L E Armentano

University of Wisconsin–Madison, Madison, Wisconsin, United States

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Publications (86)184.87 Total impact

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    Glen A Broderick, Antonio P Faciola, Louis E Armentano
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    ABSTRACT: Previous research suggested that crude protein (CP) from canola meal (CM) was used more efficiently than CP from solvent soybean meal (SBM) by lactating dairy cows. We tested whether dietary CP content influenced relative effectiveness of equal supplemental CP from either CM or SBM. Fifty lactating Holstein cows were blocked by parity and days in milk into 10 squares (2 squares with ruminal cannulas) in a replicated 5 × 5 Latin square trial. Five squares were fed: (1) low (14.5-14.8%) CP with SBM, (2) low CP with CM, (3) low CP with SBM plus CM, (4) high (16.4-16.7%) CP with SBM, and (5) high CP with CM; the other 5 squares were fed the same diets except with rumen-protected Met plus Lys (RPML) added as Mepron (Degussa Corp., Kennesaw, GA) and AminoShure-L (Balchem Corp., New Hampton, NY), which were assumed to provide 8 g/d of absorbed dl-Met and 12 g/d of absorbed l-Lys. Diets contained [dry matter (DM) basis] 40% corn silage, 26% alfalfa silage, 14 to 23% corn grain, 2.4% mineral-vitamin premixes, and 29 to 33% neutral detergent fiber. Periods were 3 wk (total 15 wk), and data from the last week of each period were analyzed using the Mixed procedures of SAS (SAS Institute Inc., Cary, NC). The only effects of RPML were increased DM intake and milk urea N (MUN) and urinary N excretion and trends for decreased milk lactose and solids-not-fat concentrations and milk-N:N intake; no significant RPML × protein source interactions were detected. Higher dietary CP increased milk fat yield and tended to increase milk yield but also elevated MUN, urine volume, urinary N excretion, ruminal concentrations of ammonia and branched-chain volatile fatty acids (VFA), lowered milk lactose concentration and milk-N:N intake, and had no effect on milk true protein yield. Feeding CM instead of SBM increased feed intake, yields of milk, energy-corrected milk, and true protein, and milk-N:N intake, tended to increase fat and lactose yields, and reduced MUN, urine volume, and urinary N excretion. At low CP, MUN was lower and intake tended to be greater on SBM plus CM versus SBM alone, but MUN and N excretion were not reduced to the same degree as on CM alone. Interactions of parity × protein source and parity × CP concentration indicated that primiparous cows were more responsive than multiparous cows to improved supply of metabolizable protein. Replacing SBM with CM reduced ruminal ammonia and branched-chain VFA concentrations, indicating lower ruminal degradation of CM protein. Replacing SBM with CM improved milk and protein yield and N-utilization in lactating cows fed both low- and high-CP diets. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 06/2015; DOI:10.3168/jds.2015-9563 · 2.55 Impact Factor
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    ABSTRACT: Prior to genomic selection on a trait, a reference population needs to be established to link marker genotypes with phenotypes. For costly and difficult-to-measure traits, international collaboration and sharing of data between disciplines may be necessary. Our aim was to characterize the combining of data from nutrition studies carried out under similar climate and management conditions to estimate genetic parameters for feed efficiency. Furthermore, we postulated that data from the experimental cohorts within these studies can be used to estimate the net energy of lactation (NEL) densities of diets, which can provide estimates of energy intakes for use in the calculation of the feed efficiency metric, residual feed intake (RFI), and potentially reduce the effect of variation in energy density of diets. Individual feed intakes and corresponding production and body measurements were obtained from 13 Midwestern nutrition experiments. Two measures of RFI were considered, RFIMcal and RFIkg, which involved the regression of NEL intake (Mcal/d) or dry matter intake (DMI; kg/d) on 3 expenditures: milk energy, energy gained or lost in body weight change, and energy for maintenance. In total, 677 records from 600 lactating cows between 50 and 275 d in milk were used. Cows were divided into 46 cohorts based on dietary or nondietary treatments as dictated by the nutrition experiments. The realized NEL densities of the diets (Mcal/kg of DMI) were estimated for each cohort by totaling the average daily energy used in the 3 expenditures for cohort members and dividing by the cohort's total average daily DMI. The NEL intake for each cow was then calculated by multiplying her DMI by her cohort's realized energy density. Mean energy density was 1.58 Mcal/kg. Heritability estimates for RFIkg, and RFIMcal in a single-trait animal model did not differ at 0.04 for both measures. Information about realized energy density could be useful in standardizing intake data from different climate conditions or management systems, as well as investigating potential genotype by diet interactions. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 02/2015; 98(4). DOI:10.3168/jds.2014-8580 · 2.55 Impact Factor
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    ABSTRACT: The objective of this study was to evaluate the effect of integrating dairy and bioenergy systems on land use, net energy intensity (NEI), and greenhouse gas (GHG) emissions. A reference dairy farm system representative of Wisconsin was compared with a system that produces dairy and bioenergy products. This integrated system investigates the effects at the farm level when the cow diet and manure management practices are varied. The diets evaluated were supplemented with varying amounts of dry distillers grains with solubles and soybean meal and were balanced with different types of forages. The manure-management scenarios included manure land application, which is the most common manure disposal method in Wisconsin, and manure anaerobic digestion (AD) to produce biogas. A partial life cycle assessment from cradle to farm gate was conducted, where the system boundaries were expanded to include the production of biofuels in the analysis and the environmental burdens between milk and bioenergy products were partitioned by system expansion. Milk was considered the primary product and the functional unit, with ethanol, biodiesel, and biogas considered co-products. The production of the co-products was scaled according to milk production to meet the dietary requirements of each selected dairy ration. Results indicated that land use was 1.6 m2, NEI was 3.86 MJ, and GHG emissions were 1.02 kg of CO2-equivalents per kilogram of fat- and protein-corrected milk (FPCM) for the reference system. Within the integrated dairy and bioenergy system, diet scenarios that maximize dry distillers grains with solubles and implement AD had the largest reduction of GHG emissions and NEI, but the greatest increase in land use compared with the reference system. Average land use ranged from 1.68 to 2.01 m2/kg of FPCM; NEI ranged from −5.62 to −0.73 MJ/kg of FPCM; and GHG emissions ranged from 0.63 to 0.77 kg of CO2-equivalents/kg of FPCM. The AD contributed 65% of the NEI and 77% of the GHG emission reductions.
    Journal of Dairy Science 01/2015; 98(3). DOI:10.3168/jds.2014-8850 · 2.55 Impact Factor
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    ABSTRACT: Our long-term objective is to develop breeding strategies for improving feed efficiency in dairy cattle. In this study, phenotypic data were pooled across multiple research stations to facilitate investigation of the genetic and nongenetic components of feed efficiency in Holstein cattle. Specifically, the heritability of residual feed intake (RFI) was estimated and heterogeneous relationships between RFI and traits relating to energy utilization were characterized across research stations. Milk, fat, protein, and lactose production converted to megacalories (milk energy; MilkE), dry matter intakes (DMI), and body weights (BW) were collected on 6,824 lactations from 4,893 Holstein cows from research stations in Scotland, the Netherlands, and the United States. Weekly DMI, recorded between 50 to 200 d in milk, was fitted as a linear function of MilkE, BW(0.75), and change in BW (ΔBW), along with parity, a fifth-order polynomial on days in milk (DIM), and the interaction between this polynomial and parity in a first-stage model. The residuals from this analysis were considered to be a phenotypic measure of RFI. Estimated partial regression coefficients of DMI on MilkE and on BW(0.75) ranged from 0.29 to 0.47 kg/Mcal for MilkE across research stations, whereas estimated partial regression coefficients on BW(0.75) ranged from 0.06 to 0.16kg/kg(0.75). Estimated partial regression coefficients on ΔBW ranged from 0.06 to 0.39 across stations. Heritabilities for country-specific RFI were based on fitting second-stage random regression models and ranged from 0.06 to 0.24 depending on DIM. The overall heritability estimate across all research stations and all DIM was 0.15 ± 0.02, whereas an alternative analysis based on combining the first- and second-stage model as 1 model led to an overall heritability estimate of 0.18 ± 0.02. Hence future genomic selection programs on feed efficiency appear to be promising; nevertheless, care should be taken to allow for potentially heterogeneous variance components and partial relationships between DMI and other energy sink traits across environments when determining RFI. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 01/2015; 98(3). DOI:10.3168/jds.2014.8510 · 2.55 Impact Factor
  • C Yao, L E Armentano, M J VandeHaar, K.A. Weigel
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    ABSTRACT: As feed prices have increased, the efficiency of feed utilization in dairy cattle has attracted increasing attention. In this study, we used residual feed intake (RFI) as a measurement of feed efficiency along with its component traits, adjusted milk energy (aMilkE), adjusted dry matter intake (aDMI), and adjusted metabolic body weight (aMBW), where the adjustment was for environmental factors. These traits may also be affected by prior health problems. Therefore, the carryover effects of 3 health traits from the rearing period and 10 health traits from the lactating period (in the same lactation before phenotype measurements) on RFI, aMilkE, aDMI, and aMBW were evaluated. Cows with heavier birth weight and greater body weight at calving of this lactation had significant increases in aMilkE, aDMI, and aMBW. The only trait associated with RFI was the incidence of diarrhea early in the lactation. Mastitis and reproductive problems had negative carryover effects on aMilkE. The aMBW of cows with metabolic disorders early in the lactation was lower than that of unaffected cows. The incidence of respiratory disease during lactating period was associated with greater aMBW and higher aDMI. To examine the contribution of health traits to the accuracy of predicted phenotype, genomic predictions were computed with or without information regarding 13 health trait phenotypes using random forests (RF) and support vector machine algorithms. Adding health trait phenotypes increased prediction accuracies slightly, except for prediction of RFI using RF. In general, the accuracies were greater for support vector machine than RF, especially for RFI. The methods described herein can be used to predict future phenotypes for dairy replacement heifers, thereby facilitating culling decisions that can lead to decreased feed costs during the rearing period. For these decisions, prediction of the animal's own phenotype is of greater importance than prediction of the genetic superiority or inferiority that will transmit to its offspring. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 12/2014; 98(3). DOI:10.3168/jds.2014-8707 · 2.55 Impact Factor
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    ABSTRACT: A survey was conducted in Wisconsin (WI) and Michigan (MI) to quantify the proportion of farms that use a single diet for all lactating cows and to better understand the reasons for current grouping strategies and the limitations to grouping for better nutritional management. A questionnaire was mailed to all WI dairy farmers with ≥200 lactating cows (971 farms) and to a random sample of grade-A MI dairy farmers (800 farms) of varying herd sizes. The survey return rate was 20% in WI (196 farms) and 26% in MI (211 farms; 59 of them had ≥200 lactating cows). Feeding 2 or more different diets to lactating cows was predominant: 63% in WI (124 farms, all ≥200 lactating cows), 76% in MI farms with ≥200 lactating cows (45 farms), and 28% in MI farms with <200 lactating cows (43 farms). Farmers feeding more than 1 diet used 1 or more of the following criteria for grouping lactating cows: stage of lactation, milk production, or body condition score. Overall for both states, 52% of the farms (211 from 407 farms) feeding more than 1 diet grouped cows according to their nutritional needs. However, a notable population of farms fed the same diet to all lactating cows: 37% in WI (72 farms), 24% in MI (14 farms) for herds of ≥200 lactating cows, and 72% in MI for herds of <200 lactating cows (109 MI farms). "Desire to keep it simple" and "milk drops when cows are moved to a different group" were identified as main constraints to having more groups within a farm for nutritional purposes. Farm facilities and labor were also limiting factors to grouping in farms with herd sizes of <200 lactating cows. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 12/2014; 98(2). DOI:10.3168/jds.2014-8368 · 2.55 Impact Factor
  • C M Stoffel, P M Crump, L E Armentano
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    ABSTRACT: Dietary fatty acids can affect both milk fat yield and fatty acid (FA) composition. This relationship is well established when the dietary level of FA exceeds 3% of diet dry matter (DM). We could find no reports directly examining the effects of dietary FA profile on milk fat at levels below 3%. Twenty-four primiparous and 36 multiparous lactating cows were paired by production (1 high with 1 low, within parity) to form 30 experimental units. Pairs were fed 6 diets in five 6 × 6 balanced Latin squares with 21-d periods, and data were collected during the last 5 d of each period. Two control diets were fed: a corn control diet (CC; 29% corn silage, 16% alfalfa silage, 19% corn grain, and 8% distillers grain on a DM basis) containing 1.8% FA; and a low-oil control diet (LOC; 9% corn silage, 35% alfalfa silage, 20% food-grade corn starch, and 8% corn gluten feed on a DM basis) containing 1.2% FA. A portion of the food-grade corn starch in LOC was replaced with 4 different FA supplements to create the 4 treatment diets. Treatments were 1.7% (DM basis) of a 50:50 blend of corn oil and high-linoleic safflower oil (LO), 1.7% high-oleic sunflower oil (OO), 1.7% palm oil (PO), or 1.8% calcium salts of palm fatty acids (PFA). The resultant diets were thus enriched in linoleic (LO), oleic (OO), or palmitic acid (PO and PFA). Dietary treatments did not affect dry matter intake. Addition of any of the fat sources to LOC resulted in increased milk yield, but milk fat yields and milk FA composition were variable for the different treatments. The LO treatment resulted in lower milk fat yield, fat concentration, and C16:0 yield but increased both trans-10 C18:1 and trans-10,cis-12 C18:2 yields compared with the other added FA treatments. Diets PO and PFA resulted in increased milk C16:0 yield and decreased total milk C18 yield compared with OO. Regression analysis revealed a negative coefficient for dietary linoleic acid content over basal (LOC) for both milk short-chain FA yield and C16:0 yield. Dietary linoleic acid content also had a positive coefficient for milk trans-10 C18:1 and trans-10,cis-12 conjugated linoleic acid yield. These results demonstrate that even when total dietary FA are below 3%, free oils rich in linoleic acid can reduce milk fat yield by reducing secretion of milk FA with fewer than 18 carbons. Fatty acid composition of fat supplements is important even at this low level of total dietary fat. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 10/2014; 98(1). DOI:10.3168/jds.2014-8328 · 2.55 Impact Factor
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    ABSTRACT: Abstract Text: Improving feed efficiency in dairy cattle is a costly and complex challenge, due to the difficulty in measuring individual animal feed intakes and the need to consider energy demands for growth, lactation, maintenance, health, and fertility. Research projects are underway in several countries to provide genomic breeding values for dry matter intake or residual feed intake of dairy bulls based on genotypes and phenotypes of reference animals in experimental herds. Heritability estimates suggest that direct selection for biological efficiency of feed utilization could lead to significant progress, and this is important because future gains in efficiency due to indirect selection for improved milk yield will be modest. Estimated genetic correlations suggest that residual feed intake is largely independent of the production and type traits currently considered in dairy cattle selection programs, but relationships with health and fertility traits must also be considered. Keywords: dairy cattle genomics feed efficiency
    10th World Congress on Genetics Applied to Livestock Production; 08/2014
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    ABSTRACT: Abstract Text: ABSTRACT: The genetic architecture of residual feed intake (RFI) and related traits was evaluated using a dataset of 2,894 cows. A Bayesian analysis estimated that markers accounted for 14% of the variance in RFI, and RFI had considerable genetic variation. Effects of marker windows were small, but QTL peaks were identified. Six of 8 chromosomes harboring QTL influencing RFI did not contain QTL influencing dry matter intake (DMI), net energy for lactation, or metabolic body weight. In contrast, 7 of 9 chromosomes with QTL influencing DMI also harbored QTL for one or more of the other traits evaluated. These results represent the first genomic analysis of RFI using a large (~3,000 animals) international dataset. In general they suggest RFI is a trait that should respond to selection, and that its genetic regulation is different from that of DMI. Keywords: dairy cattle feed efficiency genome wide association study
    10th World Congress on Genetics Applied to Livestock Production; 08/2014
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    ABSTRACT: Abstract Text: The goal of this study was to identify the effect of weight variation in cow pairs on animal performance and ingestive behavior under competitive conditions. Twenty-four primiparous and 36 multiparous lactating cows were paired (within parity) to form 30 experimental units (feeding gates). Pairs were fed 6 diets in five 6 × 6 balanced Latin squares with 21-d periods, using data from the last 5 d. Each pair had access to one gate that allowed one animal to eat at a time, and cows that filched feeds in other gate were excluded during the statistical analysis. Each dyad was categorized based on the difference in weight within dyad. Differences above average (60 kg) were categorized as High. Below average differences in size were categorized as Low. Within cow pair, individual animals were classified by size as either the larger animal in the pair (Large) or the smaller animal in the pair (Small). The effect of size (large/small) and difference (high/low) were tested. For High and Low difference pairs the number of displacement (gate exchange < 1 min) per week were 55.79 and 90.38 per week, respectively (P<0.05). An interaction between size and difference was significant for dry matter intake, feeding rate, displacements and milk yield, (P< 0.05). In High differences, small cows had greater DMI (% BW) compared to large cows (P<0.05). In Low difference pairs, size did not impact DMI. Milk yield was 4.4 ± 1.1 kg/d lower for Small cows compared to Large cows (P<0.05). For High difference pairs, Size was not associated with milk yield (P>0.05). These results suggest that in highly competitive situations, cows close in size have more aggression, poorer welfare, and milk production than animals with a greater difference in weight. This has implications for identifying animals with poor welfare in competitive environments. Keywords: animal behavior, competition, performance
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
  • Clayton M Stoffel, Louis E. Armentano
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    ABSTRACT: Abstract Text: Dietary fatty acid (FA) composition can affect milk fat yield but also relative yields of different FA. This study examined the effects on yield of individual milk FA resulting from different dietary FA profiles at FA levels below 3% of diet dry matter (DM). Trial design and production performance data were discussed in a 2013 ADSA abstract. Briefly, 60 cows were paired (within parity) to form 30 experimental units. Pairs were fed six diets in five 6x6 balanced Latin squares with 21-d periods. There were two control diets: a corn control diet (CC) containing 1.8% FA and a low oil control (LOC) containing 1.2% FA. A portion of the food grade corn starch in LOC was replaced with 1.7% diet DM of a 50/50 blend of corn and high linoleic safflower oils (CO), high oleic sunflower oil (OO), palm oil (PO), or 1.8% diet DM calcium salts of palm FA (ML, Megalac®) to create four treatment diets that were enriched in either linoleic (CO), oleic (OO), or palmitic acid (PO and ML). Milk FA composition was measured on d 20, and milk yield and fat concentration were measured for the last 5 d of each period; these data were combined to determine yield of individual milk FA. There were significant treatment effects on the yield of 31 out 53 milk FA measured including 10 out of 14 C18:1 isomers (P<0.05). Palmitic acid (C16) yield was lower for CO compared to other treatments (P<0.01) and C18:1 and total C18 yield were higher for OO when compared to PO and ML (P<0.01, P<0.01). Trans-10 C18:1 yield was higher for CO when compared to the other treatments (P<0.01) and for OO compared to PO and ML (P=0.01). Trans-10, cis-12 yield was also higher for CO when compared to all other treatments (P<0.01). Linear regression analysis was also conducted to examine the effect on milk FA yield of the increased dietary linoleic, oleic, and palmitic acid concentrations of the treatment diets over LOC. Dietary linoleic decreased short chain (<C16) and C16 FA yield (P=0.02, P<0.01), dietary oleic increased total C18 yield (P<0.01), and dietary palmitic increased C16 yield (P<0.01). These differences in milk FA profile are consistent with the idea that linoleic acid depresses short chain and C16 FA, resulting in milk fat depression even at dietary FA levels below 3%. Keywords: Biohydrogenation Milk Fat Depression Milk Fatty Acid
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
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    ABSTRACT: Abstract Text: The objective was to validate an in vitro model to predict the total tract fiber digestibility (TTNDFD) in dairy cattle. Nineteen diets from six different trials conducted at University of Wisconsin-Madison were analyzed for fiber digestibility using the in vitro standardized model (Goeser and Combs, 2009). Forages varied amongst diets (corn, alfalfa, tall-fescue and meadow fescue and wheat straw silages) and nutrient composition (NDF ranges from 22.5 to 32.1 %, CP 15.8 to 18.9 % and NFC 38.0 to 51.0 %). Total NDF digestibility observed from the in vivo trials was calculated using indigestible NDF or lignin as marker analyzed in fecal, diet and orts samples. The in vitro TTNDFD model predicts total tract fiber digestibility from the rate of pdNDF degradation (kd, ranges from 1.5 to 4.8 %/h), the rate of passage of pdNDF (kp, ranges from 2.5 to 2.8 %/h) and the proportion of total NDF that is potentially digestible. The kd is calculated from in vitro NDFD measurements taken at 24, 30 and 48 h of incubation using first order kinetics model with an indigestible fraction (Mertens, 1993). Passage of potentially digestible fiber is predicted from a regression model (Krizsan et al., 2010) for iNDF which is adjusted to account for the selective retention of pdNDF (Lund et al., 2006). The pool of indigestible fiber was estimated from 240 h in vitro NDF residues. Data were analyzed using SAS procedure of logistic regression. The coefficient of determination (R2) was used to measure the proportion of variation explained by the model. The range of in vivo TTNDFD was 26.3 to 55.6 % compared to 33.8 to 52.8% for predicted in vitro TTNDFD. The relationship between predicted in vitro TTNDFD and in vivo TTNDFD was TTNDFD in vivo = -5.7531 + 1.1561 TTNDFD in vitro predicted with R² of 61.6%, Root-MSE of 4.3% and p-value of <0.001. The in vitro test of diets from six different trials demonstrated that TTNDFD model can provide important insights into fiber utilization by dairy cattle that could be used in the field. The TTNDFD value can also be used as a stand-alone value to index forages, as already shown in other publications from our lab. The ability to predict total tract fiber digestibility from a model based on in vitroNDF degradation and incorporate this information into rations could improve our ability to optimize forage utilization and milk production. Keywords: iNDF-Fiber-Digestibility
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
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    ABSTRACT: Abstract Text: Continued improvements in feed efficiency are essential for a thriving and sustainable dairy industry. Gross efficiency (GrEff) is defined as the energy captured in milk and body tissues as a percentage of gross energy intake. Our objective was to characterize the relationships among component traits for feed efficiency in lactating Holsteins and to determine their relationships to GrEff. Milk energy output per day (MilkE), calculated from milk, fat, protein, and lactose yields, dry matter intakes (DMI), body weights (BW), and body condition scores (BCS) were collected on 4452 lactating Holstein cows ranging from 50 to 200 days in milk from Scotland, the Netherlands, and the United States. The first 42-day records were analyzed with multivariate animal model in ASREML 3.0. Daily body energy change (dBE) was estimated from body weight change and BCS. Metabolic BW (MBW) was BW to the 0.75 power. GrEff was calculated as (MilkE + dBE) / Gross Energy intake, assuming all diets were 4.5 Mcal/kg. For these cows, MilkE was 26 ± 6 Mcal/d, BW was 600 ± 70 kg, DMI was 22 ± 5 kg/d, and intake as a multiple of maintenance was 3.9 ± 0.6. Genetic correlations for feed efficiency traits were 0.07 ± 0.04 for MilkE and MBW, 0.73 ± 0.03 for MilkE and DMI, and 0.40 ± 0.03 for MBW and DMI. Phenotypic correlations for feed efficiency traits were 0.16 ± 0.02 for MilkE and MBW, 0.60 ± 0.01 for MilkE and DMI, and 0.37 ± 0.01 for MBW and DMI. All correlations were reasonably consistent across countries. Genetic correlations of GrEff with MilkE, MBW, and DMI were 0.61 ± 0.04, -0.14 ± 0.05, and 0.04 ± 0.06, respectively. Phenotypic correlations of GrEff with MilkE, MBW, and DMI were 0.47 ± 0.01, -0.05 ± 0.02, and -0.17 ± 0.01, respectively. We conclude that, for Holsteins at a multiple of maintenance around 4, selection for milk component yield remains the overwhelming determinant of feed efficiency, and that selection for smaller body size may benefit feed efficiency but its impact will be slight compared to selection for more milk. Moreover, selection for greater milk will have a greater impact on profitability than would selection for BW. We suggest that that direct selection for body size (either larger or smaller) is likely not warranted as a means to enhance milk production or feed efficiency. Keywords: lactating dairy cow, feed efficiency, body weight
    2014 ADSA-ASAS-CSAS Joint Annual Meeting; 07/2014
  • C Arndt, L E Armentano, M B Hall
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    ABSTRACT: The objective of this study was to determine the effect of substituting corn bran (CB) for dried ground corn grain (CG) in the nonforage portion of high-forage (HF) and low-forage (LF) diets. Twelve multiparous and 12 primiparous Holsteins were assigned to 4 diets using six 4 × 4 Latin squares with 3-wk periods. Forage was 64 or 38% of the total mixed ration (% of dry matter). On a dry matter basis, the HFCG diet had 20% CG, the LFCG diet had 39% CG, the HFCB diet had 19% CB, and the LFCB diet had 38% CB. Digestible organic matter intake (OMI) and milk energy yield were lower for CB compared with CG within forage level. Digestible OMI was greater (1.9 kg/d) for the LFCG compared with the HFCG treatment. When CB replaced forage (LFCB vs. HFCB), digestible OMI was not different but milk energy yield was greater with the LFCB diet. The LFCG diet supported the greatest milk, milk protein, and milk energy yield. Decreased concentration of milk protein and increased concentration of milk urea nitrogen when feeding CB compared with CG suggests that lack of fermentable energy in the CB diets may have limited rumen microbial protein synthesis. Total substitution of CG with CB in the nonforage portion did not support maximum milk production, even when forage was reduced at the same time (HFCG vs. LFCB). Predicted neutral detergent fiber (NDF) digestibility at 1 times maintenance, based on chemical analysis of the individual feeds, was 22 percentage units greater for CB than for the forage mix (68.9 vs. 46.9%). In vitro NDF digestibility (30 h) was 19.4 percentage units greater for CB than for the forage mix (68.9 vs. 49.5%). However, in vivo NDF digestibility of the diet when CB replaced forage (HFCB vs. LFCB) was similar (44.1 vs. 44.5%). Similarly, predicted total digestible nutrients at the production level of intake, based on chemical analysis, were greater for the CB treatments and lower for the CG treatments than those observed in vivo.
    Journal of Dairy Science 07/2014; 97(9). DOI:10.3168/jds.2013-7815 · 2.55 Impact Factor
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    ABSTRACT: Feed efficiency is an economically important trait in the beef and dairy cattle industries. Residual feed intake (RFI) is a measure of partial efficiency that is independent of production level per unit of body weight. The objective of this study was to identify significant associations between single nucleotide polymorphism (SNP) markers and RFI in dairy cattle using the Random Forests (RF) algorithm. Genomic data included 42,275 SNP genotypes for 395 Holstein cows, whereas phenotypic measurements were daily RFI from 50 to 150 d postpartum. Residual feed intake was defined as the difference between an animal's feed intake and the average intake of its cohort, after adjustment for year and season of calving, year and season of measurement, age at calving nested within parity, days in milk, milk yield, body weight, and body weight change. Random Forests is a widely used machine-learning algorithm that has been applied to classification and regression problems. By analyzing the tree structures produced within RF, the 25 most frequent pairwise SNP interactions were reported as possible epistatic interactions. The importance scores that are generated by RF take into account both main effects of variables and interactions between variables, and the most negative value of all importance scores can be used as the cutoff level for declaring SNP effects as significant. Ranking by importance scores, 188 SNP surpassed the threshold, among which 38 SNP were mapped to RFI quantitative trait loci (QTL) regions reported in a previous study in beef cattle, and 2 SNP were also detected by a genome-wide association study in beef cattle. The ratio of number of SNP located in RFI QTL to the total number of SNP in the top 188 SNP chosen by RF was significantly higher than in all 42,275 whole-genome markers. Pathway analysis indicated that many of the top 188 SNP are in genomic regions that contain annotated genes with biological functions that may influence RFI. Frequently occurring ancestor-descendant SNP pairs can be explored as possible epistatic effects for further study. The importance scores generated by RF can be used effectively to identify large additive or epistatic SNP and informative QTL. The consistency in results of our study and previous studies in beef cattle indicates that the genetic architecture of RFI in dairy cattle might be similar to that of beef cattle.
    Journal of Dairy Science 08/2013; 96(10). DOI:10.3168/jds.2012-6237 · 2.55 Impact Factor
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    ABSTRACT: The effects of rumen digesta volume and pH on VFA absorption and its relation to rumen wall morphology were evaluated. Nine rumen cannulated cows formed three groups based on desired variation in rumen morphology: The High group was formed by Holsteins yielding 25.9 kg Milk/d and fed on a high-grain TMR, the Medium group by Holstein-Zebu crossbreds yielding 12.3 kg Milk/d and fed on corn silage, tropical pasture and a commercial concentrate, and the Dry group by non-lactating grazing Jerseys fed exclusively on tropical pasture. Within each group, a sequence of three ruminal conditions was induced on each cow in 3x3 Latin Squares, with seven-day periods: High digesta volume and high pH (HVHP); low volume and high pH (LVHP); and low volume and low pH (LVLP). Rumen mucosa was biopsied on the first day of period one. Ruminal morphometric variables evaluated were mitotic index, absorptive surface and papillae number per cm(2) of wall, area per papillae, papillae area as a % of absorptive surface, and epithelium, keratinized layer, and non-keratinized layer thickness. There was marked variation in rumen morphology among the groups of cows. Grazing Jerseys had decreased rumen wall absorptive surface area and basal cells mitotic index, and increased thickness of the epithelium and of the keratin layer compared to cows receiving concentrates.Mean rumen pH throughout the four hour sampling period was: 6.78 for HVHP, 7.08 for LVHP and 5.90 for LVLP (P<0.01). The capacity of the rumen wall to absorb VFA was estimated by the Valerate/CrEDTA technique. The fractional exponential decay rate for the ratio of valeric acid to Cr (k Val/Cr) was determined by rumen digesta sampling at 20-minute intervals during four hours, following the mixing of markers and the return of the evacuated ruminal content. The k Val/Cr values for treatments HVHP, LVHP and LVLP were, respectively (%/h): 19.6, 23.9 and 35.0 (SEM=2.01; P=0.21 for contrast HVHP vs. LVHP and P<0.01 for contrast LVHP vs. LVLP). The k Val/Cr was faster under low pH, while decreasing digesta volume under high pH did not elicit such a response. The correlation between the absorptive surface area per cm2 of rumen wall and the mean of the three k Val/Cr values of each cow was 0.90 (P<0.01). Cows capable of maintaining a less acidic rumen environment had greater inflow of water into the digestive cavity, had a more developed rumen mucosa, and were more efficient VFA absorbers.
    Journal of Animal Science 01/2013; 91(4). DOI:10.2527/jas.2011-4999 · 1.92 Impact Factor
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    C. Leonardi, S. Bertics, L.E. Armentano
    Journal of Dairy Science 11/2012; 95(11):6830. DOI:10.3168/jds.2012-95-11-6830 · 2.55 Impact Factor
  • E.A. French, S J Bertics, L E Armentano
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    ABSTRACT: The objective of this study was to determine if ruminally infusing volatile fatty acid (VFA) increased concentration of their homologous odd- and branched-chain fatty acid (OBCFA) in rumen contents and milk. The influence of VFA on dry matter intake (DMI), blood metabolites, and blood insulin was also evaluated. Four mid-lactation cows were assigned to a 4×4 Latin square design with 48-h periods. Infusion treatments were acetate (AC), propionate (PR), isovalerate (IV), and anteisovalerate (AIV). Infusions began (time = 0) 5.5 h before feeding at 17.4 mmol of VFA/min and were terminated at 18 h. Infusions rates were well above physiological levels for IV and AIV. Surprisingly, the greatest differences in rumen OBCFA were increases in rumen liquid iso C15:0 and nonbranched C17:0 for AIV. In addition, infusing AIV increased anteiso C15:0 and anteiso C17:0 in rumen solid contents. Infusing IV increased iso C15:0 in both rumen solids and milk. Propionate increased milk C15:0 and C17:0. Both gluconeogenic compounds, PR and AIV, had similar proportions of milk C15:0, which was greater than that obtained with AC and IV. Rumen and blood VFA were as expected, with increased concentrations of the VFA present in the infusate. At 23 h, and consistently throughout infusions, DMI was similar for AC compared with PR and for AIV compared with IV. Both IV and AIV decreased DMI and energy balance; however, only IV increased plasma nonesterified fatty acids (121, 78, 172, and 102 mM for AC, AIV, IV, and PR), increased β-hydroxybutyrate (10.8, 5.9, 51.9, 5.4 mg/dL for AC, AIV, IV, and PR), and reduced plasma glucose (56.3, 59.1, 31.9, and 64.3 mg/dL for AC, AIV, IV, and PR). Rumen and milk OBCFA responses were minimal following infusion of large amounts of IV and AIV, suggesting limited use of IV, and AIV for de novo OBCFA synthesis, either pre- or postabsorption. Minor increases in milk odd-chain fatty acids following large doses of ruminal PR support the presence of postabsorptive synthesis of these milk odd-chain fatty acids.
    Journal of Dairy Science 04/2012; 95(4):2015-26. DOI:10.3168/jds.2011-4827 · 2.55 Impact Factor
  • M He, K L Perfield, H B Green, L E Armentano
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    ABSTRACT: The effect of feeding increasing levels of oleic and linoleic acid both independently and together, with or without monensin, on milk fat depression was evaluated. Fifty-six Holstein cows were blocked by parity and then were divided by milk production into 2 groups (high or low) of 14 cows each within each parity block. A cow pair of 1 high and 1 low production cow within each parity block was fed in a single electronic feeding gate. Gates (n = 28) were considered the experimental unit and were assigned to monensin (17.5 g/t of dry matter) or control as the main plot (n = 14 each). The 7 cow pairs in each of the fixed effect groups were further assigned to a sequence of fat blend diets as split plot. Seven fat blend treatments in the split plot 7 × 7 Latin square were no added fat (no fat) and diets with increasing levels of oleic or linoleic acid: low C18:1 + low C18:2 (LOLL); low C18:1 + medium C18:2 (LOML); low C18:1 + high C18:2 (LOHL); medium C18:1 + low C18:2 (MOLL); medium C18:1+medium C18:2 (MOML); and high C18:1+low C18:2 (HOLL). Monensin feeding did not affect milk yield or concentration and yield of milk fat. Feeding monensin decreased the proportion of C <16, increased the proportion of total C18, increased the proportion and yield of trans-10 C18:1, and increased the proportion of trans-10,cis-12 conjugated linoleic acid in milk fatty acids (FA). As dietary C18:1 or C18:2 increased beyond the concentration present in LOLL, milk fat concentration, milk fat yield, and proportion and yield of milk C <16 all decreased, and the proportion and yield of milk trans-10 C18:1 increased. A quadratic effect on milk fat concentration and yield was noticed for C18:2 feeding, but not for C18:1 feeding. When dietary contents of total FA and FA other than C18:1 and C18:2 were similar, C18:2-rich diets decreased milk fat concentration and yield compared with C18:1-rich diets (LOML vs. MOLL, and LOHL vs. HOLL), indicating that C18:2 is more potent than C18:1 for depressing milk fat. Increasing dietary FA content from no fat to LOLL, which increased primarily C18:1 and C18:2 with small increases in C18:0 and C16:0, decreased the secretion of C <16 but increased total C18 secretion in milk. This suggests that biohydrogenation intermediates act to decrease mammary FA synthesis at low levels of added C18:1 and C18:2. No significant monensin × fat interactions were detected for the milk composition parameters analyzed; however, a monensin × fat interaction was found for milk fat trans-10 C18:1 proportion.
    Journal of Dairy Science 03/2012; 95(3):1447-61. DOI:10.3168/jds.2011-4635 · 2.55 Impact Factor
  • M He, L E Armentano
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    ABSTRACT: This study was conducted to evaluate the effect of dietary supplementation of unprotected vegetable oils differing in fatty acid profiles with or without a commercial antioxidant (Agrado Plus, Novus International, St. Charles, MO) on dairy cattle performance, milk fatty acid profiles, and milk fat depression. Twenty-four multiparous Holstein cows were blocked by production (high and low) and assigned to Agrado Plus or no Agrado Plus diets as the main plot in this experiment. The 6 cows in each of the fixed effect groups (high with and without Agrado, low with and without Agrado) were then assigned to a 6 × 6 Latin square as a split plot with 21-d periods. The 6 dietary treatments in the split-plot Latin square were no added oil (control), or 5% DM as oil from palm (PO), high-oleic safflower (OSAF), high-linoleic safflower (LSAF), linseed (LNSD), or corn (CO). Added oil replaced corn starch in the total mixed ration. Diets were formulated to have similar crude protein and neutral detergent fiber, and consisted of 41.2% alfalfa silage, 18.3% corn silage, and 40.5% concentrate mix (dry matter basis). Feeding Agrado Plus did not affect milk, milk fat, or milk protein production or milk fatty acid composition in this study. No significant differences were found between oil feeding versus control for dry matter intake, milk yield, and milk protein yield, but oils other than PO significantly decreased milk fat concentration and proportion and yield of milk short- and medium-chain fatty acids (C(<16)). Feeding PO effectively maintained milk fat yield (1.18 kg/d) and concentration (3.44%), whereas the oils rich in linoleic acid (CO and LSAF) significantly decreased milk fat yield (0.98 and 0.86 vs. 1.14 kg/d) and concentration (3.05 and 2.83 vs. 3.41%) compared with control. Similar lactation performance between OSAF and LNSD suggests that oleic and linolenic acids are roughly equal in potency of milk fat depression.
    Journal of Dairy Science 05/2011; 94(5):2481-91. DOI:10.3168/jds.2010-3755 · 2.55 Impact Factor

Publication Stats

2k Citations
184.87 Total Impact Points

Institutions

  • 1985–2015
    • University of Wisconsin–Madison
      • Department of Dairy Science
      Madison, Wisconsin, United States
    • Virginia Polytechnic Institute and State University
      • Department of Dairy Science
      Блэксбург, Virginia, United States
  • 1992
    • Agricultural Research Service
      ERV, Texas, United States
  • 1981–1985
    • Iowa State University
      • Department of Animal Science
      Ames, Iowa, United States