish National Research Plan. C. Minguez acknowledges a Formacion de Personal Investigador (FPI) grant from the Ministerio de Economia y Competitividad (MEC), Spain.Mínguez Balaguer, C.; Sánchez Serrano, JP.; Hernández, P.; Ragab, M.; El Nagar, AGF.; Baselga Izquierdo, M. (2017). Genetic analysis of meat quality traits in maternal lines of rabbit and their diallel cross. Meat Science. 131:1-8. https://doi.org/10.1016/j.meatsci.2017.04.005S1813

Genetic comparison of milk production and composition in three maternal rabbit lines

[EN] The aim of this study was to compare 3 Spanish maternal rabbit lines (A, V and LP) in terms of milk production and composition. These lines were founded on different criteria but selected for litter size at weaning. A total of 194 mature does in their third or higher parity were used. The milk yield of does was recorded at 1, 2, 3, 4, 8, 9, 10, 11, 15, 16 and 17 d post-partum (dpp). The milk production traits studied were weekly milk yield (WMY; g/wk) and milk conversion ratio (MCR; grams of litter gain per grams of milk suckled during the first 21  dpp). The milk composition traits studied were fat (%), protein  (%), ash (%), lactose (%) and total solids (%). The milk samples to be analysed were collected from each doe at 18 dpp. Data were analysed using single trait mixed and fixed models with and without covariates; the covariates were number born alive (NBA) and doe weight at kindling (DW). The overall mean of WMY, during the first 3 wk, was 1547±16 g/wk. Milk yields during the different lactation weeks were for line A 872±39, 1503±39 and 1865±39 g for first, second and third lactation weeks, respectively. In line V, the corresponding values were 919±35, 1633±35 and 2004±35  g, and in line LP, they were 1043±36, 1819±36 and 2254±36  g. Means of MCR were 0.41±0.01, 0.41±0.01 and 0.42±0.01 for A, V and LP lines, respectively. Overall means of fat, protein, ash, lactose and total solids (%) were 14.62±0.17, 11.10±0.07, 1.89±0.04, 2.67±0.12 and 30.27±0.24, respectively. The differences between lines for milk production traits were significant except for MCR, while the differences between lines for milk composition traits were not significant. NBA had significant effects on all milk yield traits but had no significant effects on milk composition traits. DW only had a significant effect on weekly milk yield. The parity order had no significant effect either for milk production traits or milk composition traits in multiparous does, except for ash %.This work was supported by the Spanish project AGL2011-30170-C02-01 from the Spanish National Research Plan. Ayman EL Nagar acknowledges a MAEC-AECID grant from The Spanish Agency for International Cooperation for Development (AECID). The authors are very grateful to Prof. Juan Jose Pascual professor of Animal Nutrition, Institute for Animal Science and Technology, Universitat Politecnica de Valencia for revising the manuscript and his fruitful comments.El Nagar, AGF.; Sánchez, JP.; Ragab, MM.; Mínguez Balaguer, C.; Baselga Izquierdo, M. (2014). Genetic comparison of milk production and composition in three maternal rabbit lines. World Rabbit Science. 22(4):261-268. doi:10.4995/wrs.2014.1917261268224Abou Khadiga G., Youssef Y.M.K., Baselga M. 2012. Characterization of reproductive performance of the APRI line of rabbits. In Proc.: 10th World Rabbit Congress, 3-6 September, 2012. Sharm El-Sheikh, Egypt. 743-747.AOAC. 1980. Official Methods of Analysis. 13th Edition, Association of Official Agricultural Chemists, Washington, D.C., USA.Case R.A., Bradley R.L., Williams R.R. 1985. Chemical and physical methods. In: Standard Methods for the examination of Dairy Products. Richardson G.H., (ed.), 15th Edition, American Public Health Association, Washington, D.C., USA. 327-402.Castellini C., Dal Bosco A., Cardinali R., Mugnai C., Sciascia E. 2004. Effect of dietary N-3 fatty acids on the composition of doe's milk and tissues of suckling rabbits. In Proc.: 8th World Rabbit Congress, 7-10 September, 2004. Puebla, Mexico. 771-777.Cowie A.T. 1968. Lactation in the rabbit. Natl. Inst. Res. Dairying, Rep 1968, 84.El-Maghawry A.M., Soliman A.M., Khalil H.H. 1993. Doe milk production as affected by some genetic and environmental factors in New Zealand White and Californian rabbits under the Egyptian conditions. Egypt. J. Rabbit Sci., 3: 141-150.Fernández-Carmona J., Blas E., Cervera C., Pascual J.J. 2004. The measure of milk rabbit. In Proc.: 8th World Rabbit Congress, 7-10 September, 2004. Puebla, Mexico. 824-828.Fortun-Lamothe L., Bolet G. 1995. Les effects de la lactation sur les performances de reproduction chez la lapine. INRA, Prod. Anim., 8: 49-56.Garreau H., Piles M., Larzul C., Baselga M., Rochambeau H de. 2004. Selection of maternal lines: last results and prospects. In Proc.: 8th World Rabbit Congress, 7-10 September, 2004. Puebla, Mexico. 14-25.Hassan N.S., El-Feel F.M.R., Sallam M.T., Ahmed M.F. 1992. Evaluation of milk production and litter milk efficiency in two and three-way crosses of three breeds of rabbits. Egypt. J. Anim. Prod., 29: 307-319.Iraqi M.M. and Youssef Y.M.K. 2006. Genetic analysis for milk production traits in New Zealand White rabbits raised in Egypt. Egypt. J. Rabbit Sci., 16: 1-13.Khalil M.H., Al-Saef A.M. 2012. Genetic groups comparison for litter and lactational traits and feeding parameters in programs of synthesizing new lines of rabbits. In Proc.: 10th World Rabbit Congress, 3-6 September, 2012. Sharm El-Sheikh, Egypt. 235-239.Khalil M.H., Mehaia M.A., Al-Homidan A.H., Al-Sobayil K.A. 2004. Genetic analysis for milk yield and components and milk conversion ratio in crossing of Saudi rabbits with V-line. In Proc.: 8th World Rabbit Congress, 7-10 September, 2004. Puebla, Mexico. 82-89.Lukefahr S., Hohenboken W.D., Cheeke P.R., Patton N.M. 1983. Characterization of straightbred and crossbred rabbits for milk production and associative traits. J. Anim. Sci., 57: 1100-1107.McNitt J.I., Lukefahr S.D. 1990. Effect of breed, parity, day of lactation and number of kits on milk production of rabbits. J. Anim. Sci., 68: 1505-1512.Pascual J.J., Cervera C., Blas E., Fernández-Carmona J. 1996. Milk yield and composition in rabbit does using high fat diets. In Proc.: 6th World Rabbit Congress, 9-12 July, 1996. Toulouse, France. 1: 259-262.Pascual J.J., Cervera C., Blas E., Fernández-Carmona J. 1999. Effect of high fat diets on the performance, milk yield and milk composition of multiparous rabbit does. Anim. Sci., 68: 151-162.Zerrouki N., Lebas F., Berchiche M., Bolet G. 2005. Evaluation of milk production of an Algerian local rabbit population raised in the Tizi-Ouzou area (Kabylia). World Rabbit Sci., 13: 39-47

Effect of supplementation with fresh orange pulp (Citrus sinensis) on mortality, growth performance, slaughter traits and sensory characteristics in meat guinea pigs

The objective of this research was to investigate the effect of the partial replacement of alfalfa (Medicago sativa) with fresh orange pulp (Citrus sinensis) in a diet fed to guinea pigs on their mortality, growth performance, slaughter traits and sensory characteristics during the fattening period. A total of 450 guinea pigs were housed in collective pens of ~10 animals. Animals were divided into three groups: Control group (CG), supplied with fresh alfalfa as forage and treatment groups (G15 and G30), in which 15 and 30% of alfalfa was replaced by orange pulp, respectively. No significant differences were found between CG and G15 for traits studied. However, G30 showed the lowest values for growth and carcass traits. No significant differences were found for sensory characteristics. In conclusion, a moderate inclusion of orange pulp could contribute to diminishing dependence of alfalfa on guinea pig meat productionVeterinari

A comparison of the growth performance, carcass traits, and behavior of guinea pigs reared in wire cages and floor pens for meat production

To achieve efficient production of guinea pigs for meat, it is essential to determine the most suitable housing system. A total of 220 guinea pigs were maintained in either wire cages (n = 11, 10 animals per cage) or floor pens (n = 11, 10 animals per pen) containing a deep litter of woodchips, both housing systems having the same dimensions (2 × 1 × 0.4 m). Growth traits, food intake and feed conversion ratio were recorded weekly and expressed as the difference between the two groups. After 77 days, the animals were slaughtered, and carcass traits were evaluated. Growth performance and carcass trait parameters, as well as mortality and behavior trends, were not affected by the housing system type. Nonetheless, the use of wire cages is recommended for raising guinea pigs since water, urine and feces pass through the wire floor, resulting in cleaner animalsVeterinari

Crossbreeding effects on rabbit reproduction from four maternal lines of rabbits

Litter size is essential for an ef&#64257;cient production of rabbit meat . A diallel cross between four maternal lines was carrie d ou t and the analysis of the components of litter size has been already done. This paper presents the analysis of litter size traits themselves (total born (TB), number born alive (NBA) , number weaned (NW)) and kindling interval (KI ), that complete the analysis of the reproductive performance. The 16 genetic groups were distributed in four Spanish farms . The V line was present in all farms in order to be used as reference group. A total of 34 546 parities from 7111 does, were analysed. The crossbreeding parameters were estimated according to Dickerson model. The diffe ences between lines performance were of low magnitude and not signi&#64257;cant for litter size traits. The LP line showed the shortest KI follow ed by H respect to lines A and V. These differences re&#64258;ected the differences between direct and maternal genetic effects. The differences between the average of all crosses and line V were f ou n d to be signi&#64257;cant and seemed to be important, being 0.46 for TB, 0.56 for NBA, 0. 75 for NW and &#8722; 2.21 days for KI. The differences between reciprocal crosses for litter size were of low magnitude and non- sign &#64257;cant, which indicate that the maternal effects are not important between these lines. In general, the lines did not show signi&#64257;cant diffeences in direct and maternal genetic effects for TB, NBA and NW but there were some signi&#64257;cant differences for KI, which ranged from 1.54 to 6.85 days in direct effects and from 0.63 to 3.38 days for maternal effects. A positive and, in some cases, relevant heterosis was found. The largest heterosis was for TB in the HV c oss (1.05 rabbits), followed by the AH (0.74 rabbits), AV (0.57 rabbits) and LH (0.55 rabbits) crosses. For NBA , signi&#64257;cant heterosis was found in HV (1.11 rabbit s) and AV (0.49 rabbits) and for NW in AV ( 0.90 rabbits ), LH ( 0.70 rabbits ) and LV (0.58 rabbits). Favourable and signi&#64257;cant heterosis for KI was found in AV and LV crosses, whereas it was unfavourable in AL and in LH. The more recommended crosses were AV and LH, showing the greatest performances on NW, while the cross HV, which shows the greatest performances an NBA, could be highly recommended when cross-fostering is practised to equalise litter sizes after birth, in this situation the lower NW performance observed could be improved.This work was supported by the Spanish project AGL2011-30170-C02-01 from the Spanish National Research Plan.Mohamed Ragab, M.; Sánchez Serrano, JP.; Mínguez Balaguer, C.; Baselga Izquierdo, M. (2016). Crossbreeding effects on rabbit reproduction from four maternal lines of rabbits. Animal. 10(7):1-7. https://doi.org/10.1017/S1751731115002918S1710