Pig rearing is popular in many parts of Nigeria, which has the highest pig production in Africa (Adebambo, 2002). In recent years, progress made in the field of genetics has created a modern pig that grows faster, lays down more protein and less fat, and yields a leaner carcass. At the same time, modern pigs have become better eaters, enabling high feed intake even from the very early days of life. Pork is the largest source of meat at the world level. Feeding and growing pigs with diets containing higher crude protein level is a metabolic and economically costly process (Kumar et al., 2012). Undoubtedly, low protein diets, adequate in all amino acids, ensure that no excess will end up in the large intestine to function as substrate for the micro flora (bacteria).
If this were to happen, the fermentation of the undigested protein would cause a reduction in the ability of the colon to absorb water and all of these makes it a metabolically costly process. During the last five years, the cost of cereals and proteins sources has increased by 30-40 percent. As a result, animal protein has become a luxury instead of a dietary necessity since only a certain class of citizen finds it convenient to buy, Olaloku (2007). Therefore, because of high cost associated with feeding pigs in the recent times, feeding with low crude protein measures has to be adopted. Proteins have higher caloric increment than carbohydrates and fat which is a result of the energy released as heat during digestion, absorption and metabolism of nutrients and other physiological mechanisms (Noblet& Shi, 2004). As such, reducing dietary crude protein (CP) will result in a decrease in deamination of the excess of amino acids and consecutive synthesis and excretion of urea in urine which also contributes to lower heat production of pigs.
Optimizing feed energy utilization by adjusting the dietary net energy content in low crude protein diets is important to lower formulation costs without reducing pig performance or carcass composition (Cahn et al., 2008; le Belegroet al., 2002; Kerr et al., 2003). As a result, reducing crude protein in the diet will also improve the efficiency of metabolizable energy utilization, with consecutive increase in the net energy availability, and attenuate heat stress of weaner pigs under high environmental temperatures, a common condition in most part of Nigeria. Low crude protein diets can also markedly reduce nitrogen excretion enhancing sustainable pig production (létourneau-montminyet al., 2011). In addition to the positive effects of low crude protein diets on energy utilization by pigs, the Nitrogen excretion from the pig will be reduced by 8-10% and the ammonia emission will be reduced by 10 – 12% (Cahn et al., 2002). That is the amount of surplus nutrients in excreta and gaseous losses to the environment. The major nutrients of concern are Nitrogen, Phosphorus, and heavy metals and main gaseous losses of concern are Ammonia and Methane i.e. the green house gases. Thus, low-crude protein diets have special environmental advantages for pig production.
Various researchers have explored the use of low crude protein with Amino Acid Supplementation without first establishing the minimum level of tolerance to the low crude protein before the amino acid supplementation. Many genetic suppliers today recommend pig diets with low levels of crude protein, and lower than before levels of digestible lysine, while at the same time maintaining high energy levels, for all growth phases. Clearly, this arises from the ability of the modern pig to consume more feed and thus receive -on a daily basis- the required amount of nutrients. Nevertheless, the correct amino acid profile (amino acid concentrations relative to lysine) were still in adequate proportion, just that the excess of it is being trimmed off .So, at the level at which they can no longer tolerate low crude protein to carry out their various physiological processes i.e. for growth, Amino Acids will be introduced to meet the nutrient requirements of the animal. In etc feeding manuals from different pig genetic companies offer quite different nutrient specifications, especially when it comes to amino acid ratios.
In addition, excess crude protein in the large intestine of weanling pigs increases the risk of these pigs developing diarrhea and scouring (Goransonet al., 2005). It is, therefore, possible to reduce the risk of pigs developing diarrhea if low protein diets are fed during the immediate post weaning period. It is, therefore, possible to use this strategy to reduce scouring and post weaning diarrhea in pigs. Finally, studies with weaner pigs also has been shown that low-crude protein diets has economic advantages compared to pigs fed normal Crude Protein diets (Yue &Qiao, 2008)
The increased cost of feedstuffs has necessitated new ways of pig production. As a result of feed representing the most important cost of pig production, and energy also being considered the first most expensive component in pig diets (létourneau-montminy et al., 2011), there is therefore need to reduce cost without deleterious effect in pigs performance.
1.2 General Objectives
To determine the response of weaner pigs fed with low crude protein diet without excess synthetic amino acids.
1.3 Specific Objective
To evaluate the:
- Growth performance of weaner pigs fed low crude protein diet.
- Hematological parameter of weaner pigs fed low crude protein diet
- Carcass quality of pigs fed low crude protein diet