Effects of Prepartum Administration of a Monensin Controlled Release Capsule on Rumen pH, Feed Intake, and Milk Production of Transition Dairy Cows

Abstract

Effects of prepartum administration of a monensin controlled release capsule (CRC) on rumen pH, dry matter intake, and milk production during the transition period and early lactation were determined in 16 multiparous Holstein cows. Cows were divided into blocks of 2 depending on calving date. Cows were fed either a close-up dry cow or a lactating cow total mixed ration ad libitum. Rumen pH was monitored continuously using indwelling probes. Monensin did not affect average daily rumen pH, time below pH 6, time below pH 5.6, area below pH 6, and area below pH 5.6 throughout the experiment. Average daily pH, time below pH 6, and time below pH 5.6 before calving were 6.62, 65.6 min/d, and 17.6 min/d, respectively, and did not differ among the weeks before calving. Average daily pH, time below pH 6, and time below pH 5.6 were 6.19, 443.3 min/d, and 115.5 min/d, respectively, during the first week after calving, and were 6.36, 204.3 min/d, and 52.4 min/d, respectively, during the sixth week after calving. In the weeks after calving, average daily pH showed a quadratic increase, time below pH 6 showed a quadratic decrease, and time below pH 5.6 showed a linear decrease. Monensin did not affect dry matter intake and daily yields of milk, milk fat, and milk protein. Results suggest that prepartum administration of a monensin CRC did not increase rumen pH in multiparous cows fed the experimental diets during the transition period and early lactation.

Effect of Feed Additives on Digestibility and Milk Yield of Holstein Cows Fed Wet Brewer Grains

“…Because there were not significant differences on treatment x sampling time, only main effects of ruminal pH, ammonia-N and total VFA are shown in Table 1. Similar responses were found for supplementation of monensin (Fairfield et al, 2007), bentonite (Gulsen et al, 2000) or enzymes (Miller et al, 2008) in dairy cow diets.…”

Close relationship between pre- and post-calving reticuloruminal pH levels in dairy cows

“…The periparturient period is known as being the most critical phase for dairy cows, as it includes the transition from gestation to lactation as well as the change from dry-period diet to the early-lactation cow diet. This is also reflected in ruminal physiology as the risk of acute ruminal acidosis and subacute ruminal acidosis (SARA) is highest in the first weeks after calving (Kleen et al, 2003;Fairfield et al, 2007). However, there is evidence of individual variability concerning: (1) microbial community composition;…”

Scientific progress in ruminant production in the 1st decade of the XXI century

“…In a meta-analysis of the impact of monensin on cow performance, Duffield et al (2008a) reported that monensin supplemented from day 21 to 60 before calving as topdress or CRC with doses ranging from 254 and 320 mg/d decreases the incidence of ketosis, abomasum displacement and mastitis although there was no effect on the incidence of milk fever, laminitis, dystocia, placenta retention and metritis. Monensin has no effect on dry matter intake (DMI) of dairy cows during the transition period and in early lactation (Ruiz et al, 2001;Eifert et al, 2005;Fairfield, et al, 2007). However, Duffield et al (2008b) observed that monensin depressed DMI (0.3 kg/d) and increased milk production (0.7 kg/d), thus improving milk production efficiency (2.5%).…”

“…Nevertheless, the effects of ionophore supplementation on milk yield are inconsistent. Some studies have shown positive effects of ionophores on milk yield and milk protein yield (McGuffey et al, 2001) but others reported no significant effects (Juchem et al, 2004;Zahra et al, 2006;Fairfield et al, 2007;Chung et al, 2008;Conti et al, 2008).…”