Cashew nut meal (Anacardium occidentale L.) in the feeding of growing rabbits

Abstract Two trials were conducted: (1) to determine the chemical composition, digestibility of nutrients and energy of cashew nut meal (CNM); and (2) to evaluate the effects of increasing its levels (0, 5, 10, 15, 20 and 25%) in diets for growing rabbits on performance, carcass characteristics and economic evaluation. The digestibility assay utilized 24 rabbits (55 days of age), distributed in a completely randomized design with two treatments and 12 repetitions, with one reference and another test feed composed of 70% basal diet and 30% CNM. The digestibility of dry matter, crude protein and gross energy from CNM were, respectively, 76.61, 61.71 and 56.53%. The digestible dry matter, digestible protein and digestible energy were, respectively, 74.28, 16.97 and 3,549 kcal/kg. The performance assay utilized 120 rabbits, with an average of 45 days of age and weight 1090 ± 151g, distributed in a completely randomized design with six treatments and 10 repetitions with two rabbits of the same sex per cage. The inclusion of CNM above 5% promoted a linear reduction in feed intake and improved feed conversion, without affecting weight gain and carcass characteristics to the 20% level of inclusion. There was also a linear reduction in feed cost per kilogram of weight gain and linear improvement in rates of economic efficiency and cost index up to 25% CNM inclusion. Based on these findings - and to not hurt performance - it is recommended to include up to 20% CNM in rabbits' diet.

Dried brewers grains in growing rabbits: nutritional value and effects on performance

<p>Two assays were carried out to determine i) the nutritional value of dried brewers’ grains and ii) the effects of inclusion of this ingredient in growing rabbit diets on animal performance and economic performance of the breeding unit. In the digestibility assay, a total of 28 male rabbits were distributed in 2 groups differing in the diet offered to animals: a reference diet (35.51% neutral detergent fibre and 16.50% crude protein [CP]) and a test diet (60% of reference diet and 40% of dried brewers grains). The dried brewers’ grain contained 37.9% of CP and 3371 kcal digestible energy/kg dry matter. In the performance study, 80 weaned rabbits (40 males and 40 females) were allotted at 40 d of age to 5 groups differing in the inclusion levels of dried brewers’ grains (0, 7, 14, 21 and 28%) from 40 d to 90 d of age. Inclusion of dried brewers’ grains did not affect the live weight at 90 d, the feed intake between 40 d and 90 d or the dressing percentage of rabbits (on average 223 g, 96 g/d and 51.3%, respectively). There was no effect of diet on the meat quality parameters (69.5% water holding capacity, 25.6% cooking loss, 3.4 kg/cm² Warner-Bratzler shear force and pH 5.70) and inclusion levels above 14% reduced the feed cost (–18%; P</p>

The effect of age on the carcass composition, portion yield and proximate composition of two rabbit genetic types in South Africa

This study investigated the carcass component yields and meat proximate composition of 2 rabbit genetic types (Californian and hybrid New Zealand Red×Californian), with 5 rabbits per genetic type being slaughtered every 2 wk throughout the study period (9-17 wk) to evaluate the effect of age on these traits. Slaughter weight, reference yield, portion yield (hind leg, foreleg and fore part, as percentage of slaughter weight), meat yield, skin weight and the fat content of the meat (percentage of wet weight) increased significantly with age, while the full gastrointestinal tract, liver, head and feet decreased significantly. This is likely a reflection of the early-maturing nature of bone and viscera and later maturing nature of muscle and fat. These results indicate that delaying slaughter to 13 wk tends to improve yields for valuable carcass components. The Californian had a significantly higher total meat yield at 11 and 17 wk and higher portion meat yields at 9 (hind leg), 11 (hind leg and fore part) and 13 (foreleg) weeks than the hybrid. This was likely due to the later maturation of the hybrid and the influence of the New Zealand Red on carcass quality. It therefore appears that the Californian may be more favourable for meat production, from a carcass and meat quality perspective.

Performance and sustainability of two alternative rabbit breeding systems

<p>The aim of this study was to evaluate 2 alternative breeding systems that differ from the current system in terms of reproduction rhythm, age of females at first insemination and the age of kits at weaning and at slaughter. We measured the performance of 332 females and their offspring over 4 consecutive cycles, as well as the sustainability of the systems. We compared an intensive (group I: reproduction rhythm [RR]=35 d; first insemination [AI₁]=20.6 wk of age; weaning age [WA]=32 d; slaughter age [WS]=63 d) an extensive (group E: RR=49 d; AI₁=16.6 wk; WA=30 d; WS=70 d) and a semi-intensive system (group S: RR=42 d; AI₁=19.6 wk; WA=35 d; WS=70 d) considered as the control system. Sustainability was evaluated using a multicriteria assessment method that takes 14 economic, environmental and social criteria into account, for which 3 to 5 indicators were expressed as the relative score [–1; –0.5; 0; +0.5; +1] for alternative systems compared to the control system. The productivity measured at 28 d (3.5, 4.2 and 4.6 kg/AI, for groups I, S and E, respectively), at 63 d post-partum (30, 38 and 42 kg/female for 4 cycles, respectively), and the total body energy measured 3 d after the 1st and at the 4th insemination (45.4, 46.8 and 49.5 MJ, respectively), were significantly increased when the reproductive rhythm decreased (P&lt;0.001). Before and after weaning, kit mortality decreased when the reproduction rhythm decreased (11.4, 7.3, and 1.9% and 18.3, 15.3 and 10.6% for groups I, S and E, respectively, P&lt;0.05). Carcass quality (weight and dressing percentage) was lower in I than in the S and E groups (P&lt;0.001). On this basis, the yearly productivity per doe at weaning could be estimated at 79, 83, and 78 kg for groups I, S and E, respectively. Consequently, the productivity per reproductive cycle increases with the extensification of the breeding system. Nevertheless, compared with the current French system (S), simultaneous changes in several breeding practices could lead to new coherent and functional systems capable of improving various aspects of sustainability.</p>

Carcass composition and meat characteristics of two rabbit breeds of different degrees of maturity

Carcass and meat characteristics of rabbits from two synthetic breeds of different size were compared. Breed R had a higher adult weight and reached slaughter weight 1 week before breed V. Sixty rabbits of each breed were slaughtered when they (approximately) reached the Spanish commercial liveweight of 2 kg in order to compare their carcasses and meat quality. The carcasses were measured and retailed according to the norms of the World Rabbit Scientific Association. Breed R had a considerably more developed liver, a less developed hind part, and a more developed thoracic cage. Dissectible fat content was 3.1% and 2.5% of the carcass weight for the breeds V and R, respectively. Meat content was higher in the V breed than in the R breed (53 and 51% with respect to the chilled carcases). The ratio meat bone was better for breed V (2.18 and 2.05, respectively). Muscular fat content, estimated in the meat of one side of the carcass, was higher for breed V. All these differences are related to the lower degree of maturity of breed R at equal weights. Muscular pH, measured on the B. femoris and on the M. Longissimus lumborum at the level of the 5th lumbar vertebra, was the same for both breeds. Colour was measured on the carcass surface and in cuts of the M. Longissimus lumborum. Some colour differences were found for the carcass surface, but not for the meat.

Efeito da fibra de coprodutos agroindustriais e sua avaliação nutricional para coelhos

Estudou-se a influência da fibra oriunda de diferentes fontes - feno de alfafa, polpa de cítrus e casca de soja - sobre o desempenho, coeficientes de digestibilidade, parâmetros sanguíneos e características da carne de coelhos submetidos às dietas experimentais. Os animais foram distribuídos em três tratamentos, que consistiram de: FA - ração-controle, com feno de alfafa; PC - substituição total do feno de alfafa por polpa de cítrus; e CS - substituição total do feno de alfafa por casca de soja. As diferentes frações da fibra advindas da polpa de cítrus e da casca de soja não influenciaram o desempenho dos animais aos 89 dias e mostram que esses ingredientes podem ser utilizados como substitutos do feno de alfafa na dieta de coelhos. A qualidade de fibra da polpa de cítrus reduziu os níveis séricos de triacilglicerol, colesterol e hemoglobina dos animais. A baixa quantidade de lignina em relação à celulose e à hemicelulose da casca de soja propiciou melhor coeficiente de digestibilidade dos nutrientes e maior maciez da carne, porém menor deposição proteica quando comparada com a dieta com polpa de cítrus.

Desempenho, características de carcaça e viabilidade econômica de coelhos sexados abatidos em diferentes idades

Avaliaram-se o desempenho, as características de carcaça e a viabilidade econômica de coelhos sexados abatidos em diferentes idades. Foram usados 100 coelhos (50 machos e 50 fêmeas), em delineamento de blocos inteiramente ao acaso e arranjo fatorial 2×2 (dois sexos e duas idades ao abate), com quatro tratamentos e cinco repetições. Os coelhos foram desmamados aos 35 e abatidos aos 75 ou 90 dias de idade. Não houve diferença entre sexo (P>0,05) nos parâmetros avaliados. Os animais abatidos aos 90 dias (P<0,001) eram mais pesados e consumiram (diário) mais ração. Os abatidos aos 75 dias (P<0,001) ganharam mais peso (diário) e apresentaram melhor conversão alimentar. Coelhos abatidos aos 90 dias de idade tiveram maiores pesos relativos de carcaça (P<0,04), de coxa (P<0,001), de gordura interna (P<0,001) e de fígado (P<0,01) e, ainda, apresentaram maior peso final e melhores características de carcaça, cuja venda foi mais lucrativa quando realizada aos 75 dias ou quando foram abatidos aos 90 dias de idade.

Chemical and fatty acid composition of meat from Spanish wild rabbits and hares

The differences in the chemical and fatty acid compositions between the meats of five Spanish wild rabbits (Oryctolagus cuniculus) and five Spanish wild hares (Lepus europaeus) for foreleg, loin, hindleg and perirenal fat have been studied. Only significant differences (P < 0.05) in the meat chemical composition were observed between rabbits and hares for dry matter and fat in loins, and for ash in hindlegs. Significant differences (P < 0.05) between saturated fatty acids in foreleg and perirenal fat and between unsaturated C-18:1 and C-18:2 fatty acids in loins were observed.