In developing economy, like Nigeria, emphases are placed more on quality, wholesome as well as affordable animal protein for the growing population. The per capita intake of protein, that of animal protein in particular, of the growing population of Nigeria remains very low. This situation is worsening, because other sources of cheap animal protein such as wild animals and other microlivestock such as snails, rats, and grass cutter, etc. are being depleted as a result of deforestation, bush fires, and indiscriminate and uncontrolled hunting (Abeke et al., 2009).
In Nigeria as in most developing countries, it has been realized that the development of pig industry is one of the fastest means of bridging the prevailing protein deficiency gap which has developed over the years due to the increasing population. This is undermined by the inadequate supply of their products due, largely, to high cost and inadequate feeding and nutrition, poor breeding stock, and poor management practices involving; proper housing, disease prevention and control.
Aduku (1992) opined that 70 – 90 percent (%) of the cost of production of eggs, chickens, pork, and rabbits have been attributed to feed input. However, the availability of cheap and balanced feed is a key to abundant animal protein production. This is because, feed indicates how many animals a farmer can grow and how fast they can mature for the market.
Pigs, like other non- ruminants compete with man for feed. This is because both categories of consumers depend on the same source for food which supplies are already inadequate. Therefore, in an effort to increase animal protein source, pig production should be encouraged so as to make available pork and bacon to Nigerian meat consumers. This is because according to Serres (1992), pigs are known to be highly prolific and very efficient in converting feed materials into high quality animal protein.
Recent concerns regarding the use of antibiotics as growth stimulating agent in animal production and their residual effects on the part of the consumers has demanded for alternative strategies to improve animal production and health without need for antibiotics. Studies, in recent years, have shown that lactic acid bacteria including Bacillus spp. are widely used as probiotics in humans, and their use has reportedly led to health benefits against gastrointestinal disorder; including diarrhea, inflammatory bowel disease, lactose intolerance, and infections (Madson, 2001). Although various Bacillus spp. are widely used as probiotics for human and animals, their mechanism of action is not yet fully understood (Hong et al., 2005).
Food and Agricultural Organization (FAO, 2005) defined probiotics as a live microorganism administered in adequate amount which confers a beneficial health effect on the host. Ezema (2007) defined probiotics as life culture of microbes often lactic acid bacteria but also other species such as saccharomyces which are fed to animals to improve their health and growth by altering intestinal microbial balance.
Also, searching for hypolipidemic agent in predominantly vegetation human diet has yielded considerable information concerning the effects of plant materials on cholesterol metabolism in animal models. Garlic (Allium sativum), which has been used as spice and folk medicine since antiquity, has been considered to be beneficial to animal health as the allicin, the bioactive substance of garlic has antibacterial, anti parasitic and antifungal activities. The magnitude of this action varies from 14% lowering of serum cholesterol in human to a lowering of 80% in cholesterol fed rabbits (Badia et al., 1975; Badia, 1981). Sharma et al. (1979) also reported that egg cholesterol was reduced by feeding 1 or 3% garlic powder to laying hens during 3 weeks; Sklan et al. (1992) reported that hepatic cholesterol concentration of laying hens was decreased when 20% garlic was fed for 2 weeks. Accordingly, various herbs or their extracts are now being utilized as feed additives due to their widespread anti oxidative and antimicrobial actions, beneficial effects on palatability and gut functions. In order to produce quality and affordable pork for Nigerian consumers, the present study was designed to achieve the under listed objectives.
1.1 Objectives of the Study
The study was designed to achieve the following objectives;
- Determine the effects of garlic and probiotics additives on the growth performance of grower pigs.
- Determine the hematological characteristics of grower pigs’ diets containing garlic and probiotics additives.
- Determine the effects of garlic and probiotics additives on the serum chemistry of grower pigs.
1.2 Significance of the Study
A success in providing meat with low cholesterol content will help rekindle the confidence of meat consumers. This is against the background that many meat consumers have reduced the quantity of meat they consume because of the apparent cholesterol content of meat. Literature evidence suggests that garlic and probiotics have ability to reduce cholesterol content of animals. Garlic supplemented diet may inhibit the synthesis of cholesterol and fatty acid in the liver (Yeh and Liu, 2001). Warshafsky et al. (1993) suggested that cholesterol lowering of 9% (0.59 mmol/L) could be achieved by a daily consumption of 1.5 – 3g of garlic for 2 – 6 months. Allicin, which causes the characteristic garlic odour, is believed to be the active lipid-lowering compound in garlic.
In the same vein, probiotics have been found to be beneficial to the host gut health, by their antimicrobial activities against gastrointestinal pathogens such as Salmonella and E. Coli, prevention and treatment of diarrhea in infants and adults, and alteration of the composition and metabolism of the intestinal micro biota (Servin, 2004).