Michael J. Brouk

Effects of monensin on metabolic parameters, feeding behavior, and productivity of transition dairy cows

The effects of monensin on transition cow metabolism may be dependent on modulation of feeding behavior, rumen pH, and expression of key metabolic genes. Multiparous Holstein cows were used to determine the effects of monensin (400mg/cow daily) on these variables. Cows were randomly assigned, based on calving date, to control or monensin treatments (n = 16 per treatment) 21 d before their expected calving date, and cows remained on treatments through 21 d postpartum. Feeding behavior and water intake data were collected daily. Liver biopsies were conducted after assessing BCS and BW on d -21, -7, 1, 7, and 21 relative to calving for analysis of triglyceride (TG) content as well as mRNA abundance of cytosolic phosphoenolpyruvate carboxykinase, carnitine palmitoyltransferase 1a, and apolipoprotein B. Blood samples were collected 21, 7, and 4 d before expected calving and 1 (day of calving), 4, 7, 14, and 21 d postpartum for nonesterified fatty acid, β-hydroxybutyrate, glucose, insulin, and haptoglobin analyses. Ruminal pH was collected every 5 min on d 1 through 6 postpartum via a wireless indwelling probe. On d 7 postpartum, a caffeine clearance test was performed to assess liver function. Data were analyzed using mixed models with repeated measures over time. Monensin decreased mean plasma β-hydroxybutyrate (734 vs. 616 ± 41 μM) and peak concentrations (1,076 vs. 777 ± 70 μM on d 4 postpartum). Monensin also decreased time between meals prepartum (143 vs. 126 ± 5.0 min) and postpartum (88.8 vs. 81.4 ± 2.9 min), which was likely related to a smaller ruminal pH standard deviation in the first day after cows changed to a lactation ration (0.31 vs. 0.26 ± 0.015). Monensin also increased liver mRNA abundance of carnitine palmitoyltransferase 1a (0.10 vs. 0.15 ± 0.002 arbitrary units), which corresponded to a slower rate of liver TG accumulation from d -7 to +7 (412 vs. 128 ± 83 mg of TG/g of protein over this time period). No significant effects of monensin supplementation were observed on milk production, liver cytosolic phosphoenolpyruvate carboxykinase, apolipoprotein B, plasma nonesterified fatty acid, glucose, insulin, or haptoglobin. No effects on disease incidence were detected, but sample size was small for detecting such effects. Overall, results confirm that the effects of monensin on transition cows extend beyond altered propionate flux.

Relocation and expansion planning for dairy producers

Relocating or expanding a dairy facility requires a tremendous amount of time and planning. Owners or managers of dairies will go through a number of steps including: 1) developing a business plan; 2) choosing a design process; 3) developing specifications; 4) selecting location/site; 5) obtaining permits/legal; 6) obtaining bids; 7) selecting contractors; 8) buying cattle; 9) purchasing feeds; 10) financing; 11) managing construction; 12) hiring and training employees; 13) developing management protocols for the dairy; and 14) managing information flow. The dairy can be divided into these components: 1) milking parlor; 2) cow housing; 3) special needs facility (e.g., hospital, closeups); 4) replacement heifer housing; 5) manure management system; and 6) feed center. This article will focus on milking parlors, cow housing, grouping strategies, and site selection.

Performance of lactating dairy cows fed corn as whole plant silage and grain produced from genetically modified corn containing event DAS-59122-7 compared to a nontransgenic, near-isogenic control

The nutritional equivalency of grain plus whole plant silage from genetically modified corn plants containing the DAS-59122-7 (59122) event expressing the Cry34Ab1 and Cry35Ab1 proteins to grain and silage from a near-isogenic corn hybrid without this trait (control) was assessed using lactating dairy cows. Corn plants with event 59122 are resistant to western corn rootworm and tolerant to the herbicide active ingredient glufosinate-ammonium. Effects on feed intake, milk production, and milk composition were determined. The 59122 grain and the control grain were produced in 2005 from isolated plots in Richland, Iowa. Whole plant corn silage for the 59122 and control treatments were grown in isolated plots at the Kansas State University Dairy Center and ensiled in Ag-Bags. Thirty lactating Holstein cows blocked by lactation number, day of lactation, and previous energy-corrected milk production were used in a switchback design. All cows were fed diets that contained 22.7% grain plus 21.3% whole plant silage from either the 59122 or the control hybrid, in addition to 21% wet corn gluten feed, 12.3% protein mix, 8.0% whole cottonseed, and 14.7% alfalfa hay. Each period of the switchback trial included 2 wk for diet adjustment followed by 4 wk for data and sample collection. Milk samples (a.m. and p.m.) collected from 2 consecutive milkings of each collection wk were analyzed for fat, protein, lactose, solids-not-fat, milk urea nitrogen, and somatic cell count. Percentages of milk fat, protein, lactose, and solids-not-fat were not affected by dietary treatment. Yields of milk, 4% fat-corrected milk, energy-corrected milk, solids-corrected milk, and the concentrations and yields of milk fat, milk protein, milk solids, and milk lactose were not significantly different between treatments. Efficiencies of milk, fat-corrected milk, energy-corrected milk, and solids-corrected milk production also were not different when cows were fed crops from 59122 than when they were fed the control hybrid. Milk production efficiency averaged 1.48 and 1.50 kg/kg of dry matter intake for cows fed diets containing the control and 59122 corn, respectively. These data indicate that the nutritional value for milk production was not different between a diet containing grain plus whole plant corn silage produced from a 59122 corn hybrid versus a diet containing grain and corn silage from its near-isogenic control corn hybrid.

Availability to lactating dairy cows of methionine added to soy lecithins and mixed with a mechanically extracted soybean meal

We evaluated a product containing methionine mixed with soy lecithins and added to a mechanically extracted soybean meal (meSBM-Met). Lactational responses of cows, plasma methionine concentrations, and in vitro degradation of methionine were measured. Twenty-five Holstein cows were used in a replicated 5 × 5 Latin square design and fed a diet designed to be deficient in methionine or the same diet supplemented either with 4.2 or 8.3g/d of supplemental methionine from a ruminally protected source or with 2.7 or 5.3g/d of supplemental methionine from meSBM-Met. All diets were formulated to provide adequate amounts of metabolizable lysine. Concentration of milk true protein was greater when methionine was provided by the ruminally protected methionine than by meSBM-Met, but milk protein yield was not affected by treatment. Milk yields and concentrations and yields of fat, lactose, solids-not-fat, and milk urea nitrogen were not affected by supplemental methionine. Body condition scores increased linearly when methionine from meSBM-Met was supplemented, but responses were quadratic when methionine was provided from a ruminally protected source. Nitrogen retention was not affected by supplemental methionine. Plasma methionine increased linearly when methionine was supplemented from a ruminally protected source, but plasma methionine concentrations did not differ from the control when supplemental methionine from meSBM-Met was provided. In vitro degradation of supplemental methionine from meSBM-Met was complete within 3h. Data suggest that meSBM-Met provides negligible amounts of metabolizable methionine to dairy cows, and this is likely related to extensive ruminal destruction of methionine; however, cow body condition may be improved by ruminally available methionine provided by meSBM-Met.

Short communication: Supplementing lysine and methionine in a lactation diet containing a high concentration of wet corn gluten feed did not alter milk protein yield

Primiparous (n=33) and multiparous (n=63) lactating Holstein cows (186±51 d in milk) were used to evaluate the effects of supplementing metabolizable amino acids using lysine in a matrix of Ca salts of fatty acids (Megamine-L, Arm & Hammer Animal Nutrition, Princeton, NJ) and the isopropyl ester of 2-hydroxy-4-(methylthio) butanoic acid (MetaSmart, Adisseo Inc., Antony, France) in diets containing >26% wet corn gluten feed (dry matter basis). Cows were blocked by production level, parity, and pregnancy status, then randomly assigned to 1 of 8 pens and allowed a 7-d adaption period before receiving dietary treatments for 28 d. Pens were assigned randomly to either of 2 diets formulated to differ by metabolizable amino acid supply. Dry matter intake and production were monitored daily and milk components analyzed 3d/wk. Data were analyzed using mixed models with repeated measures. The original design of the study consisted of a control diet predicted to be deficient in lysine and methionine; however, after ingredient nutrients were analyzed and modeled with animal requirements at dry matter intake [26.6±0.35 kg/d (mean ± SEM)] and milk production levels achieved during the study (40.1±0.46 kg/d), only marginal deficiencies were predicted for the control (-8.1g/d for lysine; -1g/d for methionine) according to the National Research Council method, whereas the Cornell Net Carbohydrate and Protein System 5.0 and 6.1 models indicated positive balances for these amino acids (25.9 and 21.8 g/d for lysine, 14.7 and 18.9 g/d for methionine, respectively). Supplementing 30 g/d of metabolizable lysine in a Ca soap matrix and 2.4 g/d of metabolizable methionine as 2-hydroxy-4-(methylthio) butanoic acid led to positive predicted lysine and methionine balances by all 3 models, and predicted metabolizable lysine-to-methionine ratios ranging from 2.9 to 3.1. No treatment effects were observed for dry matter intake, milk yield, milk component concentrations or yields, or energy-corrected milk yield. Despite the negative lysine balance and low lysine-to-methionine ratio predicted by the National Research Council model, results provided no evidence of a lysine deficiency in the control diet.

Comparison of full-fat corn germ, whole cottonseed, and tallow as fat sources for lactating dairy cattle.

Twenty-four multiparous Holstein cows (124 +/- 39 d in milk; 682 +/- 72 kg of body weight) were used in 6 simultaneous 4 x 4 Latin squares to evaluate full-fat corn germ as a fat source for lactating dairy cows. Experimental diets were a control (containing 28% ground corn, 23% alfalfa hay, 19% wet corn gluten feed, and 10% corn silage, dry matter basis), and 3 diets with either whole cottonseed (WCS), tallow (TAL), or full-fat corn germ (FFCG) added to provide 1.6% supplemental fat. Cows were fed twice daily for ad libitum intake. Dry matter intake, milk yield, and energy-corrected milk did not differ among diets. Efficiency of milk production (energy-corrected milk/dry matter intake) was greater for cows fed WCS than for cows fed the control, TAL, or FFCG. Milk fat percentage from cows fed FFCG was less than that of cows fed WCS or the control, but was similar to that of cows fed TAL. Milk protein percentage was less for cows fed FFCG than for those fed the control. Total saturated fatty acids were less in milk from cows fed fat sources, and cows fed WCS and TAL had greater saturated fatty acids in milk than did cows fed FFCG. Unsaturated fatty acids were greater in milk from cows fed FFCG than in milk from cows fed the control, WCS, or TAL. The cis-9, trans-11 conjugated linoleic acid content was greater in milk from cows fed WCS, TAL, and FFCG than from cows fed the control, and it was greater in milk from cows fed FFCG than in milk from cows fed WCS or TAL. These results indicate that FFCG can be used effectively as a fat source in diets for lactating dairy cattle.

Performance of lactating dairy cattle housed in two-row freestall barns equipped with three different cooling systems

Ninety-three multiparous Holstein cows averaging 130 days in milk (DIM) were utilized to evaluate three cooling treatments installed in separate pens of a four-row freestall barn in northeast Kansas during the summer of 1999. Treatments were: 1) a double row of 36-inch fans spaced at 24-ft intervals over the freestalls; 2) a single row of 36-inch fans spaced at 24-ft intervals over the freestalls and over the cow feed line; and 3) a double row of 36-inch fans spaced at 24-ft intervals over the freestalls and a single row over the feed line. Each pen was equipped with identical sprinkler systems over the cow feed line. The 85-day study evaluated milk production, body condition score, respiration rate, and feed intake of cows cooled with the systems. Cows cooled with fans over the freestalls and feed line produced more (P< .05) milk (98.8 vs 93.9 lb/cow/day) than those cooled with fans only over the freestalls. Milk production was similar for cows cooled with fans over the freestalls and feed line, and doubling the number of fans over the freestalls had no apparent advantage. Cows in all treatments consumed similar amounts of feed, and those cooled only by fans over the freestalls tended to gain more body condition than cows in the other two treatments. Estimated increase in net income realized from using these cooling systems ranged from

Characteristics of Low-Profile Cross-Ventilated Freestalls

3,500-6,100/year/pen.

Impact of dried seaweed meal on heat-stressed lactating dairy cattle

The ventilation characteristics in a low-profile cross-ventilated freestall building were monitor in May and August 2006. Three different ventilation rates were evaluated in an 800 cow facility located in North Dakota. The high, medium and low ventilation rates selected were based on exchanging the air inside the building every 60, 120 and 240 seconds, respectively. The particle concentrations from the three samplers were 78.2 µg/m3 near the east end, 74.8 µg/m3 in the center and 94.8 µg/m3 near the west end. Hydrogen sulfide measurements were 14, 8 and 7 ppb at the low, medium and high ventilation rates respectively. Gases emitted from the LPCV were predominately nitrogen-based gases (NH3, NO2, NO) during the spring and summer testing periods. Ammonia concentrations and emission rates were higher during the springtime at the lowest ventilation rate. No statistical differences were found between NH3 concentration and emission rates at the high ventilation rate during springtime, low ventilation rate during the summer, and high ventilation rate during the summer. No statistical differences in NH3 concentrations were observed during the medium ventilation rates of both seasons. Average concentrations of NH3 observed were 1219 +/-5 ppb during the spring and 1117 +/- 4 ppb during summer. The NH3 emissions rate at the low ventilation rate was 856 mg/h/500-kg live weight during the spring and 678 mg/h/500-kg live weight during the summer. The indoor and outdoor temperature and indoor relative humidity were found to be significant factors contributing to the prediction of the maximum NH3 concentration within the LPCV dairy barn during the spring.

Using vaginal temperature to evaluate heat stress in dairy cattle

Twenty-four lactating Holstein cows were used to determine the production response to the inclusion of brown seaweed in the basal diet during summer heat stress. Cows were blocked by lactation number, days in milk, and energy-corrected milk and then allotted to either a control or control + brown seaweed diet. Cattle on the brown seaweed diet were fed 4 ounces per cow per day for 7 days , and then 2 ounces per cow per day for 14 days, before the start of the experiment. All cattle were housed in a tie-stall barn, fed individually, and milked twice daily. Cows fed brown seaweed produced more (P<0.01) milk (77.6 vs 73.8 lb) and milk protein than controls did. But the addition of brown seaweed did not reduce respiration rates, rectal temperature, or rear-udder skin temperature. This indicated a similar heat-stress response for treated and control cows. Other studies have shown a reduction in respiration rates and body temperature when stressed cattle were fed brown seaweed. Further investigation is necessary to determine the factors that resulted in the observed milk and milk-protein responses in this study.