The Effect of Applying Herbal Extracts on The Performance of Starter and Grower Pigs

The modern pig production is unthinkable without the use of various growth promoters, especially in young animals with not yet developed digestive and immune system. This topic became especially trending after the EU's ban the use of subtherapeutic doses of antibiotics as growth stimulants. Assessing the importance of the problem, over the last ten years, scientists around the world have focused on the search for new "natural", "safe" and environment-friendly growth stimulants, substitutes for the nutritional antibiotics used so far. The abundance of unique herbs in our country provides for the opportunity to manufacture feed additives, applicable in livestock breeding, which can successfully substitute for the already banned antibiotics, used for many years as growth stimulants.

The aim of this research is to determine the effect on productivity of pigs, when supplemented with the biologically active herbal feed additive VemoHerb BP to compound feed.

The series VemoHerb is a feed additives produced by “Vemo 99” Ltd., Sofia, Bulgaria and is a mixture of biologically active natural compounds. The product contains saponins, sterols, flavonoids, tannins, polyphenols and others and has been tested in a series of experiments in starter and grower pigs. The trials with pigs have been conducted in the Experimental site of the Institute of Stock-Breeding Sciences, Konstinbrod, Bulgaria.

Results and Discussion

In the trials with starter pigs have been used a total of 30 pigs from the breed "Dunavska byala". The piglets were included in the trial immediately after transferring to self-feeding. Three groups were formed, including ten piglets each – 5 castrated males and 5 females (3x5x2). The first is control group and the animals received compound feed without added growth stimulant. For the second group feed formula is enriched with nutritional antibiotic and a third group is with a test product VemoHerb BP in the amount of 15 g/t feed.

The obtained results are shown in the following table:

Groups Parameters	Control	Control + antibiotic	Control + VemoHerb BP
Total number of pigs	10	10	10
Period, days	60	60	60
Body weight, kg - at the beginning - at the end	7.19±0.89 17.68±1.73	7.16±0.54 18.61±0.65	7.30±0.53 20.9±0.92
Growth, g/day - % compared to Control	175±21.5a* 100.0	191±7c* 109.1	226±8.2ac* 129.1
Feed intake Intake/day/g - % compared to Control - for 1 kg gain, kg - % compared to Control	523 100.0 2.99±0.6c* 100.0	496 94.8 2.599±0.06b* 86.9	543 103.8 2.398±0.1bc* 80.2

*The value marks of the same letters are significant at: a, b – P < 0.05; c – P < 0.01.

Taking a look at the trial results we can conclude that comparing the Control Group with the group supplemented with antibiotic, the starter pigs that have not received the growth stimulant are significantly lagging behind in their development. Their actual values of growth intensity, determined by the average daily gain are 175 g/day and 191 g/day, for the Control and Control + antibiotic respectively, or the growth difference is 9.1%. The low growth rate in the Control Group is directly connected with the low nutrient absorption from the feed. The feed intake per 1 kg gain (FCR) is 2.99 and 2.599 kg respectively, or 13.1% higher compared to Control + antibiotic.

The experimental data shows what would be the lost in pig breeding after the prohibition of nutritive antibiotics in case that have not found alternative solutions. By the replacement of the nutritive antibiotic with VemoHerb BP was found reliably increase in average daily gain compared with the first and second group. The experimental data shows that the starter pigs supplemented with VemoHerb BP have 29.1% higher growth intensity, compared to the Control group (P < 0.05), and 18.3% increased growth, compared to the group supplemented with antibiotic (P < 0.01).  Analogical results are observed in the FCR values – better feed utilization with 20% and 8%, compared to the Control group (P < 0.01) and the Control + antibiotic group (P < 0.05).

At the end of the experiment with starter pigs, they were divided into separate grower groups and their live weight was between 20 and 50 kg. In the results from the grower pigs experiment, shown in table below, we observe a tendency for growth and feed utilization.

Groups Parameters	Control	Control + antibiotic	Control + VemoHerb BP
Total number of pigs	6	6	6
Period, days	57	57	57
Body weight, kg - at the beginning - at the end	18.28±0.54 43.6±2.99	18.94±0.93 46.32±3.65	20.73±1.13 50.67±1.4
Growth - g/day - %compared to Control	444±47.1 100.0	480±52.4 108.1 100.0	525±16.03 118.24 109.38
Feed intake: - for 1 kg gain, kg - %compared to Control	3.68±0.51а* 100.0	3.40±0.34 92.4	3.006±0.07а* 81.7

*The value marks of the same letters are significant at: a – P < 0.05.

The absolute values for the average daily gain are 444, 480, and 525 g/day, respectively for the three groups. The group supplemented with VemoHerb BP has higher growth intensity compared to the Control and Control + antibiotic groups, by 18% and 9%, respectively.

Similar results are observed with the FCR values. The pigs supplemented with nutrition antibiotic show better feed utilization with 8%, compared to the Control (P < 0.05), while the group supplemented with VemoHerb BP has better feed utilization with 18%, compared to the Control (P < 0.05).