Performance of early-lactation dairy cows as affected by dietary starch and monensin supplementation

Abstract

The objective of this study was to evaluate the effect of postpartum dietary starch content and monensin supplementation throughout the periparturient period and into early lactation on production performance of dairy cows during early lactation. Prior to parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% NDF, 22.7% ADF, 15.5% CP) or low-starch (LS; 21.5% starch, 36.9% NDF, 25.2% ADF, 15.4% CP) total mixed ration with a daily topdress of either 0mg/d of monensin or 450mg/d monensin (MON), continuing with prepartum topdress treatment assignment. From d 22 through 63 postpartum, cows were fed HS and continued with their assigned daily topdress. Interactions of starch content and MON supplementation were not significant for any of the variables measured. Cows fed HS from wk 1 to 3 postpartum had higher early-lactation milk yields (starch × week interaction) compared with LS cows, but HS cows also had lower percentages of milk fat, true protein, lactose, and total solids during the same period, resulting in similar yields of energy-corrected milk (ECM) between starch treatments. Cows fed HS had higher early-lactation dry matter intake (DMI; starch × week interaction) and lost less body condition score during wk 1 to 3, contributing to improved energy balance postpartum. No effect of starch treatment was observed on apparent total-tract dry matter or starch digestibilities assessed during d 18 to 19 (±2) postpartum, although cows fed the LS diet had greater apparent total-tract NDF digestibility compared with cows fed the HS diet. Cows fed MON had higher DMI and higher milk yields during the first 9 wk of lactation. However, all cows had similar yields of ECM because of trends for lower milk fat content during early lactation. In part because of similar yields of ECM between these treatments and higher DMI for cows fed MON, ECM per DMI during the first 9 wk of lactation was not affected by MON treatment. There was no effect of MON treatment on apparent total-tract dry matter, NDF, or starch digestibilities. Overall, cows fed more propiogenic diets in early lactation (HS or MON) had increased milk yield and DMI during the immediate postpartum period, indicating that diets with greater propiogenic capacity do not have detrimental effects on early-lactation DMI.

Effects of supplementing a Saccharomyces cerevisiae fermentation product during the periparturient period on performance of dairy cows fed fresh diets differing in starch content

“…Contrary to the results of current study, Rabelo et al (2003) and McCarthy et al (2015) reported that animal responses to high-starch diets in DMI or milk yield were greater. The discrepancy between their studies (Rabelo et al, 2003;McCarthy et al, 2015) and our study might be explained by differences in close-up diets that the animals were fed before calving, as proposed by Dann (2016); cows were fed controlled-energy closeup diets in our study to reduce postpartum metabolic complications Janovick et al, 2011), but high-starch close-up diets were fed in the previous studies (Rabelo et al, 2003;McCarthy et al, 2015). In the study of Rabelo et al (2003), even the low-energy close-up diet contained 38.2% NFC, which was much higher than that of our study (25.6% NFC).…”

Effects of prepartum dietary cation-anion difference on aspects of peripartum mineral and energy metabolism and performance of multiparous Holstein cows

“…Milk yield at the corresponding milking was used to weight milk composition and calculate yield of components. Weekly average yield of ECM were calculated from weekly yield and composition as described by McCarthy et al (2015).…”

“…The average of the 2 BCS were used for sta-tistical analysis. Weekly calculations of prepartum and postpartum net energy balance (EBAL) were determined according to NRC (2001) equations as described by McCarthy et al (2015).…”

Reproductive and Metabolic Responses of Early‐lactating Dairy Cows Fed Different Dietary Protein Sources

“…Grain legumes are feedstuffs of high protein and metabolizable energy content (McCarthy et al. ). They are readily accepted by cattle, and animals require little adaptation to avoid rumen acidosis and reduced intakes.…”

“…Among dietary protein sources, research has clearly shown that legumes can increase growth rates in ruminants due to higher nitrogen utilisation efficiency and dry matter intake (Speijers et al 2004;Marley et al 2007;Chand et al 2014). Grain legumes are feedstuffs of high protein and metabolizable energy content (McCarthy et al 2015). They are readily accepted by cattle, and animals require little adaptation to avoid rumen acidosis and reduced intakes.…”