Influence of the genetic origin and sex on live performance and carcass traits in the rabbit. Preliminary results

The study compared the growth performance and carcass traits of 41 rabbits of both sexes derived from 3 genetic origins (GO): sire Vienna Blue (B), sire Burgundy Fawn (F) and hybrid rabbits (H). From weaning they were reared indoor in bicellular cages and fed ad libitum the same pelleted diet until a fixed slaughter weight (2.8±0.11kg). The rabbits of the 3 GO differed in slaughter age (88 vs 109 vs 122d for H, B and F-GO, respectively; P<0.001). Growth performance of B was better than that of F, while that of H was better than B+F groups. Carcass traits were not modified by the GO; only perirenal fat percentage increased from H (1.2%) to B (1.7%) to F (2.5% of the reference carcass; P<0.05) accordingly to the slaughter age. The sex effect was significant only for the dressing out percentage, being higher in males than females (59.0 vs 57.6%; P<0.05)

Do insects as feed ingredient affect meat quality?

 The development of sustainable feed ingredients for monogastric livestock is nowadays considering insect meals and oils to replace or supplement conventional feedstuffs. Although the regulation on the use of insect products differs among  countries resulting in restrictions on use in the diets of  monogastric meat producers, global research is exploring all the  strengths and weaknesses of their inclusion. Therefore, whereas  the scientific literature has extensively studied both the  relationship between insect farming systems and safety (potential health risks), and between the dietary use of insects  and the nutritional value of diets and production performance of farm animals (fish, poultry, swine, rabbit), the relationship  between insect-containing diet and meat quality has only recently been considered. The present review therefore aims to  collect the results of the studies that have related the dietary use of some insect species, such as the black soldier fly (Hermetia  illucens), the yellow mealworm (Tenebrio molitor) and the silkworm (Bombyx mori), on the physicochemical and sensory  traits of the poultry, swine and rabbit meat. The variable that has been most affected by the inclusion of insects as feed on  livestock meat quality is the fatty acid (FA) profile, which, as is well known, in monogastrics tends to reflect that of the diet.  Therefore, the black soldier fly inclusion has always originated meats with a more saturated FA profile, the yellow mealworm a  more monounsaturated fatty acid profile, whereas the silkworm a more unsaturated fatty acid profile and rich of valuable  omega-3 FA, but rarely changed the related physicochemical  variables, or the sensory profile of the meat.

rabbit farming for meat purposes

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Influence of the paternal genetic origin and season on the live performances and the carcass yield of rabbits reared in the organic production system

Organic rabbit production (ORP) must follow the guidelines for organic livestock system (EC regulation 1804/1999) but they give very few indications for rabbit rearing. In Italy, two organisms of certification (ICEA, AIAB) provide respectively the control system and the guidelines for the rabbit reared under organic system. Regarding to the breed, only pure breeds and their crosses of first generation must be used; the red-eyes breeds are forbidden. The choice of the breed must consider mainly their resistance to disease, their rusticity and slow growth. The latest rule is needed because of the rabbits must be slaughtered when reaching the 14th wk of age. In Italy, the ORP is just developing so, the permitted breeds are not yet selected for carcass and meat quality. Among the adoptable breeds, Vienna Blue and Burgundy Fawn are those the more profitable for the ORP. The aim of this study was to compare the live performance and the carcass yield of rabbits derived from two sire genetic origins, Vienna Blue and Burgundy Fawn, reared in organic system and under different rearing season

Influence of rabbit sire genetic origin, season of birth and parity order on doe and litter performance in an organic production system

The aim of this study was to compare both the performance of litters derived from two sire genetic origins (SGO), Vienna Blue (VB) and Burgundy Fawn (BF), along successive seasons of birth (SB; winter, spring, summer and autumn), and doe reproductive performance in an organic production system. A total of fifty-eight does consisting of a mixture of crosses of several medium-large size breeds at different parity order (P, 1 = nulliparous; 2 = primiparous; 3 = multiparous) and twelve males (6 VB and 6 BF) were housed indoor at environmental conditions that followed seasonality. An extensive reproductive rhythm was used and kits were weaned at 466 d of age. Doe reproductive performance and the data of 105 litters (55 from VB and 50 from BF SGO) were recorded throughout the SB. No statistically significant differences related to SGO effect were observed. As regards parity order, multiparous does showed higher live weights (LW) (p<0.05), total born (p<0.01), total born alive (p<0.05) per delivery, and litter weight of born alive (p<0.05), but lower milk output at 21st d than primiparous does (p<0.05). The extensive reproductive rhythm mainly increased litter performance at birth in multiparous does but was not sufficient to permit a complete recovery of body reserves lost during lactation. Autumn SB negatively affected doe LW variation between deliveries. The number of pups born and born alive per delivery (p<0.05) and litter size at 21 d of age and at weaning (p<0.01) were lower during hot SB. Due to the lower litter size of pups born in summer and autumn, their individual weight at 21st d of age and daily individual growth rate 0 to 21 d were higher than those of pups born in winter (p<0.001). Litter performance at 21st d of age and individual pup pre-weaning growth rate were poorer for those born in spring than in other seasons due to the suffering caused by the effects of increased environmental temperatures. SB affected most of the performance traits of does and young rabbits reared under the organic farming system. The rabbits seemed better suited to organic rearing conditions during winter than in other seasons. The worst results overall were obtained in the spring SB, whereas the hot SB negatively affected both doe energy balance and prolificacy. In conclusion, the pups of the 2 SGO showed good pre-weaning performance and seemed suited to the organic rabbit production system

Dried chicory root (Cichorium intybus L.) as a natural fructan source in rabbit diet: effects on growth performance, digestion and caecal and carcass traits

[EN] Three experimental diets were formulated including (per kg) 100 g oats (control diet), 50 g chicory root (Chicory 5 diet) or 100 g chicory root (Chicory 10 diet) at the expense of oats. The diets differed with respect to starch and fructan contents. In the performance trial, 120 Hyplus rabbits were randomly allocated to three groups (two rabbits per cage) and fed one of the three experimental diets between 31 and 73 days of age. At the end of the trial period, 20 rabbits per treatment were slaughtered and used for evaluation of carcass traits. In addition, the coefficients of total tract apparent digestibility (CTTAD) of the diets and caecal traits were determined from 45 to 49 days of age in 10 rabbits per treatment. The diets did not differ significantly in terms of weight gain, feed intake, feed conversion ratio, health status or carcass traits of rabbits. The CTTADs of crude protein (P=0.041) and ether extract (P=0.006) were lower in rabbits fed the Chicory 10 diet than in rabbits fed the control diet. The CTTAD of starch (P<0.001) was lower, whereas that of fructans (P<0.001) higher, in rabbits fed the diets based on chicory root. The caecum weight (P=0.037), the weight of its contents (P=0.025) and the lactic acid (P=0.028) concentration were higher in rabbits fed the Chicory 10 diet than in control rabbits. On the contrary, rabbits fed with the chicory diets showed lower caecal pH (P=0.048) than rabbits fed the control diet. There was a tendency towards a lower caecal dry matter content and higher total VFA concentration in rabbits fed the chicory diets. It may be concluded that chicory root can serve as a natural source of inulin-type fructans in rabbit feed. Diet supplementation with 10% dried chicory root beneficially affected the caecal fermentative activity in the rabbits, without significant reductions in the nutritive value of the diet, growth performance or carcass quality.Financial support for this study was provided by the institutional research project MZE 0002701404Volek, Z.; Marounek, M. (2011). Dried chicory root (Cichorium intybus L.) as a natural fructan source in rabbit diet: effects on growth performance, digestion and caecal and carcass traits. World Rabbit Science. 19(3):143-150. https://doi.org/10.4995/wrs.2011.850SWORD14315019

Dietary inclusion of tannin extract from red quebracho trees (Schinopsis spp.) in the rabbit meat production

Two levels (1% and 3%) of condensed tannin extract from red quebracho (QT) were added to a diet of growing rabbits in a 6-wk feeding trial up to 12 wk of age. Health status was unaf- fected by the QT supplementation. The E. coli count of caecal content denoted a bactericidal activity of the QT. Weight gain and slaughter weigh were significantly higher and conversion index was sig- nificantly lower in rabbits fed QT diets, compared to those fed the control diet (P<0.05). Meat traits, as well the meat fatty acid profile weren't influenced by the QT supplementation. Our results contributed to increase the knowledge on the dietary use of QT in the rabbit. QT extract supplemented at 1% and 3% in fattening rabbits diet had a clear beneficial effect on live performance. Further studies are needed to assess if supplementing diets with QT can be a valuable strategy

Effect of "wooden breast" appearance on poultry meat quality, histological traits, and lesions characterization

The purposes of the study were to investigate the effects of Wooden Breast (WB) myodegeneration on poultry meat quality and to give a contribution in typing lesions morphology. At a poultry meat cutting facility, 474 carcasses of a high-breast-yield hybrid chickens were inspected for WB condition, and 30 normal (N) and 30 affected (WB) breast fillets (Pectoralis major) were randomly selected. The WB condition represented 53.2% of the examined carcasses. Weight, cross sectional area (CSA), pH, L*, a*, b* colour values, water-holding capacity, and Warner-Bratzler shear force were determined. Samples were also visually and histologically evaluated. Affected samples were heavier, thicker, paler (P < 0.001), and characterized by palpatory hardness and lower water holding capacity (P < 0.05). Macroscopically, abnormalities were primarily localized in the cranial portion of the fillet and defined by the presence of bulges, petechiae, fluid and clear exudate, and higher pH. Microscopically, the WB condition was characterized by muscle fibres with greater CSA (P < 0.001) and higher giant fibres prevalence (P < 0.01). Data suggest a relationship between breast weight and WB condition

The dietary inclusion of Portulaca oleracea to the diet of laying hens increases the n-3 fatty acids content and reduces the cholesterol content in the egg yolk

The effect of n-3 polyunsaturated fatty acids (PUFA)-enriched diet on yolk fatty acid profile and cholesterol content was evaluated. Dried Poutulaca oleracea (purslane: PO diet) was added to a commercial diet (C diet) at 20% of inclusion level. The effect of the supplemented diet was compared to that of C diet. Twenty-six laying hens were fed ad libitum for 21 days with the 2 diets, supplemented also with 300 mg α-tocopherol acetate/kg. Eggs were collected and then the fatty acids (FA) profile and the cholesterol content were analysed. The PO diet significantly reduced the saturated FA content (P<0.05) and increased that of the polyunsaturated FA (PUFA): 18:2 n-6 (P<0.001), 18:3 n-3 (P<0.001) and 22:6 n-3 (DHA; P<0.01). Both n-6 and n-3 PUFA significantly increased with the PO diet and the n-6/n-3 ratio was improved (10.4 vs 11.3; P<0.05)