Effects of supplementing lactating dairy cow ration with sodium sesquicarbonate on reticulorumen pH, rumination, and dry matter intake

Abstract Text:

The objective of this study was to assess the effects of sodium sesquicarbonate (SQ-810), a reticulorumen buffer, on rumen pH, rumination time, and dry matter intake (DMI).  Sixteen early lactation multiparous, Holstein cows were housed in a tie-stall barn and milked twice daily at the University of Kentucky Coldstream Dairy from October 31, 2015 to January 1, 2016.  Cows were balanced by parity and milk production then split into 2 treatment groups for a crossover study with a low buffer (LB, n = 8) group and a high buffer (HB, n= 8) group.  The base TMR contained 16kg/d sodium bicarbonate.  The LB group did not receive any SQ-810 while the HB group received 0.30 kg of SQ-810 as fed.  Eight cows proceeded through sequence 1: three, 21 day periods receiving the LB diet in period 1, HB diet in period 2, and the LB diet in period 3.  The remaining 8 cows proceeded through sequence 2: three, 21 day periods receiving the HB diet in period1, LB diet in period 2, and the HB diet in period 3.  Each group was fed ad-libitum and dry matter intake (DMI) was collected.  All cows were administered an iNovotec Animal Care (iNovotec Animal Care, Austria) reticulorumen pH and temperature bolus.  Daily rumination time was recorded using HR tags (SCR Engineers Ltd., Netanya, Israel) and CowManager SensOor (SENRUM) tags (Agis Automatisering, Harmenlen, Netherlands).  Low pH was calculated as the total time where pH was < 5.80.  The MIXED procedure of SAS (SAS Institute, Inc., Cary, NC) was used to evaluate the effects of cow, sequence, treatment and period on each parameter measured.  Rumen pH and low pH time (pH<5.80) were significantly influenced by treatment (P < 0.01).  Rumen pH was 5.82 ± 0.07 for LB cows and 5.85 ± 0.07 for HB cows.  Low pH time (pH<5.80) was greater (P < 0.01) for LB days 10.70± 0.23 h/d than for HB days, 9.40±0.23 h/d.  Dry matter intake was 25.68±0.61 kg/d with LB cows and 26.53±0.61 kg/d for HB cows.  Treatment affected SCR rumination times (P < 0.01) LB 457.84±19.15 min/d and HB 435.02±19.15 min/d. However, the rumination time measured using SENRUM was not significantly different between treatments.   The addition of SQ-810 to the TMR increased reticulorumen pH and DMI significantly (P < 0.01). This research demonstrates the positive effects of SQ-810 rumen buffer in a lactating cow diet.

Keywords: sodium sesquicarbonate, rumen pH