Introduction

It is recognized that the feeding behavior measured in pig cattle, may indicate the degree of acceptance of a new food resource by the animals, measured by individual preferences, or to detect the presence of toxic substances in that material (^{Ly, 1979}; ^{Belmar & Morris, 1994}). The feedstuff acceptability can be defined as voluntary intake by the animals without being forced or limited by the handling and production conditions they face, this has been linked to hedonic signals to control food intake affecting the food consumption pattern in animals (^{Rentería & Shimada, 2018}). On the other hand, fibrous feedstuffs, such as those of arboreal origin, which are locally available in the tropics (^{Bindelle et al., 2008}; ^{Martens et al., 2012}), allow to establish useful interdependences between traits of the feed intake pattern and zootechnics of economic interest (^{Kanengoni et al., 2015}). In this sense, such tree materials could be present in diets where the energy source, such as sugar cane molasses, are poor in proteins and do not contain a fibrous component of quantitative importance (^{Preston & Murgueitio, 1992}).

Albizia lebbeck (L.) is considered an economically important plant, since it has a high potential to be used as a source of protein (17-26 %) and mineral supplement (7.84 %) for animals. In addition, numerous therapeutic proprieties are attributed to it (^{Mishra et al., 2010}; ^{Ly et al., 2018}). In the particular case of Albizia lebbeck (L.) Benth, knowing its potential as supplier of foliage for pigs in the cut and hauling strategy could be useful. This idea arises from the knowledge of its dasonomy already acquired, which qualifies this legume as a species which can grow with good foliar biomass yield in tropical semiarid regions of the planet and promote its use in tropical pig farming, having the knowledge of consumption and acceptability, since it is considered that there is a high correlation between daily weight gain and voluntary intake of feed.

The aim of this work was to report an experimental sequence where acceptability and pattern of feed consumption were determined in young pigs fed with sugar cane molasses diets, formulated to contain variable levels of albizia foliage meal, which could be an alternative to pig feeding without limiting its productivity.

Material and Methods

A total of 32 Yorkshire x Landrace x Duroc castrated male pigs of 30 kg live weight were used, completely randomly distributed in four treatments consisting in diets formulated to meet the requirements of the ^{National Research Council [NRC], (1998)} with a proportion of type B sugar cane molasses/soybean meal (67.6/30.4, dry basis) in which 0, 5, 10 and 15 % was substituted by albizia (Albizia lebbeck (L.) Benth) foliage meal. The characteristics of the diets are shown in Table 1. The origin of the foliage, its collection as well as the preparation of the foliage meal were already described by ^{Ly et al. (2019)}. In summary, the albizia foliage came from an uncultivated plantation, located in the northwest of Havana province, Cuba. This foliage was made from the terminal branches of young trees (5 years). The foliage meal was produced after drying the material in the sun for a period of 5 days and it was subsequently milled in a hammer mill provided with a screen 1µ. This foliage meal had on average 20 and 35 % of crude protein and cell wall, on dry basis, respectively. Those data concerning the chemical composition of albizia foliage are not far from others related to that arboreal legume (^{Leterme & Buldgen, 2007}; ^{Chitra & Balasubramanian, 2016}).

The DM (Dry Matter), nutrients and energy content in albizia foliage as well as those of the diets was determined in representative samples according to recognized procedures (^{AOAC, 2016}).

The animals were housed in individual corrals with cement floor provided with a feeder and a drinking trough, in an open stable without side walls. The property belonged to an experimental farm located in the northwest of Havana province, Cuba. During the experimental period the average temperature was 25 °C.

Throughout the experiment, water and feed consumption was ad libitum. In the first week, the individuals gradually changed from a conventional diet of maize meal/soybean meal, to that of type B sugar cane molasses/soybean meal. On the first day of the third week, the acceptability of the four diets containing albizia foliage meal was determined using a modification of the short-term feed intake test of ^{Belmar & Morris (1994)}. On the first day of the fourth week, the pattern of feed intake was measured according to the procedure of ^{Faliu & Griess (1969)}, described by ^{Ly et al. (1994)}. Briefly, the animals were observed for 60 minutes continuously and directly by four observers who recorded the feeding behavior of the animals every minute. The observations were made from 9:00 am, after serving ad libitum the previously weighed feed. The recording of feeding behavior was carried out by trained personnel who were familiarized with the examined animals. At the end of the 60 minutes, the food residue was weighed. Between the third and seventh week, the feed intake was recorded daily and pigs were weighed weekly to measure behavioral traits.

The data were manipulated according to a one-way classification (^{Steel et al., 1997}). When the contrast of means was significant (p < 0.05), the separation was carried out by means of the Tukey test. An appropriate statistical software (^{Minitab, 2014}) was utilized for the entire statistical evaluation.

Results and Discussion

Conclusions

It is suggested that albizia foliage meal does not appear to contain substances which are strong inhibitors of the voluntary feed intake of the animals. The consumption of up to 15 % of albizia foliage meal in the diet, may determine notable changes in the magnitude of the pattern of feed intake when the foliage is offered to young pigs fed diets with type B sugar cane molasses. Up to what degree this status quo has an influence on the behavioral traits of the pigs during the growing and fattening periods is yet to be established.