Near infrared spectroscopy (NIRS) as a tool to predict meat chemical composition and fatty acid profile in different rabbit genotypes

Two hundreds rabbits were obtained from 3 different maternal lines and 5 pa- ternal lines, for a total of 11 combinations. After slaughtering the fresh hind legs (HL) and Longis- simus dorsi muscles (LD) were scanned in the near infrared region by using a Foss NIRSystem 5000 (λ=1100-2498 nm). The WINISI software (v 1.50) was used for the spectra analysis and samples selection (49 HL and 11 LD). Selected samples were analyzed chemically for dry matter (DM), protein, lipid, ash and fatty acid profile (FA). The obtained results were used to expand and improve the existing calibration equations for fresh rabbit's meat. Afterwards these equations were used to predict meat composition of the unselected samples. Discriminant analysis didn't segregate genetic lines. The calibration results for the 400 meat samples were accurate in predicting DM, protein, lipid and some FA (R2>0.80). Poor results were obtained for ash and for physical properties of meat. It was demonstrated that NIRS is a reliable and af- fordable technology to predict fresh rabbit meat composition, but because of the small differences between genotypes, NIRS wasn't able to discriminate samples according to their genetic belonging

Effect of maternal lysine supplementation on the performance of growing rabbits. Preliminary results

The experiment studied the effect of dietary lysine supplementation to rabbit does on the performance and on meat's protein and lysine content of their offspring. Half of the does (n=43) fed control diet (C; Lys: 0.68%), while the other half a lysine supplemented diet (L; Lys: 0.80%) from 3 days before AI until weaning. After kindling, half of the litters of C does were put under C does, while the other half under L does. The same procedure was followed for offspring of L does. After weaning, rabbits fed the same diet (0.68% Lys). Does' dietary treatment significantly affected the weaning weight, however, only lysine supplementation during suckling age had negative effect (340 vs 315g for C and L does, respectively; P<0.01). The kit's milk intake, measured at 3rd and 7th day of age, nursed by L does was significantly lower. Other productive and carcass traits did not differ significantly

Sample preparation and storage effects on fatty acid profile of rabbit Longissimus thoracis et lumborum muscle

[EN] Twenty-five Pannon White male rabbits reared and fed in similar conditions were slaughtered at 11 weeks of age. The longissimus thoracis et lumborum muscles (LTL; right and left) were removed at 24 h post-mortem and allocated to four sampling/storage treatments: the left side of LTL muscle was divided in half perpendicularly, with the posterior portion being analysed within one day (fresh), and the anterior portion vacuum packaged and stored for 1 mo at 20°C (whole-frozen); the right LTL side was ground with half of the product vacuum packaged and frozen for 1 mo at 20°C (ground-frozen), whereas the other half was freeze-dried, vacuum packaged, and stored for 1 mo at 4°C (freeze-dried refrigerated). Treatments impacted percentages of total saturated (P<0.01), monounsaturated (P<0.05), and polyunsaturated fatty acids (P<0.001), whole-frozen treatment affecting the most the fatty acids profile of the meat. Method of preparation and storage of meat samples before performing fatty acid analysis had an impact on the percentage of specific fatty acids, which could render the precision of study-to-study comparisons less reliable.Dalle Zotte, A.; Pranzo, G.; Tenti, S.; Szendr?, Z.; Szabó, A. (2022). Sample preparation and storage effects on fatty acid profile of rabbit Longissimus thoracis et lumborum muscle. World Rabbit Science. 30(3):187-193. https://doi.org/10.4995/wrs.2022.1716018719330

Effect of Digestarom® Dietary Supplementation on the Reproductive Performances of Rabbit Does: Preliminary Results

The study investigated the effect of Digestarom® dietary supplementation on the reproductive performances of rabbit does. Pannon Ka (maternal line) multiparous does were randomly divided into two dietary groups since insemination and fed ad libitum. In the first group (n=51), rabbit does were fed with a commercial diet (C), whereas in the other group (n=52) they received the same diet supplemented with 300 mg/kg of Digestarom® (D). The experiment lasted for two reproductive cycles (kindling 1=K1; kindling 2=K2). Body weight of does and litter size (kits born total, alive, stillborn) were recorded at kindling. Litter size and litter weight were registered at 7, 14, 21 days of age after nursing, and the average individual weight of kits was calculated. Kits' mortality was recorded daily. At K1, rabbit does performances were unaffected by dietary treatments. During K2, D does were significantly lighter than C ones (P<0.05) and displayed a lower kindling rate (P<0.05). Digestarom® did not improve the reproductive performance of rabbit does. They seemed to dislike the D diet in K1 and such behavior could have led to the negative results in K2. Further studies should focus on feed acceptance, dose-dependent effect, physiological adaptation and in vivo oxidative status of does. Finally, several consecutive reproductive cycles are recommended to test the efficacy of new feed supplements

Real-time ultrasound (RTU) imaging methods for quality control of meats

In this chapter the use of real-time ultrasonography to predict in vivo carcass composition and meat traits will be reviewed. The chapter begins by discussing background and principles of ultrasound. Then aspects affecting the suitability of realtime ultrasonography and image analysis for predicting carcass composition and meat traits of meat producing species and fish will be presented. This chapter also provides an overview of the present and future trends in the application of real-time ultrasonography in the meat industry. © 2012 Woodhead Publishing Limited All rights reserved.info:eu-repo/semantics/publishedVersio

Effect of floor type on carcass and meat quality of pen raised growing rabbits

[EN] The aim of the experiment was to compare the carcass and meat quality traits of growing rabbits housed on different floor types. At the age of 35 d, rabbits (n=126) were randomly sorted into 3 groups and housed in pens with different floor types: plastic-mesh, deep-litter straw or wire-mesh. Slaughter weight, carcass and its parts’ weight, meat (Longissimus thoracis et lumborum [LL] muscle and hind leg) pH and colour, oxidative status and fatty acid profile were measured and correlations calculated. The deep-litter straw rabbits showed the lowest pHu and b* values of LL muscle and oxidation of the both muscles. The fatty acid profile of LL muscle of deep-litter straw rabbits showed a higher percentage of monounsaturated fatty acids and long chain n-3 polyunsaturated (PUFA) fatty acids, whereas the content of  18:2n-6 and total PUFA was lower. We concluded that housing the growing rabbits on wire- or plastic-mesh floors showed no substantial differences, while housing rabbits on deep-litter negatively affected certain qualitative traits.This research was supported by the GOP-1.3.1-11/B-2011-0045 projectDal Bosco, A.; Szendrö, Z.; Matics, Z.; Castellini, C.; Ruggeri, S.; Szendrö, K.; Martino, M.... (2015). Effect of floor type on carcass and meat quality of pen raised growing rabbits. World Rabbit Science. 23(1):19-26. https://doi.org/10.4995/wrs.2015.3270SWORD1926231Dalle Zotte, A., Cullere, M., Sartori, A., Szendrő, Z., Kovàcs, M., Giaccone, V., & Dal Bosco, A. (2014). Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: Effects on raw and cooked meat quality, nutrient true retention and oxidative stability. Meat Science, 98(2), 94-103. doi:10.1016/j.meatsci.2014.05.005Enser M., 1999. Nutritional effects on meat flavour and stability. In: Richardson, R.I., Mead, G.C. (Eds.). Poultry Meat Sci. Poultry Science Symposium Series. Vol. 25. CABI Publishing, Oxon, 197-215.Folch J., Lees M., Sloane-Stanley H. 1961. A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. Chem., 226: 497-502.Jekkel G., Milisits G. 2009. Comparison of the behaviour of growing rabbits reared on wire net or combined floor at different stocking densities. Ital. J. Anim. Sci., 3: 202- 204.Jekkel G., Milisits G., Nagy I., Biró-Németh E. 2008. Analysis of the behaviour of growing rabbits housed in deep litter at different stages of rearing. In: Proceeding 9th World Rabbit Congress, June 10-13, 2008. Verona, Italy, pp. 1189-1193.Korkeala, H., Mäki-Petäys, O., Alanko, T., & Sorvettula, O. (1986). Determination of pH in meat. Meat Science, 18(2), 121-132. doi:10.1016/0309-1740(86)90088-4Matics Zs., Szendrő Zs., Radnai I., Biró-Németh E., Gyovai M. 2003. Examination of free choice of rabbits among different cage-floors. Agric. Consp. Scient., 68: 265-269.Szendrő, Z., & McNitt, J. I. (2012). Housing of rabbit does: Group and individual systems: A review. Livestock Science, 150(1-3), 1-10. doi:10.1016/j.livsci.2012.09.017Trocino A., Xiccato G., Queaque P.I., Sartori A. 2004. Group housing of growing rabbits: Effect of stocking density and cage floor on performance, welfare, and meat quality. In: Proceedings of the 8th World Rabbit Congress, September 7-, 2004. Puebla City, Mexico, pp. 1277-1281.Trocino A., Xiccato G., Majolini D., Fragkiadakis M. 2008. Effect of cage floor and stocking density on growth performance and welfare of group-housed rabbits. In: Proc. of the 9th World Rabbit Congress, June 10-13, 2008. Verona, Italy, pp. 1251-1255

Milk production of pseudopregnant multiparous does

The aim of the experiment was to evaluate the milk production of pseudopregnant does. In this experiment, data of multiparous, inseminated, pregnant (IP, n=15) does and two groups of presumably pseudopregnant multiparous does: inseminated, non-pregnant (INP, n=17) and induced to ovulation by GnRH (1.5 microgram per animal) at the day of insemination (11 d after parturition) (non-inseminated, ovulating: NIO, n=15) were analysed. The progesterone level was measured at the 12th d after treatment to determine if females were pseudopregnant. All IP and NIO does were pregnant and pseudopregnant, respectively. Within the INP group, 10 and 7 does were diagnosed as positive (INPO) or negative (INPNO) for pseudopregnancy. Two of the INPNO does perished during lactation. The average milk production of groups IP, INP and NIO was 212, 92 and 72 g/d, respectively (P160 g in the various groups were: IP=0, 0, 0, 0 and 100%, NIO=20, 13, 27, 40 and 0%, INP=15, 15, 15, 55 and 0%, respectively. The daily milk yield of the 5 INPNO does was 2, 6, 27, 84 and 139 g, respectively. These results demonstrated that multiparous empty does, pseudopregnant or non-pseudopregnant, can produce milk, but in lower quantities than multiparous does after kindling.Szendrö, Z.; Matics, Z.; Brecchia, G.; Theau-Clément, M.; Nagy, Z.; Princz, Z.; Biró-Németh, E.... (2010). Milk production of pseudopregnant multiparous does. World Rabbit Science. 18(2). doi:10.4995/WRS.2010.18.1018

Effect of group size and stocking density on productive, carcass, meat quality and aggression traits of growing rabbits

[EN] The aim of the experiment was to examine the effect of group size and stocking density on productive, carcass and meat quality traits. The trial was conducted using 230 Pannon white rabbits weaned at 5 weeks and reared until the age of 11 weeks. Seven groups were formed with different cage/pen sizes (group size) and stocking densities: SC16=small cage (0.12 m2), 16 rabbits/m2 (2 rabbits/cage); LC16=large cage (0.50 m2), 16 rabbits/m2 (8 rabbits/cage); LC12=large cage, 12 rabbits/m2 (6 rabbits/cage); SP16=small pen (0.86 m2), 16 rabbits/m2 (13 rabbits/cage); SP12=small pen, 12 rabbits/m2 (10 rabbits/cage); LP16=large pen (1.72 m2), 16 rabbits/m2 (26 rabbits/cage); LP12=large pen, 12 rabbits/m2 (20 rabbits/cage). Stocking density did not affect production significantly, as stocking densities lower than 16 rabbits/m2 had no effect on the growing rabbits¿ performance. Group size (size of the cage or pen) had an effect on certain growth, carcass and meat quality traits. Increasing group size resulted in lower values for weight gain (SC: 39.2>LC: 39.0> SP: 38.7> LP: 37.8 g/d; P=0.22) and body weight (SC: 2506>LC: 2498> SP: 2487> LP: 2446 g; P=0.35), similarly to other results in the literature, but the differences were not significant. Aggressive behaviour was observed to be more frequent in the larger group sizes. At the age of 11 weeks the proportion of rabbits with ear lesions in the SC, LC, SP and LP groups were 0.0, 7.1, 8.7, and 17.4%, respectively, demonstrating that larger group size increases the risk of ear lesions. The effect of group size on the ratio of the fore part to the reference carcass (SC: 28.5, LC: 28.2, LP: 29.0%; P=0.02) and on the amount of perirenal fat (SC: 21.3, LC: 18.0, LP: 13.7 g; P<0.001) was significant. Meat quality traits (dry matter, protein, fat and ash content, drip loss, pH, L*, a*, b* values) were not affected by group size (cage vs. pen), but successful discriminations were performed using the NIRS method.The authors gratefully acknowledge the financial assistance received from the GAK OMFB-01335/ALAP1- 00121 project.Szendrö, Z.; Princz, Z.; Romvári, R.; Locsmándi, L.; Szabó, A.; Bázár, G.; Radnai, I.... (2009). Effect of group size and stocking density on productive, carcass, meat quality and aggression traits of growing rabbits. World Rabbit Science. 17(3):153-162. https://doi.org/10.4995/wrs.2009.65515316217

Rabbit milk: A review of quantity, quality and non-dietary affecting factors

This literature review focuses on the milk yield and milk composition of rabbits and the non-nutritional factors affecting both quantity and quality. Actual highly efficient hybrid does have an average daily milk yield of 250 g or 60 g/kg of live weight during the 4-weeks lactation period. However, compared with cow and sow milk, rabbit’s milk is much more concentrated in fat (12.9 g/100 g), protein (12.3 g/100 g) and energy (8.4 MJ/kg) which explains the extremely rapid growth of the young (weight × 6 after 3 weeks). Characteristic of rabbit milk is also the nearly absence of lactose (&lt;2 g/100 g). At peak lactation, protein output per kg metabolic weight (13.4 g/day/kg 0.75 ( exceeds even those of Holstein milk cows. The non-nutritional factors having the largest impact on the milk yield are the number of suckling kits, the parity order (primiparous  vs. multiparous) and the gestation overlapping degree (rapid decline after 17-20 days of gestation). However, also through the reduction of feed intake, heat stress has a detrimental impact especially when the night temperature remains above 25°C. Rabbit milk lipids are highly saturated (70.4% SFA) due to the high content of C8:0  – C12:0  (50% of total FA) and further characterised by nearly equal quantities of oleic and linoleic acid and an w-6/w-3 ratio around 4. Finally some data about the amino acid, milk proteins including the immmunoglobulins, mineral and vitamin composition are presented. This literature review focuses on the milk yield and milk composition of rabbits and the non-nutritional factors affecting both quantity and quality. Actual highly efficient hybrid does have an average daily milk yield of 250 g or 60 g/kg of live weight during the 4-weeks lactation period. However, compared with cow and sow milk, rabbit&rsquo;s milk is much more concentrated in fat (12.9 g/100 g), protein (12.3 g/100 g) and energy (8.4 MJ/kg) which explains the extremely rapid growth of the young (weight &times; 6 after 3 weeks). Characteristic of rabbit milk is also the nearly absence of lactose (&lt;2 g/100 g). At peak lactation, protein output per kg metabolic weight (13.4 g/day/kg 0.75 ( exceeds even those of Holstein milk cows. The non-nutritional factors having the largest impact on the milk yield are the number of suckling kits, the parity order (primiparous&nbsp; vs. multiparous) and the gestation overlapping degree (rapid decline after 17-20 days of gestation). However, also through the reduction of feed intake, heat stress has a detrimental impact especially when the night temperature remains above 25&deg;C. Rabbit milk lipids are highly saturated (70.4% SFA) due to the high content of C8:0 &nbsp;&ndash; C12:0 &nbsp;(50% of total FA) and further characterised by nearly equal quantities of oleic and linoleic acid and an w-6/w-3 ratio around 4. Finally some data about the amino acid, milk proteins including the immmunoglobulins, mineral and vitamin composition are presented&nbsp