Highly fermentable starch at different diet starch concentrations decreased feed intake and milk yield of cows in the early postpartum period

Abstract

The objective of this study was to evaluate the effects of diet starch concentration and fermentability (SF) fed during the early postpartum (PP) period on dry matter intake (DMI), yields of milk and milk components, body reserves, and metabolism. Fifty-two multiparous Holstein cows were used in a randomized block design with a 2 × 2 factorial arrangement of treatments. Treatment diets were formulated to 22% (LS) or 28% (HS) starch with dry ground corn (DGC) or high-moisture corn (HMC) as the primary starch source. Treatments were fed from 1 to 23 d PP and cows were switched to a common diet until 72 d PP to measure carryover (CO) effects. Treatment period (TP) diets were formulated for 22% forage neutral detergent fiber and 17% crude protein, and starch concentration was adjusted by substitution of corn grain for soyhulls. Throughout the experiment DMI and milk yield were measured daily, and milk components, body condition score (BCS), and body weight were measured weekly. Blood was collected weekly during the TP and every second week during the CO period. During the TP, HMC decreased DMI more when included in the HS (3.9 kg/d) than in the LS (0.9 kg/d) diets and HMC decreased yields of milk, fat, and FCM by 4.3, 0.19, and 4.8 kg/d, respectively. Treatments also interacted over time to decrease DMI and yields of milk and milk components more for HMC compared with DGC as time progressed during the TP. Loss of BCS was increased when HMC was fed in a HS diet (-0.38 vs. -0.17) and decreased when included in a LS diet (-0.21 vs. -0.29) with no effects on body weight change during the TP. Treatments interacted with time to affect plasma concentrations of glucose and insulin with HS increasing concentrations early in the TP compared with LS but with similar effects by the end of the TP. During the CO period, treatment effects on DMI diminished over time with no main effects of treatment for the entire period. Starch concentration and SF interacted to affect yields of milk, fat, and FCM during the CO period, which were greater for HS-DGC and LS-HMC (54.8 and 52.8, 1.76 and 1.81, and 51.3 and 52.2 kg/d, respectively) than for LS-DGC and HS-HMC (51.2 and 51.0, 1.68 and 1.64, and 48.4 and 48.6 kg/d, respectively). Treatments did not affect BCS change during the CO period but HS lost body weight compared with LS (-5.7 vs. 7.0 kg). Blood glucose and insulin concentrations were not affected by treatments during the CO period. Feeding a highly fermentable starch source during the early PP period decreased DMI and yields of milk and milk components compared with a less fermentable starch source and the depression in DMI was greater when fed in the higher starch diet. However, diet starch concentration had no effects on yield of milk or milk components.

Changes in fermentation and animal performance during recovery from classical diet-induced milk fat depression using corn with differing rates of starch degradability

“…Overall, milk fat yield was numerically greater for LDS-fed animals, and fat yield tended (P = 0.07) to be greater for the LDS-fed animals on d 28. This is consistent with findings of Albornoz and Allen (2018), who reported a reduction in milk fat yield with high-moisture corn feeding in the early postpartum period. Oba and Allen (2003a) reported an interaction of corn grain conservation method and dietary starch concentration on milk fat concentration and milk fat yield, suggesting that milk fat is most markedly affected when dietary starch is elevated and the source of starch is rapidly fermentable.…”

“…Cholecystokinin suppresses feed intake by inhibiting gastric emptying, which may also stimulate tension receptors in the reticulorumen, thereby limiting intake (Allen, 2000). Similarly, high-starch diets increase ruminal propionate production and flux to the liver, stimulating hepatic oxidation and generation of ATP, which can also reduce DMI (Bradford and Allen, 2005;Albornoz and Allen, 2018). Ramirez Ramirez et al (2015) and Harvatine and Allen (2006a) reported reductions in DMI with high PUFA intake.…”

Review: Control of feed intake by hepatic oxidation in ruminant animals: integration of homeostasis and homeorhesis

“…Although increasing dietary starch can increase feed intake when cereal grains are substituted for forages by decreasing ruminal distention (Allen, 1996), increased ruminal starch fermentability decreased feed intake by up to 3 kg/day in several experiments reported in the literature (Allen, 2000). High-moisture corn decreased energy intake of cows in the postpartum period to a greater extent when fed in rations at higher starch concentrations (28% v. 22%) compared with less fermentable dry ground corn (Albornoz and Allen, 2018). Hypophagic effects of a more fermentable starch source in lactating cows were from decreased meal size despite a decreased inter-meal interval, so satiety was likely caused by the absorption of propionate within the timeframe of meals (Oba and Allen, 2003b).…”

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

“…However, these studies were conducted using dairy cows after peak lactation. A recent study reported that decreasing dietary starch content during the early postpartum period prevented reductions in DMI of cows fed a highly fermentable starch source, but rumen pH was not measured (Albornoz and Allen, 2018).…”