Jersey calf performance in response to high-protein, high-fat liquid feeds with varied fatty acid profiles: blood metabolites and liver gene expression.

Most available Jersey calf milk replacers (CMR) use edible lard as the primary fat source, which lacks medium-chain fatty acids (MCFA). However, Jersey cow milk consists of over 10% MCFA. The objective of this trial was to determine whether altering the fatty acid profile of CMR by increasing the amount of MCFA would alter liver lipid infiltration, liver gene expression, and blood metabolites when fed to Jersey calves. Fifty Jersey calves were fed 1 of 4 diets: pasteurized saleable whole milk (pSWM) from Jersey cows [27.9% crude protein (CP), 33.5% fat, dry matter (DM) basis]; CMR containing 100% of fat as edible lard (100:00; 29.3% CP, 29.1% fat, DM basis); CMR containing 20% of fat as coconut oil (CO; 80:20; 28.2% CP, 28.0% fat); or CMR containing 40% of fat as CO (60:40; 28.2% CP, 28.3% fat). Liquid diet DM intake averaged 0.523, 0.500, 0.498, and 0.512 kg/d for pSWM, 100:00, 80:20, and 60:40, respectively. Calves were fed their assigned liquid diet daily at 0600 and 1800 h from 2 d of age until 7 wk of age, and once daily until 8 wk of age. Calves were taken off trial at 9 wk of age. Calves had access to water and grain (23.8% CP, 2.71% fat, DM basis). Grain DM intake averaged 0.386, 0.439, 0.472, and 0.454 kg/d for pSWM, 100:00, 80:20, and 60:40, respectively. Liver biopsy cores were obtained from 15 calves at 42 d of age (pSWM, n=4; 100:00, n=4; 80:20, n=3; 60:40, n=4) and from 4 baseline calves <2d of age. Liver biopsy cores were used for histological appraisal of lipid infiltration and gene expression analyses of short-, medium-, and long- chain acyl-coenzyme A dehydrogenases, sterol regulatory element binding transcription factor 1, acetyl coenzyme A carboxylase, and fatty acid synthase. Lipid infiltration and expression of selected genes were not different among diets. After an overnight fast, weekly blood samples were taken immediately before feeding at 0600 h via jugular venipuncture in all calves. Serum and plasma obtained from blood samples were used in the analyses of total protein, glucose, triglycerides, nonesterified fatty acids, and plasma urea nitrogen (PUN). Nonesterified fatty acids and PUN were the only blood metabolites affected solely by diet. Nonesterified fatty acids decreased in a linear manner with increased dietary CO inclusion. Calves fed pSWM had higher PUN than calves fed 80:20. In this trial, altering the fatty acid profile of CMR with the addition of medium-chain fatty acids from CO had minimal effects on liver lipid infiltration, liver gene expression, and blood metabolites when fed to Jersey calves.

Jersey calf performance in response to high-protein, high-fat liquid feeds with varied fatty acid profiles: intake and performance.

The objective of this study was to determine whether altering the fatty acid (FA) profile of milk replacer (MR) with coconut oil, which contains a high concentration of medium-chain FA, to more closely match the FA profile typically found in whole milk from Jersey cows, would improve Jersey calf performance. Male (n=18) and female (n=32) Jersey calves were assigned at birth to 1 of 4 liquid diets: (1) pasteurized Jersey saleable whole milk [pSWM; 27.9% crude protein (CP) and 33.5% fat]; (2) 29.3% CP and 29.1% fat MR, containing 100% of fat as edible lard (100:00); (3) 28.2% CP and 28.0% fat MR, containing 80% of fat as lard and 20% as coconut oil (80:20); and (4) 28.2% CP and 28.3% fat MR, containing 60% of the fat as lard and 40% as coconut oil (60:40). Calves were fed their respective liquid diet twice daily during wk 1 through 7 and once daily until weaning (approximately wk 8). Calves had ad libitum access to grain and water, and calves were monitored 1 wk postweaning. Average daily gain and body weight did not differ by treatment. Calves fed pSWM tended to have greater hip height (HH) than calves fed 80:20 (80.5 vs. 79.7 cm). Coconut oil tended to have a quadratic effect on HH, with calves fed 100:00, 80:20, and 60:40 at 79.2, 79.7, and 78.5 cm, respectively. No difference was observed in withers height between pSWM and 80:20. Coconut oil had a quadratic effect on withers height, with calves fed 100:00, 80:20, and 60:40 at 76.6, 77.5, and 76.5 cm, respectively. Change in HH from birth to 9 wk tended to be greater for calves fed pSWM than calves fed 80:20 (0.218 vs. 0.194 cm/d). Calves fed pSWM had higher milk dry matter intake (DMI) than calves fed 80:20 (0.580 vs. 0.518 kg/d). No effect of coconut oil was observed on milk DMI. Grain DMI and total DMI did not differ among treatments. Calves fed pSWM had an increase in days with a fecal score >2 compared with calves fed 80:20 (4.24 vs. 2.00 d). Coconut oil had a quadratic effect on fecal score, with calves fed 100:00, 80:20, and 60:40 scoring 4.00, 2.00, and 3.63 d, respectively. Respiratory score did not differ among treatments. In conclusion, DMI and average daily gain were similar among treatments. However, differences among treatments in skeletal growth and fecal scores are indicative of some possible benefits of medium-chain FA on calf health and performance.