Two experiments were conducted to determine the optimal brining levels and effective chlorinated antimicrobials in three selected commercial poultry abattoirs of south Africa.The objective of the study was two fold: Firstly, the primary objective of the study was to determine the optimal inclusion level of brine for application in chicken processing to elongate the shelf life by reducing spoilage bacteria under refrigeration stage while the secondary objective of the study was to determine the most effective chlorinated antimicrobial to be applied in poultry processing plants to reduce spoilage bacteria. For each experiment, a complete randomized design was used. The general linear model procedure was used to determine the effects of brining and chlorine antimicrobials on the Psychrotrophic bacterial load of individually quick frozen (IQF) chicken portions. Simultaneously, a quadratic type equation was used to determine the optimal inclusion level of brine in relation to the responses of Psychrotrophic bacterial loads. The results indicated that control samples (0% brine) had higher (P < 0.05) bacterial load than all samples injected with various injection levels. There were significant differences (P < 0.05) between samples injected with 15% and 20% for all major abattoirs combined. However, there were no differences (P > 0.05) between samples injected with 20% and 25% brine, respectively. In addition, there was a significant difference (P < 0.05) in Psychrotrophic bacterial load between the samples treated with 25% and 30% brine inclusion level as well as those treated with 30% and 35% brining levels in all abattoirs. Futhermore, the results of the study also showed that Acidified Sodium Chloride had significantly lower bacterial load than both aqueous chlorine and chlorine dioxide. However, the effect of percentage brining on average Psychotrophic bacterial count had minimum quadratic values of 24.45 – 0.517 brining + 0.805 brining2 with r = 0.995; r2= 0.989, with optimum percentage brining dose being 43.08%. By extension, the result implies that the lowest reduction in spoilage bacteria is attained at 43.08% of brine inclusion level. These findings have implications on the most effective and convenient antimicrobial to be used in chicken abatoirs as well as reduction of psychotrophic bacterial load on individually quick frozen (IQF) chicken portions / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)