Performance of lactating cows fed procressed grain sorghum and expeller soybean meal

Forty-four Holstein cows were used to measure milk production responses to dryrolled vs processed grain sorghum and expeller vs solvent soybean meal (SBM) in a 2×2 factorial arrangement of four treatments. Processing of grain sorghum decreased feed intake 5%, but increased milk by 3%, protein by 4%, and efficiency by 7%, with fat being unaffected. Replacement of solvent SBM with expeller SBM had little effect on intake, but increased milk by 3%, fat by 5%, and efficiency by 4%, with protein being unaffected. The processing of grain sorghum seems to be a valuable method to improve its nutritive value for lactating cows. Total milk and fat yield, but not protein yield, were increased in response to feeding expeller SBM in the place of solvent SBM

Guanidinoacetic Acid as a Precursor of Creatine for Cattle

Creatine serves as an energy-storing molecule in muscle, and in mammals it can be synthesized in the liver from guanidinoacetic acid (GAA). With this study, we evaluated whether GAA supplementation would lead to creatine production in cattle similarly to other species. Because the synthesis of creatine from GAA requires the use of a methyl group, we also evaluated the effect of supplementing methionine, as a methyl group donor, on the synthesis of creatine.Supplemental GAA did increase plasma concentrations of creatine. Also, blood concentrations of arginine, a precursor to GAA, were increased by GAA supplementation, suggesting that arginine use for GAA synthesis was spared by GAA provision. Plasma homocysteine, a marker that is inversely related to methyl group status, was not affected by GAA supplementation when heifers received 12 g/d methionine; however, it was increased by 30 or 40 grams per day of GAA supplementation when methionine was not supplemented. Results suggest that post-ruminal GAA supplementation increases creatine supply to cattle and spares arginine utilization. Moreover, GAA supplementation induced a methyl group deficiency that was resolved with methionine supplementation

Diet digestibility and rumen traits in response to feeding wed corn gluten feed and a pellet consisting of raw soybean hulls and corn steep liquor

Four ruminally cannulated and two intact multiparous Holstein cows were used in a 3 x 3 replicated Latin square design to evaluate digestibility and rumen traits in lactating dairy cows in response to feeding wet corn gluten feed and a novel product containing raw soybean hulls and corn steep liquor. Three dietary treatments were fed in the experiment. The control contained (DM basis) 30% alfalfa hay, 15% corn silage, 32% corn, 9.3% whole cottonseed, 4.4% solvent soybean meal (SBM), 3.3% expeller SBM, 1.3% fish meal, 1% wet molasses, and 3.7% vitamins/ minerals. Wet corn gluten feed replaced 10% alfalfa hay, 5% corn silage, 5% corn grain, and expeller SBM replaced solvent SBM to maintain diet rumen undegradable protein. The novel product replaced 10% alfalfa hay, 5% corn silage, 3% solvent SBM, and 2% corn. Diets were analyzed to have dietary crude protein percentage and energy density values (Mcal/lb, NEL) of 18.7, 0.75; 18.7, 0.77; 18.7, 0.74; for control, wet corn gluten feed, and the novel product, respectively. Experimental periods were 14 days (10 days adaptation and 4 days collection). Acid insoluble ash was used to estimate fecal output. Dry matter intake averaged 37.9 lb/day and total tract digestibilities of dry matter (DM), organic matter, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude protein did not differ among diets: 71.7%, 73.2%, 63.1%, 58.5% and 73.0%, respectively. Diets affected liquid dilution rate, ruminal pH, and ruminal concentrations of total volatile fatty acids and ammonia similarly. The molar ratio of acetate to propionate was greater (P\u3c0.05) for control (3.38) than for wet corn gluten feed (2.79) and the novel product (2.89). Inclusion of wet corn gluten feed and the novel product at 20% of dietary DM as a partial replacement for alfalfa hay, corn silage, corn grain, and SBM in diets fed to lactating dairy cattle supported lactational performance similar to the control diet. Additionally, combining wet corn gluten feed or the novel product with corn silage and alfalfa hay maintained milk fat yields and ruminal pH, thereby demonstrating that wet corn gluten feed and the novel product can serve as an effective source of fiber when fed at 20% of dietary DM. These results indicate that wet corn gluten feed and the novel product tested can serve as alternative feedstuffs in lactating dairy cattle diets.; Dairy Day, 2002, Kansas State University, Manhattan, KS, 2002

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

Efficiency of lysine utilization by growing steers

Citation: Batista, E. D., Hussein, A. H., Detmann, E., Miesner, M. D., & Titgemeyer, E. C. (2016). Efficiency of lysine utilization by growing steers. Journal of Animal Science, 94(2), 648-655. doi:10.2527/jas2015-9716This study evaluated the efficiency of Lys utilization by growing steers. Five ruminally cannulated Holstein steers (165 +/- 8 kg) housed in metabolism crates were used in a 6 x 6 Latin square design; data from a sixth steer was excluded due to erratic feed intake. All steers were limit fed (2.46 kg DM/d), twice daily, diets low in RUP (81% soybean hulls, 8% wheat straw, 6% cane molasses, and 5% vitamins and minerals). Treatments were 0, 3, 6, 9, 12, and 15 g/d of L-Lys continuously abomasally infused. To prevent AA other than Lys from limiting performance, a mixture providing all essential AA to excess was continuously abomasally infused. Additional continuous infusions included 10 g urea/d, 200 g acetic acid/d, 200 g propionic acid/d, and 50 g butyric acid/d to the rumen and 300 g glucose/d to the abomasum. These infusions provided adequate ruminal ammonia and increased energy supply without increasing microbial protein supply. Each 6-d period included 2 d for adaptation and 4 d for total fecal and urinary collections for measuring N balance. Blood was collected on d 6 (10 h after feeding). Diet OM digestibility was not altered (P >= 0.66) by treatment and averaged 73.7%. Urinary N excretion was decreased from 32.3 to 24.3 g/d by increasing Lys supplementation to 9 g/d, with no further reduction when more than 9 g/d of Lys was supplied (linear and quadratic, P < 0.01). Changes in total urinary N excretion predominantly were due to changes in urinary urea N. Increasing Lys supply from 0 to 9 g/d increased N retention from 21.4 to 30.7 g/d, with no further increase beyond 9 g/d of Lys (linear and quadratic, P < 0.01). Break-point analysis estimated maximal N retention at 9 g/d supplemental Lys. Over the linear response surface of 0 to 9 g/d Lys, the efficiency of Lys utilization for protein deposition was 40%. Plasma urea N tended to be linearly decreased (P = 0.06) by Lys supplementation in agreement with the reduction in urinary urea N excretion. Plasma concentrations of Lys linearly increased (P < 0.001), but Leu, Ser, Val, and Tyr (P <= 0.02) were linearly reduced by Lys supplementation, likely reflecting increased uptake for protein deposition. In our model, Lys supplementation promoted significant increases in N retention and was maximized at 9 g/d supplemental Lys with an efficiency of utilization of 40%

Bioavailability of Ruminally or Abomasally Infused L-carnitine in Holstein Heifers

This study evaluated the relative bioavailability of carnitine delivered by different methods in dairy cattle. Four Holstein heifers were used in a split-plot design to compare ruminally or abomasally infused L-carnitine. The study included 2 main-plot periods, with infusion routes allocated in a crossover design. Within main-plot periods, each of 3 subplot periods consisted of 4-d infusions separated with 4-d rest periods. Subplot treatments were infusion of 1, 3, and 6 g L-carnitine daily. Doses were increased within a period to minimize carryover. Treatments were delivered in two 10-h infusions daily. Blood was collected before the start of infusions and on day 4 of each infusion to obtain baseline and treatment carnitine concentrations. There was a dose × route interaction (P \u3c 0.05) and route effect (P \u3c 0.01) for increases in plasma carnitine above baseline, with increases above baseline being greater across all dose levels when infused abomasally compared to ruminally. Results demonstrated superior bioavailability of carnitine when ruminal exposure was physically bypassed

Condensed Tannins in Tropical Legumes: Concentration, Astringency and Effects on the Nutrition of Ruminants

A feeding trial was carried out to determine the effect of extractable condensed tannins (ECT) concentration and tannin astringency in tropical legumes on nitrogen (N) digestion by sheep. Test legumes were Desmodium ovalifolium (Do) and Flemingia macrophylla (Fm) which had similar concentrations of Extractable CT (9% DM) but tannins with different degree of astringency (Do, 0.6 and Fm, 0.3 g protein bound/g of ECT). Chopped sun-dried forage of each legume was sprayed with either water (control) or polyethylene glycol (PEG, 3.5% DM) to reduce ECT and fed to 8 sheep with ruminal and duodenal canulas arranged in a replicated 4 x 4 Latin Square changeover design. Greater (P\u3c0.05) N flow to duodenum, and fecal N were observed with Fm than with Do. Estimates of escape N were similar (58 to 61%) for both legumes. Reduction of ECT with PEG in both legumes (9.0-9.4 to 4.7-5.4%) resulted in lower (P\u3c0.05) proportion of N reaching the duodenum. Results indicate that concentration of ECT had a greater effect on N digestion by sheep than tannin astringency

Effects of rumensin and bovatec on growth, feed intake, and feed efficiency in dairy calves

One hundred Holstein heifers were used to examine the effects of monensin (Rumensin®) and lasalocid (Bovatec®) included in calf starter and grower diets. Heifers were assigned alternately at birth to a starter feed containing either Rumensin (28 g/ton, 90% dry matter basis) or Bovatec (40 g/ton, 90% dry matter basis). The Bovatec group was switched to a starter feed containing 28 g Bovatec/ton (90% dry matter basis) at 6 weeks of age. Both groups were switched at 8 weeks of age to grower diets designed to deliver 100 mg/head/day of either Rumensin or Bovatec. No treatment differences were observed between birth and 8 weeks of age. Heifers were moved from individual hutches at 8 weeks of age to group pens (five heifers/pen) and remained on the same treatment for the next 84 days. During this 84-day period, heifers receiving Rumensin gained more weight at a faster rate and tended to be more efficient than heifers fed Bovatec. No differences were observed in feed intake, skeletal growth as measured by hip height, or body condition score

Effect of ruminal ammonia supply on lysine utilization by growing steers

Citation: Hussein, A. H., Batista, E. D., Miesner, M. D., & Titgemeyer, E. C. (2016). Effect of ruminal ammonia supply on lysine utilization by growing steers. Journal of Animal Science, 94(2), 656-664. doi:10.2527/jas2015-9717Six ruminally cannulated Holstein steers (202 +/- 15 kg) were used to study the effects of ruminal ammonia loading on whole-body lysine (Lys) utilization. Steers were housed in metabolism crates and used in a 6 x 6 Latin square design. All steers received 2.52 kg DM/d of a diet (10.1% CP) containing 82% soybean hulls, 8% wheat straw, 5% cane molasses, and 5% vitamins and minerals, and 10 g/d of urea (considered to be part of the basal diet) was ruminally infused continuously to ensure adequate ruminal ammonia concentrations. All steers were ruminally infused continuously with 200 g/d of acetic acid, 200 g/d of propionic acid, and 50 g/d of butyric acid and abomasally infused with 300 g/d of glucose continuously to increase energy supply without increasing microbial protein supply. Steers were also abomasally infused continuously with an excess of all essential AA except Lys to ensure that Lys was the only limiting AA. Treatments were arranged as a 3 x 2 factorial with 3 levels of urea (0, 40, or 80 g/d) continuously infused ruminally to induce ammonia loading and 2 levels of Lys (0 or 6 g/d) continuously infused abomasally. Treatments did not affect fecal N output (P = 0.37). Lysine supplementation decreased (P < 0.01) urinary N excretion from 51.9 g/d to 44.3 g/d, increased (P < 0.01) retained N from 24.8 to 33.8 g/d, increased (P < 0.01) plasma Lys, and decreased (P <= 0.05) plasma serine, tyrosine, valine, leucine, and phenylalanine. Lysine supplementation also tended (P = 0.09) to reduce plasma urea-N. Urea infusions linearly increased (P = 0.05) retained N (27.1, 29.3, and 31.5 g/d) and also linearly increased (P < 0.01) urinary N excretion (31.8, 48.1, and 64.4 g/d), urinary urea (21.9, 37.7, and 54.3 g/d), urinary ammonia (1.1, 1.4, and 1.9 g/d), and plasma urea (2.7, 4.0, and 5.1 mM), and linearly decreased plasma alanine (P = 0.04) and plasma glycine (P < 0.01). Assuming that retained protein is 6.25 x retained N and contains 6.4% Lys, the incremental efficiencies of infused Lys utilization were 51%, 59%, and 69% for steers receiving 0, 40, and 80 g/d of urea, respectively, indicating that ruminal ammonia loads may improve the efficiency of Lys utilization. This is supported by observed increases in whole body-protein deposition in response to ammonia loading of our steers that were, by design, Lys deficient

Urea recycling in beef cattle fed prairie hay- based diets

Maximizing utilization of native rangeland is an important aspect of the cow/calf phase of beef production. Native rangeland is often of poor quality (less than 7% crude protein). Protein content of the rangeland is important because nitrogen is a key growth factor used by ruminal microbes. Without adequate nitrogen, the ruminal ecosystem will not operate at peak efficiency, which subsequently reduces the supply of nutrients to the animal. Historically, producers have provided supplemental nutrients to their cattle to achieve maximum performance. Both supplemental protein and energy have been provided to cattle consuming low-quality forage with varying levels of success. Typically, supplemental energy without adequate protein reduces fiber digestion by cattle. On the other hand, supplemental protein consistently improves overall performance