Introduction

Rabbit meat has several advantages with respect to the meat of other species, it is known that this meat has a better profile of fatty acids; in addition to the amount of protein, vitamins, minerals, its low content of cholesterol and sodium; coupled with the lack of uric acid (^{Para, 2015}). Despite the qualities described above of rabbit meat, its consumption and production is relatively low, since ^{Armada (2016)} indicates that the per capita consumption in Mexico fluctuates between 30 and 134 g; it is also known that rabbit production in the country is centralized in states such as Hidalgo, Puebla, Estado de México and Guanajuato. It has also been recognized that various governmental and non-governmental institutions encourage the production and consumption of this meat, either fresh or through various meat products. However, one of the main problems of rabbits, as in other animal species is the cost of feeding; coupled with this, the scourge of some digestive problems of the rabbit. One of the ways to alleviate these problems is the search for new food alternatives, such as the use of plants that are a problem of weeds in crops, mainly corn.

The Tithonia genus is distributed mainly in Mexico and Central America; eleven species are recognized divided into two groups, including annual and perennial plants. The plant Tithonia tubaeformis is an herbaceous plant, annual, with stems of 1 to 3 m, round with colors from yellow to brown, alternate leaves of 2 to 11 cm, peduncles of 10 to 45 cm long and 4 to 11 mm in diameter (Figure 1). Its flowering period is from August to November (^{Duke, 1982}); also according to ^{Sánchez-Blanco and Guevara-Fefer (2013)} is a weed in corn crops, which represents a competition for soil nutrients.

Figure 1 Tithonia tubaeformis 

There is no evidence of reports that this plant is used in the feeding of rabbits, however, ^{Garcia et al. (2016)} found this plant in the botanical composition of the diet of grazing goats in a xerophilous scrub. This plant is used in traditional medicine, ^{Gheno-Heredia et al. (2011)} mention that the leaves are used to alleviate skin problems, while ^{Bello-González et al. (2015)} indicates that the cooked flower can be used to relieve digestive problems. However, ^{Hinojosa et al., (2013)} studied this plant to know the presence of phytochemical compounds from methanol: water extracts; finding that the main phenols present are pyrogallic and catechol type, which have a high anti-inflammatory response.

Taking into account these antecedents, the aim of this study was to use different parts of the Tithonia tubaeformis plant in the feeding of rabbits, with the purpose of observing the effect on the productive parameters, the morphometric characteristics and the carcass yield in fattening animals.

Material and Methods

Results and Discussion

The results of the productive parameters of fattening rabbits fed with different parts of the Tithonia tubaeformis plant can be seen in Table 2. No significant differences were observed (P> 0.05) between the treatments; however, there is a tendency to have lower feed consumption during the first week of the fattening period of the rabbits that consumed the different parts of the Tithonia tubaeformis plant with respect to the control treatment; subsequently, rabbits fed with plant leaf tended to present lower feed consumption, which coincides with the total food consumption, being the treatment that consumed the least food. It should be mentioned that the lower consumption resulted in lower weight gain.

Because there are no differences between the treatments, it can be said that the use of Tithonia tubaeformis in the feeding of rabbits in fattening is a feeding alternative, which coincides with that reported by ^{Duilio et al., (2011)}, who using flour of Tithonia diversifolia in fattening rabbits did not obtain differences in consumption, neither in daily gain of weight, with respect to the control.

In other works within the research group, similar results have been obtained to those shown here with other plants, such as the inclusion of plants in the feeding of fattening rabbits under the same experimental conditions, as in the case of epazote (^{García-Vázquez et al., 2017}), mint, chamomile, rue or ginger (unpublished data). In these works it has been observed that the inclusion of plants can improve or have productive parameters similar to those of the control treatment, this suggests that Tithonia tubaeformis and other medicinal plants can have beneficial effects on the health of rabbits, since these plants can present phenols that make the digestive system of the rabbit healthy and respond appropriately to have productive parameters that encourage its use during fattening.

In Table 3, the morphometric measurements of live animals and their corresponding in the carcass of rabbits fed with various parts of Tithonia tubaeformis can be seen. Live weight, weight and carcass yield are also included. Unlike what ^{Molina et al. (2018)} reported in relation to the length of the carcass, which was greater as the amount of amaranth in the diet of rabbits in fattening increases at 87 d. As regards other morphometric measurements, no differences were found.

Conclusion

According to the results found in this study, it can be concluded that the Tithonia tubaeformis plant can be used in the feeding of fattening rabbits without deteriorating their health and with similar production parameters to the control treatment. However, a tendency was found to obtain better productive parameters, when using the leaf of this plant and the carcass weight when consuming the whole plant. Therefore, these results allow us to continue investigating other productive aspects as well as quality of the carcass in rabbits fed with Tithonia tubaeformis; as well as the properties of this plant, or extracts thereof, which allow its use in the feeding of fattening rabbits or in other areas.