Effect of breeding system and farm hygiene on performances of growing rabbits and lactating does over two reproductive cycles

[EN] The aim of this paper was to study the effect of the intensive breeding system (IBS: insemination 4 d postpartum and weaning age at 25 d) vs. the semi-intensive breeding system (SIBS: insemination 11 d post-partum and weaning age at 35 d) on lactating does' performance and the combined effect of the type of farm hygiene (cleaned and disinfected or not) on the performance of growing rabbits from weaning until 56 d of age. A total of 58 New Zealand x Californian rabbit does (29/reproductive rhythm) and 168 young rabbits per combination weaning age x type of farm were selected at random over two consecutive reproductive cycles. Mortality during lactation presented higher values (P=0.067) in young rabbits weaned at 35 d than in those weaned at 25 (19.1 vs. 9.60%). In the first cycle, the number of kits weaned per litter was similar for both reproductive rhythms (7.89 and 8.01 for IBS and SIBS, respectively), whereas in the second cycle, the number of rabbits weaned was lower in rabbit does that weaned their litters later (6.90 vs. 9.06; P=0.049). Weight at parturition and at weaning, fertility, parturition interval, numerical productivity and the number of young rabbits born dead and weaned were not affected by treatments. The fattening mortality was higher in the second cycle than in the first (20.2 vs. 14.5 %, P=0.051), in the farm without cleaning and disinfection between cycles (20.0 vs. 14.2%, P=0.032) and in the animals weaned at 35 d than at 25 d (20.0 vs. 14.7 %, P=0.063). Animals weaned at 25 and 35 d of age both had a peak of mortality around two weeks after weaning. The average weight of rabbits at 56 d was not significantly different between the animals weaned at 25 or 35 d (1805 vs. 1787 g, respectively; P=0.64). However, the feed efficiency in the whole fattening period was higher in young rabbits weaned at 25 d than in those weaned at 35 d (0.392 vs. 0.298 g/g; P<0.001).Garrido, S.; Nicodemus, N.; García, J.; Chamorro, S.; Blas, JD. (2009). Effect of breeding system and farm hygiene on performances of growing rabbits and lactating does over two reproductive cycles. World Rabbit Science. 17(2):71-78. doi:10.4995/wrs.2009.660717817

Nutritional impact on health and performance in intensively reared rabbits

The present work summarizes research related to the definition of nutrient recommendations for feeds used in the intensive production of rabbit's meat. Fibre is the main chemical constituent of rabbit diets that typically contain 320 to 360 and 50 to 90 g/kg of insoluble and soluble fibre, respectively. Instead, the dietary contents of cereal grains (∼120 to 160 g/kg), fat (15 to 25 g/kg) and protein concentrates (150 to 180 g/kg) are usually low with respect to other intensively reared monogastric animals. Cell wall constituents are not well digested in rabbits, but this effect is compensated by its stimulus of gut motility, which leads to an increasing rate of passage of digesta, and allows achieving an elevated dry matter intake. A high feed consumption and an adequate balance in essential nutrients are required to sustain the elevated needs of high-productive rabbits measured either as reproductive yield, milk production or growth rate in the fattening period. Around weaning, pathologies occur in a context of incomplete development of the digestive physiology of young rabbits. The supply of balanced diets has also been related to the prevention of disorders by means of three mechanisms: (i) promoting a lower retention time of the digesta in the digestive tract through feeding fibre sources with optimal chemical and physical characteristics, (ii) restricting feed intake after weaning or (iii) causing a lower flow of easily available substrates into the fermentative area by modifying feed composition (e.g. by lowering protein and starch contents, increasing its digestibility or partially substituting insoluble with soluble fibre), or by delaying age at weaning. The alteration in the gut microbiota composition has been postulated as the possible primary cause of these pathologies

Nutritive value of palm kernel meal in diets for growing rabbits

The aim of this work was to determine the nutritive value of palm kernel meal (PKM) in diets for growing rabbits. In Experiment 1, 20 New Zealand × Californian growing rabbits 50 d-old were used to determine energy, crude protein, fibre and fat digestibility of PKM. The nutritive value was estimated by the difference method using a basal diet and another diet made by substituting 200 g/kg of basal diet with PKM. Energy, crude protein, ether extract and neutral detergent fibre of PKM digestibilities were, respectively, 0.549 (±0.056, SE), 0.541 (±0.069), 0.850 (±0.048) and 0.430 (±0.101), and the digestible energy concentration was 10.9 MJ/kg (±1.03) DM. In Experiment 2, 412 rabbits were allocated at random to the two experimental diets to measure growing performance. Inclusion of 200 g PKM/kg in the diet did not affect feed or digestible energy intake but decreased slightly (by around 5%) average daily gain (P = 0.003) and feed efficiency (P < 0.001). Neither mortality nor Clostridium perfringens counts in soft faeces were affected by type of diet. Palm kernel meal can be considered a palatable source of fibre, protein and fat for rabbits and can substitute significant amounts of other fibrous ingredients in the diet without adverse effects on growth performance

Aluminum slurry coatings to replace cadmium for aeronautic applications

Cadmium has been widely used as a coating to provide protection against galvanic corrosion for steels and for its natural lubricity on threaded applications. However, it is a toxic metal and a known carcinogenic agent, which is plated from an aqueous bath containing cyanide salts. For these reasons, the use of cadmium has been banned in Europe for most industrial applications. However, the aerospace industry is still exempt due to the stringent technical and safety requirements associated with aeronautical applications, as an acceptable replacement is yet to be found. Al slurry coatings have been developed as an alternative to replace cadmium coatings. The coatings were deposited on AISI 4340 steel and have been characterized by optical and electron microscopy. Testing included salt fog corrosion exposure, fluid corrosion exposure (immersion), humidity resistance, coating-substrate and paint-coating adhesion, electric conductivity, galvanic corrosion, embrittlement and fatigue. The results indicated that Al slurry coatings are an excellent alternative for Cd replacement