Effects of slow-release urea and rumen-protected methionine and histidine on performance of dairy cows

Abstract

This experiment was conducted with the objective to investigate the effects of slow-release urea and rumen-protected (RP) Met and His supplementation of a metabolizable protein (MP)-deficient diet (according to NRC, 2001) on lactation performance of dairy cows. Sixty lactating Holstein cows were used in a 10-wk randomized complete block-design trial. Cows were fed a covariate diet for 2 wk and then assigned to one of the following treatments for an 8-wk experimental period: (1) MP-adequate diet [AMP; 107% of MP requirements, based on the National Research Council (NRC, 2001)]; (2) MP-deficient diet (DMP; 95% of MP requirements); (3) DMP supplemented with slow-release urea (DMPU); (4) DMPU supplemented with RPMet (DMPUM); and (5) DMPUM supplemented with RPHis (DMPUMH). Total-tract apparent digestibility of dry matter, organic matter, neutral detergent fiber, and crude protein, and urinary N and urea-N excretions were decreased by DMP, compared with AMP. Addition of slow-release urea to the DMP diet increased urinary urea-N excretion. Dry matter intake (DMI) and milk yield (on average 44.0±0.9kg/d) were not affected by treatments, except DMPUMH increased DMI and numerically increased milk yield, compared with DMPUM. Milk true protein concentration and yield were increased and milk fat concentration tended to be decreased by DMPUMH, compared with DMPUM. Cows gained less body weight on the DMP diet, compared with AMP. Plasma concentrations of His and Lys were not affected by treatments, whereas supplementation of RPMet increased plasma Met concentration. Plasma concentration of 3-methylhistidine was or tended to be higher for DMP compared with AMP and DMPU, respectively. Addition of RPHis to the DMPUM diet tended to increase plasma glucose and creatinine. In conclusion, feeding a 5% MP-deficient diet (according to NRC, 2001) did not decrease DMI and yields of milk and milk components, despite a reduction in nutrient digestibility. Supplementation of RPHis increased DMI and milk protein concentration and yield. These results are in line with our previous data and suggest that His may have a positive effect on voluntary feed intake and milk production and composition in high-yielding dairy cows fed MP-deficient diets.

Extruded soybean meal increased feed intake and milk production in dairy cows

“…The greater concentrations of His, Leu, and Val with ESBM in the current experiment can be explained with increased supply of these AA with RUP, compared with SSBM. Carnosine is a dipeptide containing β-Ala and His and muscle carnosine is considered an endogenous source of His in ruminants or monogastric animals (see discussion in Giallongo et al, 2015). Its increased concentration with the ESBM diets is in agreement with the increased plasma His concentrations.…”

Effects of slow-release urea and rumen-protected methionine and histidine on mammalian target of rapamycin (mTOR) signaling and ubiquitin proteasome-related gene expression in skeletal muscle of dairy cows

“…The experimental procedures were in accordance with the guidelines of the Animal Care and Use Committee at The Pennsylvania State University. Cows, experimental design, and treatments were described in detail by Giallongo et al (2015). Briefly, the trial was conducted in 2 phases each consisting of 30 lactating Holstein cows.…”

“…Feeding a nutrient-restricted diet (68.1% of NE M and 86.7% of MP requirements) to Angus-Gelbvieh crossbred cows was associated with a downregulation of mTOR signaling and a higher amount of ubiquitinated proteins, suggesting a decrease in protein synthesis and enhanced protein degradation in muscle (Du et al, 2005). In the main experiment of this study (Giallongo et al, 2015), feeding a 5% MPdeficient diet based on the NRC (2001) requirements did not decrease DMI and yields of milk and milk components; however, it increased or tended to increase plasma concentrations of 3-methylhistidine (3-MH; an indicator of myofibrillar protein breakdown) when compared with an MP-adequate diet and an MP-deficient diet supplemented with slow-release urea, respectively. In addition, the results from the main experiment demonstrated that cows receiving the MP-deficient diet had less BW gain than those fed MP-adequate diet or slowrelease urea and RPAA-supplemented diets (Giallongo et al, 2015).…”

“…Therefore, we evaluated the effects of slow-release urea and RPMet and RPHis supplementation of a MPdeficient diet, according to NRC (2001) requirements, on expression of key factors of the mTOR pathway and UPS in skeletal muscle of dairy cows. Muscle samples together with comprehensive production data, including milk yield and composition and plasma and muscle AA concentrations, were available from the main experiment (i.e., Giallongo et al, 2015).…”

Effect of Complete Feed Silage Made from Agricultural Waste on Milk Yield and Quality of Dairy Cows

“…The DMI and milk production were decreased when feeding of metabolizable protein deficient diets (Lee et al, 2011;2012a). On the contrary, when DMI did not decrease, milk production was also not different from diets with adequate metabolizable protein (Lee et al, 2012b;Giallongo et al, 2015).…”