The effects of rbST (POSILAC®) on heat stressed, lactating, dairy cows

Two hundred cows located on a commercial dairy in Mesquite, NM were used to evaluate response to rbST (POSILAC®) during heat stress in the summer of 1996. Cows were paired by days in milk (average = 153 d at initiation of experiment), parity, and milk yield (average = 92 lb at start of experiment). Prior to initiation of the experiment, all cows received rbST, then rbST treatment was discontinued for one cow from each pair. Milk production was monitored for 4 months. No interactions were detected between lactation number and treatment. Cows maintained on rbST gained .09 of a score (1 to 5scale) less (P\u3c.05) body condition but produced more (P\u3c.05) milk in June, July, August, and September. The average milk productions for rbST-maintained vs rbST-discontinued cows were 80.7 vs 73.5 lb/d in June, 80.1 vs 74.6 lb/d in July, 72.6 vs 67.1 lb/d in August, and 65.1 vs 59.2 lb/d in September. Although rbST-discontinued cows had greater declines in production discontinued cows had greater declines in production persistency was similar between groups during the final 3 months. Under conditions of heat stress, cows maintained on rbST produced 6.2 lb/d more milk than cows for which treatment with rbST was discontinued.; Dairy Day, 1997, Kansas State University, Manhattan, KS, 1997

Effectiveness of Two Ruminally Protected Methionine Sources for Lactating Dairy Cows

Two sources of ruminally protected methionine were tested for their ability to provide available methionine to lactating dairy cattle. Based on milk protein yield and milk protein percent, NTP-1401 (an unreleased product from Novus International, Inc., St. Charles, MO) and Smartamine (Adisseo, αretta, GA) provided similar amounts of available methionine to the cows. These two products led to different methioninerelated compounds appearing in blood plasma, suggesting that they contained different methionine precursors

Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage

Citation: Batista, E. D., Detmann, E., Titgemeyer, E. C., Valadares, S. C., Valadares, R. F. D., Prates, L. L., . . . Paulino, M. F. (2016). Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage. Journal of Animal Science, 94(1), 201-216. doi:10.2527/jas2015-9493Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers (Bos indicus) consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 +/- 9 kg) were used in a 5 x 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [(NN)-N-15-N-15]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected (P >= 0.37) by supplementation, but supplementation did increase ruminal NDF digestion (P < 0.01). Total N intake (by design) and N retention increased (P < 0.001) with supplementation and also linearly increased with RUP provision. Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation (P < 0.001). Supplementation with RUP linearly increased (P = 0.02) urea entry rate and tended (P = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended (P = 0.07) to be increased by supplementation, and RUP provision also tended (P = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater (P < 0.001) for control (22%) than for supplemented (9%) heifers. Urinary 3-methylhistidine: creatinine of control heifers was more than double that of supplemented heifers (P < 0.001). Control heifers reabsorbed a greater (P < 0.001) fraction of urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis

Smartamine M Supplementation Reduces Inflammation but Does Not Affect Performance in Receiving Beef Heifers

Objective: This study was conducted to evaluate the ability of supplemental methionine to improve health, inflammation status, and performance of receiving cattle. Study Description: A group of 384 crossbred heifers (initial weight 489 lb) of Tennessee origin were used in a 45-day receiving trial with limit-feeding to evaluate the effects of supplemental methionine (Smartamine M; Adisseo, Alpharetta, GA) on health, inflammation, and performance. Cattle received either 0 (control) or 10 grams/day Smartamine M, a ruminally protected methionine product. Plasma haptoglobin levels measured on days 0, 14, and 45 were used as a biomarker of inflammation. The Bottom Line: Supplemental methionine supplied by Smartamine M does not improve performance but reduces inflammation and possibly improves immune function in receiving heifers

The Chitobiose-Binding Protein, DasA, Acts as a Link between Chitin Utilization and Morphogenesis in Streptomyces Coelicolor

Streptomycetes are mycelial soil bacteria that undergo a developmental programme that leads to sporulating aerial hyphae. As soil-dwelling bacteria, streptomycetes rely primarily on natural polymers such as cellulose, xylan and chitin for the colonization of their environmental niche and therefore these polysaccharides may play a critical role in monitoring the global nutritional status of the environment. In this work we analysed the role of DasA, the sugar-binding component of the chitobiose ATP-binding cassette transport system, in informing the cell of environmental conditions, and its role in the onset of development and in ensuring correct sporulation. The chromosomal interruption of dasA resulted in a carbon-source-dependent vegetative arrest phenotype, and we identified a second DasR-dependent sugar transporter, in addition to the N-acetylglucosamine phosphotransferase system (PTS(GlcNAc)), that relates primary metabolism to development. Under conditions that allowed sporulation, highly aberrant spores with many prematurely produced germ tubes were observed. While GlcNAc locks streptomycetes in the vegetative state, a high extracellular concentration of the GlcNAc polymer chitin has no effect on development. The striking distinction is due to a difference in the transporters responsible for the import of GlcNAc, which enters via the PTS, and of chitin, which enters as the hydrolytic product chitobiose (GlcNAc(2)) through the DasABC transporter. A model explaining the role of these two essentially different transport systems in the control of development is provided

Leucine Supplementation Did Not Improve Protein Deposition or Lysine Utilization in Growing Steers

Objective: This study was conducted to determine if leucine supplementation could improve protein deposition and lysine utilization in growing steers. Study Description: Ruminally cannulated Holstein steers (380 lb) were provided treatments of postruminal infusions of 0 or 0.212 oz/day of lysine, and 0, 0.529, or 1.058 oz/day of leucine, with all 6 combinations tested. Ruminal infusions of volatile fatty acids and abomasal infusions of glucose provided energy, and all essential amino acids, except lysine, were infused abomasally to make lysine the sole limiting amino acid. Urine and fecal collections were used to measure nitrogen retention (protein deposition). The Bottom Line: Supplementation with leucine did not affect protein deposition of growing steers when lysine was a limiting amino acid, suggesting that, at the levels included in this study, leucine did not stimulate protein synthesis

Glucose kinase of Streptomyces coelicolor A3(2): large-scale purification and biochemical analysis

Metals in Catalysis, Biomimetics & Inorganic Material

Effects of Biuret and Lasalocid (Bovatec) Inclusion into a Commercial Mineral Supplement on Growth Performance of Yearling Calves Grazing in the Kansas Flint Hills

Objective: The objective of this experiment was to measure the effects of non-protein nitrogen (NPN; i.e., biuret) or NPN + ruminal modifier (i.e., biuret + lasalocid) inclusion in a commercial mineral mix on growth performance of yearling beef calves grazing in the Kansas Flint Hills. Study Description: Over a two-year period, 742 crossbred steers [initial body weight (BW): 655 ± 52.2 lb] of Texas and Nebraska origin previously backgrounded at the Kansas State Beef Stocker Unit were used in this experiment. The three mineral treatments consisted of a basal supplement (Control), a basal supplement plus biuret (Biuret), and a basal supplement plus biuret and lasalocid (Bovatec; Zoetis, Parsippany, NJ) with a 4 oz/head daily mineral consumption target. Each treatment was randomly assigned to one of 18 pastures with a total of six pastures per treatment. To determine days-to-empty, mineral feeders were checked daily. Mineral feeders were also weighed weekly to determine mineral consumption. At the onset and conclusion of the experiment, pasture weights were taken to determine average initial and average final BW. Results: Total BW gain, average daily gain (ADG), and mineral consumption did not differ (P ≤ 0.15). However, final BW did differ between mineral treatments (P ≤ 0.03). Likewise, there was an interaction between treatment and week for days-to-empty (P ≤ 0.05). The Bottom Line: These data were interpreted to suggest that the addition of biuret or biuret + Bovatec to a commercial mineral supplement may improve the growth performance of yearling beef cattle grazing in the Kansas Flint Hills

Effects of Almond Hull Inclusion on Growth Performance of Limit-Fed Growing Cattle

Objective: The objective of this experiment was to evaluate the effects of almond hull inclusion and almond hull processing on growth performance of limit-fed growing beef cattle during a 56-day growing period. Study Description: A total of 364 steers were assigned to one of four diets. The control diet contained (dry matter basis) 39.5% dry-rolled corn, 7.5% supplement, 40% wet-corn gluten feed, and 13% prairie hay. Almond hulls replaced prairie hay or prairie hay and dry-rolled corn and were fed at 13 and 26% of the diet, respectively. A subset of almond hulls was processed using a grinder mixer with no screen. Processed almond hulls replaced prairie hay and were fed at 13% of the diet. Diets were limit-fed for 56 days. The Bottom Line: These data were interpreted to suggest almond hulls can be utilized as an alternative to prairie hay in limit-fed growing beef cattle diets while maintaining or slightly improving growth performance

The sugar phosphotransferase system of Streptomyces coelicolor is regulated by the GntR-family regulator DasR and links N-acetylglucosamine metabolism to the control of development

peer reviewedMembers of the soil-dwelling, sporulating prokaryotic genus Streptomyces are indispensable for the recycling of the most abundant polysaccharides on earth (cellulose and chitin), and produce a wide range of antibiotics and industrial enzymes. How do these organisms sense the nutritional state of the environment, and what controls the signal for the switch to antibiotic production and morphological development? Here we show that high extracellular concentrations of N-acetylglucosamine, the monomer of chitin, prevent Streptomyces coelicolor progressing beyond the vegetative state, and that this effect is absent in a mutant defective of N-acetylglucosamine transport. We provide evidence that the signal is transmitted through the GntR-family regulator DasR, which controls the N-acetylglucosamine regulon, including the pts genes ptsH, ptsI and crr needed for uptake of N-acetylglucosamine. Deletion of dasR or the pts genes resulted in a bald phenotype. Binding of DasR to its target genes is abolished by glucosamine 6-phosphate, a central molecule in N-acetylglucosamine metabolism. Extracellular complementation experiments with many bld mutants showed that the dasR mutant is arrested at an early stage of the developmental programme, and does not fit in the previously described bld signalling cascade. Thus, for the first time we are able to directly link carbon (and nitrogen) metabolism to development, highlighting a novel type of metabolic regulator, which senses the nutritional state of the habitat, maintaining vegetative growth until changing circumstances trigger the switch to sporulation. Our work, and the model it suggests, provide new leads towards understanding how microorganisms time developmental commitment