Ractopamine does not rescue Halothane and Rendement Napole metabolism postmortem

Area of Science:

• Animal Science
• Meat Science
• Biochemistry

Background:

• Ractopamine (RAC) is a feed additive used to improve leanness in livestock.
• Halothane (HAL) and Rendement Napole (RN) are genetic mutations affecting pig muscle metabolism and pork quality.
• Understanding RAC's impact on these specific genetic backgrounds is crucial for optimizing pork production.

Purpose of the Study:

• To investigate the effects of ractopamine (RAC) on postmortem muscle metabolism.
• To assess RAC's influence on pork quality in Halothane (HAL) and Rendement Napole (RN) mutant pigs.
• To determine if RAC modifies the characteristic meat quality traits associated with HAL and RN mutations.

Main Methods:

• Pigs with HAL and RN mutations and wild-type (WT) pigs were fed ractopamine (RAC).
• Postmortem muscle metabolism, including pH, temperature, glycogen, and lactate levels, was analyzed.
• Pork quality traits, such as L* values, were measured.

Main Results:

• Ractopamine (RAC) feeding increased L* values in all pigs.
• Muscle pH was lower in HAL and RN mutants, with no effect from RAC.
• RN mutants exhibited altered initial glycogen and lactate levels, with RAC reducing glycogen specifically in RN mutants.

Conclusions:

• Ractopamine (RAC) influences postmortem energy metabolism but does not alter the pH and pork quality hallmarks of HAL and RN mutations.
• The biochemical drivers of meat quality traits are complex and may not be solely explained by major gene mutations.
• Further research is needed to fully elucidate the intricate relationship between feed additives, genetics, and meat quality.