Endrinal, Erwin P. <br/><br/>
Evaluation of the growth performance of pigs fed with ractopamine hydrochloride supplemented rations/ 
Erwin P. Endrinal 
 - Bayombong:  Nueva Vizcaya State University,  2015. 
 - xii, 53 leaves :  illustrations, photos ;  28 cm. 
<br/><br/> The study evaluated the effect of supplementation of Ractopamine hydrochloride on the growth performance of pigs. A total of eighteen pigs around eight to ten weeks old with weights ranging from 14 to 22 kg were used as experimental animals.<br/><br/>The experimental animals were randomly assigned into three (3) treatment groups replicated three (3) times with two (2) animals assigned per replicate. The experimental animals were laid out using complete randomized design (CRD) and the data was analyzed using analysis of variance (ANOVA) The animals were fed with age-appropriate rations for twelve weeks (84 days).<br/><br/>Animals in treatment 1 (T₁) were fed rations without ractopamine HCI supplementation. Animals in treatment 2 (T2) were given starter, grower, and finisher rations with ractopamine HCl supplemented at the finisher stage. Animals in treatment 3 (T1) were fed similar rations but with ractopamine HCl added at the starter and grower stages. <br/><br/>Results of the study showed that there were significant differences among treatment groups on some growth parameters such as the mean average daily gain during the grower stage and the feed to gain ratio during the finisher stage. While in the other parameters, there were no significant differences observed which means that the analyzed results from the other parameters were comparable with each other.<br/>There were significant differences observed in the mean average daily gain (ADG) during grower stage. The highest ADG was treatment 3 (0.804 kg) followed by treatment 2 (0.789 kg) and least was treatment 1 (0.700 kg).<br/><br/>During the finisher stage, there was a marked shift in the computed average daily gain (ADG) among the treatment groups. Treatment 1 had the highest computed ADG which is 0.949 kg. This was followed by treatment 2 (0.889kg) and treatment 3 (0.770kg). In this observation the stunting effect of ractopamine in pigs over the long duration of use was observed in treatment 3 During the finisher stage an apparent increase in feed to gain ratio was observed. The mean feed to gain ratio of treatment 3 was 3.283 kg followed by treatment 1 which was 2.646 kg and for treatment 2 which was 2.836kg It shows that treatment 3 was significantly different among the treatments 1 and 2, but treatment I has a lower feed to gain ratio. A lower feed to gain ratio is more efficient which means that T2 is more efficient than the other treatment groups. <br/><br/>This result is similar to other studies performed which also shows that long-term feeding of ractopamine to pigs will result to less efficient feed conversion due to the down regulating effect of ractopamine in cells after long term administration.<br/><br/>In terms of economic profitability, it shows that administration of ractopamine at the finishing stage can increase the net profit. It also shows that administration of ractopamine at the finishing stage can decrease the cost of feed per unit body gain by making the pigs more efficient in converting the feed into meat. <br/><br/>The results of the study show that supplementation of ractopamine is profitable if given during the finishing stages.<br/> <br/>  Thesis (Doctor of Veterinary Medicine) 
<br/><br/>Includes appendices and bibliographical references.