Abstract #M318

# M318
Functional oils or monensin on milk production and feed efficiency of Holstein cows during the summer.
F. P. Rennó*1, C. S. Takiya2, G. G. Silva1, T. A. Del Valle1, E. M. C. Zilio1, L. G. Ghizzi1, J. Torrent3, 1University of Sao Paulo, Pirassununga, SP, Brazil, 2Kansas State University, Manhattan, KS, 3Oligo Basics, Cascavel, Parana, Brazil.

Essential (Oligo Basics, Cascavel, Brazil) is a feed additive that contains cashew nut shell liquid (CNSL) and castor oil (CO) as active ingredients. CNSL and CO are considered functional oils (FO) due to their anti-oxidative and gastro-protective properties. This study aimed to compare the milk production and feed efficiency of cows fed FO or monensin (MON) during the summer season in Pirassununga, Brazil. Thirty-six cows (201 ± 63 DIM, 599 ± 78 kg BW, and 28.7 ± 3.92 kg/d milk yield) were used in a randomized complete block design experiment. Cows were allocated in a barn containing forced ventilation with 25.0 ± 0.83°C temperature, 81.5 ± 4.67% of relative humidity, and 75 ± 0.8 ITU during the 5 wk of experiment. Cows within block were assigned to one of treatments: control (CON); FO, 500 mg/kg DM of Essential; or MON, 22 mg/kg DM of MON (Rumensin, Elanco Animal Health, Greenfield, IN). Additives were provided mixed into the concentrate of a TMR fed twice daily. Samples of ingredients and orts were collected weekly to determine DM intake. Cows were milked twice daily, being the milk samples collected weekly during 6 consecutive milkings to determine the contents of fat, protein and lactose by infrared method. Data were analyzed as repeated measures using the PROC MIXED of SAS, and differences were calculated by PDIFF test. Data from one week before the start of experiment were used for covariate adjustments. FO-fed cows had greater milk fat concentration and DM intake than MON (Table 1). In addition, FO numerically increase milk fat concentration and had similar DM intake in relation to CON. FO may improve milk fat concentration of cows in summer. Table 1.
Production, kg/d
 3.5% FCM28.728.329.90.430.153<.001
Milk concentration, g/kg
 DMI, kg/d24.6a23.0b24.5a0.460.0210.158
 Milk yield/DMI1.211.301.200.030.0920.386
Diet by time (wk.) interaction effect >0.10 for all variables.

Key Words: ionophore, milk fat