Animals returned

Table 2 shows the evolution of the animals returned during each period studied, observing an overall decrease in the percentage of individuals over the years.

Most of the specimens were returned after a third of rods, where there is a greater physical wear of the bull, which usually shows the lack of force that makes it impossible to continue the fighting. The evolution of 7.46% and 6.21% of animals returned during the first periods to the current 4% shows a better physical preparation of the animal, thanks to the improvement in feeding and the physical training protocols implemented in most of the in the last ten years.

In the present study, only clinical signs of a problem that can be caused by multiple causes were recorded; among them, the stress suffered by the animal in the transport to the square, or during its stay in the corrals. Obviously the transport has evolved a lot in the last years, both the vehicles and the roads, improving the conditions and duration of the same; which may have diminished the stress of the bull and this influence in the manifestation of falls in the square. Likewise, the facilities and corrals of the bullrings are currently more spacious and comfortable for the animal, which undoubtedly affects the welfare prior to the fight.

2-Frequency of fall presentation

The total percentage of bulls that presented some type of fall has been decreasing with the years, from the 99.56% registered initially (1991-1993) to 79.82% registered in the last three years 2014-2016, (Figure 1).

Figure 1 Evolution of the rate of presentation of fall (%). 

The data explain that the great prevalence that existed during the decade of the 90¨s of the syndrome of fall has been diminishing until the present time. In the 80's, ^{Castejón (1985}) states that in the Plaza de Madrid it was asked to return 80% of bulls to the pens for showing weakness; this problem has been reduced in recent years, presumably in relation to an improvement in food and sanitary management (^{Bartolomé et al., 2011}); however the falls persist and it is a big problem to solve.

Other authors have studied the fall, but each one with a different valuation method, which makes that we can not compare the results (^{Jordano and Gómez Cárdenas (1954}), ^{García-Belenguer et al., (1992)}, ^{Alonso Menéndez et al. (2007)}, ^{Aceña et al. (1995}) and ^{Costa (1992}).

3- Duration of the different parts of the fight and distribution of the fall per third

The average duration of the fight in our study rises from 14.07 min in the 1990s, to the current 17.65 min; basically due to an increase in the duration of the third of the crutch, which has been accentuated in recent years (Table 3).

The predominance of the last third is consistent with the assessments made by Sanes et al. (1994), which indicate that the duration of the third of Muleta is 38.37%, 48.08% and 50.85% of the total fighting time. In our case we have observed for the most recent years, the object of our study, an increase of this percentage to 51.82%, the highest percentage recorded for this third in comparison with previous studies.

Although the duration of these periods of the fight will depend in a significant way, first of all, the category of the square, because in first places is counted a third of rods of greater duration, since it is imperative that the animal go at least twice to the horse, and the third of banderillas is usually more lucid and long. Secondly it will depend on the skill of the bullfighters, and finally on the bull provenance; it is known that some encastes are usually characterized by the fixation and repetition of the thrust in the cloak, being therefore propitious animals to realize thirds of rods and short banderillas (^{Domecq, 2008}); while others are characterized by being very "distrait", that is, distracted animals, which in the beginning do not focus their attention on any stimulus, thus prolonging the duration of the previous thirds to that of Muleta (red cloth draped over a short stick) (^{Purroy 2003}, ^{Rodríguez Montesinos, 2002}).

It is the third of Muleta that presents the highest fall occurrence in all the studied periods, the manifestations of fall are aggravated and increase of frequency as the different thirds of the fight pass, reaching in the Muleta more than 55% of the claudications (Table 4).

Animals in the first thirds move faster than in successive phases, employing on average 41% of the total third time, which gives the effort an intermediate character between the continuous model and the intermittent exercise pattern. On the other hand, in the third third, the bull adopts a model of intermittent exercise, during which long-distance, isolated or serial muleta (red cloth draped over a short stick) alternate. This type of low head movement during 45.6% of the time of the third predisposes the animal to suffer type 1, 2 and 3 falls, fundamentally. In addition, the animal accumulates at this moment a high and progressive state of fatigue, evidenced by the opening of the mouth in the 47.3% of its time and the increase of the respiratory rate.

Also, as mentioned above, taking into account that the third of Muleta is the last of the fight and it is the longest, it is understandable that most falls are expressed in this third. On the other hand, the lower number of falls are registered in the third of banderillas, where the bull makes a less physical effort, that is, it does not move as much as in the beginning; it is allowed certain pauses and the animal is fundamentally quoted clean body by the banderillero, charging with the head high, with fast displacements, but of short route.

4- Types of falls experienced

The varieties of claudication type 1 and 2 may pass unnoticed for any spectator who is not aware of the extremities of the bull, as these slight falls do not suppose an appreciable interruption of the normal run of the show. The falls 3, 4, 5 and 6 do present an obvious problem for the fight, causing interruptions that detract from the task. In this sense, the animal has considerably reduced the suffering of more serious falls in the last two periods studied (2010-2012 and 2014-2016), thanks to its better adaptation to the show; made evident by the non-presentation of falls 4, 5 and 6 in these periods. However, we see that the percentages of animals with falls remain high: more than 60% of the animals suffer from falls type 1 and 2 in recent years (Table 5).

Figure 2 shows how these percentages have declined over the years, with the majority falling in type 1 in the 1990s (69.4% of falls), to currently occupy types 1 and 2 at a very high rate (35.12% and 35.62%).

Figure 2 Percentage of each type of fall of total claudications manifested. 

The number of falls type 1, 2 and 3 has been standardized, occupying very similar percentages in the last 10 years. The reduction in the number of falls and the decrease in their severity are accompanied by improvements in the field of genetic selection and feeding of the bull in its finishing phase, complemented by the introduction of physical training protocols, which according to studies by ^{Agüera et al. (1998}, 2001) contribute to the preparation of the bull's physiology to the physical effort it develops during the fight, for which it is not adapted due to its sedentary nature (^{Picard et al., 2006}). Perhaps the most exhaustive selection of livestock today may influence the breeding of an animal that is more physiologically adapted to the physical effort involved in the fighting (^{Escalera et al. 2012}; ²⁰¹³).