RESEARCH WORK
Effect of the inclusion of the Sorbifauna probiotic on lamb growth
Y. López, J. Arece, F. Ojeda y N. Aróstica
Estación Experimental de Pastos y Forrajes "Indio Hatuey". Central España Republicana CP 44280, Matanzas, Cuba
Email: yoel.lopez@indio.atenas.inf.cu
Abstract
With the objective of evaluating the effect of the inclusion of the Sorbifauna probiotic on lamb growth, a study was conducted during the dry season (November-March) at the Experimental Station "Indio Hatuey", Matanzas province, Cuba. The live weight and its variability according to parturition type were determined in 36 Pelibuey lambs. The data were processed through the program SPSS® version 15.0 for Windows®. A slight effect of the probiotic use on lamb live weight was detected in the last lactation days, with significant differences (p<0,05) as compared to the control. In the first three months no significant differences were observed in the mean daily gain, between treatments; however, after 120 days the group which received the probiotic was significantly higher (p<0,05) than the control (151 vs 99 g/animal/day). The live weight of the lambs with regards to the parturition type showed little variation during their first months of life. Since the lambs were 105 days old until weaning, the values were higher in the group with probiotic. It is concluded that during the first two months of life no effect of the probiotic was observed on the performance of live weight in the lambs, independently from the parturition type; after 60 days there was effect of Sorbifauna, which was remarkable 120 days after birth.
Key words: Growth, probiotics, sheep.
INTRODUCTION
Sheep production is one of the oldest practices in the world and this species is exploited to use its skin, wool, meat and milk. The aim of this management determines the time the lambs remain in lactation and the feed type they will have in their diets.
In general, lambs are fed with dam milk or lacteal substitutes, since their birth until they are 23-27 days old, which is when they begin to consume solid feedstuffs. The continue drinking milk until they are 60 days old, although they incorporate concentrates to their diet so that their digestive system develops in order to digest pastures, forages, legumes, grains and cereals, from which they obtain nutrients for their growth and productive functions.
Carro et al. (2006) state that when applying this animal management, the use of probiotics is important for improving the utilization of fibrous diets in this sheep category. In this type of compounds, lactic bacteria are the most used (Salmeron et al., 2009).
In Cuba, under license of the Sorbial firm, the Flora and Fauna Enterprise, belonging to the Ministry of Agriculture, manufactures probiotic, which is being evaluated for its accreditation. The objective of this work was to evaluate the effect of the inclusion of the Sorbifauna probiotic on lamb growth since birth until weaning.
MATERIALS AND METHODS
Location. The study was conducted with 36 Pelibuey lambs, in the dry season (November-March), in the production areas of the small livestock facility of the Experimental Station "Indio Hatuey", which is located between 22º 48' and 7" latitude North and 81º and 2' longitude West, at 19,01 masl, Perico municipality, Matanzas province, Cuba.
Soil characteristics. The soil on which the trial was conducted has plain topography and is classified as lixiviated Ferralitic Red (hydrated ferruginous nodular Humic type), of rapid desiccation. Its natural fertility is considered good, it has slightly acid (6,4) to neutral (7,3) pH, and low to moderate organic matter content (Hernández et al., 2003).
Animals. Before starting the study, the lambs were selected at the moment of birth regarding their weight at birth, type of parturition (single or twins) and sex, to make up two homogeneous groups of 18 animals each.
Dam feeding. The dams remained in total confinement the first four days after parturition, in order to guarantee the colostrum for the lambs. The ewes of the experimental group received Sorbifauna probiotic at a rate of 60 g/animal/day, during a 30-day period; while the control group only ate the base diet and pasture. The diet consisted in pastures and king grass forage (3,5 kg/animal/day) and leucaena (0,5 kg/animal/day). Molasses-urea (1 kg/animal/day) and beneficial microorganisms (50 mL/animal/day) were also used.
The DM, CP and ME values were the following: Guinea grass, 25,6%, 9,9% and 1,81 Mcal/kg DM (Pentón and Blanco, 1999); pasture, 31,7%, 4,8% and 1,83 Mcal/kg DM; leucaena, 31%, 20,5% and 2,25 Mcal/kg DM; king grass, 18,5%; 9,2% and 2,07 Mcal/kg DM; concentrate, 86,7%, 12,4% and 2,82 Mcal/kg DM (Cáceres et al., 2002).
Lamb feeding. Both groups remained in the sheds, without grazing during the first month of life. Since that age Sorbifauna probiotic, at a rate of 30 g/animal/day, and a supplement from corn distillery residue (North gold, 100 g/animal/day) began to be supplied to the experimental group; while the control group was fed 200 g/animal/day of this supplement. They had also access to grazing once or twice per week in order to facilitate the physiological development of their stomach cavities, until their total incorporation two months after birth.
Grazing system. The silvopastoral system was composed by the tree species Gliricidia sepium (2 400 plants/ha), Leucaena leucocephala (2 200 plants/ha) and Albizia lebbeck (1 800 plants/ha), with more than 10 years of exploitation and 4-6 m of height. The herbaceous stratum was represented by the pastures Dichanthium annulatum and Panicum maximum with predominance of the latter. The area (2,25 ha) was divided into nine paddocks, in which the ewes and the lambs grazed with the particularities of their management, from 8:00 a.m. to 3:00 p.m.; the resting time was 40 days as average for the period. No mineral fertilization was used.
The treatments were: I) control; II) Sorbifauna probiotic.
Measurements. The live weight was measured with a dynamometer of 10 kg ± 0,02, every 15 days, since birth (W15, W30, W45, W60, W75, W90, W105 days) until weaning (WW), to determine the mean daily gain (MDG) in each measurement interval. Live weight variability by parturition type was also determined in the studied groups.
Statistical analysis. The data were processed with the program SPSS®, version 15.0 for Windows®. The effect of the intervals on the variables was determined through a variance analysis (ANOVA). The difference among means was found through comparison test for two paired means.
RESULTS AND DISCUSSION
The live weight of the lambs at birth and its fortnightly variation, in each group (fig. 1) did not show significant difference between the treatments in the first days after birth. The inclusion of probiotic in the ewes and its effect on the lambs during the first 30 days postpartum- was not significant, which suggests that the base diet they received was capable of guaranteeing milk production in both groups.
In this sense, the lambs are considered functional monogastric, as they are under a fully lacteal regime during the first 60 days (Caja et al., 2003), aspect which did not allow detecting whether the probiotic participated in the degradation of this type of feedstuff. On the other hand, although it is not accurately known which the effects of probiotics are on these categories, it has been determined that one of them is preventing pathogen microorganisms for example: Salmonella and E. coli- from colonizing the digestive tract or, at least, reducing their concentration to levels that are not capable of producing toxins. Van Eys and den Hartog (2003) suggested that the required dosage to modify, by colonization or implantation, the microflora of any compartment of the animal, should be taken into consideration.
These results indicate that if the dam milk is suppressed in the diet of the lambs since they are 60 days old and they are forced to eat roughages when grazing, that is the moment when the advantages of using the Sorbifauna probiotic could become evident.
The values are higher than the ones found by López et al. (2004) and León et al. (2006), under grazing conditions and receiving supplementation with leucaena and molasses-urea, but similar to the ones reported by Fonseca (2003), Herrera and Pulgarón (2005) and López et al. (2008), who used feeding variants of high nutritional quality in a system with natural pasture plus leucaena.
In the first three months no significant differences were observed in the mean daily gain between the treatments (table 1); after 120 days, the group with probiotic was significantly higher with regards to the control (152 vs 99 g/animal/day, respectively). This performance was ascribed, firstly, to the diet composition with different feedstuffs, which varied the ruminal fermentation pattern in the animals (Sales et al., 2000; Atasoglu et al., 2001); it was also related to a positive effect of the probiotic since the moment the animals started consuming roughages permanently (60 days), which favored the digestion and absorption of pastures with low nutritional quality (Hernández et al., 1998; López et al., 2008). This improved the activity of the group of microbial enzymes present in the rumen, with actions capable of favoring the fermentative processes of the fibrous diet and making a more efficient use of the generated energy (Chen et al., 2007).
Ortiz-Rubio et al. (2009), in an evaluation with growing sheep, found that the incorporation of a probiotic based on lactic bacteria in the diets favored a better pH and NH3 stabilization at rumen level, with increases in fermentation and higher weight gains. When these functions are combined, this allows an increase in fiber degradation and the production of volatile fatty acids, and a better efficiency in feed utilization. In addition, by increasing degradation of the fibrous fraction of the feedstuff, ingestion is stimulated (Carro et al., 1992; Galina et al., 2004).
The live weight of the lambs with regards to the parturition type between groups showed that singles (fig. 2) and twins (fig. 3) maintained little variation regarding the studied groups during the first months of life and there were no significant differences; however, from the biological point of view, the live weight values in the group with probiotic supply were higher than in the control and the significant differences (p<0,05) appeared since the lambs were 105 days old until weaning (120 days), in singles and twins. This is explained, first of all, because lambs a few days after birth have little development in the rumen and the population present includes organisms capable of utilizing the milk, which is the only feedstuff they consume (Lewis, 1962). Among the most numerous microorganisms in this stage are Lactobacillus and Streptococcus, high producers of lactic acid, which maintain very low pH. At this age protozoa are not present, they are established later, when roughage intake increases and also due to the contact with other adult animals or which have an established fauna.
Secondly, as time passes and the lambs begin their contact with roughages, their rumen is developed, pH increases, the different physiological groups of bacteria begin to emerge and protozoa are established (Perón and Ruíz, 1972). This moment is considered essential for any manipulation practice of the ruminal flora and, in fact, for the application of an additive or probiotic, which was confirmed in this work when analyzing the live weight performance in the lambs after this stage and at the end of lactation.
CONCLUSIONS
RECOMMENDATIONS
To evaluate the effect of the Sorbifauna probiotic on the substitution of ewe milk in lambs, since they are 60 days old with the beginning of roughage intake, is recommended.
