Small livestock farms in The Caribbean are affected by an incidence of gastrointestinal (GI) parasites. These farms make up most of the production within the Caribbean livestock industry. Unfortunately, parasitism and parasitosis constitute serious animal health problems that predispose them to other, more serious health conditions [1] . GI nematodes are responsible for economic losses in large ruminants and are characterized by reduced milk production, decreased working efficiency, and even death [2] . Such conditions can reduce their productivity and marketability, reducing their economic values [1] . When needing to treat hundreds or even thousands of heads of cattle, a livestock farmer can quickly expect to spend thousands of dollars on treatment. With most herds, specific helminths such as Oesophagostomum and Trichostrongylus are particularly resistant to multiple drugs [3] . Such resistance requires higher dosages of conventional medicine to be administered to ruminants to suppress helminth reproduction. Therefore, additional medication must be purchased to compensate for poorly affected parasites. Considering these factors, the cost of decreasing the incidence of intestinal parasites can negatively affect the finances of livestock farmers.

Productivity losses cause economic problems for the farmers and weaken the meat production industry [4] . Part of The Bahamas’ commitment to the United Nations (UN) small island developing states agenda, its Sustainable Development Goals (SDGs), and 2030 Agenda for Sustainable Development is food security and seeing a drastic reduction in this country’s “growing” $1.1 billion food import bill [5] . Therefore, the health of livestock animals used to produce milk, and meat is crucial not only to the farmers’ income but also to the sustainability of the country’s economy.

In large quantities, medicine (Cydectin in the case of this experiment) can become costly. Therefore, to reduce production costs and practice sustainability, small farmers need a less expensive and effective treatment for controlling GI parasites in livestock animals. The drawbacks of conventional anthelmintics have peaked scientific interest in the use of botanicals to address helminth infestations [6] - [8] .

The anthelmintic properties of Azadirachta indica have been observed across journals of parasitology. Typically, administration is in the form of a powder [9] - [12] or oral drench [13] —anthelmintic efficacies of neem range from 34% to roughly 99% [11] [13] . Neem grows naturally in the Bahamas, where this study was done, and in other parts of the Caribbean. These factors make Neem a promising, inexpensive supplement to the anthelmintic regiments of livestock farmers.

Table 1 shows the mean EPG of Groups A and B at day 0 was 1320 ± 680.8 and 620 ± 299.8, respectively. After day 28 post-treatment, the mean EPG was recorded as 380 ±147.3 and 170 ± 156.8, respectively. The results indicated a 61.9% and 75.3% decrease in the EPG in treatment groups A and B, respectively, on day 28 post-treatment. Furthermore, on day 56 post-treatment, the EPG was recorded at 170 ± 144.03 and 70 ± 66 in treatment groups A and B. These results indicate a peak efficacy of 74.2% for Neem extract and 88.2% for Cydectin.

Note: a. Values above are mean ± SE of 5 sheep, different superscripts (a and b) differ significantly (p < 0.05) from other values in column, *significantly decreased (p < 0.05).

According to Villarroel A. (2013), Cydectin, as a registered anthelmintic, has proven to be an effective drug against internal parasites, reaching 100% effectiveness in eliminating 11 species of nematodes, including Heamochus placei, Ostertagia ostertagi, and Trichostrongylus axei [14] . Comparatively, Neem has also been known to reach high efficacies. Azadirachta was shown to have 98% effectiveness against Strongyles [10] , a mere 2% less than Cydectin. The results of these two experiments suggest that Neem and Cydectin have similar properties. Based on the results of this study ( Table 2 ), it was shown that the efficacy of the Neem extract and the Cydectin drench peaked at 74.2% and 88.2%, respectively, at day 55 post-treatment, which is not agreeable with the studies done by Williams et al. (1991) and Jamra et al. (2014). However, the findings of this study agrees that the anthelmintic properties of Neem and Cydectin do not differ significantly (p < 0.05) across all sampling days. Neem significantly (p < 0.05) decreased EPG on day 55 post treatment whereas Cydectin showed a significant decrease on day 28, suggesting that Neem is slower acting.

The results of this study also convey inconsistencies in EPG for individual subjects throughout the experiment which may have caused the disagreement between this experiment and the previously mentioned ones. The EPG of subject 90 was reduced from 2500 on day 0 to 200 on day 28, which is a 92% decrease in EPG and 20.8% above the average efficacy of the neem extract. Results also show that in some animals, there was an increase in EPG at day 55 post-treatment. For example, subjects 991 and 191 experienced an increase in EPG from 0 to 50 and 250 to 350, respectively, at day 55 post-treatment. To the best of our knowledge, studies have evaluated the anthelmintic properties of botanicals and other dewormers over a shorter period, typically 14 - 28 days [15] - [18] . This roughly coincides with the life cycle of many Trychostrongyloids [19] . This study aimed to observe the effects over a longer period, modeled after the deworming practices of the BAMSI farm managers. Coverage of multiple life cycles allows for more irregularities in EPG levels as L1, L2 or L3 larvae outside of the animal at the time of anthelmintic administration would be less affected without pasture treatment. Studies with extended periods display this [20] . However, no such irregularities in EPGs were consistent across subjects suggesting that other factors influenced the changes.

This study demonstrated the anthelmintic potential of Azadirachta indica in the control of GI parasites with it being similar in efficacy to Cydectin. Further research is necessary to determine specific active chemicals, their lethal and effective dosages, the most effective route of administration and the helminths that are most susceptible to Neem treatments. Furthermore, the effect of neem on the health/productivity of animals affected by helminths needs to be investigated to enhance its usefulness as a control for helminth infection in livestock.

The authors confirm that the funder of this article did not influence the contents or journal chosen for publication in any way. They are thankful to their colleagues at The Bahamas Agriculture and Marine Science Institute and Florida Agricultural and Mechanical University. Also, the authors are thankful to the employees of the livestock department of BAMSI farm for their records and expertise in animal handling.