The Effect of Various Fat Levels and Fat Sources on Growth and Performance of Calves Fed Milk Replacer

Abstract Text: Seventy-one (71) 3 – 10 d old Holstein bull calves with average initial BW of 45.6 kg (SD = 1.95 kg) were shipped from Wisconsin to the Land O’ Lakes Research Facility. The objective of this study was to examine the growth and performance of calves fed milk replacer (MR) varying in fat level and fat source. Calves were randomly assigned according to BW and blood gamma globulin to their respective MR diet offered in a 15.0% solids solution. Calves were assigned to 1 of 3 diets: 22% crude protein (CP), 20% fat with lard as the primary fat source; 22% CP, 15% fat with medium-chain triglycerides (MCT) as the primary fat source; 22% CP, 15% fat with lard as the primary fat source and supplemented with 8 g essential fatty acids per calf daily (EFA; Neotec4^TM, Provimi North America, Inc., Brookville, OH). Calves were fed to provide 680 g DM/d in 2 feedings at 0600 and 1515 h. Calves were offered 340 g DM/d in one feeding during the last week. Calf starter (20% CP, as fed basis) was fed ad libitum throughout this 42 d trial. Data were analyzed by Mixed Procedures of SAS. There were no statistical differences (P > 0.05) in total BW gain, starter feed intake, or feed:gain among treatments. Calves fed a 22:20 MR with lard as the primary fat source consumed less (P < 0.05) MR compared to calves fed a 22:15 MR with lard as the primary fat source and supplemented with EFA. Milk replacers with MCT as the primary fat source may allow for a reduction in fat levels while supporting equal calf performance and growth.

		MR Diet
Item1	22:20 w/ Lard	22:15 w/ MCT	22:15 w/ lard, EFA	S.E.
BW Gain, kg	22.9	26.0	24.4	1.51
MR Intake (DM), kg	24.3a	24.8ab	25.3b	0.280
Starter Intake (DM), kg	20.2	23.2	20.8	1.56
Feed:Gain	1.98	1.89	1.97	0.070
Scour Score*, 2 wk avg	1.43	1.33	1.45	0.060

¹ Means in the same row not followed by a common letter differ (P < 0.05).

* 1 - 4 scale: 1= normal, 2= loose, 3= water separation, 4= 3 with severe dehydration.

Keywords: calf, milk replacer, medium-chain triglyceride