Introduction

The ¨palo escrito¨ is a tree that is mainly used by the characteristics of its wood in the elaboration of musical instruments and furniture. It is an endemic plant that is located in the states of Hidalgo, Querétaro and San Luisde Potosí; however, there are over 100 species of this genus in the various tropical zones of the world. The leaves of this plant contain high amounts of protein; it is perhaps for this reason that, in some animals, this genus forms part of their diet (^{Sosa et al., 2000}). High feed costs in the production of rabbits through the use of commercial foods make it possible to search for feeding alternatives for this species. Alfalfa and palo escrito as a source of protein fiber in multinutritional blocks could become an alternative. In addition, not only do we want to explore the nutritional content, but also what happens to the effect of those ingredients used in the production of diets on the quality of the carcass and meat of rabbits.

The objective of the present work was to replace the proportion of alfalfa per Palo escritoin the diet of rabbits for fattening, in order to check the quality of the carcass and rabbit meat.

Material and Methods

Fifteen Chinchilla x New Zealand x California crossbred rabbits were used and they were weaned at 35 d of age; which were submitted to three different diets with isoprotein, isoenergetic and isofibrous multinutritional blocks; T1 fed with a diet based on corn, T2 fed with a diet based on alfalfa and T3 fed with a diet based on palo escrito. The rabbits were fed during a fattening period (35 d). Food and water consumption were measured daily and animals were weighed once a week. Once the rabbits fulfilled the fattening period, they were transported to the Meat Workshop of the Institute of Agricultural Sciences, where they were sacrificed according to NOM-033-SAG/ZOO 2015, to obtain the weight of warm carcass, skin, viscera and organs. The carcass was stored in cooling at 4 °C for 24 h, then dissected according to the recommendations of ^{Blasco and Ouhayoun (1996}), obtaining the weights of the cold carcass, head, front, middle, back and legs. The quality of the meat was measured in the loin, for which the pH (Oakton), color (Microoptix S560, I-Lab) and texture (Brookfield CT3) were determined. A completely randomized design with two treatments was used for the statistical analysis.

Results and Discussion

Feeding rabbits with ¨palo escrito¨ (Dalbergia palo-escrito), as a substitute for a forage plant such as alfalfa, had a detrimental effect on the life of rabbits; due to the fact that the animals that consumed the multinutritional blocks having as basis ¨palo escrito¨, presented a mortality of 100% during the first week of the experiment. The ¨palo escrito¨ is used in several regions as a pesticide (^{Villavicencio-Nieto et al., 2010}); however, it has been reported that this plant is consumed by cattle (^{Sosa et al., 2000}) and by some monkeys (^{Pozos et al., 2006}); as it has high protein content (40%). Due to its high protein content it was decided to experiment as a nutritional alternative in rabbits. In treatments administered alfalfa and maize there was no mortality; the productive parameters such as the final weight and the daily weight gain were significantly higher (P <0.01) in the maize treatment (Table 1), compared to alfalfa; which coincides with that reported by ^{Acosta (2016}).

Concerning the quality of the carcass, the rabbits that consumed multinutritional blocks based on maize had a significantly higher weight (P <0.05) of the lungs, head, anterior and posterior part and bone; compared to animals treated with alfalfa (Table 2); which coincides with that reported by ^{Acosta (2016}), when using nutritional blocks based on corn, using as a binder mead.

In the quality of the meat it can be observed that in color, the a* value was lower in the meat of the rabbits fed with corn blocks than with the alfalfa blocks, indicating colors tending to red in the case of alfalfa, because this forage has a higher antioxidant capacity compared to maize; which coincides with that reported by ^{Dal Bosco et al., (2014)} who mention that there is a greater proportion of unsaturated fatty acids when fed with rabbits with alfalfa pellets (Table 3).

Conclusion

The productive parameters and quality of the carcass rabbits fed with maize were better than with alfalfa; but for color, the variable was a significantly higher in rabbits treated with alfalfa compared to maize. It is important to note that the substitution of ¨palo escrito¨ by alfalfa in multinutritional blocks has a detrimental effect on the life of rabbits in fattening.