Abstract
To determine the effect of Certillus on milk production, milk components and feed efficiency, primiparous (n = 13) and multiparous (n = 12) Holstein cows were assigned to one of two dietary groups starting from 8 to 120 days of lactation. The controls (n = 13) received regular TMR ration, and treated cows (n =12) received control TMR plus 2 x 109 cfu/head of Certillus (Church & Dwight Co., Inc., Waukesha, WI). Cows were housed in an open-air free-stall barn with 16 Insentec electronic feeders (8 feeders/group) to record daily feed events and intake (DMI). Cows were provided with ad libitum TMR fed twice daily and were milked twice daily. Milk samples were taken weekly during successive a.m./p.m. milkings and analyzed for percentage milk fat, protein, lactose, and milk urea nitrogen (MUN). Data were analyzed using a repeated-measures 2 x 2 factorial ANOVA. Daily milk production (4%FCM) was influenced (P < 0.05) by treatment x parity, week and parity, averaging 11% greater (P < 0.05) in Certillus-fed than control cows. Milk fat percentage increased (P < 0.005) from 4.02 to 4.41 + 0.09% with Certillus feeding. Milk lactose was influenced (P < 0.05) by week and treatment x parity. Milk protein was affected by week (P < 0.001) only. Certillus decreased (P < 0.05) MUN levels such that MUN was 1.0 mg/dL greater (P < 0.001) in Certillus-fed than control cows. Feed intake was reduced by 9% (P < 0.01) and feed efficiency (kg 4%FCM/kg DMI) was improved by 14% (P < 0.05) in Certillus-fed versus control cows. We conclude that Certillus may hold potential as an effective direct-fed microbial to increase feed efficiency and milk production.
Effect on feed intake, milk production and milk composition of Holstein cows by replacing maize grain with wheat in total mixed rations