Approximately 12,000 to 14,000 tons of catfish oil is produced each year as a byproduct of the commercial catfish meat industry. Much of this is produced on catfish farms in the southeast. Feeding supplemental fat to lactating dairy cows has been beneficial in the past by improving milk production but care must be taken in formulating the ration to prevent milk fat depression by adding the oil.

The University of Florida conducted 2 studies to evaluate catfish oil as a fat supplement for milking cows. Catfish oil (donated by Protein Products Inc.) was mixed with liquid sugarcane molasses (donated by Westway Feed Products Inc.) so that the oil made up 20% of the as-is mixture. The molasses-oil mix was added to the TMR so that catfish oil comprised 0 or 1.8% of the dietary dry matter. Both diets had the same amount of molasses - about 5%. The control diet contained 3.2% ether extract. 190 cows averaging 210 days in milk were fed the 2 diets in an alternate fashion in an 8-week study.

Cows fed the catfish oil produced 2.6 pounds more milk per day, an increase from 67.8 to 70.4 pounds per day. Concentration of milk fat was unchanged, averaging 3.34% across both diets.

In another study to examine the effects of feeding catfish oil on intake and digestion, catfish oil was fed at 0, 1.5, or 3.0% of dietary dry matter to 12 milking cows, 4 of which were ruminally cannulated. In this study using fewer cows in late lactation, milk yield and milk fat % were not changed.

Benefits of feeding increasing amounts of catfish oil included increased digestibility of dry matter and fiber, increased rate of digestion of corn silage fiber in the rumen, and increased feed intake. Improved intake of digestible feed appeared to go into increased body weight in this study. Average ruminal pH was more acidic (6.4, 6.2, and 6.1) with increased catfish oil but proportions of volatile fatty acids in the rumen were changed only modestly.

In summary, feeding about 0.8 lb of catfish oil mixed with liquid cane molasses benefited milk production without negatively affecting milk fat % of cows in mid to late lactation.

Source: Charles Staples, University of Florida Department of Animal Sciences