Effect of Plant Essential Oils on Growth Performance of Weaned Piglets

Effect of Plant Essential Oils on Growth Performance of Weaned Piglets

Wan Rui, Liu Feng, Lyu Jirong, Huang Mingya, Guo Chunhua

DadHank (Chengdu) Biotech. Corp, Chengdu 611130

Abstract: This test aimed to investigate the effects of adding a complex plant essential oil to feed on （the ）growth performance and economic benefits of weaned piglets. A total of 96 weaned piglets (Duroc × Landrace × Large white) with an average weight of 8.25±1.12 kg was selected and divided into three groups according to the principles of consistent weight, gender, and parity. Each group had four（4） replicates, and each replicate had eight（8） piglets. The control group was fed with basic diet, while the test groups were divided into two groups, one was fed with basic diet added with 500g/t antibiotic mixture (70 mg of Aureomycin + 40 mg of Kitasamycin + 50 mg of Bacitracin methylene disalicylate), and the other was fed with basic diet added with 500 g/t plant essential oil. The results showed that: (1) During day 1-14 of the test, the feed intake in antibiotic group and essential oil group increased by 14.2% and 10.0%, respectively, compared to control group. During day 15-28 of the test, the feed intake in the two test groups increased by 3.9% and 1.8%, respectively. Throughout the entire test period, the feed intake in antibiotic group and the essential oil group increased by 6.5% and 3.8%, respectively, compared to control group. (2) During day 1-14 of the test, the daily gain of the antibiotic group and the essential oil group increased by 23.3% and 12.3%, respectively, compared to control group. Throughout the entire test period, the antibiotic group and the essential oil group had a higher daily gain of 15.7% and 9.8%, respectively, compared to control group. (3) During day 1-14 days of the test, the feed-gain ratio of the antibiotic group decreased by 8.6% compared to the control group, while that of the essential oil group decreased by 2.7%. In day 15-28, the feed-gain ratio of the antibiotic group and the essential oil group decreased by 8.8% and 7.6% respectively compared to control group. Throughout the entire test period, the feed-gain ratio of the antibiotic group and essential oil group reduced by 8.7% and 5.6% respectively compared to control group. (4) For reducing diarrhea, both the antibiotic group and essential oil group showed significant advantages over control group. The antibiotic group remained the best among the three groups, and the essential oil group ranked second, but the effect was close to that of the antibiotic group.

In modern animal husbandry, to improve the health and growth rate of livestock, antibiotics have long been relied upon. Practice shows that in the growth stage of piglets, the mortality rate caused by various causes accounts for more than 70% of the whole growth period, of which the production losses caused by dysentery and slow growth account for about 50%. In addition（At the same time）, the growth rate of piglets before reaching 23 kg has an important effect on the overall growth performance of pigs ^[1]. Therefore, the use of antibiotics during the piglet stage has become an industry standard. Considering that the use of growth-promoting antibiotics in other growth stages besides infancy also has obvious effects and economic benefits, nearly half of China's antibiotics are used in animal husbandry. The resulting problems of antibiotic residues and bacterial resistance seriously endanger food safety and human health. Moreover, the problems associated with the unreasonable use and abuse of antibiotics, such as bacterial resistance, environmental pollution, and food safety, are increasingly receiving widespread attention from the whole society ^[2]. In 2015, China banned four kinds of antibacterial drugs, including Lomefloxacin, Pefloxacin, Ofloxacin and Norfloxacin, from being used in food animals, in 2016, colistin sulfate premix was banned from being used in animals to promote growth, and in May 2018, three kinds of veterinary drugs, including Olaquindox, Ampicillin and Roxarsone, were banned from being used in food animals. By July 1, 2020, all feed enterprises have to stop producing commercial feed containing growth-promoting drug feed additives (except traditional Chinese medicine). The comprehensive ban on antibiotics in feed declares that the use of antibiotics as growth-promoting agents will become history.

2.3 Effect of plant essential oil on economic benefits of weaned piglets

According to Table 4, compared with control group, adding antibiotics and plant essential oils can significantly increase the total weight gain of piglets during the test (P<0.05). Based on the market feed price of CNY4.5 per kg and fattened pig price of CNY40 per kg, the net profit of the antibiotic group and plant essential oil group increased by 17.79% (P<0.05) and 11.52% (P<0.05) respectively, compared with control group (P<0.05).

3 Discussion

The results of this test showed that the adding compound plant essential oil to diet of weaned piglets can improve the growth performance of piglets, and the effect was between control group and antibiotic group, indicating that the essential oil after ban antibiotics in feed was the first choice for antibiotic substitutes. Lyu Minzhi et al. ^[5] found that plant essential oil can replace antibiotics, increase growth performance of piglets and improve blood biochemical indexes. Zhang Lingling et al. ^[6] reported that plant essential oil preparation can improve the intestinal flora and ammonia escape in feces of piglets. Wu Sheng et al. ^[7] found that adding plant essential oil preparation to piglet feed can improve piglet growth performance. Tian Dongdong et al. ^[8] found that adding essential oil to piglet diet can effectively inhibit the bad smell in feed, improve the palatability of diet and improve the intestinal environment of pigs, and in addition, the essential oil had certain antibacterial effect, which can effectively reduce the occurrence of bacterial diarrhea and improve the health level of the animals, thus promoting the rapid growth of piglets. Wang Gaiqin et al. ^[9] found that adding compound essential oil can effectively increase the feed intake and daily gain of growing pigs and reduce the incidence of respiratory diseases and diarrhea. Diao hui ^[10] reported that adding a certain amount of thymol to piglet feed can enhance the activity of some enzymes in the digestive tract, improve digestion ability and promote piglet growth performance. In this test, compared with control group, adding antibiotics or plant essential oils to the diet significantly improved the production performance of weaned piglets. Through analyzing average daily gain, average daily feed intake, feed-gain ratio, diarrhea rate and economic benefits, although the effect of essential oil was not as good as that of antibiotic, the addition of essential oil significantly improved piglet production performance and reduced the incidence of diarrhea by 19% compared with control group, while increasing economic benefits by 11.5%. The results of this study were similar to those reported by the aforementioned researchers, suggesting that the application of plant essential oils in piglets is remarkably effective.