Rumen-protected Met Supplementation Research Articles

Evaluation of animal performance responses to the supplementation of 2 rumen-protected methionine supplements in post-peak-lactation Holstein cows

Our objective was to evaluate the performance response of dairy cows fed a Met-deficient diet and provided a rumen-protected Met (RPM) supplement. A total of 24 multiparous (95 ± 20 DIM) and 6 primiparous (71 ± 3 DIM) Holstein cows were assigned to 1 of 3 treatments using a replicated 3 × 3 Latin square design with 21-d periods: a control diet deficient in MP Met by 17 g/d (CON) or the control diet plus 14 g/d of a RPM supplement, RPM-K or RPM-S, containing approximately 80% Met. Milk samples were collected on d 13 to 14 and 18 to 21 of each period. Plasma samples were collected on d 21 of each period. Contrasts were used to evaluate the effect of RPM addition (CON vs. RPM-K + RPM-S combined) and source of RPM (RPM-K vs. RPM-S). There was no difference between RPM-S and RPM-K in milk fat percentage (3.66 vs. 3.69%, respectively; P = 0.47) or milk protein percentage (3.28% for both treatments; P = 0.98), but RPM-K decreased DMI compared with RPM-S (26.2 vs. 26.6 kg/d; P = 0.02). Milk fat and protein percentages were increased by RPM relative to CON (3.60% fat and 3.25% protein; P = 0.02 and P = 0.04, respectively). Milk fat yield was not different between RPM-K and RPM-S (1.39 and 1.40 kg/d; P = 0.74), but milk fat yield tended to increase with RPM relative to CON (1.37 kg/d, P = 0.07). Plasma free Met was not different between RPM-S and RPM-K treatments (46.6 and 46.5 μ M , respectively; P = 0.97), and RPM supplementation increased plasma concentrations relative to CON (33.0 μ M ; P < 0.001). Relative to CON, both RPM supplements similarly increased milk fat, milk protein, and plasma free Met, suggesting similar relative bioavailability.

186 Young Scholar Presentation: Immunometabolism during periods of negative nutrient balance or heat stress is altered by dietary methyl donor supply in dairy cows

Abstract Our research examined the effects of enhancing methyl donor supply on immunometabolism during periods of negative nutrient balance (NNB) or heat stress (HS). The first experiment examined the effects of post-ruminal choline supply during NNB on production and pathways of 1-carbon metabolism. Ten primiparous rumen-cannulated cows (158±24 DIM) were used in a replicated 5×5 Latin square design with 4d treatment periods and 10d of recovery. Treatments were unrestricted intake with abomasal infusion of water, restricted intake (R; 60% of net energy for lactation requirements) with abomasal infusion of water or R plus abomasal infusion of 6.25, 12.5, or 25 g/d choline ion. Liver tissue was collected at the end of each treatment period. Enhancing choline supply increased milk yields, but decreased liver triacylglycerol. Activity of betaine homocysteine methyltransferase increased with choline, while methionine synthase tended to increase, and cystathionine β-synthase was decreased. These changes were associated with increased liver and plasma Met. Overall, enhanced supply of choline during NNB increases flux through the Met cycle to regenerate Met and reduce liver triacylglycerol. The second experiment examined the effects of rumen-protected Met (RPM) during HS on mTOR (mechanistic target of rapamycin)-related signaling proteins in the mammary gland. Thirty-two multiparous cows (184±59 DIM) were assigned to an environmental treatment, and a dietary treatment [TMR with RPM (0.105% DM) or without (CON)] in a crossover design. There were 2 periods with 2 phases per period. In phase 1 (9d), all cows were in thermoneutral conditions (TN) and fed ad libitum. During phase 2 (9d), group 1 (n=16) was exposed to HS using electric heat blankets while group 2 (n=16) remained in TN but were pair-fed to HS counterparts. After a washout period (21d), the study was repeated (period 2), with environmental treatments being inverted and dietary treatments remaining the same. Mammary tissue was collected at the end of phase 2. Abundance of phosphorylated mTOR was greater with RPM and tended to be greater with HS. Control cows had a greater decrease in milk protein (%) during phase 2 (difference from phase 1) compared with RPM cows, suggesting that RPM supplementation during HS may support greater milk protein synthesis via mTOR activation. The third experiment investigated the effects of RPM during HS on the response of mammary gland explants to lipopolysaccharide (LPS). Twenty-five mg of tissue obtained from cows in the second experiment was incubated with 0 or 3 μg/mL of LPS for 2h. Incubation with LPS increased abundance of genes associated with inflammation, while HS decreased genes associated with antioxidant responses. Expression of NFKB1was greater in LPS-treated explants from non-HS compared with HS cows. These data indicate that HS reduced immune and antioxidant responses while RPM did not attenuate the inflammatory response induced by LPS in vitro. Overall, data indicated a beneficial effect of choline during NNB and Met during HS on immunometabolism in dairy cows.

Effects of rumen-protected methionine or methionine analogs in starter on plasma metabolites, growth, and efficiency of Holstein calves from 14 to 91 d of age

During weaning, methionine (Met) supply decreases as liquid feed intake is reduced and ruminal function is developing. During this transition, the calf starter should both promote ruminal development and provide adequate nutrients post-ruminally. In mature ruminants, rumen-protected Met (RPM) and the Met analogs, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBa) and HMTBa isopropyl ester (HMBi), are used to increase Met supply, stimulate ruminal fermentation, or exert both effects, respectively. To evaluate the effects of these forms of Met on calf performance during development of ruminal function, 74 Holstein calves were raised until 91 d of age, in 2 enrollment periods. Calves were individually housed from birth and, at 14 d of age, balanced for sex and randomly assigned to receive a starter with no added Met (CTRL, n = 20) or one supplemented with RPM (Smartamine M, Adisseo USA Inc., Alpharetta, GA; n = 16), HMTBa (RumenSmart, Adisseo; n = 19), or HMBi (MetaSmart, Adisseo; n = 19). Milk replacer [28% crude protein (CP), 15% fat] was offered up to 1.6 kg of dry matter (DM)/d and fed 3 times daily. Weaning was facilitated from d 49 to 63. The 4 starters (25% CP, 2.5 Mcal of metabolizable energy/kg of DM) were offered ad libitum, and supplement inclusion was set to provide an additional 0.16% DM of Met equivalents, and equal amounts of HMTBa within the analogs. Body weight and stature were measured, and blood was collected and analyzed for plasma urea nitrogen, β-hydroxybutyrate, and free AA on a weekly basis. Supplementation of RPM and HMBi increased free plasma Met, but no differences in growth or feed efficiency compared with calves fed the CTRL starter could be attributed to the additional Met supply alone. The addition of HMBi in the starter increased feed intake and body weight during the last weeks of the experiment. On the contrary, HMTBa failed to increase plasma Met and depressed intake and growth after weaning, likely because the level included in the diet was too high and intake was greater than previous studies, exacerbating the level of HMTBa ingested. No differences were observed in stature, feed efficiency, or non-AA plasma measurements among groups. These results demonstrate that RPM and HMBi are effective sources of metabolizable Met; however, Met was apparently not limiting calves fed the basal diet in this study. The increased feed intake observed with the inclusion of HMBi in the starter during the weaning and early postweaning period might be mediated by its metabolism in the rumen, and further research is needed to determine the mechanisms involved.

Rumen-protected methionine supplementation during the peripartal period alters the expression of galectin genes associated with inflammation in peripheral neutrophils and secretion in plasma of Holstein cows.

The work described in this research communication aimed to investigate whether rumen-protected methionine (Met) supplementation during the periparturient period would affect the expression of galectins in blood-derived neutrophils, and secretion of galectins, IL (interleukin)-1β, IL-6, myeloperoxidase (MPO), and glucose in plasma. Because supplementation of rumen-protected Met would alleviate inflammation and oxidative stress during the peripartal period, we hypothesized that enhancing Met supply would benefit the innate immune response at least in part by altering the expression of galectin genes associated with neutrophil activity and inflammation. Galectins (Gal) have an immuno-modulating effect acting like cell-surface receptors whose activation often results in signaling cascades stimulating cells such as neutrophils. This study revealed an association between Met supplementation and galectin expression and secretion. This implies that galectin expression and secretion can be modulated by Met supplementation. Further studies are needed to evaluate the regulation of galectin gene expression for therapeutic and dietary intervention in the peripartal cow.

Utilization of protein in red clover and alfalfa silages by lactating dairy cows and growing lambs

Feeding trials were conducted with lactating cows and growing lambs to quantify effects of replacing dietary alfalfa silage (AS) with red clover silage (RCS) on nutrient utilization. The lactation trial had a 2 × 4 arrangement of treatments: AS or RCS fed with no supplement, rumen-protected Met (RPM), rumen-protected Lys (RPL), or RPM plus RPL. Grass silage was fed at 13% of dry matter (DM) with AS to equalize dietary neutral detergent fiber (NDF) and crude protein contents. All diets contained (DM basis) 5% corn silage and 16% crude protein. Thirty-two multiparous (4 ruminally cannulated) plus 16 primiparous Holstein cows were blocked by parity and days in milk and fed diets as total mixed rations in an incomplete 8 × 8 Latin square trial with four 28-d periods. Production data (over the last 14 d of each period) and digestibility and excretion data (at the end of each period) were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Although DM intake was 1.2 kg/d greater on AS than RCS, milk yield and body weight gain were not different. However, yields of fat and energy-corrected milk as well as milk content of fat, true protein, and solids-not-fat were greater on AS. Relative to AS, feeding RCS increased milk and energy-corrected milk yield per unit of DM intake, milk lactose content, and apparent N efficiency and reduced milk urea. Relative to AS, apparent digestibility of DM, organic matter, NDF, and acid detergent fiber were greater on RCS, whereas apparent and estimated true N digestibility were lower. Urinary N excretion and ruminal concentrations of ammonia, total AA, and branched-chain volatile fatty acids were reduced on RCS, indicating reduced ruminal protein degradation. Supplementation of RPM increased intake, milk true protein, and solids-not-fat content and tended to increase milk fat content. There were no silage × RPM interactions, suggesting that RPM was equally limiting on both AS and RCS. Supplementation of RPL did not influence any production trait; however, a significant silage × RPL interaction was detected for intake: RPL reduced intake of AS diets but increased intake of RCS diets. Duplicated metabolism trials were conducted with lambs confined to metabolism crates and fed only silage. After adaptation, collections of silage refusals and excreta were made during ad libitum feeding followed by feeding DM restricted to 2% of body weight. Intake of DM was not different when silages were fed ad libitum. Apparent digestibility of DM, organic matter, NDF, and hemicellulose was greater in lambs fed RCS on both ad libitum and restricted intake; however, acid detergent fiber digestibility was only greater at restricted intake. Apparent and estimated true N digestibility was substantially lower, and N retention was reduced, on RCS. Results confirmed greater DM and fiber digestibility in ruminants and N efficiency in cows fed RCS. Specific loss of Lys bioavailability on RCS was not observed. Based on milk composition, Met was the first-limiting AA on both silages; however, Met was not limiting based on production and nutrient efficiency. Depressed true N digestibility suggested impaired intestinal digestibility of rumen-undegraded protein from RCS.

Effects of Rumen-Protected Methionine on Dairy Performance and Amino Acid Metabolism in Lactating Cows

Problem statement: Free Met as one of the most limiting AA in dairy cows would be mostly degraded in the rumen. This study was to determine the effect of different levels of Rumen-Protected Met (RPMet) on dairy performance and serum amino acid metabolism. Approach: Thirty-six Holstein cows in similar condition were randomly assigned to six experimental treatments with six replicates each. Levels of RPMet in six treatments were 0(control), 14, 28, 42, 56 and 70 g day-1 per cow, respectively. Results: Treatment had no effect on percentage of milk protein, lactose and SNF. However, milk yield of cows fed 42 g day-1 RPMet was significantly higher than that of the control group and milk fat percentage was significantly increased with 56 g day-1 RPMet supplementation. There was the trend to decrease the concentration of serum amino acids except Met and Arg with the supplementation of RPMet. Serum EAA contents of the group supplementation of 42 g day-1 RPMet were lowest although there were no significant differences among all treatments. Serum BCAA concentrations of cows fed 28 g RPMet were significantly lower than that of the control group. Supplementation of 42 g RPMet could significantly decrease the concentration of NEAA and TAA compared to the control group. Conclusion/Recommendations: Supplementation of rumen-protected methionine improved dairy performance and promoted amino acid utilization in lactating cows in the present experiment. The optimal level of RPMet in the diet was 42 g per cow day-1.

Metabolize methionine and lysine requirements of growing cattle.

Two growth studies were conducted to determine the Met and Lys requirements of growing cattle. In each 84-d trial, steer calves were fed individually diets containing 44% sorghum silage, 44% corn cobs, and 12% supplement (DM basis) at an equal percentage of BW. In Trial 1, 95 crossbred steers (251 kg) were supplemented with urea or meat and bone meal (MBM). Incremental amounts of rumen-protected Met were added to MBM to provide 0, .45, .9, 1.35, 3, and 6 g/d metabolizable Met. In Trial 2, 60 steers (210 kg) were supplemented with urea or corn gluten meal (CGM). Incremental amounts of rumen-protected Lys were added to CGM to provide 0, 1, 2, 3, 4, 5, 6, 8, and 10 g/d metabolizable Lys. Supplementation with MBM and CGM increased the supply of metabolizable protein to the animal. Steers fed MBM plus 0 Met gained 49 g/d more than steers fed urea, whereas steers fed CGM plus 0 Lys gained 150 g/d more than steers fed urea. Supplementation of rumen-protected Met and Lys improved ADG in steers fed MBM and CGM, respectively (P < .10). Nonlinear analysis, comparing gain vs supplemental Met and Lys intake, predicted supplemental Met and Lys requirements of 2.9 and .9 g/d, respectively. This amount of additional Met promoted .13 kg/ d gain greater than MBM alone, and this amount of additional Lys promoted .10 kg/d gain greater than the CGM alone. Metabolizable Met and Lys requirements were predicted from Level 1 of NRC (1996) calculated metabolizable protein supply, amino acid analysis of abomasal contents, and the maximum response to supplemental AA. Steers gaining .39 kg/d required 11.6 g/ d Met or 3. 1% of the metabolizable protein requirement, whereas steers gaining .56 kg/d required 22.5 g/d Lys or 5.7% of the metabolizable protein requirement.

Effects of the Energy Balance of Dairy Cows on Lactational Responses to Rumen-Protected Methionine

This trial was designed to investigate the interactions between level of dietary energy and the response of cows after supplementation of rumen-protected Met. We examined this interaction for dairy cows fed a diet that was deficient in Met. Two percentages of energy (87 or 100% of requirements) were supplied with two concentrations of rumen-protected Met (0 or 21g/d). Twenty-four Holstein cows (58 d in milk) were assigned to an experiment with a splitplot design including five periods of 3 wk each. The lower energy level was obtained by limiting the amount of feed offered (18.4 vs. 20.1kg of dry matter intake). Diets characterized by low or normal amounts of energy were composed of corn silage (69.4% vs. 69.7%), energy concentrate (18.5% vs. 22.1%), oil meals treated with formaldehyde (11.5% vs. 7.4%), and urea (0.8% vs. 1.0%), respectively. The interaction between energy level and Met supplementation did not affect yield or composition of milk. An increase in the supply of both energy and Met increased the true protein content of milk by 0.11 percentage units. The effects of the level of dietary energy on the protein content of milk augmented the effects caused by Met supplementation. The main practical conclusion was that rumen-protected Met can be used with diets based on corn silage and soybean meal to increase the protein content of milk, even for dairy cows that are in a negative energy balance.