PERFORMANCE OF GROWING MALE PIGS EXPOSED TO QUANTITATIVE FEED RESTRICTION

Eighteen growing pigs weighing 32.4 ± 1.4 were assigned in a completely randomized design to three levels of dietary rearmaments to know the effect of quantitative fed restriction on them. Each treatment had three replicates of two growing pigs per replicate. Each of the treatment was fed one of the 3 dietary levels as follows: 10% of the body weight as feed given to the control group (T 1 ), 7.5% for T 2 and 5.5% for T 3 . Analysis of variance at the end revealed that though the total feed intake value for T 1 differed slightly numerically than those of T 2 and T 3; there were no significant differences (P> 0.05) in feed gain and body weight gain in all the treatments. Economic analysis was also determined. Result shows that subjecting growing pigs to feed restriction made higher profit than the control.


INTRODUCTION
The ideal practice of feeding pigs at 10% body weight has sometimes not been attained due to high cost of feed, lack of skilled manpower, and government policies on the importation of raw materials/ingredients. Anthony (1991) reported that feed cost account for about 70% of total cost of production in the tropics. This has apparently resulted in high cost of pig products. Feed restriction in animal production can reduce the cost of production by 30%. Quantitative and qualitative feed Restriction for Monogastrics have been studied by Bows et al, (1988) who reported on the nature and levels of feed restriction that will not result in considerable weight loss and poor production. Food restriction and compensatory growth are an important phenomenon in temperate condition with food shortage in inter and re-alimentation in wt and dry seasons (Lee et al, 1971;Hogg, 1991). Conversely, in and semi-and areas food shortage occurs in dry season associated with thermal stress.
Fed restriction had been used on pigs as a means of reducing their excessive fat deposit and feed cost (Arafer et al. of 1983). There is a close relationship between level; of feeding an the weight of some non-carcass components particularly the metabolic organs (Atti, et al, 2002;Times et al, 1981). So, when intake changes, weights of visceral organs occur, which produce changes in the maintenance requirement (Ferrel et al, 1986). It has been shown that animals on restricted planes off nutrition have proportionally smaller livers (Ferrel et al, 1986;Marray et al, 1977) and also have lower maintenance energy requirement (MER). It has been suggested that the phenomenon of compensatory gain is directly related to liver mass and protein turn-over (Frisch and Vercoe, 1977). However, the requirements of splanchnic tissues, particularly the gut, represent a major part of MER (Hogg, 1991) and this adaptation to under feeding, by a reduction of the MER, has been explained by a decrease in the weight of the gut and some other metabolic organs in underfed animals (Mdllisson et al, 1991).
This experiment is therefore justified by the fact that exposing the pigs to quantitative feed restriction, will reduce the cost of production without a significant difference in the productivity of the animal.

Experimental site
This experiment was carried out at the piggery research unit of the department of animal production and fisheries management, Ebonyi State University, Abakaliki

Experimental animal/designed
Nine growing male pigs, cross breeds of Large white and land Race (LW x LR) between 4-5 months of age, obtained from a local farm were used in the experiment. This experiment was conducted using a completely randomized designed (C.R.D) (Steel and Torrie 1980). There were three treatments with six animal per treatment and three animals per replicate. Each group treatment was fed with one of the three (3) levels of dietary treatment designed for the animal according to the body weight of the animal. The dietary levels were 10% of the body weight for treatment one (T 1 ), 7.5% of the body weight for treatment two (T 2 ) and 5.5% of the body weight for treatment three (T 3 ). The animals were numbered and weighed at the start of this study and were randomly assigned to the experimental treatments. They were then reared for 12 week. They received no supplemental feeding or growth enhancer during the experimental period.

Experimental diet
The experimental diet were formulated using locally sourced materials/ingredients that are, chap, affordable and which provided not less than 14mj/kg digestible energy (Table  1).

Fed intake:
The daily feed requirement were measured and served to each treatment between 7:00am and 8:00am daily. Left over were weighed and recorded the next morning. The difference between the fed served and the over was assumed to have been consumed. The daily body weight gain was determined mathematically by dividing the body weight gained by the number of days/weeks the study lasted. The feed conversion ratio was determined by dividing the average daily intake by the average daily weight gain. That is: Body weight gain = initial body weight -final body weight Daily weight gain = body weight gain Number of experimental days.

Statistical analysis
Data on feed intake, body weight gain, final body weight and feed efficiency were analyzed using a one-way ANOVA (Analysis of Variance) in a Completely Randomized Design (CRD) and significant means were separate using Duncan's multiple Range Test.

Economic analysis
The following parameters were measured. (i) Cost of feed consumed (N)/kg = cost of feed/kg X quantity of fed consumed. (ii) Total revenue (N) = the selling price of the animals. (iii) Net Return (N) = Total Revenue generated -Total cost of production.

RESULT AND DISCUSSION
The summary of the effects of the treatment on the performance of the pigs is shown on Table 2 means of final body weight showed that there was no significant difference (P> 0.05) in body wt between pigs in the control (T 1 ) group and those in T 2 and T 3. Result agrees with the earlier finding of Beane et al,. (1979) in chicken, which showed that restricting the feed intakes of broilers to 85% of full fed control again, is in line with that reported by (Bohman 1955. Plavnile andHurtwiz 1985;and Tion et al, 2001) also in chicken, that was non significance difference (P< 0.05) in the growth of earlier restricted group of chicken following realimentation. The slightly numerical difference in final body wt of T 1 (45.42kg), T 2 (44.15kg) and T 3 (43. 18kg) where (T 1 = 1.27kg > T 2 = 0.97kg > (T 3 ) affirms the suggestion of Cock (1963) and Mollison et al (1984) that although the compensatory growth of the restricted animal at certain periods may equal that of the unrestricted group, the final body wt of the restricted groups never up with that of the unrestricted (control group). some of the reasons for the discrepancy have been discussed by Murray et al. and (1977) and this includes the severity, the duration and the timing of the feed restricted. In this study, the pigs were fed at three dietary levels of their body weights at growing age. Hogg (1991) gave same indication that cattle restricted before 6 months of age showed limited compensatory growth subsequently almost independent of the severity of the restriction, while cattle restricted at ages beyond 6 months exhibit compensatory growth proportional to the degree of restriction. Thus, there might have possible been a residual effect of the initial 10% body weight feeding regime (from waning to growing age) during the restriction period which did not allow the effect of the restriction to be made manifest. That is, since restriction did not start from weaning, tissue development at this phase could not have been impeded. Table 2 also reveals that the total fed intake value for T 1 differed slightly numerically, than those of T 2 and T 3, FCR (Feed gain ratio) did not differ (P> 0.05) in all the treatments. Increased appetite resulting in an increased feed intake is generally thought to be the most important factor considered to have a possible influence on compensatory live weight gains and feed efficiency. (McCartney and Brown, 1976). Though there were numerically significances (P> 0.05) in the total feed intake among the treatments. The feed efficiency did not differ (P< 0.05) among the treatments. This is supported by the report of Orr and Kirk (2001) that the level of intake may influence the rate of passage and/or digestibility and thus the efficiency of fed conversion. It is possible that the feed consumed by the full-fed animals as too much in the stomach within a given time to have limited rate of passage and/or digestion, whereas the reverse is the case in the restricted animal Further confirmatory support for the findings of this study is that feed restriction often results in apparent decrease in maintenance requirement due to depressed metabolic rate, suggesting that an animal becomes more and more efficient in utilizing a reduced food intake (Frisch and Vercoe 1977). This is based on the concept of a reduced maintenance requirement. Table 3 gives effect of fed restriction on the economy of production. The data reveled that feed cost (N)/kg weight gain increased in this order: T 3 , T 2 and T 1 (N42.69, N49.58 and N49.72 respectively). Total feed consumption and feed cost as higher in the control (T 1 ) and declined in the restricted group (T 2 and T 3 ). Thus, total feed cost was lower for the restricted group than the full fed. The cost of production of the pigs also, followed similar trend.

Feed intake and feed conversion ratio
The net returns (gain N/pig) were found to be as follows: T 1 = N1379360, T 2 = N13723.50, T 13 = N13580.80 Higher fed cost/kg feed consumed was observed in T 1 and the weight Naira/pig was higher in T3 by N7.02. Thus the increase in cost/kg gain in T 1 was a reflection of higher quantity of feed consumed and the increased weight in Naira/pig in T 3 was also as a result of efficient feed conversion.
This result agrees with the findings of Bohman (1955) and Ferrel et al (1986) that feed restriction had a significant effect on monetary returns for birds over fed. Lee et al. (1971) also indicated that birds subjected to feed restriction made higher profit than the control. From the present study pigs fed 7.5%, and 5.5% of their body weight compared favourably tot hat fed the recommended 10% body weight.

CONCLUSION
In conclusion, feeding growing pigs at almost half (5.5%) of the body weight than the recommended feeding standard (10%) body weight will have no significant effect on the growth and performance of the pigs and will reduce the cost of production by almost 30%. Thus, feeding at 10% body weight may amount to more wastage considering the cost of feed and poverty level in this part of the world.