Rumen-protected Supplement Research Articles

Rumen-protected methionine during the peripartal period in dairy cows and its effects on abundance of major species of ruminal bacteria

BackgroundExtensive degradation of amino acids in the rumen via microbial deamination decreases the post-ruminal availability of dietary indispensable amino acids. Together with the normal decrease in voluntary dry matter intake (DMI) around parturition in dairy cows, microbial metabolism contributes to a markedly negative balance of indispensable amino acids, including methionine which may be the first-limiting for milk production. The main objective of the current study was to profile changes in major bacterial species with key functions in cellulose and hemicellulose digestion, xylan breakdown, proteolytic action, propionic acid production, lactate utilization and ruminal biohydrogenation in cows supplemented with rumen-protected Methionine (SM; Smartamine M, Adisseo NA, Alpharetta, GA, USA) from −23 through 30 d relative to parturition. Because ~90% of the methionine in SM bypasses the rumen, ~10% of the methionine is released into the rumen and can be utilized by microbes.ResultsAs expected, there was an increase in overall DMI after parturition (Day, P < 0.05) during which cows consumed on average 19.6 kg/d versus 13.9 kg/d in the prepartum period. The postpartum diet contained greater concentrations of lipid and highly-fermentable carbohydrate from corn grain, which likely explains the increases in the relative abundance of Anaerovibrio lipolytica, Megasphaera elsdenii, Prevotella bryantii, Selenomonas ruminantium, Streptococcus bovis, and Succinimonas amylolytica. Despite similar DMI prepartum, cows fed SM had greater (Treatment × Day, P < 0.05) abundance prepartum of Fibrobacter succinogenes, Succinimonas amylolytica, and Succinivibrio dextrinosolvens. However, the greater DMI in cows fed SM after parturition (19.6 kg/d versus 13.9 kg/d) was associated with lower abundance of Fibrobacter succinogenes (2.13 × 10−3 versus 2.25 × 10−4) and Selenomonas ruminantium (2.98 × 10−1 versus 4.10 × 10−1). A lower abundance (Day, P < 0.05) was detected on d 20 compared with d −10 for Fibrobacter succinogenes and Succinivibrio dextrinosolvens. The relative abundance of Butyrivibrio proteoclasticus and Eubacterium ruminantium was stable across treatment and time.ConclusionsIn diets with proper balance of rumen-degradable protein and fermentable carbohydrate, the small fraction of Methionine released from the rumen-protected supplement did not seem to compromise growth of major bacterial species in the rumen. In fact, it had a positive effect on 3 major species prepartum when DMI was similar between groups. Because the actual requirements of Methionine (and Lysine, for example) by the cow during the transition period are unknown, it appears warranted to study the rumen microbiome as it relates to supply of rumen-protected amino acids.

Effect of rumen-protected supplements of fish oil on intake, digestibility and nitrogen balance of growing goats

AbstractTwo groups of six male goats were used to assess the effects of rumen-protected supplements offish oil on intake, digestibility and nitrogen (N) balance. The animals were offered a diet consisting of forage and concentrate, the latter fraction supplemented with 0 (control) or lOOg/kg of rumen-protected fish oil supplement (PFO), containing a high proportion of the n-3 series (whole diet contained 0 or 60 g PFO per kg dry matter). No significant differences (P &gt; 0.05) were found between the two groups concerning live-weight gain, food intake, digestibility of DM, organic matter, N, neutral-detergent fibre and energy. In contrast, there were differences (P &lt; 0.05) regarding the digestibility of fat and of acid-detergent fibre, which were higher among the animals given the PFO diet. With respect to the individual fatty acids, we observed higher digestibility (P &lt; 0.05) of C14:0, C16:0, C18:0 and C20:0 among the animals given the PFO diet. The digestibility of C14:0, C18:0 and C20:0 was found to be negative among the animals given the control diet. No significant differences (P &gt; 0-05) were found regarding digestibility of total C18:1. In contrast, the coefficients for C18:2 (n-6) and C18:3 (n-3) were higher (P &lt; 0.05) among the non-supplemented animals. The intake and faecal flow values of C18:0 suggest that the mono- and polyunsaturated fatty acids with 18 atoms of carbon may, in both cases, undergo partial hydrogenation, which would be greater among the control group. The utilization of C20:5 (n-3) and, especially, of C22 : 6 (n-3), which were consumed only by the animals given the PFO diet, was estimated at 1-000. The PFO diet also produced lower levels ofurinary-N excretion (P &lt; 0.05), giving rise to higher N balances (P &lt; 0.05).

Increasing Amounts of Conjugated Linoleic Acid (CLA) Progressively Reduces Milk Fat Synthesis Immediately Postpartum

Mixed conjugated linoleic acid (CLA) isomers decrease milk fat synthesis during established lactation, but their ability to cause milk fat depression (MFD) immediately postpartum remains unclear. Multiparous Holstein cows (n=19) were randomly assigned to 1 of 4 doses of rumen-protected (RP) CLA supplements (0, 200, 400, and 600 g/d); each dose provided equal amounts of fatty acids by replacing and balancing treatments with an RP supplement of palm fatty acid distallate. Doses provided a total of 468g fatty acids/d and 0, 62, 125, or 187g of mixed CLA isomers/d, respectively. The CLA supplement contained a variety of CLA isomers: 5.4% trans-8, cis-10; 6.3% cis-9, trans-11; 7.9% trans-10, cis-12; and 8.2% cis-11, trans-13 CLA. Each group received treatments from approximately −10 to 21 d relative to calving. To improve palatability and ensure complete consumption, doses were mixed with equal amounts of steam-flaked corn and dried molasses; one-half the supplement was fed at 0600h, and the remaining supplement was fed at 1800h. Milk yield and individual feed intake were recorded daily, and milk samples were obtained from each cow every 2nd day (at both milkings) starting on d 1 postpartum. There were no differences in dry matter intake (17.1 kg/d), milk yield (34.2 kg/d), protein content (3.74%), lactose content (4.61%), or yield of milk protein or lactose. The CLA supplementation decreased overall milk fat content in a dose-responsive manner (4.57, 3.97, 3.32, and 3.10, respectively), and milk fat yield displayed the same progressive decline. The dose-dependent decrease in milk fat content was evident during wk 1 and became highly significant during wk 2 and 3. The milk fat yield response pattern was similar, and by d 21, the highest RP-CLA supplement decreased milk fat content and yield by 49 and 56%, respectively. These data clearly indicate RP-CLA can markedly (40 to 50%) induce MFD immediately postpartum without negatively affecting other production parameters.