33. Intramuscular fat (IMF) deposition in finishing animals – animal-related factors, and dietary nutrition

The Rumen Room Podcasts

Intramuscular fat (IMF) is fat that’s deposited between and within individual muscle fibres (cells) in the skeletal muscle of animals. Also referred to as ‘marbling’, consumers of red meat often prefer meat that contains a higher level of IMF due to an enhanced eating experience.

In this, our second in a two-part series focusing on IMF in ruminant animals, we carry on a discussion around IMF from part one (Episode 32) that covered the basics of IMF in red meat.

In Episode 33, our current episode, we further explore the subject of IMF, covering first up, some of the animal-based factors that influence extent of IMF deposition. In the second part of this podcast we discuss the importance of the dietary nutrition of finishing animals to achieve desired levels of IMF in red meat.

The following topics are covered within Episode 33, at times within the podcast, listed below at

2.41: An introduction to the current episode

3.45: The importance of animal genetics as a key driver of IMF deposition in finishing animals

6.33: Animal-specific factors, other than genetics, that influence IMF

11.08: The conflict of outcomes between (a) keeping fattening animals on farm for longer, to achieve higher IMF %, when (b) mature, fattening animals are extremely inefficient converters of feed to liveweight gain

12.22: The differences in feed conversion efficiency (kg of dry matter per kg of liveweight gain) for young growing animals, compared to that of older fattening animals

16.47: The effects of the sex of an animal on efficiencies of IMF deposition

20.44: Effects of dietary nutrition on IMF deposition

21.00: Maternal nutrition and subsequent potential IMF deposition by progeny

26.08: IMF deposition during the finishing phase – the influence of dietary nutrition

26.56: Blood glucose drives IMF deposition – the ‘101’ basics of biochemistry helps define why blood glucose is important - including the “cricket wicket” of fat structure

29.51: IMF fat cells – glucose is the IMF cells ‘fat manufacturing ingredient of choice’

34.40: Maintaining high blood glucose levels on temperate pasture & forage crop systems

37.00: Developing a farm plan for more IMF within temperate forage systems

40.10: High dry matter intakes and IMF deposition

41.55: Very high quality forages and the potential role for rumen pH and IMF

43.29: Lamb finishing on chicory and chicory/temperate clover blends – IMF and Omega 3 polyunsaturated fatty acids

44.33: Trying to understand the “black box” of how chicory/clovers support more IMF and/or more Omega 3 fatty acids

47.23: Length of time on finishing feeds for ideal IMF deposition

48.43: Micronutrients and IMF deposition