Gender and live weight on carcass and meat characteristics of donkeys

Efeitos do gênero e peso ao vivo nas características de carcaça e carne de burros

Pedro Hernández-Briano Roque Gonzalo Ramírez-Lozano Octavio Carrillo-Muro Marco Antonio López-Carlos Fabiola Méndez-Llorente Jairo Iván Aguilera-Soto About the authors

ABSTRACT:

One hundred eighty-nine Catalan crossbreed donkeys (Equus africanus asinus) were used to evaluate the effect of gender (gelding, n=106; or female, n=83) and live weight at slaughter (LW) (<100kg, n=25; 101 to 125kg, n=42; 126 to 150kg, n=85; and 151>kg, n=37) on carcass characteristics, non-carcass components and meat and fat color. Geldings had greater (P<0.05) carcass weight, carcass dressing and *L value of subcutaneous fat than females; but females had greater (P<0.05) cooling loss, a* value of semitendinosus muscle and b* value of subcutaneous fat. Donkeys with more than 126kg of LW showed greater (P<0.05) carcass weight and dressing and lower (P<0.05) cooling loss compared to lighter donkeys. The a* value of semitendinosus muscle and abdominal fat was greater in heaviest donkeys (>151kg). Meanwhile, the LW did not affect the color (L*, a* and b* values) of subcutaneous fat (P>0.05). These results suggested that both gender and live weight should be considered when producing meat from donkeys. It is advisable to use geldings weighing more than 126kg at slaughter to obtain the greatest weight and carcass yield.

Key words:
carcass characteristics; donkey; gender; weight; meat

RESUMO:

O objetivo deste estudo foi avaliar o efeito do gênero e peso vivo (PV) nas características da carcaça, componentes não-carcaça e cor da carne e gordura dos burros (Equus africanus asinus). Foram utilizados 189 animais de sexo castrado ou feminino. Os castrados tiveram peso de carcaça maior (P <0,05), molho de carcaça e uma gordura subcutânea luminosa (valor L) nas fêmeas. As fêmeas apresentaram perda de resfriamento maior (P <0,05), *valor de cor do músculo semitendinoso e b* valor de cor da gordura subcutânea. A gordura subcutânea apresentou maior (P <0,05) b* em animais idosos. Os burros com mais de 126kg de PV apresentaram maior peso de carcaça (P <0,05), curativo de carcaça e menor (P <0,05) perda de resfriamento em comparação com burros mais leves. O músculo semitendinoso e a gordura abdominal foram avermelhadas (P <0,05), maior valor de *, em burros mais pesados (>151kg). Enquanto isso, o PV não afetou a cor (valores de L *, a * e b *) de gordura subcutânea (P> 0,05). O peso maior da carcaça e o curativo com efeitos limitados em componentes não carcaça, cor de carne e gordura foram observados em castrados com peso vivo superior a 126kg.

Palavras-chave:
características da carcaça; burro; gênero; peso; carne

INTRODUCTION:

Donkeys (Equus africanus asinus) belong to the Equidae family, and were domesticated around 4,000BC. They are used as pack animals and saddle mounts in arid climates (AGANGA et al., 2003AGANGA, A. A., et al. Carcass analysis and meat composition of the donkey. Pakistan Journal of Nutrition, v. 2, n. 3, p. 138-147, 2003. Available from: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.533.1513&rep=rep1&type=pdf>. Accessed: Jun. 22, 2017.
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), but also provide milk (MONTI et al., 2006MONTI, G., et al. Efficacy of donkey´s milk in treating highly problematic cow´s milk allergic children: An in vivo and in vitro study. Pediatric Allergy Immunology, v. 18, p. 258-264, 2006. Available from: https://doi.org/10.1111/j.1399-3038.2007.00655.x>. Accessed: May 20, 2017. doi:10.1111/j.1399-3038.2007.00655.x.
https://doi.org/10.1111/j.1399-3038.2007...
) and meat for human consumption (LORENZO et al., 2014LORENZO, J. M., et al. Carcass characteristics, meat quality and nutritional value of horsemeat: A review. Meat Science, v. 96, p. 1478-1488, 2014. Available from: https://doi.org/10.1016/j.meatsci.2013.12.006>. Accessed: Jun. 18, 2017. doi: 10.1016/j.meatsci.2013.12.006.
https://doi.org/10.1016/j.meatsci.2013.1...
). Global consumption of equine meat is mainly concentrated in some European countries such as Italy, France and Belgium, as part of their traditional food (STANCIU, 2015STANCIU, S. Horse meat consumption - between scandal and reality. Procedia Economics and finance, v. 23, p. 697-703, 2015. Available from: https://doi.org/10.1016/S2212-5671(15)00392-5>. Accessed: Sept. 18, 2017. doi: 10.1016/S2212-5671(15)00392-5.
https://doi.org/10.1016/S2212-5671(15)00...
). It is difficult to estimate with precision the consumption per capita (GILL, 2005GILL, C.O. Safety and storage stability of horse meat for human consumption. Meat Science, v. 71, n. 4, p. 506-513, 2005. Available from: https://doi.org/10.1016/j.meatsci.2005.04.030>. Accessed: May 15, 2017. doi: 10.1016/j.meatsci.2005.04.030.
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), but it was calculated in approximately 0.10kg by BELAUNZARAN et al. (2015BELAUNZARAN, X., et al. Horse-meat for human consumption -current research and future opportunities. Meat Science, v. 108, p. 74-81, 2015. Available from: https://doi.org/10.1016/j.meatsci.2015.05.006>. Accessed: May 20, 2017. doi: 10.1016/j.meatsci.2015.05.006.
https://doi.org/10.1016/j.meatsci.2015.0...
).

Consumption of equine meat is still reduced compared to other meats such as pork, chicken and beef (LOMBARDI-BOCCIA et al., 2005LOMBARDI-BOCCIA, et al. Aspects of meat quality: trace elements and B vitamins in raw and cooked meats. Journal Food and Composition Analysis, v. 18, p 39-46, 2005. Available from: https://doi.org/10.1016/j.jfca.2003.10.007>. Accessed: Jun. 20, 2017. doi: 10.1016/j.jfca.2003.10.007.
https://doi.org/10.1016/j.jfca.2003.10.0...
). However, equine meat presents desirable characteristics for consumers as they are free of growth promoters and has excellent nutritional properties (equine meat is iron-rich, low fat and an important source of unsaturated fatty acids and omega 3 fatty acids) (LOMBARDI-BOCCIA et al., 2005LOMBARDI-BOCCIA, et al. Aspects of meat quality: trace elements and B vitamins in raw and cooked meats. Journal Food and Composition Analysis, v. 18, p 39-46, 2005. Available from: https://doi.org/10.1016/j.jfca.2003.10.007>. Accessed: Jun. 20, 2017. doi: 10.1016/j.jfca.2003.10.007.
https://doi.org/10.1016/j.jfca.2003.10.0...
; TATEO et al., 2008TATEO, A., et al. Physicochemical properties of meat of Italian Heavy Draft horses slaughtered at the age of eleven months. Journal of Animal Science , v.86, n. 5, p. 1205-2014, 2008. Available from: https://doi.org/10.2527/jas.2007-0629>. Accessed: May 20, 2017. doi: 10.2527/jas.2007-0629.
https://doi.org/10.2527/jas.2007-0629...
; LORENZO et al., 2010LORENZO, J. M., et al. Intramuscular fatty acid composition of “Galician Mountain” foals breed: Effect of sex, slaughtered age and livestock production system. Meat Science, v. 86, p. 825-831, 2010. Available from: https://doi.org/10.1016/j.jfca.2003.10.007>. Accessed: Jun. 18, 2017. doi: 10.1016/j.jfca.2003.10.007.
https://doi.org/10.1016/j.jfca.2003.10.0...
; LORENZO et al., 2014LORENZO, J. M., et al. Carcass characteristics, meat quality and nutritional value of horsemeat: A review. Meat Science, v. 96, p. 1478-1488, 2014. Available from: https://doi.org/10.1016/j.meatsci.2013.12.006>. Accessed: Jun. 18, 2017. doi: 10.1016/j.meatsci.2013.12.006.
https://doi.org/10.1016/j.meatsci.2013.1...
).

Most of donkey meat comes from animals that have finished their productive life (LORENZO and CARBALLO, 2015LORENZO, J. M., CARBALLO, J. Changes in physic-chemical properties and volatile compounds throughout the manufacturing process of dry-cured foal loin. Meat Science, v. 99, p. 44-51, 2015. Available from: https://doi.org/10.1016/j.meatsci.2014.08.013>. Accessed: Jun. 18, 2017. doi: 10.1016/j.meatsci.2014.08.013.
https://doi.org/10.1016/j.meatsci.2014.0...
). In this sense, AGANGA et al. (2003AGANGA, A. A., et al. Carcass analysis and meat composition of the donkey. Pakistan Journal of Nutrition, v. 2, n. 3, p. 138-147, 2003. Available from: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.533.1513&rep=rep1&type=pdf>. Accessed: Jun. 22, 2017.
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) described that adult African donkey provide a hot carcass yield that range from 54 to 59 %. However, these yields can be considered good when compared to other species such as horses and pigs, ranging from 60 to 70% (SARRIÉS and BERIAIN, 2005SARRIÉS, M. V.; BERIAIN, M. J. Carcass characteristics and meat quality of male and female foals. Meat Science , v. 70, p. 141-152, 2005. Available from: https://doi.org/10.1016/j.meatsci.2004.12.006>. Accessed: Sept. 18, 2017. doi: 10.1016/j.meatsci.2004.12.006.
https://doi.org/10.1016/j.meatsci.2004.1...
; LANZA et al., 2009LANZA, M., et al. Meat quality and intramuscular fatty acid composition of Sanfratellano and Haflinger foals. Meat Science, v. 81, p. 142-147, 2009. Available from: https://doi.org/10.1016/j.meatsci.2009.04.022>. Accessed: Jun. 17, 2017. doi: 10.1016/j.meatsci.2009.04.022.
https://doi.org/10.1016/j.meatsci.2009.0...
). Horses have a carcass composition of 70% muscle, 20% bone and 10% fat; and therefore, produce more lean meat than other species. Different studies in horses reported that factors such as breed, gender and age affect the weight and carcass yield and the meat quality (JUÁREZ et al., 2009JUÁREZ, M., et al. Breed effect on carcass and meat quality of foals slaughtered at 24 months of age. Meat Science, v.83, p. 224-228, 2009. Available from: https://doi.org/10.1016/j.meatsci.2009.04.022>. Accessed: May 17, 2017. doi: 10.1016/j.meatsci.2009.04.022.
https://doi.org/10.1016/j.meatsci.2009.0...
; FRANCO et al., 2011FRANCO, D., et al. Carcass quality of Galician Mountain foals. Centro Tecnológico de la Carne. San Cibrao das Viñas. Archivos de Zootecnia, v. 60, n. 231, p. 385-388, 2011. Available from: http://dx.doi.org/10.4321/S0004-05922011000300017>. Accessed: May 15, 2017. doi: 10.4321/S0004-05922011000300017.
http://dx.doi.org/10.4321/S0004-05922011...
). To date there are a few scientific reports about factors affecting yield and meat characteristics of donkeys. Thus, the aim of this study was to evaluate the effect of gender and live weight on carcass characteristics, non-carcass components, and color of muscle and fat of donkeys.

MATERIALS AND METHODS:

The study was carried out at the meat packing plant “Empacadora de Carnes Fresnillo S.A. de C.V.”, Federal Inspection Type plant E42, located in the State of Zacatecas, Mexico. One hundred and eighty-nine Catalan crossbreed donkeys were slaughtered from April to June, 2014. Animals were classified according to their gender (geldingor female). Live weight (LW) was measured immediately before sacrifice using an electronic scale (model PG, Torrey, México). According to LW, animals were classified in four groups: group one with <100kg, group two from 101 to 125kg, group three from 126 to 150kg and group four from >151kg.

Donkeys were slaughtered in accordance to the Official Mexican Standard of methods for slaughter domestic and wild animals (NOM-033-SAG/ZOO-2014NOM-033-SAG/ZOO-2014. Slaughter methods for domestic and wild animals. Available from: http://201.140.167.80/wp-content/uploads/2016/08/NOM-033-SAG-ZOO-2014.pdf>. Accessed: May 17, 2017.
http://201.140.167.80/wp-content/uploads...
). After slaughter, hot carcass weight was registered and the head, legs and skin were removed and weighed individually using an electronic scale (EQB 100/200, Torrey, Mexico). Gastrointestinal content was weighed and subtracted to LW to obtain the empty BW. Carcasses were chilled for 24h at 2°C and 98% of relative humidity, and then were weighed to obtain the cold carcass weight. Hot carcass dressing ([hot carcass weight/empty BW] × 100), cold carcass dressing ([cold carcass weight/empty BW] × 100), and cooling loss (hot carcass weight - cold carcass weight/hot carcass weight) were calculated.

Non-carcass components (head, skin, stomach, small intestine, large intestine and cecum, heart, lungs, liver and spleen) were weighed from each animal separately using an electronic scale (EQB 100/200, Torrey, México) and yields of these organs were calculated as percentage of empty BW. The pH was measured in the longissimus thoracis muscle at 45min post-mortem using a pH meter equipped with a penetration electrode and thermometer (Hanna Instruments, HI-9025, Woonsocket, RI). The color (L*, a*, b*) of subcutaneous fat and semitendinosus muscle was measured directly on the carcass at 45min post-mortem using a portable spectrophotometer (CR-400, Konica Minolta Sensing Inc., Japan).The semitendinosus muscle was used to obtain meat color determination by the impossibility of dissect carcasses during the production process of the packing plant.

Data were analyzed as a completely randomized design, including the fixed effects of gender and LW of donkeys. Analysis of variance was performed using the PROC GLM procedure of SAS version University Edition (SAS Inst. Inc., Cary, NC). When significant effects were observed, a comparison of means was performed using the Tukey method with the LSMEANS instruction. Differences were considered significant at P<0.05.

RESULTS:

Geldings had greater (P<0.05) carcass weight, carcass dressing and L* value of subcutaneous fat color than females (Table 1). Females had greater (P<0.05) carcass cooling loss, small intestine weight (as percentage of the empty BW), a* value of semitendinosus muscle color and b* value of subcutaneous fat color. However, the pH value, most non-carcass components or other color values (a*, b* or L*) in meat or fat were not affected (P>0.05) by gender.

Table 1
Least square means for carcass characteristics, non-carcass components1and color (L*, a* and b*values)2 of the semitendinosus muscle, subcutaneous and abdominal fat in donkeys according to their gender.

Donkeys with more than 126kg of LW showed greater (P<0.05) carcass weight and hot carcass dressing and lower (P<0.05) cooling loss compared to lighter donkeys (Table 2), but the cold carcass dressing was greater (P<0.05) in donkeys of more than 101kg. However, the pH of the longissimus muscle (P>0.05) was unaffected by LW. In addition, the head, the skin and the large intestine (as percentage of empty BW) were greater (P<0.05) in the lighter (<100kg) donkeys. Also, the hearth and the liver occupied a greater percentage of the empty BW (P<0.05) in donkeys with a LW lower than 125kg, while the lungs were smaller (P<0.05) in the group of heaviest donkeys (>151kg).

Table 2
Least square means for carcass characteristics, non-carcass components1 and color (L*, a* and b* values)2 of the semitendinosus muscle, subcutaneous and abdominal fat in donkeys according to their live weight at slaughter.

The semitendinosus muscle showed greater (P<0.05) a* value (redness) in the heaviest donkeys (>151kg); however, the L* and b* values were similar (P>0.05) independently of the LW. The color of abdominal fat was darker (L* value) and reddish (a* value) (P<0.05) in donkeys over 150 kg, but the b* value was unaffected (P>0.05) by LW of donkeys. Meanwhile, the LW did not affect the color (L*, a* and b* values) of subcutaneous fat (P>0.05).

DISCUSSION:

AGANGA et al. (2003AGANGA, A. A., et al. Carcass analysis and meat composition of the donkey. Pakistan Journal of Nutrition, v. 2, n. 3, p. 138-147, 2003. Available from: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.533.1513&rep=rep1&type=pdf>. Accessed: Jun. 22, 2017.
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) reported that African donkeys had greater hot carcass dressing (59%) and cold carcass dressing (51%) than those observed in this study (lower than 50%). Earlier data by POLIDORI et al. (2008)POLIDORI, P., et al. Quality of donkey meat and carcass characteristics. Meat Science , v. 80, p. 1222-1224, 2008. Available from: https://doi.org/10.1016/j.meatsci.2008.05.027>. Accessed: May 20, 2017. doi: 10.1016/j.meatsci.2008.05.027.
https://doi.org/10.1016/j.meatsci.2008.0...
reported hot and cold carcass yields of 54% and 53% respectively for Martina Franca donkeys, which were greater than those observed in the present study. Moreover, SARRIÉS and BERIAIN (2006SARRIÉS, M. V.; BERIAIN, M.J. Color and texture characteristics in meat of male and female foals. Meat Science , v. 74, p. 738-745, 2006. Available from: https://doi.org/10.1016/j.meatsci.2006.06.005>. Accessed: Sept. 18, 2017. doi: 10.1016/j.meatsci.2006.06.005.
https://doi.org/10.1016/j.meatsci.2006.0...
), FRANCO et al. (2011FRANCO, D., et al. Carcass quality of Galician Mountain foals. Centro Tecnológico de la Carne. San Cibrao das Viñas. Archivos de Zootecnia, v. 60, n. 231, p. 385-388, 2011. Available from: http://dx.doi.org/10.4321/S0004-05922011000300017>. Accessed: May 15, 2017. doi: 10.4321/S0004-05922011000300017.
http://dx.doi.org/10.4321/S0004-05922011...
) and NIVIA et al. (2014NIVIA, O. A., et al. Determination of the slaughter volume and evaluation of quantitative variables of horses sacrificed in a slaughterhouse. Zootecnia Tropical, v. 32, n. 1, p. 83-89, 2014. Available from: http://www.scielo.org.ve/scielo.php?pid=S0798-72692014000100009&script=sci_arttext>. Accessed: May 10, 2017.
http://www.scielo.org.ve/scielo.php?pid=...
) stated a range from 50 to 70% for hot carcass dressing of horses. It can be expected that carcass yields of horses will be greater because there are specialized breeds in meat production unlike donkeys.

In this study, carcasses obtained showed higher values of cooling loss when compared to the values of other farm animal species reported in the literature. MAMANI-LINARES and GALLO (2011MAMANI-LINARES, L. W.; GALLO, C. Chemical composition and instrumental quality of bovine, llama (lama glama) and horse meat under an extensive production system. Revista de Investigaciones Veterinarias del Perú, v. 22, n. 4, p. 301-311, 2011. Available from: http://www.scielo.org.pe/scielo.php?pid=S1609-91172011000400003&script=sci_arttext>. Accessed: May 18, 2017.
http://www.scielo.org.pe/scielo.php?pid=...
) reported values for cooling loss of 1.37% in Llamas and 2.50% in horses. Similarly, FURTADO et al. (2010)FURTADO, C. E., et al. Influência do peso vivo, da idade e do sexo sobre características de carcaças de equinos. Revista Brasileira de Zootecnia. v. 39, n. 12, p. 2683-2686, 2011. Avaiable from: < Avaiable from: http://dx.doi.org/10.1590/S1516-35982010001200018 >. Accessed: Jul. 15, 2017. doi 10.1590/S1516-35982010001200018.
http://dx.doi.org/10.1590/S1516-35982010...
observed cooling loss ranging from 2 to 2.5% in equine meat, which are lower than those observed in the present study.

Despite it has been documented that castration reduces carcass yields (LAZZORONI et al., 2008LAZZARONI, C., BIAGINI, D. Effect of pre-and post-pubertal castration on Piemontese male cattle. II: Carcass measures and meat yield. Meat Science. v.80, p. 442-448, 2008. Available from: https://doi.org/10.1016/j.meatsci.2008.01.007>. Accessed: Jun. 17, 2017. doi: 10.1016/j.meatsci.2008.01.007.
https://doi.org/10.1016/j.meatsci.2008.0...
; JUÁREZ et al., 2009JUÁREZ, M., et al. Breed effect on carcass and meat quality of foals slaughtered at 24 months of age. Meat Science, v.83, p. 224-228, 2009. Available from: https://doi.org/10.1016/j.meatsci.2009.04.022>. Accessed: May 17, 2017. doi: 10.1016/j.meatsci.2009.04.022.
https://doi.org/10.1016/j.meatsci.2009.0...
), in this study the carcasses of geldings were heavier (P<0.05) than females. NIVIA et al. (2014NIVIA, O. A., et al. Determination of the slaughter volume and evaluation of quantitative variables of horses sacrificed in a slaughterhouse. Zootecnia Tropical, v. 32, n. 1, p. 83-89, 2014. Available from: http://www.scielo.org.ve/scielo.php?pid=S0798-72692014000100009&script=sci_arttext>. Accessed: May 10, 2017.
http://www.scielo.org.ve/scielo.php?pid=...
) reported greater averages for hot carcass weight and hot carcass dressing in males. In this study, there were no significant interactions, coinciding with FURTADO et al. (2010FURTADO, C. E., et al. Influência do peso vivo, da idade e do sexo sobre características de carcaças de equinos. Revista Brasileira de Zootecnia. v. 39, n. 12, p. 2683-2686, 2011. Avaiable from: < Avaiable from: http://dx.doi.org/10.1590/S1516-35982010001200018 >. Accessed: Jul. 15, 2017. doi 10.1590/S1516-35982010001200018.
http://dx.doi.org/10.1590/S1516-35982010...
) who reported that there was no interaction between sex and size for hot carcass yield of horses.

Meanwhile, SARRIÉS and BERIAIN (2006SARRIÉS, M. V.; BERIAIN, M.J. Color and texture characteristics in meat of male and female foals. Meat Science , v. 74, p. 738-745, 2006. Available from: https://doi.org/10.1016/j.meatsci.2006.06.005>. Accessed: Sept. 18, 2017. doi: 10.1016/j.meatsci.2006.06.005.
https://doi.org/10.1016/j.meatsci.2006.0...
) observed that there was no effect of gender on hot carcass weight. Similarly, NIVIA et al. (2014NIVIA, O. A., et al. Determination of the slaughter volume and evaluation of quantitative variables of horses sacrificed in a slaughterhouse. Zootecnia Tropical, v. 32, n. 1, p. 83-89, 2014. Available from: http://www.scielo.org.ve/scielo.php?pid=S0798-72692014000100009&script=sci_arttext>. Accessed: May 10, 2017.
http://www.scielo.org.ve/scielo.php?pid=...
) argued that gender has a low effect on these variables, and in agreement with previously reported by MARTIN-ROSSET and DULPHY (1987MARTIN-ROSSET, W.; DULPHY, J. P. Digestibility interactions between forages and concentrates in horses: influence of feeding level - comparison with sheep. Livestock Production Science, v. 17, p. 263-276, 1987. Available from: https://doi.org/10.1016/0301-6226(87)90071-6>. Accessed: May 20, 2017. doi: 10.1016/0301-6226(87)90071-6.
https://doi.org/10.1016/0301-6226(87)900...
) who mentioned that gender differences do not affect the relative growth of heavy horses.

Previous research indicated that the effect of gender on the hot carcass weight and dressing is more related to the amount of fat than to the amount of muscle (HORCADA et al., 1998HORCADA, A., et al. Effect of sex on meat quality of Spanish lamb breeds (Lancha and Rasa Aragonesa). Journal of Animal Science, v. 67, p. 541-547, 1998. Available from: https://doi.org/10.1017/S1357729800032975>. Accessed: May 17, 2017. doi: 10.1017/S1357729800032975.
https://doi.org/10.1017/S135772980003297...
; DÍAZ et al., 2003DÍAZ, M. T., et al. Physico-chemical characteristics of carcass and meat Manchego-breed suckling lams slaughtered at different weights. Meat Science, v. 65, p. 1085-1093, 2003. Available from: https://doi.org/10.1016/S0309-1740(03)00032-9>. Accessed: Jun. 20, 2017. doi: 10.1016/S0309-1740(03)00032-9.
https://doi.org/10.1016/S0309-1740(03)00...
). Meanwhile, FURTADO et al. (2010FURTADO, C. E., et al. Influência do peso vivo, da idade e do sexo sobre características de carcaças de equinos. Revista Brasileira de Zootecnia. v. 39, n. 12, p. 2683-2686, 2011. Avaiable from: < Avaiable from: http://dx.doi.org/10.1590/S1516-35982010001200018 >. Accessed: Jul. 15, 2017. doi 10.1590/S1516-35982010001200018.
http://dx.doi.org/10.1590/S1516-35982010...
) reported a hot carcass dressing below 51% in Mestizo horses, without differences due to weight, age and gender. In this study, females had greater cooling loss than males. These results can be explained by the presence of a greater subcutaneous fat appreciated in males, which protect carcass against dehydration during cooling (VERGARA and MOLINA, 1998VERGARA, H.; MOLINA, A. Influence of sex and slaughterweight on carcass and meat quality in light and mediumweight lambs produced in intensive systems. Meat Science , v. 52,p. 221-226, 1998. Available from: https://doi.org/10.1016/S0309-1740(98)00171-5>. Accessed: May 21, 2017. doi: 10.1016/S0309-1740(98)00171-5.
https://doi.org/10.1016/S0309-1740(98)00...
; FRANCO et al., 2011FRANCO, D., et al. Carcass quality of Galician Mountain foals. Centro Tecnológico de la Carne. San Cibrao das Viñas. Archivos de Zootecnia, v. 60, n. 231, p. 385-388, 2011. Available from: http://dx.doi.org/10.4321/S0004-05922011000300017>. Accessed: May 15, 2017. doi: 10.4321/S0004-05922011000300017.
http://dx.doi.org/10.4321/S0004-05922011...
).

AGANGA et al. (2003AGANGA, A. A., et al. Carcass analysis and meat composition of the donkey. Pakistan Journal of Nutrition, v. 2, n. 3, p. 138-147, 2003. Available from: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.533.1513&rep=rep1&type=pdf>. Accessed: Jun. 22, 2017.
http://citeseerx.ist.psu.edu/viewdoc/dow...
) mentioned that the yields of this species may be affected by the state of maturity, physical condition or degree completed, they also mentioned that the carcass yield of donkeys decreased with age, arguing that as the donkeys get older, increased their weight, perhaps because the fat percentage increased, thereby decreasing the ratio of muscle:bone. In horses, FURTADO et al. (2010FURTADO, C. E., et al. Influência do peso vivo, da idade e do sexo sobre características de carcaças de equinos. Revista Brasileira de Zootecnia. v. 39, n. 12, p. 2683-2686, 2011. Avaiable from: < Avaiable from: http://dx.doi.org/10.1590/S1516-35982010001200018 >. Accessed: Jul. 15, 2017. doi 10.1590/S1516-35982010001200018.
http://dx.doi.org/10.1590/S1516-35982010...
) reported an interaction between sex and age, in which males over 8 years were those with the largest hot carcass dressing. However, SALGUEIRO et al. (2008SALGUEIRO, J., et al. Efecto del peso de sacrifico y la raza en la canal de terneros alimentados con ensilados. Archivos de zootecnia, v. 57, n. 219, p. 295-306, 2008. Available from: https://dialnet.unirioja.es/servlet/articulo?codigo=3027750>. Accessed: Sept. 18, 2017.
https://dialnet.unirioja.es/servlet/arti...
) mentioned that fattening period of the animals is more important than age to determine carcass dressing. The carcass dressing obtained in this study agree with those reported by POLIDORI et al. (2008)POLIDORI, P., et al. Quality of donkey meat and carcass characteristics. Meat Science , v. 80, p. 1222-1224, 2008. Available from: https://doi.org/10.1016/j.meatsci.2008.05.027>. Accessed: May 20, 2017. doi: 10.1016/j.meatsci.2008.05.027.
https://doi.org/10.1016/j.meatsci.2008.0...
, who observed an increase of 4% in donkeys of 120kg compared with those of 100kg.

The information available on weight and yield of the non-carcass components in donkeys is limited. However, SANTOS-RICALDE et al. (2011)SANTOS-RICALDE, et al. Carcass yield and thoracic and abdominal viscera growth from 25 to 45kg in creole hairless Pigs. Revista Científica, FCV-LUZ , v. 21, n. 5, p.396 - 402, 2011. Available from: http://200.74.222.178/index.php/cientifica/article/view/15663/15637>. Accessed: Sept. 18, 2017.
http://200.74.222.178/index.php/cientifi...
there have been reported differences in the weight of the viscera between pigs slaughtered at different weights which agrees with what was observed in the present study, where the yield of viscera was affected by the weight of the donkeys. PÉREZ-MELÉNDEZ et al. (2007PÉREZ-MELÉNDEZ, P., et al. Effect of Slaughter Weight and Sex on the Carcass of Suffolk Down x German Merino Precocious Suckling Lambs. Revista Científica, FCV-LUZ, v.17, n.6, p. 621-626, 2007. Available from: http://www.scielo.org.ve/scielo.php?script=sci_arttext&pid=S0798-22592007000600010>. Accessed: Jun. 20, 2017.
http://www.scielo.org.ve/scielo.php?scri...
) reported that live weight at slaughter has an effect on the weight of body components such as head, skin, heart, liver, kidneys, lungs and legs; but, the same authors reported that gender did not influence the weight of the non-carcass components, according with what was observed in the present study. Despite the same authors reported greater weight in organs of castrated males, probably this was due to a greater proportion of fat.

The meat color is an important characteristic for the consumer that is influenced by factors such as genetics, sex, age at slaughter and nutrition (PRIOLO et al., 2002PRIOLO, A., et al. Effect of grass or concentrate feeding system on lamb carcass and meat quality. Meat Science , v.62, p. 179-185, 2002. Available from: https://doi.org/10.1016/S0309-1740(01)00244-3>. Accessed: Jul. 19, 2017. doi: 10.1016/S0309-1740(01)00244-3.
https://doi.org/10.1016/S0309-1740(01)00...
; RIPOLL et al., 2012RIPOLL, G., et al. Influence of alfalfa grazing-based feeding systems on carcass fat color and meat quality of light lambs. Meat Science , v. 90, p. 457-464, 2012. Available from: https://doi.org/10.1016/j.meatsci.2011.09.007>. Accessed: Jul. 20, 2017. doi: 10.1016/j.meatsci.2011.09.007.
https://doi.org/10.1016/j.meatsci.2011.0...
). POLLIDORI et al. (2016) POLIDORI, P., et al. A comparison of the carcass and meat quality of Martina Franca donkey foals aged or 12 months. Meat Science , v.106, p. 6-10, 2015. Available from: https://doi.org/10.1016/j.meatsci.2015.03.018>. Accessed: May 20, 2017. doi: 10.1016/j.meatsci.2015.03.018.
https://doi.org/10.1016/j.meatsci.2015.0...
mentioned that the luminosity and red coloration of the meat is due to the muscle myoglobin content and is influenced by feeding and production system. In addition, several investigations mention a relation between the color pattern with the intramuscular fat content and water in meat (LORENZO et al. 2017LORENZO, J.M., et al. Technological aspects of horse meat products- A review. Food Research International, v. 102, p. 176-183, 2017. Available from: https://doi.org/10.1016/j.foodres.2017.09.094>. Accessed: May 18, 2017. doi: 10.1016/j.foodres.2017.09.094.
https://doi.org/10.1016/j.foodres.2017.0...
). However, an inverse relationship was observed between fat and water content in meat (SMITH et al., 2011SMITH, A. M., et al. Proximate composition and energy content of beef steaks as influenced by USDA quality grade and degree of doneness. Meat Science , v. 89, p. 228-232, 2011. Available from: https://doi.org/10.1016/j.meatsci.2011.04.027>. Accessed: May 20, 2017. doi: 10.1016/j.meatsci.2011.04.027.
https://doi.org/10.1016/j.meatsci.2011.0...
).

The difference of fat content between males and the females evaluated in this work could explain the differences observed in meat color; as well as between the lighter donkeys and the heavier ones, because higher intramuscular fat content has been reported in older and heavier donkeys (DOMÍNGUEZ, et al., 2015DOMÍNGUEZ, R., et al. Effect of slaughter age on foal carcass traits and meat quality. Animal, v. 9, p. 1713-1720, 2015. Available from: https://doi.org/10.1017/S1751731115000671>. Accessed: Jul. 15, 2017. doi: 10.1017/S1751731115000671.
https://doi.org/10.1017/S175173111500067...
, POLIDORI et al., 2015POLIDORI, P., et al. A comparison of the carcass and meat quality of Martina Franca donkey foals aged or 12 months. Meat Science , v.106, p. 6-10, 2015. Available from: https://doi.org/10.1016/j.meatsci.2015.03.018>. Accessed: May 20, 2017. doi: 10.1016/j.meatsci.2015.03.018.
https://doi.org/10.1016/j.meatsci.2015.0...
; DE PALO et al., 2017DE PALO, P., et al. Martina Franca donkey meat quality: influence of slaughter age and suckling technique. Meat Science. v. 134, p. 128-134, 2017. Available from: https://doi.org/10.1016/j.meatsci.2017.07.025>. Accessed: Nov. 20, 2017. doi: 10.1016/j.meatsci.2017.07.025.
https://doi.org/10.1016/j.meatsci.2017.0...
).

CONCLUSION:

In summary, both gender and live weight are important factors that affects carcass and meat characteristics of donkeys. Geldings provide carcasses of greater weight and paler subcutaneous fat, which have less cooling loss than females. Donkeys with live weight at slaughter >126kg, have greater carcass weights and dressing, and lower cooling loss than lighter donkeys. In addition, the non-carcass components are reduced when live weight increases.

ACKNOWLEDGEMENTS:

The authors express their gratitude to the owners and personnel of the meat packing plant “Empacadora de Carnes Fresnillo S.A. de C.V.”, Federal Inspection Type plant E42, for their supportand assistance to carrying out this study.

REFERENCES:

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    CR-2017-0889.R1

Publication Dates

  • Publication in this collection
    2018

History

  • Received
    07 Dec 2017
  • Accepted
    21 Feb 2018
  • Reviewed
    12 Apr 2018
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