Influence of Level and Source of Dietary Fat on Its Comparative Feeding Value in Finishing Diets for Steers: Feedlot Cattle Growth and Performance

Abstract

Two hundred twenty-eight crossbred steers (304 kg) were used in a 125-d comparative slaughter trial to evaluate the influence of level and source of supplemental fats on their feeding value for feedlot cattle. Dietary treatments consisted of a steam-rolled, barley-based finishing diet containing 1) no supplemental fat; 2) 4% yellow grease (YG); 3) 4% blended animal-vegetable fat (BVF); 4) 8% YG; 5) 8% BVF or 6) 6% BVF and 2% crude soybean lecithin. Increasing level of supplemental fat in the diet resulted in linear improvements (P less than .01) in weight gain, feed conversion and NE value of the diet. Estimated NE values of YG and BVF were similar and did not appear to be influenced by level of supplementation, averaging 5.78 and 4.61 Mcal/kg for maintenance and gain, respectively. Fat supplementation resulted in linear increases in empty body fat (P less than .01), kidney, pelvic and heart fat (P less than .01) and marbling score (P less than .05). Partially replacing BVF with lecithin did not influence (P greater than .10) steer performance, carcass merit or estimated NE value of the diet. The comparative feeding value (in terms of both diet acceptability and NE value) of the supplemental fats tested was similar and was apparently not influenced by level of supplementation up to 8% of diet DM.

Effects of processing and fat content of coarse canola screenings on voluntary intake and total tract nutrient digestibility of beef steers

“…intake of fermentable organic matter, which would result in a slower passage rate of particulate matter. As reported previously in Trial 1, other researchers have reported shifts in fiber digestion to the hind gut to compensate for depressed microbial activity in the rumen when high fat levels are fed (Zinn 1989;Tamminga and Doreau 1991;Hussein et al 1995).…”

“…Other researchers (Zinn 1989;Tamminga and Doreau 1991;Hussein et al 1995) have reported a reduction in ruminal fiber digestion and a shift in the site of fiber digestion from the rumen to the hind gut when high-fat diets are fed. These latter results may explain why no effect on NDFD was observed as a result of exposing the dietary fat to ruminal fermentation in the present study.…”

“…The reduction in VI observed when processed canola screenings were fed was likely due to exposure of canola oil due to the breaking of the seed coat. Disruption of ruminal digestion by addition of fat to the diet has been well documented (Palmquist and Jenkins 1980;Moore et al 1986;Zinn 1989) and is more pronounced when polyunsaturated fatty acids are fed relative to saturated fatty acids (Ferlay et al 1991). Canola oil, the primary source of fat used in the present study is high in polyunsaturated fatty acids.…”

Effects of canola and soya lecithins compared with canola oil and seed on performance, carcass quality and body fat composition of growing bulls

“…Zinn (1989) found that the replacement of yellow grease and blended animal-vegetable-fat by raw soya lecithin had no effect on growth performance of steers either and Mathison (1978) found no significant effect on feed efficiency and carcass characteristics when adding to a steer diet up to 30 g/kg of rape seed gum, the non-dehydrated lecithin from the oil refining process. Due to the reason given above, differences between lecithin diets and the oil as well as oilseed diet might have been more pronounced when soyabean oil and whole soyabeans had been used instead of canola oil and seed.…”

Animal Performance, Feeding Behaviour and Carcass Traits of Feedlot Cattle Diet Fed With Agro-Industrial By-Product as Fat Source

“…The occurrence of increased DM intake and reduced feed efficiency with the use of CSB can be attributed to the lower energy intake of this ingredient (Table 1), which has possibly been compensated by a greater intake by the animals, because the energy density of the diet is an important intake regulatory factor (Zinn, 1989a). This interpretation is corroborated by the study of Galyean and Defoor (2003), who stated that bovine fed diets with lower energy might raise intake to achieve the same energy level as long as the intake is not limited by the filling of the digestive tract.…”