Feeding strategies on certified organic dairy farms in Wisconsin and their effect on milk production and income over feed costs

The purposes of this study were (1) to analyze and categorize certified organic Wisconsin dairy farms based on general farm characteristics and feeding strategies during the course of 2010, and (2) to evaluate herd milk production and income over feed costs (IOFC). An on-site survey containing sections on farm demographics, feeding, grazing, and economics was conducted on 69 farms (12.6% survey response rate). A nonhierarchical clustering method using 9 variables related to general farm characteristics, feed supplementation, and grazing was applied to partition the farms into clusters. A scree plot was used to determine the most appropriate number of clusters. Dry matter intake was approximated based on farmer-reported total amounts of feed consumed (feed offered less refusals). Milk production was evaluated using reported milk rolling herd averages (RHA). Income over feed costs was calculated as milk sales minus feed expenses. The farms in clusters 1 (n = 8) and 3 (n = 32), the large and small high-input farms, respectively, included more feed ingredients in their lactating cow diets and relied more heavily on concentrates than farms in other clusters. Cows on these farms were predominantly Holstein. Clusters 1 and 3 had the highest RHA (6,878 and 7,457 kg/cow per year, respectively) and IOFC ($10.17 and $8.59/lactating cow per day, respectively). The farms in cluster 2 (n = 5) were completely seasonal, extremely low-input farms that relied much more heavily on pasture as a source of feed, with 4 out of the 5 farms having all of their operated land in pasture. Farms in cluster 2 relied on fewer feeds during both the grazing and nongrazing seasons compared with farms in the other clusters. These farms had the lowest RHA and IOFC at 3,632 kg/cow per year and $5.76/lactating cow per day, respectively. Cluster 4 (n = 24), the partly seasonal, moderate-input, pasture-based cluster, ranked third for RHA and IOFC (5,417 kg/cow per year and $5.92/lactating cow per day, respectively). Breeds other than Holstein were used more prevalently on farms in clusters 2 and 4. Results indicated extreme variation in animal breed, structure, and feeding strategies among Wisconsin organic dairy farms. Feeding strategies appeared to be major determinants of RHA and IOFC. These findings may serve current organic and transition farmers when considering feeding management changes needed to meet organic pasture rule requirements or dealing with dietary supplementation challenges.     

Feeding soyhulls to high-yielding dairy cows increased milk production, but not milking frequency, in an automatic milking system

To attract a cow into an automatic milking system (AMS), a certain amount of concentrate pellets is provided while the cow is being milked. If the milking frequency in an AMS is increased, the intake of concentrate pellets might increase accordingly. Replacing conventional starchy pellets with nonstarchy pellets increased milk yield, milk fat, and milk protein and decreased body weight. The hypothesis was that a nonroughage by-product rich in digestible neutral detergent fiber, such as soyhulls and gluten feed, could replace starchy grain in pellets fed in an AMS. Sixty cows were paired by age, milk yield, and days in milk, and were fed a basic mixture ad libitum [16.2 ± 0.35 (mean ± SE) kg of dry matter intake/d per cow] plus a pelleted additive (6 to 14 kg of dry matter/d per cow) that was consumed in the AMS and in a concentrate self-feeder, which could only be entered after passing through the AMS. The 2 feeding regimens differed only in the composition of the pelleted additives: the control group contained 52.9% starchy grain, whereas the experimental group contained 25% starchy grain, plus soyhulls and gluten feed as replacement for part of the grain. Wheat bran in the control ration, a source of fiber with low digestibility, was replaced with more digestible soyhulls and gluten. During the first 60 d in milk, a cow received 10 to 12 kg of concentrate pellets. After 60 DIM, concentrate feed was allocated by milk production: ≤25 kg/d of milk entitled a cow to 2 kg/d of concentrate feed; >25 kg/d of milk entitled a cow to receive 1 kg/d of additional concentrate feed per 5 kg/d of additional milk production, and >60 kg/d of milk entitled a cow to receive 9 kg of concentrate. The concentrate feed was split between the AMS and concentrate self-feeder. The 2 diets resulted in similar frequencies of voluntary milking (3.12 ± 0.03 to 2.65 ± 0.03 visits/d per cow vs. 3.16 ± 0.00 to 2.60 ± 0.01 visits/d per cow). Average milk yields were higher in the experimental group (42.7 ± 0.76 to 39.09 ± 0.33 kg/d per cow vs. 39.69 ± 0.68 to 37.54 ± 0.40 kg/d per cow) and percentages of milk protein (3.02 ± 0.06 to 3.12 ± 0.05% vs. 3.07 ± 0.04 to 3.20 ± 0.04%) and milk fat (3.42 ± 0.17 to 3.44 ± 0.08% vs. 3.38 ± 0.13 to 3.55 ± 0.06%) were similar in the 2 groups. The results suggest that the proposed pellets high in digestible neutral detergent fiber can be allocated via the AMS to selected high-yielding cows without a negative effect on appetite, milk yield, or milk composition while maintaining a high milking frequency.     

Changes in milk production and estimated income over feed cost of group-housed dairy cows when moved between pens

Several studies have shown advantages of feeding cows in groups according to their nutrient requirements. However, there are concerns about losing milk when cows change from a high- to a low-nutrient diet. Data from 1,960 cows from 3 herds were analyzed to assess the impact on milk yield and estimated income over feed cost (IOFC) when moving cows between pens and rations. Pen feed intake and individual body weight and milk yield were recorded daily for 21 d before and 21 d after every pen movement. The data included 2,142 pen movements, and for each movement, milk production was recorded for 21 d before and 21 d after the change. Within farm, group, and cow, milk yield during the 21 d preceding a pen movement was used to predict milk yield for the subsequent 21 d using linear regression. Individual dry matter intake was estimated based on cow performance and diet composition, and then individual IOFC was calculated. Differences between actual and predicted milk yield and IOFC during the 21 d following a movement were determined and contrasted against zero using t-tests. In all 3 farms, every pen movement involved a change from a more expensive ration with more energy and protein than the one fed after the movement. On average, in all cases but one, observed milk yield was lower than the forecasted milk yield had cows not been moved. However, IOFC, on average, was positive in all cases except for 2 pen movements on 2 farms. Reasons for the improved IOFC with lower milk yield were due to a nutrient cost advantage, whereas, when IOFC decreased, differences in nutrient supply and dietary cost were not able to offset differences in milk yield. Moving cows according to milk production level does not result in economic advantages when the unit cost of nutrients is greater in the original than in the receiving ration. However, when the cost and nutrient difference between the diets offset potential losses in milk, forming groups according to production is advantageous.     

Mean-reversion in income over feed cost margins: Evidence and implications for managing margin risk by US dairy producers

With the increased volatility of feed prices, dairy farm managers are no longer concerned with managing only milk price volatility, but are considering the adoption of risk management programs that address income over feed cost (IOFC) margin risk. Successful margin risk management should be founded on an understanding of the behavior of IOFC margins. To that end, we have constructed forward IOFC margins using Class III milk, corn, and soybean meal futures prices. We focus on the characteristics of the term structure of forward IOFC margins, that is, the sequence of forward margins for consecutive calendar months, all observed on the same trading day. What is apparent from the shapes of these term structures is that both in times when margins were exceptionally high and in times when they were disastrously low, market participants expected that a reversal back to average margin levels would not come quickly, but rather would take up to 9 mo. Slopes of the forward margin term structure before and after most of the major swings in IOFC indicate these shocks were mostly unanticipated, whereas the time needed for recovery to normal margin levels was successfully predicted. This suggests that IOFC margins may exhibit slow mean-reverting, rather than predictable cyclical behavior, as is often suggested in the popular press. This finding can be exploited to design a successful catastrophic risk management program by initiating protection at 9 to 12 mo before futures contract maturity. As a case study, we analyzed risk management strategies for managing IOFC margins that used Livestock Gross Margin for Dairy Cattle insurance contracts and created 2 farm profiles. The first one represents dairy farms that grow most of their feed, whereas the second profile is designed to capture the risk exposure of dairy farms that purchase all their dairy herd, dry cow, and heifer feed. Our case study of this program encompasses the 2009 period, which was characterized by exceptionally poor IOFC margin conditions. We analyzed the dynamics of realized IOFC margins in 2009 under 4 different risk management strategies and found that optimal strategies that were founded on the principles delineated above succeeded in reducing the decline in IOFC margins in 2009 by 93% for the Home-Feed profile and by 47% for the Market-Feed profile, and they performed substantially better than alternative strategies suggested by earlier literature.     

Compost bedded pack dairy barn management,performance, and producer satisfaction

The objective of the research was to characterize herd performance, producer satisfaction and recommendations, and management practices used by compost bedded pack (CBP) managers in Kentucky (42 farms and 47 CBP facilities). Farms were visited between October 2010 and March 2011. A random selection of cows housed solely in the CBP were scored for locomotion and hygiene. Changes in monthly Dairy Herd Improvement Association performance records, including milk production, SCC, reproductive performance, and daily bulk-tank somatic cell count after moving into the CBP were analyzed using the MIXED procedure of SAS (SAS 9.3; SAS Institute Inc., Cary, NC). The GLM procedure of SAS (SAS 9.3) was used to develop models to describe CBP moisture, CBP temperature at 20.3 cm, and mean herd hygiene. Producers provided 9.0 ± 2.2 m² of pack space per cow (n = 44). Barns constructed with an attached feed alley cost $1,051 ± 407 per cow (n = 40). Barns constructed without an attached feed alley cost $493 ± 196 per cow (n = 13). Kiln-dried shavings required 0.05 ± 0.04 m³ of bedding per cow per day (n = 15). Green shavings required 0.07 ± 0.06 m³ of bedding per cow per day (n = 12). The most-frequently cited benefits of the CBP included cow comfort (n = 28), cow cleanliness (n = 14), and the low-maintenance nature of the system (n = 10). Increased stirring frequency, stirring depth, and ambient temperature increased pack temperature, measured at 20.3 cm below the CBP surface. Increased stirring depth, pasture-adjusted space per cow, and drying rate decreased CBP moisture. Mean herd locomotion and hygiene scores were 1.5 ± 0.3 (n = 34) and 2.2 ± 0.4 (n = 34), respectively. Increased 20.3-cm depth CBP temperature and ambient temperatures improved mean herd hygiene. Bulk-tank somatic cell count decreased from the year before to the year after moving into the CBP barn (323,692 ± 7,301 vs. 252,859 ± 7,112 cells/mL, respectively) for farms using the CBP barn as the primary housing facility (n = 9). Daily milk production, collected from monthly Dairy Herd Improvement Association tests, increased from before moving into the CBP barn to the second year after (29.3 ± 0.3 vs. 30.7 ± 0.3 kg, respectively) for farms using the CBP barn as the primary housing facility (n = 8). Calving interval decreased from the year before to the second year after (14.3 ± 0.1 vs. 13.7 ± 0.1 mo) moving into the CBP barn for farms using the CBP as primary housing (n = 8).     

Identifying cost-minimizing strategies for guaranteeing target dairy income over feed cost via use of the Livestock Gross Margin dairy insurance program

Milk and feed price volatility are the major source of dairy farm risk. Since August 2008 a new federally reinsured insurance program has been available to many US dairy farmers to help minimize the negative effects of adverse price movements. This insurance program is referred to as Livestock Gross Margin Insurance for Dairy Cattle. Given the flexibility in contract design, the dairy farmer has to make 3 critical decisions when purchasing this insurance: 1) the percentage of monthly milk production to be covered, 3) declared feed equivalents used to produce this milk, and 3) the level of gross margin not covered by insurance (i.e., deductible). The objective of this analysis was to provide an optimal strategy of how a dairy farmer could incorporate this insurance program to help manage the variability in net farm income. In this analysis we assumed that a risk-neutral dairy farmer wants to design an insurance contract such that a target guaranteed income over feed cost is obtained at least cost. We undertook this analysis for a representative Wisconsin dairy farm (herd size: 120 cows) producing 8,873 kg (19,545 lb) of milk/cow per year. Wisconsin statistical data indicates that dairy farms of similar size must require an income over feed cost of at least $110/Mg ($5/cwt) of milk to be profitable during the coverage period. Therefore, using data for the July 2009 insurance contract to insure $110/Mg of milk, the least cost contract was found to have a premium of $1.22/Mg ($0.055/cwt) of milk produced insuring approximately 52% of the production with variable monthly production covered during the period of September 2009 to June 2010. This premium represented 1.10% of the desired IOFC. We compared the above optimal strategy with an alternative nonoptimal strategy, defined as a contract insuring the same proportion of milk as the optimal (52%) but with a constant amount insured across all contract months. The premium was found to be almost twice the level obtained under the cost-minimizing solution representing 1.9% of the insured amount. Our model identifies the lowest cost insurance contract for a desired target guaranteed income over feed cost.     

Economic comparison of natural service and timed artificial insemination breeding programs in dairy cattle

The objective was to compare the costs of natural service (NS) and timed artificial insemination (TAI) as breeding programs for dairy cows. Both programs were directly compared in a field study from November 2006 to March 2008. Reproductive results in that study were similar and served as inputs for this study. A herd budget accounting for all costs and revenues was created. Net cost during the field study for the NS program was $100.49/cow per year and for the TAI program was $67.80/cow per year, unadjusted for differences in voluntary waiting period for first insemination (VWP) and pregnancy rates (PR). After inclusion of the differences in VWP and PR, the economic advantage of the TAI program was $9.73/cow per year. Costs per day a cow was eligible for insemination were estimated at $1.45 for the NS program and $1.06 for the TAI program. Sensitivity analysis revealed that if the marginal feed cost increased to $5/hundredweight (cwt; 1 cwt = 45.36 kg), the advantage of TAI increased to $48.32/cow per year. In addition, higher milk prices and greater genetic progress increased the advantage of TAI. When semen price increased from $6 to $22, the NS program had an economic advantage of $33.29/cow per year. If each NS bull was replaced by an additional cow, the advantage of the TAI program was $60.81/cow per year. Setting the PR for both programs at 18% and the VWP at 80 d resulted in an advantage of $37.87/cow per year for the TAI program. In conclusion, any advantage of TAI depended greatly on cost to feed bulls, semen price, and genetic merit of semen.     

Feeding management and characteristics of rations for high-producing dairy cows in freestall herds

The objectives of this cross-sectional observational study were to 1) describe the feeding management and characteristics of rations for high-producing Holstein cows housed in freestall barns in Minnesota, 2) evaluate ration change over time, and 3) investigate herd-level risk factors for ration change. Each of 50 randomly selected freestall dairy herds was visited once during the study. Samples of TMR were collected from the high-production group feed bunk to represent the initial ration as delivered to the cows, 3 additional samples were collected every 2 to 3 h after feed delivery, and the accumulated orts were cleaned out of the feed bunk. Feeding management practices and TMR formulation were also collected at the time of visit. Seventy percent of herds fed once daily, 22% fed twice daily, and 8% fed 3 times daily. Frequency of feed push-up was 5.4 ± 2.3 times daily. Linear feed bunk space per cow was 0.45 ± 0.11 m. Sixty-two percent of the farms had 3-row pens and 38% had 2-row pens. Linear feed bunk space per cow was greater in 2-row pens (0.56 m/cow) than in 3-row pens (0.39 m/cow). Post and rail was the most common type of feed barrier; it was used by 60% of the herds. Headlocks were used by 28% of the herds, combination of post and rail with headlocks was used by 8%, and diagonal bars were used by 4%. Water trough linear space was 4.6 ± 2.1 cm/cow. Estimated dry matter intake was 24.3 kg/cow per day. The forage content of the formulated ration was 52% of the ration DM, and corn silage was the most commonly used forage. The NDF content of the analyzed ration was greater than the NDF content of the formulated ration (30.6 and 29.8%, respectively). In contrast, the CP content was lower (17.5 and 17.9%, respectively). Some feeding management practices (e.g., feeding frequency) were associated with ration NDF content change over time. This association may be minimized by implementing ration and management changes.     

Identifying efficient dairy heifer producers using production costs and data envelopment analysis

During November and December 2011, data were collected from 44 dairy operations in 13 Pennsylvania counties. Researchers visited each farm to collect information regarding management practices and feeding, and costs for labor, health, bedding, and reproduction for replacement heifers from birth until first calving. Costs per heifer were broken up into 4 time periods: birth until weaning, weaning until 6 mo of age, 6 mo of age until breeding age, and heifers from breeding to calving. Milk production records for each herd were obtained from Dairy Herd Improvement. The average number of milking cows on farms in this study was 197.8 ± 280.1, with a range from 38 to 1,708. Total cost averaged $1,808.23 ± $338.62 from birth until freshening. Raising calves from birth to weaning cost $217.49 ± 86.21; raising heifers from weaning age through 6 mo of age cost $247.38 ± 78.89; raising heifers from 6 mo of age until breeding cost $607.02 ± 192.28; and total cost for bred heifers was $736.33 ± 162.86. Feed costs were the largest component of the cost to raise heifers from birth to calving, accounting for nearly 73% of the total. Data envelopment analysis determined that 9 of the 44 farms had no inefficiencies in inputs or outputs. These farms best combined feed and labor investments, spending, on average, $1,137.40 and $140.62/heifer for feed and labor. These heifers calved at 23.7 mo of age and produced 88.42% of the milk produced by older cows. In contrast, the 35 inefficient farms spent $227 more on feed and $78 more on labor per heifer for animals that calved 1.6 mo later and produced only 82% of the milk made by their mature herdmates. Efficiency was attained by herds with the lowest input costs, but herds with higher input costs were also able to be efficient if age at calving was low and milk production was high for heifers compared with the rest of the herd.     

Diet fermentability influences lactational performance responses to corn distillers grains: a meta-analysis

Increasing supply of corn distillers grains (CDG) raises questions about the extent to which they can be used in diets of lactating dairy cows. A database of treatment means (n = 44) reported in 16 peer-reviewed journal articles published from 1985 to 2008 was developed. The database included response (within study) to a CDG diet compared with the control (no CDG) for milk yield (MY), milk fat concentration and yield, CDG content of the diet, and dietary composition of control and CDG diets (% of dietary dry matter). Additionally, corn grain fermentability was classified as high moisture (n = 7) or dry (n = 37). Data from studies with diets including more than one grain source (n = 8) had been eliminated from the analysis. Dietary concentrations of CDG ranged from 4.2 to 42% across studies. Dietary concentrations in diets containing CDG were 16.8 ± 1.91% (mean ± standard deviation) crude protein, 36 ± 15.5% corn silage, 23 ± 8.8% corn grain, and 28 ± 5.8% starch. Responses to CDG were 0.5 ± 2.10 kg/cow per day (mean ± standard deviation) for MY, 0.05 ± 0.178 percentage units for milk fat concentration, and 26 ± 77.6 g/cow per day for milk fat yield. Only MY response was related to increasing concentrations of CDG in diets and peaked at 1.2 kg/cow per day for 21% CDG. Diet fermentability was associated with responses. The greatest MY response to CDG was with 24% corn silage or 23% starch, and concentrations greater than 47% corn silage or 32% starch resulted in negative MY responses. Responses in MY differed by level of MY and were often more evident in higher- (>30.0 kg MY/d) than in lower-producing cows. Milk fat concentration response was not related to dietary CDG, but was correlated linearly with milk fat concentration of cows fed the control diet. Milk fat concentration greater than 3.6% for the control treatment was related to a negative milk fat concentration response to CDG, regardless of dietary concentration of CDG. Partially replacing high-moisture corn with CDG increased milk fat concentration by 0.16 percentage units compared with that from dry corn. When formulating diets with CDG, diet fermentability and level of MY (higher vs. lower) must be considered. Concentrations of corn silage and starch must be moderate to optimize lactational responses to CDG. Overall, lactational response to CDG in this database was dependent on diet fermentability and milk fat concentration in the control.     

Milk production and enteric methane emissions by dairy cows grazing fertilized perennial ryegrass pasture with or without inclusion of white clover

An experiment was undertaken to investigate the effect of white clover inclusion in grass swards (GWc) compared with grass-only (GO) swards receiving high nitrogen fertilization and subjected to frequent and tight grazing on herbage and dairy cow productivity and enteric methane (CH₄) emissions. Thirty cows were allocated to graze either a GO or GWc sward (n = 15) from April 17 to October 31, 2011. Fresh herbage [16 kg of dry matter (DM)/cow] and 1 kg of concentrate/cow were offered daily. Herbage DM intake (DMI) was estimated on 3 occasions (May, July, and September) during which 17 kg of DM/cow per day was offered (and concentrate supplementation was withdrawn). In September, an additional 5 cows were added to each sward treatment (n = 20) and individual CH₄ emissions were estimated using the sulfur hexafluoride (SF₆) technique. Annual clover proportion (±SE) in the GWc swards was 0.20 ± 0.011. Swards had similar pregrazing herbage mass (1,800 ± 96 kg of DM/ha) and herbage production (13,110 ± 80 kg of DM/ha). The GWc swards tended to have lower DM and NDF contents but greater CP content than GO swards, but only significant differences were observed in the last part of the grazing season. Cows had similar milk and milk solids yields (19.4 ± 0.59 and 1.49 ± 0.049 kg/d, respectively) and similar milk composition. Cows also had similar DMI in the 3 measurement periods (16.0 ± 0.70 kg DM/cow per d). Similar sward and animal performance was observed during the CH₄ estimation period, but GWc swards had 7.4% less NDF than GO swards. Cows had similar daily and per-unit-of-output CH₄ emissions (357.1 ± 13.6 g of CH₄/cow per day, 26.3 ± 1.14 g of CH₄/kg of milk, and 312.3 ± 11.5 g of CH₄/kg of milk solids) but cows grazing GWc swards had 11.9% lower CH₄ emissions per unit of feed intake than cows grazing GO swards due to the numerically lower CH₄ per cow per day and a tendency for the GWc cows to have greater DMI compared with the GO cows. As a conclusion, under the conditions of this study, sward clover content in the GWc swards was not sufficient to improve overall sward herbage production and quality, or dairy cow productivity. Although GWc cows had a tendency to consume more and emitted less CH₄ per unit of feed intake than GO cows, no difference was observed in daily or per-unit-of-output CH₄ emissions.     

Variation in nutrients formulated and nutrients supplied on 5 California dairies

Computer models used in ration formulation assume that nutrients supplied by a ration formulation are the same as the nutrients presented in front of the cow in the final ration. Deviations in nutrients due to feed management effects such as dry matter changes (i.e., rain), loading, mixing, and delivery errors are assumed to not affect delivery of nutrients to the cow and her resulting milk production. To estimate how feed management affects nutrients supplied to the cow and milk production, and determine if nutrients can serve as indexes of feed management practices, weekly total mixed ration samples were collected and analyzed for 4 pens (close-up cows, fresh cows, high-milk-producing, and low-milk-producing cows, if available) for 7 to 12 wk on 5 commercial California dairies. Differences among nutrient analyses from these samples and nutrients from the formulated rations were analyzed by PROC MIXED of SAS (SAS Institute Inc., Cary, NC). Milk fat and milk protein percentages did not vary as much [coefficient of variation (CV) = 18 to 33%] as milk yield (kg; CV = 16 to 47 %) across all dairies and pens. Variability in nutrients delivered were highest for macronutrient fat (CV = 22%), lignin (CV = 15%), and ash (CV = 11%) percentages and micronutrients Fe (mg/kg; CV = 48%), Na (%; CV = 42%), and Zn (mg/kg; CV = 38%) for the milking pens across all dairies. Partitioning of the variability in random effects of nutrients delivered and intraclass correlation coefficients showed that variability in lignin percentage of TMR had the highest correlation with variability in milk yield and milk fat percentage, followed by fat and crude protein percentages. But, variability in ash, fat, and lignin percentages of total mixed ration had the highest correlation with variability in milk protein percentage. Therefore, lignin, fat, and ash may be the best indices of feed management to include effects of variability in nutrients on variability in milk yield, milk fat, and milk protein percentages in ration formulation models.     

Short communication: Responses to supplemental Saccharomyces cerevisiae fermentation product and triticale grain in dairy cows grazing high-quality pasture in early lactation

Supplementing cows grazing highly digestible pasture with a Saccharomyces cerevisiae fermentation product (SCFP) was hypothesized to increase dry matter (DM) intake and milk production. Sixty multiparous dairy cows were fed 3 kg of crushed triticale DM/cow per day for 23 ± 4.4 d before calving. Half of the cows received SCFP (60 g/d; Diamond V Original XP; Diamond V Mills, Inc., Cedar Rapids, IA). Cows in both treatment groups were randomly allocated at calving to 1 of 2 amounts (3 or 6 kg of DM/d) of triticale feeding with or without 60 g of SCFP/day (n = 15/treatment) until 84 days in milk. The amount of pasture harvested (kg of DM/cow per day) and milk yield (kg/cow per day) were not affected by SCFP. Milk protein content and yield were greater in cows receiving 6 kg of crushed triticale DM/d. Plasma nonesterified fatty acids and β-hydroxybutyrate concentrations were not affected by SCFP supplementation, but were lower in cows fed 6 kg of crushed triticale DM/d than those fed 3 kg of DM/d. Supplementation with SCFP increased milk lactose content without affecting milk production under the conditions investigated.     

Short communication: The effect of feeding high protein distillers dried grains on milk production of Holstein cows

The objectives of this study were to evaluate the effects of feeding high-protein distillers dried grains (HPDDG) on rumen degradability, dry matter intake, milk production, and milk composition. Sixteen lactating Holstein cows (12 multiparous and 4 primiparous) averaging 80 ± 14 d in milk were randomly assigned to 1 of 2 dietary treatments in a 2 × 2 crossover design. A portion of forage and all soy-based protein in the control diet were replaced by HPDDG (20% dry matter). Milk production and dry matter intake were recorded daily and averaged for d 19 to 21 of each 21-d period. Milk samples were collected on d 20 to 21 of each period. Milk yield increased with the inclusion of HPDDG (33.4 vs. 31.6 ± 2.13 kg/d), and 3.5% FCM was higher for the ration containing HPDDG (36.3 vs. 33.1 ± 2.24 kg/d). Percentage protein was not affected by treatment (average 3.04 ± 0.08%), but protein yield increased with inclusion of HPDDG (0.95 to 1.00 ± 0.05 kg/d). Milk fat concentration was not different between treatments (average 3.95 ± 0.20%), but fat yield increased for the ration containing HPDDG (1.35 vs. 1.21 ± 0.09 kg/d). Dry matter intake was not affected and averaged 21.9 ± 0.80 kg across treatments. Because of greater milk production, feed conversion was improved by the inclusion of HPDDG (1.47 to 1.73 ± 0.09). Milk urea N was greater for the HPDDG ration than the control (14.5 vs. 12.8 ± 0.67 mg/dL). This research suggests that HPDDG may effectively replace soy-based protein in lactating dairy cow diets.     

Energy balance and reproduction on dairy cows fed to achieve low or high milk production on a pasture-based system

This study investigated the energy balance, metabolic changes, reproduction, and health in Australian Holstein-Friesian cows of average genetic merit fed to produce 6,000 L of milk/cow per lactation (restricted production; Rp) on a predominantly grazed pasture diet, or 9,000 L of milk/cow per lactation (high production: Hp) on a more intensive feeding regimen by using a partial mixed ration to supplement pasture. The mean 4% fat-corrected milk (FCM) and standard deviation achieved was 8,466 ± 1,162 L/cow per lactation for the Hp herd and 6,748 ± 787 L/cow per lactation for the Rp herd. During early lactation, the degree of estimated negative energy balance was less in the Hp cows than in the Rp cows (−16.1 vs. −29.1 MJ/cow per day, respectively). Consequently, the mobilization of body reserves was also lower in the Hp cows, and this was reflected in lower concentrations of nonesterified fatty acids (0.70 vs. 0.84 mmol/L) and β-hydroxybutyrate (0.51 vs. 0.69 mmol/L) and greater concentrations of glucose (3.51 vs. 3.34 mmol/L) and insulin-like growth factor-I (78.9 vs. 58.7 ng/mL) for Hp and Rp cows, respectively. After calving, body condition score and body weight decreased to a similar extent in both herds and did not reflect the differences in mobilization of body reserves between the 2 herds. Reproductive performance was not significantly related to level of milk yield. The mean interval from calving to first active corpus luteum was 33 (SD = 20) d postpartum, and there were 1.4 (SD = 0.8) estrus cycles before the beginning of the breeding period (>50 d postpartum). The interval from calving to pregnancy was 114 d, and the pregnancy rate after 12 wk of mating was 74%. The number of cows with ovarian abnormalities was also similar between the 2 herds. Cows with a long postpartum anestrus had the lowest concentration of insulin-like growth factor-I. The number of health-related disorders was also similar between the herds, with the exception of mastitis, for which the incidence was significantly greater in the Hp cows. The results indicate that the production per cow could be increased from 6,748 L of FCM/cow per lactation for cows grazing pasture and supplemented with concentrates only at milking to 8,466 L of FCM/cow per lactation, in one lactation, by supplementing pasture with a partial mixed ration. Despite the fact that production per cow increased substantially, the degree of estimated negative energy balance and the metabolic changes in early lactation were lower and reproductive performance was maintained.     

Space allowance and barriers influence cow competition for mixed rations fed on a feed-pad between bouts of grazing

The objective of this experiment was to evaluate how feeding space allowance and provision of feed barriers interact to affect feeding and social behavior of dairy cows fed a partial mixed ration on a feed-pad. The treatments were factorial with 3 feeding space allowances (0.6, 0.75, or 1.0 m of trough space per cow) and feed troughs that were either open or had head barriers that physically separated adjacent cows to reduce interactions during feeding. One hundred and forty-four Holstein-Friesian cows in mid lactation were allocated into 12 groups of 12 cows, with 1 of 6 treatments (3 × 2) randomly assigned to 2 groups out of 12. Treatments were changed weekly over 3 wk according to a row-column, crossover design, with week corresponding to rows and group corresponding to columns. Thus, the design included 2 replicated groups per treatment in each week. Grazed pasture intake was approximately 6.1 kg of dry matter (DM)/cow per day, supplemented with 3.5 kg of DM/cow per day of wheat (Triticum aestivum) grain fed during milking and 10.7 kg of DM/cow per day of a mixed ration offered on the feed-pad after each milking. The experiment comprised a 7-d pre-experimental period followed by a 21-d experimental period. The social hierarchy within each group was determined before the experiment commenced. Feeding and social behaviors of cows were analyzed using video recordings and the changes in heart rate and heart rate variability were determined using heart rate monitors. Data were analyzed using mixed effect models by REML. When feeding space allowance was increased, we observed an increase in the time a cow spent feeding and a decrease in the number of feeding bouts in relation to the total time feed was available, particularly in subordinate cows. The number of aggressive behaviors and displacements decreased when space allowance increased. In addition, HR was reduced and the reduction was more pronounced in subordinate cows compared with dominant cows. Use of feed barriers increased cow feeding time and decreased the number of feeding bouts in relation to the total time feed was available, particularly in subordinate cows, and reduced the number of cow displacements during feeding. We conclude that increasing the feeding space from 0.6 to 0.75 to 1.0 m reduces aggressive interactions and improves cow feeding behavior, with the effects being greatest for subordinate cows. The use of feed barriers further reduces competition at the feed trough in a partial mixed ration feeding system.     

Capturing urine while maintaining pasture intake, milk production, and animal welfare of dairy cows in early and late lactation

Capturing urine and spreading it evenly across a paddock reduces the risk of nitrogen loss to the environment. This study investigated the effect of 16 h/d removal from pasture on the capture of urination events, milk production, pasture intake, and animal welfare from cows grazing fresh pasture in early and late lactation. Forty-eight Holstein-Friesian cows in early [470 ± 47 kg of body weight (BW); 35 ± 9 days in milk] and late (498 ± 43 kg of BW; 225 ± 23 days in milk) lactation were allocated to 3 treatment groups. Cows had access to pasture for either 4 h after each milking (2 × 4), for 8 h between morning and afternoon milkings (1 × 8), or for 24 h, excluding milking times (control). When not grazing, the 2 × 4 and 1 × 8 groups were confined to a plastic-lined loafing area with a woodchip surface. In early lactation, the proportion of urinations on pasture and laneways was reduced from 89% (control) to 51% (1 × 8) and 54% (2 × 4) of total urinations. The 1 × 8 cows ate less pasture [10.9 kg of dry matter (DM)/cow per day] than the control (13.6 kg of DM/cow per day) and 2 × 4 (13.0 kg of DM/cow per day) cows, which did not differ from each other. The 1 × 8 and 2 × 4 cows produced less milk (21 and 22 kg of milk/cow per day, respectively) compared with control cows (24 kg of milk/cow per day). There were no differences in BW or body condition score (BCS) change across treatment groups, with all groups gaining BW and BCS during the experimental period. In late lactation, there was no difference in pasture intake (mean = 8.8 kg of DM/cow per day), milk production (mean = 10 kg of milk/cow per day), and BW or BCS change (mean = 3.7 kg and −0.2 U/cow per week, respectively) between treatment groups. As in early lactation, urinations on pasture and laneways were reduced from 85% (control) to 56% (1 × 8) and 50% (2 × 4) of total urinations. These findings highlight an opportunity to maintain performance and welfare of grazing cows in early and late lactation while capturing additional urine. This can subsequently be spread evenly across pasture to minimize nitrogen loss to the environment.     

Dietary protein quality and quantity affect lactational responses to corn distillers grains: a meta-analysis

Diet fermentability influences lactational responses to feeding corn distillers grains (CDG) to dairy cows. However, some measures of diet fermentability are inherently related to the concentration and characteristics of corn-based ingredients in the ration. Corn-based feeds have poor protein quality, unable to meet the essential AA requirements of lactating cows. We conducted a meta-analysis of treatment means (n = 44) from the scientific literature to evaluate responses in milk yield (MY) and milk true protein concentration and yield to dietary CDG. The test variable was the difference in response between the CDG diet mean and the control diet mean (0% CDG) within experiment. Fixed variables were CDG concentration of the diet [% of dietary dry matter (DM)] and crude protein (CP) concentration and fractions of CP based on origin (corn-based versus non-corn-based feeds) of control and CDG diets. Diets with CDG ranged from 4 to 42% CDG, DM basis. Non-corn-based dietary CP averaged 6.3 ± 3.32% of total DM. Milk yield and milk true protein yield responses to added CDG were maximized when approximately 8.5% of the total dietary DM was non-corn-based CP. Milk yield response peaked for higher-producing cows (>30.0 kg MY/cow per day) at 4.3% dietary corn-based CP, but decreased linearly for lower-producing cows (<30.0 kg MY/cow per day) as corn-based dietary CP increased. Milk true protein yield response decreased as corn-based dietary CP concentration increased but milk true protein concentration response was not decreased when CDG diets had more than 6.5% dietary non-corn-based CP. Overall, 8.5% dietary non-corn-based CP was necessary in lactation diets to maximize lactational responses to dietary CDG. The necessity of dietary non-corn-based CP to maximize milk and milk protein yields limits the amount of dietary corn-based CP, including that from CDG, which can be included in rations without overfeeding N.     

Three-breed rotational crossbreds of Montbéliarde,Viking Red,and Holstein compared with Holstein cows for feed efficiency,income over feed cost,and residual feed intake

Rotational 3-breed crossbred cows of Montbéliarde, Viking Red, and Holstein (CB) were compared with Holstein (HO) cows for alternative measures of feed efficiency as well as income over feed cost (IOFC) and residual feed intake (RFI) during the first 150 d of first, second, and third lactations. Primiparous and multiparous CB (n = 63 and n = 43, respectively) and HO (n = 60 and n = 37, respectively) cows were fed the same total mixed ration twice daily with refusals weighed once daily. Feed was analyzed for dry matter content, net energy for lactation, and crude protein content. Body weight (BW) was recorded twice weekly. Daily production of milk, fat, and protein were estimated from monthly test days with best prediction. Measures of efficiency from 4 to 150 d in milk (DIM) were feed conversion efficiency (FCE), defined as fat plus protein production (kg) per kilogram of dry matter intake (DMI); ECM/DMI, defined as kilograms of energy-corrected milk (ECM) per kilogram of DMI; net energy for lactation efficiency (NE_LE), defined as ECM (kg) per megacalorie of net energy for lactation intake; crude protein efficiency (CPE), defined as true protein production (kg) per kilogram of crude protein intake; and DMI/BW, defined as DMI (kg) per kilogram of BW. The IOFC was defined as revenue from fat plus protein production minus feed cost. The RFI from 4 to 150 DIM for each lactation was the residual error remaining from regression of DMI on milk energy output (Mcal), metabolic BW, and energy required for change in BW (Mcal). Statistical analysis of measures of feed efficiency and RFI for primiparous cows included the fixed effects of year of calving and breed group. For multiparous cows, statistical analysis included breed as a fixed effect and cow as a repeated effect nested within breed group. Primiparous CB cows had higher means for FCE (+5.5%), ECM/DMI (+4.0%), NE_LE (+4.0%), and CPE (+5.2%) and a lower mean DMI/BW (–5.3%) than primiparous HO cows. Primiparous CB cows ($875) also had higher mean IOFC than primiparous HO cows ($825). In addition, mean RFI from 4 to 150 DIM was significantly lower (more desirable) for primiparous CB cows than HO cows. Likewise, multiparous CB cows had higher means for FCE (+8.2%), ECM/DMI (+5.9%), NE_LE (+5.8%), and CPE (+8.1%) and a lower mean for DMI/BW (–4.8%) than multiparous HO cows. Multiparous CB cows ($1,296) also had a higher mean for IOFC than multiparous HO cows ($1,208) and a lower mean for RFI from 4 to 150 DIM than HO cows.     

Effects of dietary forage level and monensin on lactation performance, digestibility and fecal excretion of nutrients, and efficiency of feed nitrogen utilization of Holstein dairy cows

Two experiments (Exp. 1 and 2) were conducted using a 4 × 4 Latin square design with 2 replications (n = 8) to evaluate effects of feeding Holstein dairy cows a total mixed ration containing 50 or 60% of ration dry matter (DM) from forages with or without supplementation of monensin. In Exp. 1, alfalfa silage (AS) was used as the major forage (55% forage DM), and corn silage (CS; 45% forage DM) was used to make up the rest of the forage portion of diets (55AS:45CS). In Exp. 2, CS was used as the major forage (70% forage DM) and alfalfa hay (AH; 30% forage DM) was used to make up the rest of the forage portion of diets (70CS:30AH). Experimental diets were arranged in a 2 × 2 factorial with 50 or 60% ration DM from forages and monensin supplemented at 0 or 300 mg/cow daily. In Exp. 1 (55AS:45CS), feeding 60% forage diets decreased DM intake (DMI; 27.3 vs. 29.6 kg/d) but maintained the same levels of milk (45.8 vs. 47.0 kg/d) compared with 50% forage diets. The efficiency of converting feed to milk or 3.5% fat-corrected milk was greater for cows fed 60% compared with 50% forage diets (1.7 vs. 1.6 kg milk or 3.5% fat-corrected milk/kg of DMI, respectively). Increasing dietary forage level from 50 to 60% of ration DM increased milk fat percentage (3.4 to 3.5%); however, adding monensin to the 60% forage diet inhibited the increase in milk fat percentage. Feeding 60% forage diets decreased feed cost, but this decrease ($0.5/head per day) in feed cost did not affect income over feed cost. Feeding 60% forage diets decreased fecal excretion of DM (10.6 to 9.6 kg/d) and nitrogen (N; 354 to 324 g/d) and improved apparent digestibility of neutral detergent fiber from 43 to 49% and apparent efficiency of feed N utilization from 32.3 to 35.9% compared with 50% forage diets. In Exp. 2 (70CS:30AH), feeding 60% forage diets decreased DMI from 29.6 to 28.2 kg but maintained the same level of milk (41.1 vs. 40.8 kg/d) and therefore increased the efficiency of converting feed to milk (1.46 vs. 1.38 kg milk/kg DMI) compared with 50% forage diets. Daily feed cost for feeding 60% forage diets was $0.3/head lower than for the 50% forage diets. Fecal excretion of DM (10.3 vs. 11.5 kg/d) was lower and fecal excretion of N (299 vs. 328 g/d) tended to be lower for 60% compared with 50% forage diets. Results from these 2 experiments suggest that a 60% forage diet consisting of either AS or CS as the major forage can be fed to high producing Holstein dairy cows without affecting milk production while improving or maintaining the efficiency of converting feed to milk and the apparent efficiency of utilization of feed N. Cows receiving a 60% forage diet had a similar or improved digestibility of nutrients with a similar or reduced fecal excretion of nutrients. Effects of monensin under the conditions of the current experiments were minimal.