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This study investigates whether dry matter (DM) or water intake is affected by the presence of disease or estrus in dairy cows and whether water intake can serve as an accurate substitute for monitoring changes in DM intake (DMI). A combined cumulative sum (CUSUM) and Shewhart monitoring scheme is proposed to detect DMI changes and emerging disease or estrus. Daily readings from 35 inline water meters for 35 water cups in a tie-stall barn at the University of Minnesota were collected from September 2005 until June 2006. Two cows were assigned to each water cup. Individual DMI were recorded for each of the 70 cows on the study. All drug or hoof treatments administered to the cows along with breeding and calving events were also recorded and classified as 1 of the following 6 event categories: estrus, calving, mastitis, fever, hoof treatment, and other. Analysis of covariance was used to identify factors significantly changing intake. Only the first 150 d in milk (DIM) were considered in the analysis. Six event categories plus DIM, ambient temperature, relative humidity, and parity were entered as independents into the model. Calving, primiparity, and health events categorized as “other” were associated with decreased DM and water intake. Mastitis decreased DMI and fever negatively affected water intake. Both intakes increased with DIM, and water intake decreased with increase in humidity. Covariance analysis was used to investigate the relationship between DMI and water intake. In model 1, analysis was done for a pair of cows, whereas model 2 modeled DMI of the whole group of 70 cows. Water intake, ambient temperature, humidity, and DIM were entered as independents in both models and parity was entered in model 1. Polynomial models and 2-way interactions were also considered. Water intake, ambient temperature, DIM, and DIM2 were kept in final models 1 and 2, and parity was kept in model 1. Final models for cow pairs and a group of 70 cows resulted in R2 of 0.50 and 0.82, respectively. The proposed CUSUM-Shewhart DMI monitoring scheme successfully detected emerging disease even in the first week of lactation. Monitoring water intake can serve as an alternative to measurements of DMI for groups of cows and has the potential of predicting change in individual cow health and estrus status.

Three corn hybrids (Pioneer 36F30, Mycogen TMF2450, and Mycogen TMF2404) were compared for yield and quality traits, and lactation performance and apparent digestibility by Holstein cows. The three corn silages were harvested at a target of 33 to 35% dry matter. Before harvest, six corn plants were randomly selected for plant fractionation. Grain-to-stover ratios were 0.92, 0.70, and 0.95 for the 36F30, TMF2450, and TMF2404 corn plants, respectively. Fifty-two multiparous Holstein cows were placed on a 120-d lactation trial after a 21-d covariate diet. Cows were blocked by calving date and randomly assigned within block to one of three dietary treatments, containing approximately 40% (dry matter basis) corn silage. Milk yield, milk components, and dry matter intake did not differ among dietary treatments. In vitro true and neutral detergent fiber digestibilities were numerically higher for TMF2404 than the other corn silage hybrids. Apparent total-tract crude protein and neutral detergent fiber digestibilities, as measured by acid insoluble ash, were higher for TMF2450 than the other two hybrids, but starch digestibility was not different between the corn silage dietary treatments. Although small differences in nutrient content and digestibility existed among corn silage hybrids, inclusion of these leafy hybrids in lactating cow diets at 40% of the dietary dry matter did not have a significant impact on lactation performance of dairy cattle.

The objective of this study was to determine the effect of feeding direct-fed microbial (DFM) products containing Lactobacillus acidophilus and Propionibacteria freudenreichii on the performance, nutrient digestibility, and rumen fermentation of Holstein dairy cows in midlactation. Experiments were conducted from February to May 2003. Cows were fed 1 of 3 dietary treatments: 1) 1 x 10(9) colony-forming units (cfu)/d of live L. acidophilus strain LA747 and 2 x 10(9) cfu/d of live P. freudenreichii strain PF24 (DFM1); 2) 1 x 10(9) cfu/d of live L. acidophilus strain LA747, 2 x 10(9) cfu/d of live P. freudenreichii strain PF24, and 5 x 10(8) cfu/d of L. acidophilus strain LA45 (DFM2); or 3) lactose (control). Treatments were administered by mixing 45 g of finely ground corn with 5 g of DFM products or lactose and top dressing on the total mixed rations once daily. All cows received the same total mixed ration: 12.7% alfalfa hay, 46.2% corn silage, and 41.1% concentrate on a dry matter (DM) basis. In study 1 (lactation study), 39 multiparous and 18 primiparous Holstein cows were blocked by parity and randomly assigned to treatments for 84 d. Starting on d 35, fecal grab samples were collected from each cow at 5- to 8-h intervals over 48 h for digestibility measurements. A rumen fermentation study (study 2) was conducted concurrently with the lactation study. Three rumenfistulated, multiparous Holstein cows were randomly assigned to dietary treatments DFM1, DFM2, and control in a 3 x 3 Latin square design with 28-d periods. In study 1, there was no difference in average DM intake (23.9, 23.6, and 24.2 kg/d) or 4% fat-corrected milk (36.8, 35.3, and 36.2 kg/d) for treatments DFM1, DFM2, and control. Percentage or yield of milk components also did not differ among treatments. Feed efficiency averaged 1.52 kg of 4% fat-corrected milk/kg of DM intake and did not differ among treatments. There were no differences in apparent DM, crude protein, neutral detergent fiber, or starch digestibility among treatments. In study 2, there was no difference in rumen pH and concentrations of ammonia or total volatile fatty acids measured at 0, 1, 3, and 6 h after feeding. Under the conditions of these studies, supplementing midlactation cows with DFM products containing L. acidophilus and P. freudenreichii did not affect cow performance, diet digestibility, or rumen fermentation.

Jersey×Holstein crossbreds (J×H; n=76) were compared with pure Holsteins (n=73) for 305-d milk, fat, and protein production; conception rate; days open; proportion of cows pregnant within fixed intervals postpartum; and body and udder measurements during first lactation. Cows were housed at 2 research locations of the University of Minnesota and calved from September 2003 to May 2005. The J×H were mated to Montbeliarde sires, and Holstein cows were mated to Holstein sires. Best Prediction was used to determine actual production (milk, fat, and protein) for 305-d lactations with adjustment for age at calving, and records less than 305 d were projected to 305 d. The J×H (274kg) and pure Holsteins (277kg) were not significantly different for fat production, but J×H had significantly less milk (7,147 vs. 7,705kg) and protein (223 vs. 238kg) production than pure Holsteins. The J×H had significantly fewer days open than pure Holsteins (127 vs. 150 d). Also, a significantly greater proportion of J×H were pregnant at 150 and 180 d postpartum than pure Holsteins (75 vs. 59% and 77 vs. 61%, respectively). The J×H had significantly less body weight (60kg) at calving, but significantly greater body condition (2.80 vs. 2.71). Furthermore, J×H had significantly less udder clearance from the ground to the bottom of the udder than pure Holsteins (47.7 vs. 54.6cm), and greater distance between front teats (15.8 vs. 14.0cm) than pure Holsteins during first lactation.

Jersey x Holstein crossbred (JxH) cows (n = 24) were compared with pure Holstein cows (n = 17) for body weight, body condition score, dry matter intake (DMI), and feed efficiency during the first 150 d of first lactation. Cows were housed in the University of Minnesota dairy facility at the St. Paul campus and calved from September 2004 to January 2005. The JxH cows were mated by artificial insemination with Montbeliarde bulls, and Holstein cows were mated by artificial insemination with Holstein bulls. Cows were weighed and body condition was scored every other week. Cows were individually fed a TMR twice daily, and feed refusals were measured once daily. The DMI of cows was measured daily and averaged across 7-d periods. Milk production and milk composition were from monthly Dairy Herd Improvement records. Best Prediction was used to calculate actual production (milk, fat, protein) for each cow from the 4th to 150th day of first lactation. The JxH cows had significantly less body weight (467 vs. 500 kg) and significantly higher body condition scores (2.90 vs. 2.76) than pure Holstein cows. The JxH cows had significantly less milk production (4,388 vs. 4,644 kg) during the 4th to 150th day of lactation than did pure Holstein cows. However, fat plus protein production during the first 150 d of lactation was not significantly different for JxH (302 kg) and Holstein (309 kg) cows. The JxH and pure Holstein cows did not differ significantly for daily DMI (22.0 vs. 22.7 kg, respectively), and the JxH (4.7%) and pure Holstein (4.5%) cows consumed similar DMI based on percentage of body weight. Consequently, feed efficiency for the 4th to 150th day of lactation did not differ for JxH and pure Holstein cows.

A lactation study was conducted to evaluate the effect of increasing the proportion of inorganic versus organic trace minerals (polysaccharides and amino-acid chelates) on reproductive performance and milk production of multiparous and primiparous Holstein cows. Trace minerals evaluated were copper (Cu), manganese (Mn), and zinc (Zn). All minerals were supplemented to meet the NRC (1989) recommended level (10, 40, and 40 mg/kg of Cu, Mn, and Zn, respectively) in diet DM. A total of 101 cows were randomly assigned by expected calving date to 1 of 4 trace mineral treatments: 1) 100% from inorganic sulfate (SULF); 2) 67% SULF:33% polysaccharide complex (SULF-POLY); 3) 67% SULF:33% specific amino-acid complex (SULF-AA); and 4) 100% polysaccharide complex (POLY). Treatments were implemented the day of calving. Number of days open was reduced (P < 0.05) for all cows receiving the POLY versus SULF treatments. Cows receiving the POLY treatment were also more likely (P = 0.008) to become pregnant from the first service than were cows receiving the other treatments. Milk production and composition were not affected by supplements fed. Under the conditions of this study, reproductive performance of cows fed a trace-mineral supplement composed of 100% polysaccharide complexed trace minerals was enhanced versus sulfate, sulfate and polysaccharide, or sulfate and amino acid complexed supplements.