The objective of this paper was to evaluate the effect of four levels (0%, 4.32%, 8.39% or 12.25%) of avocado waste (AW) included in the diets on productive performance, carcass characteristics and meat nutritional quality of fattening rabbits. For that, one hundred and twenty male rabbits (New Zealand × California; 945 ± 47 g initial body weight) were fed over 28 days, randomly distributed to one of the four treatments (T) (T1 = 0, T2 = 4.32, T3 = 8.39 and T4 = 12.25% AW as fed). The chemical and fatty acids profiles were evaluated in the Longissimus thoracis et lumborum (LTL) muscle. The rabbits fed with 8.39% of AW reported the best productive parameters (p < 0.05), the greater (p < 0.05) dissectible adipose tissue and higher polyunsaturated fatty acids (PUFAs) n-3 content (p < 0.05) than control meat. It is concluded that the inclusion of AW in the growing–finishing rabbit’s diet can modify the nutritional quality of the meat, reducing the n-6/n-3 ratio and the thrombogenic index.

The inclusion of triticale in rabbit diets can negatively affect production parameters due to the presence of arabinoxylans that increase the viscosity of intestinal contents, making digestion and absorption of nutrients difficult. Therefore, the addition of the enzyme xylanase can improve intestinal morphology and the digestive process. This study aimed to conduct histological and histochemical evaluations of the small intestine and caecal appendix in growing-finishing rabbits fed diets containing 14% triticale supplemented with varying levels of xylanase. The rabbits had an initial average live weight of 822 g and reached a final weight of 2097 g. For this purpose, forty 35-d-old male rabbits crossbred New Zealand × California were used. Rabbits were housed in individual cages and randomly divided into four experimental treatments (xylanase at doses of 0, 4000, 8000 and 12 000 xylanase units (XU)/kg of dry matter). At the end of the experimental period, rabbits were slaughtered at seventy days of age and samples were taken from the duodenum, jejunum, ileum and caecal appendix. Samples were stained using the standard Haematoxylin-Eosin (HE) technique for the histological evaluation and Alcian Blue (PAS) for the histochemical evaluation. The addition of xylanase linearly increased the height of villi in the duodenum, jejunum and ileum, while villi width was linearly reduced in jejunum and increased in ileum. Crypt depth was linearly reduced by xylanase dose in duodenum, while the response was linear and quadratic in jejunum and ileum. The villi height to crypt depth ratio was linearly increased by the xylanase dose in the duodenum and jejunum, although the effect was quadratic in the ileum. The dome height of the caecal appendix increased linearly with the addition of xylanase. Epithelial mucus count was linearly reduced by xylanase dose in the base of the duodenum, jejunum and caecal appendix, although this linear reduction was only observed in the villi of the jejunum and in the caecal appendix. In conclusion, the addition of xylanase positively affected the histological and histochemical characteristics of the small intestine and caecal appendix, so its use could improve digestive and productive performance in rabbits.

The objective was to evaluate the addition of xylanase on the productive performance and histological aspects of the small intestine and cecal appendix of rabbits fed diets containing triticale. 120 rabbits were randomly distributed to one of the four treatments differentiating them from the inclusion of xylanase (0, 4000, 8000 y 12000 XU/kg, respectively), the animals were weighed weekly and at the end of the experimental period, the rabbits were slaughtered taking samples of the duodenum, jejunum and cecal appendix to perform the technique of staining with Hematoxylin-Eosin (HE). An analysis of variance was performed using the GLM procedure of SAS (2002) and Tukey’s test. The addition of xylanase enzyme increased (p<0.05) the live weight at day 4 and 7 of the rabbits and increased (p<0.05) the areas of intestinal villi of the duodenum, jejunum and cecal appendix.

Background: The consumption per capita of rabbit meat in Mexico is limited (120g) due to the lack of information among consumers about the nutritional quality of rabbit meat, and at the same time, to the appearance of color, since they prefer a redder meat with more intramuscular fat. Objective: To evaluate the effect of the addition of Zinc-Methionine (Zn-Met), marigold flower pigment (FC) and two slaughter ages (MS) on carcass characteristics and meat quality in rabbits. Methodology: A total of two hundred 40-day-old rabbits (New Zealand X California, 1124±48 g initial live weight) were randomly assigned to one of 4 experimental diets and two fattening periods (68 and 82 days of age), using a completely randomized experimental design with a 2 x 2 x 2 factorial design. The control diet contained no additives, the second diet contained 200mg/kg-1 Zinc Methionine (Zn-Met), the third diet contained 80 mg/kg-1 marigold flower pigment (FC) and the fourth diet (Zn-Met*FC) contained both additives (200mg/kg-1 Zn-Met and 80 mg/kg-1 FC). The color, pH, meat-bone-to-dissectible fat ratio, water loss by cooking, shear strength and nutritional quality of rabbit meat were measured in the Longissimus thoracis et lumborum (LTL) muscle. Results: In meat color, L* values showed interactions (P < 0.05) between Zn-Met*EM and FC*EM; interaction was observed for carcass bone weight (g) (P < 0.05) between Zn-Met*FC, finding higher values (P < 0.05) in rabbits slaughtered at 82 d of age (g and %). With respect to the amount of dissectible adipose content of the carcass (g and %), there was interaction between Zn-Met*EM (P<0.05), with the highest values found in rabbits killed at 82 d (P<0.05). On the other hand, there was interaction in crude protein content (g/100g-1) (P<0.05) between Zn-Met,*FC*EM; while in moisture content and ethereal extract (g/100g-1) there was a difference (P<0.05) between animals slaughtered at different ages. MS increased the saturated fatty acid (SFA) content, while in the monounsaturated fatty acid (MUFA) content there was an interaction between Zn-Met*MS (P<0.05), with rabbits killed at 82 d of age presenting the highest values (P<0.05). Implications: The addition of Zn-Met modifies the fatty acid profile of meat in cattle and sheep, while the FC pigment modifies the color of poultry meat; however, the addition of these additives has not been studied in rabbits. Conclusion: The inclusion of Zn-Met, FC at two ages at slaughter modifies meat color and nutritional composition of rabbit meat.

The objective was to evaluate the effect of the inclusion of avocado waste (AW) in the diet of rabbits on lipid composition, color, and lipid and protein oxidative stability in the meat of growing rabbits. For this purpose, 80 male rabbits (New Zealand × California) with an average initial weight of 945 ± 47 g were fed for 28 days, being randomly distributed to one of the four experimental treatments (T) (T1: 0%, T2: 4.32%, T3: 8.39%, and T4: 12.25% of waste avocado inclusion, respectively). A decrease (p < 0.05) in the amount of saturated fatty acids was observed in the meat of rabbits fed 8.39% and 12.25% AW, a lower (p < 0.05) concentration of malondialdehyde (mg MDA/kg) in the meat of rabbits fed the AW, and a lower (p < 0.05) concentration of dinitrophenylhydrazine (DNPH) in the treatments with 4.32 and 8.39% AW. The results suggest that the addition of AW in rabbit diets increases the content of n-3 polyunsaturated fatty acids and protects the meat from the products of lipid and protein oxidation, decreasing discoloration and delaying oxidation, generating a final product with a longer shelf life.