Objectives were to evaluate the effects of rumen-protected glucose (RPG) supplementation on milk production, post-absorptive metabolism, and inflammatory biomarkers in transition dairy cows. Fifty-two multiparous cows were blocked by previous 305-d matureequivalent milk (305ME) yield and randomly assigned to 1 of 2 iso-energetic and iso-nitrogenous treatments:(1) control diet (CON; n = 26) or (2) a diet containing RPG (pre-fresh 5.3% of dry matter and 6.0% of dry matter postpartum; n = 26). Cows received their respective dietary treatments from d −21 to 28 relative to calving, and dry matter intake was calculated daily during the same period. Weekly body weight, milk composition, and fecal pH were recorded until 28 d in milk (DIM), and milk yield was recorded through 105 DIM. Blood samples were collected on d −7, 3, 7, 14, and 28 relative to calving. Data were analyzed using repeated measures in the MIXED procedure (SAS Institute Inc., Cary, NC) with previous 305ME as a covariate. Fecal pH was similar between treatments and decreased (0.6 units) postpartum. Dry matter intake pre-and postpartum were unaffected by treatment, as was milk yield during the first 28 or 105 DIM. Milk fat, protein, and lactose concentration were similar for both treatments. Blood urea nitrogen and plasma glucose concentrations were unaffected by treatment; however, results showed increased concentration of circulating insulin (27%), lower nonesterified fatty acids (28%), and lower postpartum β-hydroxybutyrate (24%) in RPG-fed cows. Overall, circulating lipopolysaccharide-binding protein and haptoglobin did not differ by treatment, but at 7 DIM, RPG-fed cows had decreased lipopolysaccha-ride-binding protein and haptoglobin concentrations (31 and 27%, respectively) compared with controls. Supplemental RPG improved some biomarkers of postabsorptive energetics and inflammation during the periparturient period, changes primarily characterized by increased insulin and decreased nonesterified fatty acids concentrations, with a concomitant reduction in acute phase proteins without changing milk production and composition.
The study objective was to determine the effects of rumen-protected methionine (Met) by microencapsulation (RPM) on amino acid (AA) supply to the udder, milk production, and manure nitrogen (N) losses of dairy cows. A corn and soybean-based diet deficient in metabolizable Met (~10 g/d) was supplemented with RPM providing 0, 11.0, 19.3, and 27.5 g/d of Met. Dry matter intake (DMI), milk production, plasma essential AA (EAA), mammary plasma flow (MPF), and fecal (FN) and urinary N (UN) outputs (g/d) were determined. The RPM increased linearly milk yield, milk protein yield, and energy corrected milk yield (p < 0.040) without affecting DMI. Milk protein yield increased by 50 g/d for the 19.3 vs. 0 g/d dose (p = 0.006) but the rate of increment decreased for 27.5 g/d dose. Plasma Met, and MPF increased linearly with RPM dose (p < 0.050). Apparent total tract digestibility of crude protein (p = 0.020) and FN (p = 0.081) decreased linearly with RPM. The UN did not change but total manure N decreased linearly with RPM (p = 0.054). The RPM (19.3 g/d) seemed to help cows overcome the metabolizable Met deficiency while mitigating manure N excretions to the environment.
In 2017, 2.6 million ha of American farmland were destined for corn silage production, which was estimated at 116.5 million tons. Data for 2018 are yet to be compiled but field observations provide insight of a difficult year for growing and harvesting conditions. In recent years, there has been a renewed interest in making the most efficient use of forage resources. Since corn silage is a predominant forage for beef and dairy cattle, most advances have focused on improving harvesting, storage and feeding methods of this crop. The harvesting process has been modified with the introduction of various designs of kernel processors; commercial laboratory data show a trend towards greater and more uniform processing score since 2010. Furthermore, the degree of processing can now be objectively evaluated by combining hydrodynamic separation and image processing software to obtain a kernel processing score in real time in field conditions. Applications of plastic film technology, such as oxygen barriers, to seal and maintain an anaerobic environment, have aroused interest due to the possibility of reducing spoilage with a concomitant increase in recovery of dry matter from the uppermost layer of a silage pile. Throughout the storage phase, it has been recognized that starch digestibility increases over time due to prolamin solubilization. Recent work with reconstituted high-moisture corn demonstrated that bacterial proteolytic activity contributes 60% to protein solubilization and that fermentation acids play a minor role in this process. The field of inoculants has also seen innovations in terms of application equipment and species and strain selection, with Lactobacillus buchneri becoming relevant for certain conditions that require longer aerobic stability. During feed-out, dry matter monitoring can be done with instant measurements using NIR technology in various applications ranging from tractor-mounted instruments to hand-held devices. Even though silage making has been a longstanding practice, specific aspects of the process have evolved over time and are worthy of consideration to improve forage management and quality in support of ruminant nutrition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.