A review on the potentials of using feeds rich in water-soluble carbohydrates to enhance rumen health and sustainability of dairy cattle production.

Cows are adapted to degrade structural plant carbohydrates (SC), such as cellulose and hemicelluloses, prevailing in grasses. Yet, the need for energy-dense diets in many intensive dairy production systems has shifted the dairy cattle's diet from SC-rich to high levels of starch. Feeding of starch-rich diets increases the risk of ruminal acidosis in cows, and feeding starch in the form of grains intensifies the competition over cereal grains and arable land among different livestock species, as well as between livestock and humans. Besides cellulose and hemicelluloses, grasses are also often rich in water-soluble carbohydrates (WSC), which comprise mono-, di-, oligo- and polysaccharides (fructans). Although the ruminal fermentation profile of mono- and disaccharides resembles that of starch, the degradation of oligo- and polysaccharides is slower, and their fermentation elicits a rather protecting effect on ruminal pH. When harvested in an early phase (i.e. ear emergence), grass hay and silages can reach WSC levels up to 150-200 g kg-1 dry matter and energy levels close to starch-rich diets, allowing a significantly reduced inclusion of concentrate supplements. By doing so, this will enhance both rumen health and the sustainability of milk production. However, because the WSC are chemically very heterogeneous, the patterns and extent of their ruminal fermentation are difficult to predict without a clear analytical characterization. This review article aims to summarize both the benefits and potentials, as well as the challenges, with respect to using WSC-rich feedstuffs in the nutrition of dairy cattle and their effects on ruminal fermentation characteristics and milk production. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Random-effects linear model application to herd-level assessment of bovine hepatic trace mineral concentrations.

To evaluate the utility of random-effects linear modeling for herd-level evaluation of trace mineral status, we performed a retrospective analysis of the results for trace mineral testing of bovine liver samples submitted to the Michigan State University Veterinary Diagnostic Laboratory between 2011 and 2017. Our aim was to examine random-effects models for their potential utility in improving interpretation with minimal sample numbers. The database consisted of 1,658 animals distributed among 121 herds. Minerals were assayed by inductively coupled plasma-mass spectroscopy, and included cobalt, copper, iron, molybdenum, manganese, selenium, and zinc. Intraclass correlation coefficients for each mineral were significantly different (p < 0.001) from zero and ranged from 0.38 for manganese to 0.82 for selenium, indicating that the strength of herd effects, which are presumably related to diet, vary greatly by mineral. Analysis of the distribution and standard errors of best linear unbiased predictor (BLUP) values suggested that testing 5-10 animals per herd could place herds within 10 percentile units across the population of herds with 70-95% confidence, the confidence level varying among minerals. Herd means were generally similar to BLUPs, suggesting that means could be reasonably compared to BLUPs with respect to the distributions reported here. However, caution in interpreting means relative to BLUPs should be exercised when animal numbers are small, the standard errors of the means are large, and/or the values are near the extremes of the distribution.

Challenges and opportunities for quantifying greenhouse gas emissions through dairy cattle research in developing countries.

The global dairy sector is facing the challenge of reducing greenhouse gas (GHG) emissions whilst increasing productivity to feed a growing population. Despite the importance of this challenge, many developing countries do not have the required resources, specifically funding, expertise and facilities, for quantifying GHG emissions from dairy production and research. This paper aims to address this challenge by discussing the magnitude of the issue, potential mitigation approaches and benefits in quantifying GHG emissions in a developing country context. Further, the paper explores the opportunities for developing country dairy scientists to leverage resources from developed countries, such as using existing relevant GHG emission estimation models. It is clear that further research is required to support developing countries to quantify and understand GHG emissions from dairy production, as it brings significant benefits including helping to identify and implement appropriate mitigation strategies for local production systems, trading carbon credits and achieving the nationally determined contribution obligations of the Paris Agreement.

Quantitative analysis of lead in cows and buffaloes for health assessment.

The present study aimed to investigate the concentration of highly toxic heavy metal, lead (Pb), in cows and buffaloes of Sargodha district, Punjab, Pakistan. Samples of three major organs (spleen, lungs, bones) from five localities were obtained from two age groups (< 2 years, > 2 years) of each animal. With the confidence level of 95%, the investigated results demonstrated that lead concentration ranged from 0.28 to 1.12 mg kg-1 and 0.31 to 0.83 mg kg-1 in cows and buffaloes respectively. Out of the three tested organs, spleen contained the highest level of Pb (0.64-0.83 mg/kg) followed by lungs (0.28-1.12 mg/kg) and bones (0.36-0.87 mg/kg). Furthermore, a significant increase of Pb was observed in older animals. It was demonstrated that both age groups had Pb accumulation higher than the standard limit of 0.1 mg kg-1. Serving as bioindicators, the presence of toxic levels of lead in the animals indicated environmental pollution and possible risks for public health. High lead concentration in dietary commodities from Sargodha district calls for the sound management of hazardous waste. High levels of this toxic metal also indicate the possible health risks to human population of the areas in Sargodha. It is highly needed to address this metal contamination and its probable entry route into the food chain of the domesticated animals. This must be further investigated to prevent animals from lead exposure.

Investigation into the Concentrations and Sources of Nitrates and Nitrites in Milk and Plant-Based Powders.

Milk powders in the United States (US) may contain nitrates and nitrites from several potential sources. These sources include the ingestion of nitrates and nitrites by dairy cows during grazing and drinking, nitric acid used during the sanitization of dairy equipment, and the production of nitrous oxides in directly heated spray dryers. Recently, milk powders manufactured in the US have been rejected during import to other countries because nitrite concentrations were greater than 2 mg/kg (ppm). To date, the concentrations of nitrates and nitrites in milk and plant-based powders in the US are unknown. In this study the nitrate and nitrite concentrations present in diverse milk powders were investigated including 81 milk powders from local and online retailers from 2015 to 2018. In addition, 71 commercial milk powders were obtained from blinded production facilities. Nitrate and nitrite concentrations were determined using ion chromatography with conductivity and UV detection. A subset of samples was analyzed for N-nitrosodimethylamine using gas chromatography-mass spectrometry. Carbon and nitrogen bulk isotope ratios analyzed using isotope ratio mass spectrometry were used to obtain some insights into the production method (organic vs conventional) and geographic source of the milk powder samples. Background nitrate concentrations in US-produced milk powder samples averaged 17 ± 12 mg/kg. Nitrite was detected at concentrations greater than 2 mg/kg in 5 out of 39 different brands of retail milk and plant-based powders. Of these brands, two were plant-based (soy and coconut) powders and the other three had consistently high nitrites. The analysis of milk powders using stable isotope analysis revealed further information about the cow's diet.

Structural equation models to disentangle the biological relationship between microbiota and complex traits: Methane production in dairy cattle as a case of study.

The advent of metagenomics in animal breeding poses the challenge of statistically modelling the relationship between the microbiome, the host genetics and relevant complex traits. A set of structural equation models (SEMs) of a recursive type within a Markov chain Monte Carlo (MCMC) framework was proposed here to jointly analyse the host-metagenome-phenotype relationship. A non-recursive bivariate model was set as benchmark to compare the recursive model. The relative abundance of rumen microbes (RA), methane concentration (CH4 ) and the host genetics was used as a case of study. Data were from 337 Holstein cows from 12 herds in the north and north-west of Spain. Microbial composition from each cow was obtained from whole metagenome sequencing of ruminal content samples using a MinION device from Oxford Nanopore Technologies. Methane concentration was measured with Guardian® NG infrared gas monitor from Edinburgh Sensors during cow's visits to the milking automated system. A quarterly average from the methane eructation peaks for each cow was computed and used as phenotype for CH4 . Heritability of CH4 was estimated at 0.12 ± 0.01 in both the recursive and bivariate models. Likewise, heritability estimates for the relative abundance of the taxa overlapped between models and ranged between 0.08 and 0.48. Genetic correlations between the microbial composition and CH4 ranged from -0.76 to 0.65 in the non-recursive bivariate model and from -0.68 to 0.69 in the recursive model. Regardless of the statistical model used, positive genetic correlations with methane were estimated consistently for the seven genera pertaining to the Ciliophora phylum, as well as for those genera belonging to the Euryarchaeota (Methanobrevibacter sp.), Chytridiomycota (Neocallimastix sp.) and Fibrobacteres (Fibrobacter sp.) phyla. These results suggest that rumen's whole metagenome recursively regulates methane emissions in dairy cows and that both CH4 and the microbiota compositions are partially controlled by the host genotype.

Multi-trait meta-analyses reveal 25 quantitative trait loci for economically important traits in Brown Swiss cattle.

BACKGROUND: Little is known about the genetic architecture of economically important traits in Brown Swiss cattle because only few genome-wide association studies (GWAS) have been carried out in this breed. Moreover, most GWAS have been performed for single traits, thus not providing detailed insights into potentially existing pleiotropic effects of trait-associated loci. RESULTS: To compile a comprehensive catalogue of large-effect quantitative trait loci (QTL) segregating in Brown Swiss cattle, we carried out association tests between partially imputed genotypes at 598,016 SNPs and daughter-derived phenotypes for more than 50 economically important traits, including milk production, growth and carcass quality, body conformation, reproduction and calving traits in 4578 artificial insemination bulls from two cohorts of Brown Swiss cattle (Austrian-German and Swiss populations). Across-cohort multi-trait meta-analyses of the results from the single-trait GWAS revealed 25 quantitative trait loci (QTL; P < 8.36 × 10- 8) for economically relevant traits on 17 Bos taurus autosomes (BTA). Evidence of pleiotropy was detected at five QTL located on BTA5, 6, 17, 21 and 25. Of these, two QTL at BTA6:90,486,780 and BTA25:1,455,150 affect a diverse range of economically important traits, including traits related to body conformation, calving, longevity and milking speed. Furthermore, the QTL at BTA6:90,486,780 seems to be a target of ongoing selection as evidenced by an integrated haplotype score of 2.49 and significant changes in allele frequency over the past 25 years, whereas either no or only weak evidence of selection was detected at all other QTL. CONCLUSIONS: Our findings provide a comprehensive overview of QTL segregating in Brown Swiss cattle. Detected QTL explain between 2 and 10% of the variation in the estimated breeding values and thus may be considered as the most important QTL segregating in the Brown Swiss cattle breed. Multi-trait association testing boosts the power to detect pleiotropic QTL and assesses the full spectrum of phenotypes that are affected by trait-associated variants.

A quantitative case study assessment of changes to hepatic metabolism from nonlactating grazing dairy cows consuming a large proportion of their diet as fodder beet.

Because of its high yield and the ability of cows to graze it in situ, fodder beet (FB) has become a popular crop in grazing systems, particularly for nonlactating cows. Due to its high sugar content, however, the transition to FB must be managed carefully to avoid rumen acidosis and associated metabolic dysfunction. The initial consumption of FB reduces ruminal pH; however, it is unclear whether this affects liver metabolism and results in systemic inflammation, as has been reported during subacute ruminal acidosis from high-grain diets. We used a quantitative case study approach to undertake additional measurements on a project demonstrating the effects of FB on urinary nitrogen excretion. The objective of our component, therefore, was to determine whether the inclusion of high rates of FB in the diet of nonlactating cows changed indicators of hepatic metabolism relative to a standard diet for nonlactating grazing cows. During the nonlactating period, multiparous, pregnant Holstein-Friesian cows were randomly assigned (n = 15 per treatment) to either pasture (8 kg of DM/cow per day) with corn silage (4 kg of DM/cow per day; PA) or transitioning onto an FB diet (8 kg of DM/cow per day) with pasture silage (4 kg of DM/cow per day; BT) over 14 d. Blood was sampled and the liver was biopsied during the adaptation period and after 7 d of full diet allocation. The hepatic expression of genes involved in peroxisomal oxidation was increased in cows adapting to FB, whereas the expression of genes involved in mitochondrial oxidation was increased when cows were on their full allocation of FB. These results indicate changes to fatty acid metabolism with FB consumption. Expression of 2 genes involved in the unfolded protein response was greater during the adaptation period in cows consuming FB, potentially reflecting negative effects of transitioning onto the FB diet on hepatic metabolism. Interestingly, expression of genes involved in the methionine cycle was increased in the BT cows. We hypothesize that this is a result of FB betaine absorption, although it is unclear to what extent betaine escapes ruminal degradation. While on the full diet allocation, there were lower serum concentrations of markers of hepatic stress in BT cows and no difference in expression of genes involved in oxidative stress compared with pasture-fed cows. However, there was an increase in plasma haptoglobin concentrations, indicative of an acute inflammatory response in BT cows. From this case study, we conclude that the results indicate no negative effects of the FB diet on liver metabolism and, possibly, positive effects on hepatic function. It appears, therefore, that the transition of nonlactating cows onto an FB diet can be managed to minimize the negative effects of the high sugar intake. Further research on the amount of betaine that escapes ruminal degradation in cows consuming FB would be of value to better understand whether betaine reduces liver damage in dairy cows consuming FB.

Energy to protein ratios in supplements for grazing heifers in the rainy season.

This study evaluated the effect of energy and protein supplementation on the nutritional characteristics, ingestive behavior, and productive performance in grazing heifers during the rainy season. Forty crossbred heifers (Nelore breed predominance) were used in the study, with an age of 14 months and an initial mean weight of 182 ± 1.13 kg. The treatments consisted of mineral supplementation ad libitum (control) and three supplements formulated to contain an energy: protein ratio (TDN:CP) of 1.13, 2.62, and 4.06; these were denominated as low (LC, 0.5 kg animal d-1), medium (MC, 1.0 kg animal d-1), and high consumption (HC, 1.5 kg animal d-1), respectively, in order to guarantee an intake of 300 g of crude protein (CP) animal-1 d -1, with variation in energy content. There was a difference (P < 0.05) in crude protein intake, with a 44% reduction for the LC treatment in relation to HC. The lowest grazing time (398 min) was observed with the MC treatment. Urinary urea-N (UreaN) was lower for control animals (P < 0.05). Average daily gain (ADG) was lower for the control animals than for the supplemented animals (P < 0.05); there was no difference in ADG between the animals receiving supplementation. High supplementation levels and TDN:CP ratios are not recommended because they do not justify the increased costs of supplementation. Therefore, when forage presents great nutritional characteristics, it is possible to optimize the performance of the animals with low to medium consumption supplementation.

Needs assessment for cooperative extension dairy programs in California.

The present study aimed to identify dairy producer needs and how best to direct and deliver cooperative extension (CE) programming. In March 2017, we mailed a needs assessment survey to grade A dairy producers in California (n = 1,080). The response rate was 15.4% (n = 166) and herd size averaged 1,405 milking cows (range 83-5,500). The geographic distribution of survey responses was representative of the distribution of dairies throughout the state. Producers were asked to indicate the level of concern for a predetermined list of 11 issues. Rank of concern had 3 numeric levels: (1) very concerned, (2) somewhat concerned, or (3) not concerned. Mean and percentage of responses in each rank for each issue topic were calculated. The top 5 concerns/obstacles indicated were (1) milk price, (2) labor availability/quality, (3) environmental issues/regulations, (4) labor costs, and (5) water quality/availability. Surveyed respondents were also asked to determine the level of priority of a predetermined list of 13 CE research and educational opportunities. Producers ranked topics as low, medium, or high priority. The 5 highest priority research topics were (1) herd health, (2) environmental issues, (3) reproduction, (4) milk quality, and (5) water quality. The 5 highest priority educational topics were (1) herd health, (2) milk quality, (3) reproduction, (4) environmental issues, and (5) calf and heifer management. Producers were then asked to identify the target audience for CE information delivery and preferred information delivery method. Most respondents indicated that the target audience should be dairy owners (93%) or managers (66%). Fewer producers indicated a target audience of dairy employees (27%) or allied industry (23%). Preferable information delivery methods were newsletter or magazine articles (81%), half-day/short meetings (47%), and on-farm training/meetings (39%). Webinars and 2- or 3-d destination meetings were the least preferable methods (27 and 9%, respectively). Survey results will serve to develop future dairy cooperative extension programs in California.

Chemical Composition of Commercial Cow's Milk.

Bovine milk is a nutritionally rich, chemically complex biofluid consisting of hundreds of different components. While the chemical composition of cow's milk has been studied for decades, much of this information is fragmentary and very dated. In an effort to consolidate and update this information, we have applied modern, quantitative metabolomics techniques along with computer-aided literature mining to obtain the most comprehensive and up-to-date characterization of the chemical constituents in commercial cow's milk. Using nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-mass spectrometry (LC-MS), and inductively coupled plasma-mass spectrometry (ICP-MS), we were able to identify and quantify 296 bovine milk metabolites or metabolite species (corresponding to 1447 unique structures) from a variety of commercial milk samples. Through our literature analysis, we also found another 676 metabolites or metabolite species (corresponding to 908 unique structures). Detailed information regarding all 2355 of the identified chemicals in bovine milk have been made freely available through a Web-accessible database called the Milk Composition Database or MCDB ( http://www.mcdb.ca/ ).

Effect of rumen-protected branched-chain amino acid supplementation on production- and energy-related metabolites during the first 35 days in milk in Holstein dairy cows.

Essential AA are critical for multiple physiological processes. Branched-chain AA (BCAA) supplementation has beneficial effects on body weight, lipogenesis, and insulin resistance in several species. The BCAA are used for milk and body protein synthesis as well as being oxidized by the tricarboxylic acid cycle to produce ATP during catabolic states. The objective was to evaluate the effect of rumen-protected BCAA (375 g of 27% l-Leu, 85 g of 48% l-Ile, and 91 g of 67% l-Val) with or without propylene glycol (PG) oral administration on milk production, dry matter intake, nonesterified fatty acids, ß-hydroxybutyrate, and plasma urea nitrogen during the first 35 d in milk (DIM) in dairy cattle. Multiparous Holstein cows were enrolled in blocks of three 28 d before expected calving and assigned randomly to either the control or 1 of 2 treatments. The control (n = 26) received 200 g/d of dry molasses, the BCAA treatment (n = 23) received BCAA mixed with 200 g/d of dry molasses from calving until 35 DIM, and the BCAA plus PG (BCAAPG) treatment (n = 25) received BCAA mixed with 200 g/d of dry molasses from calving until 35 DIM plus 300 mL of PG once daily from calving until 7 DIM. Postpartum, dry matter intake least squares means (LSM; 95% confidence interval) were 20.7 (19.9, 21.7), 21.3 (20.4, 22.3), and 21.9 (20.9, 22.8) kg for control, BCAA, and BCAAPG, respectively. Milk yield (1-35 DIM) LSM were 41.7 (39.4, 44.0), 42.7 (40.3, 45.0), and 43.7 (41.4, 46.0) kg for control, BCAA, and BCAAPG, respectively. Energy-corrected milk LSM were 50.3 (46.8, 53.7), 52.4 (48.9, 55.8), and 52.9 (49.5, 56.4) kg for control, BCAA, and BCAAPG, respectively. Milk urea nitrogen LSM in milk for control, BCAA, and BCAAPG were 8.60 (8.02, 9.22), 9.70 (9.01, 10.45), and 9.75 (9.08, 10.47) mg/dL. Plasma urea nitrogen concentrations LSM for control, BCAA, and BCAAPG were 8.3 (7.7, 8.9), 10.1 (9.4, 10.9), and 9.6 (9.4, 10.3) mg/dL, respectively. The numbers of plasma samples classified as hyperketonemia were 77, 44, and 57 in control, BCAA, and BCAAPG, respectively. The BCAA supplementation increased plasma urea nitrogen and milk urea nitrogen, free valine concentration in plasma, and decreased hyperketonemia events during the postpartum period.

Projected heat stress challenges and abatement opportunities for U.S. milk production.

Cost-effective heat mitigation strategies are imperative for maintaining milk production and dairy farm profitability in the U.S. with projected climate change. This study investigated the cost-effectiveness of four heat abatement strategies, including Minimal (open barn or shading), Moderate (forced ventilation), High (fans and misting), and Intense (air conditioning). Heat stress and subsequent impacts on milk production per cow were predicted across nine climatic regions in the U.S. for early (2015 to 2034), mid (2045 to 2064) and late (2081 to 2100) 21st century, using downscaled climate projections. Heat abatements were used to adjust predicted milk production losses and illustrate the potential to reduce milk production losses due to heat stress. Economic analysis included a cost-benefit ratio calculation associated with the implementation of each heat abatement. Results showed that milk production losses were expected to accelerate across the U.S. at a mean rate of 174±7 kg/cow/decade, with the fastest rate in the Southeast region. Relative to Minimal heat abatement, Moderate, High, and Intense heat abatements increased annual milk production per cow by 3%, 4%, and 6% during early-21st century, 3%, 6%, and 11% during mid-21st century, and 3%, 8%, and 21% during late-21st century, respectively. The cost effectiveness of different heat abatement strategies generally increased with subsequently stronger heat abatements. In mid- and late-21st century, mean annual net values of High and Intense heat stress abatement implementation approached -$30 to $190 /cow and -$20 to $590 /cow, respectively, with the largest net annual benefit in late-21st century under Intense abatement. Findings from the study demonstrate the value of using downscaled climate projections to shed light on local and regional strategies to abate heat stress on cattle and mitigate potential milk production losses due to climate change.

Prevotella copri, a potential indicator for high feed efficiency in western steers.

There has been a great interest to identify a microbial marker that can be used to predict feed efficiency of beef cattle. Such a marker, specifically one that would allow an early identification of animals with high feed efficiency for future breeding efforts, would facilitate increasing the profitability of cattle operations and simultaneously render them more sustainable by reducing their methane footprint. The work presented here suggests that Prevotella copri might be an ideal microbial marker for identifying beef cattle with high feed efficiency early in their life span and in the production cycle. Developing more refined quantification techniques that allow correlation of P. copri to feed efficiency of beef cattle that can be applied by lay people in the field holds great promise to improve the economy of cattle operations while simultaneously reducing their environmental impact by mitigating methane production from enteric fermentation.

Nutritional properties of organic and conventional beef meat at retail.

BACKGROUND: Consumers perceive that organic meat has superior nutritional properties compared to conventional meat, although the available evidence from commercial samples is very scarce. The present study compared the nutritional composition of organic and conventional beef meat sold at retail, including, for the first time, the bioactive compounds coenzyme Q10 , carnosine, anserine, creatine and taurine. Sampling comprised two muscles: longissimus thoracis and supraspinatus. RESULTS: Organic beef had 17% less cholesterol, 32% less fat, 16% less fatty acids, 24% less monounsaturated fatty acids, 170% more α-linolenic acid, 24% more α-tocopherol, 53% more ß-carotene, 34% more coenzyme Q10 and 72% more taurine than conventional beef. Differences between organic and conventional samples were clearly dependent on the muscle because longissimus thoracis and supraspinatus showed different patterns of compound accumulation. CONCLUSION: To our knowledge, a higher amount of bioactive compounds in organic beef meat is reported for the first time in the present study. Retail organic beef had a higher nutritional value than retail conventional beef, which resulted from better-balanced lipid and bioactive compound contents. © 2019 Society of Chemical Industry.

Enhancing lactational performance of Holstein dairy cows under commercial production: malic acid as an option.

BACKGROUND: In Experiment 1 we studied the effect of malic acid addition at 0, 1, 2 and 3 mg g-1 dry matter (DM) feed on in vitro ruminal fermentation. In Experiment 2, the effect of supplementing malic acid on feed intake, digestion and milk production and composition of lactating cows was studied. 200 multiparous lactating Holstein dairy cows were randomly assigned to two treatments: a basal diet containing concentrate and roughage at 58:42, respectively, with no additive (control treatment) or supplemented with malic acid at 30 g per cow daily (malic treatment). RESULTS: In Experiment 1, malic acid inclusion at 3 mg g-1 DM decreased in vitro methane production by 33%. In Experiment 2, malic acid decreased (P < 0.01) nutrient intake and increased nutrient digestibility. Greater (P < 0.05) milk yields, energy-corrected milk yields and milk component yields were observed in cows supplemented with malic acid. Greater milk (feed) efficiency was observed with malic acid treatment compared with the control treatment. CONCLUSION: The results show that the inclusion of malic acid at 30 g daily in the diet of lactating cows enhanced the nutrient digestibility and increased the milk production as well as feed efficiency. © 2018 Society of Chemical Industry.

Simulating consequences of choosing a breeding goal for organic dairy production.

In Denmark, Finland, and Sweden, the Nordic Total Merit index is used as the breeding selection tool for both organic and conventional dairy farmers based on common economic models for conventional dairy farming. Organic farming is based on the principles of organic agriculture (POA) defined by the International Federation of Organic Agriculture Movements. These principles are not set up with an economic point of view, and therefore it may be questionable to use a breeding goal (BG) for organic dairy production based on economic models. In addition to economics and the principles of organic agriculture, it is important to look at farmers' preferences for improving BG traits when setting up a BG for organic farming. The aim of this research was to set up, simulate, and compare long-term effects of different BG for organic and conventional dairy production systems based on economic models, farmers' preferences, and POA, with particular emphasis on disease resistance or on roughage consumption and feed efficiency. The BG based on economic models and on farmers' preferences were taken from previous studies. The other BG were desired gains indices, set up by means of a questionnaire about relatedness between the POA and BG traits. Each BG was simulated in the stochastic simulation program ADAM. The BG based on POA, with particular emphasis on disease resistance or on roughage consumption and feed efficiency, caused favorable genetic gain in all 12 traits included in this study compared with 6 traits for the other BG. The BG based on POA, with particular emphasis on disease resistance or on roughage consumption and feed efficiency, were very different from BG for organic and conventional production based on economic models and farmers' preferences in both simulated genetic change and correlations between BG. The BG that was created based on the principles of organic agriculture could be used as a specific index for organic dairy farming in Denmark, but this index was economically not very sustainable. Hence, an intermediate breeding goal could be developed by breeding companies to address both economics and the principles of organic agriculture.

Food Footprint as a Measure of Sustainability for Grazing Dairy Farms.

Livestock productions require significant resources allocation in the form of land, water, energy, air, and capital. Meanwhile, owing to increase in the global demand for livestock products, it is wise to consider sustainable livestock practices. In the past few decades, footprints have emerged as indicators for sustainability assessment. In this study, we are introducing a new footprint measure to assess sustainability of a grazing dairy farm while considering carbon, water, energy, and economic impacts of milk production. To achieve this goal, a representative farm was developed based on grazing dairy practices surveys in the State of Michigan, USA. This information was incorporated into the Integrated Farm System Model (IFSM) to estimate the farm carbon, water, energy, and economic impacts and associated footprints for ten different regions in Michigan. A multi-criterion decision-making method called VIKOR was used to determine the overall impacts of the representative farms. This new measure is called the food footprint. Using this new indicator, the most sustainable milk production level (8618 kg/cow/year) was identified that is 19.4% higher than the average milk production (7215 kg/cow/year) in the area of interest. In addition, the most sustainable pasture composition was identified as 90% tall fescue with 10% white clover. The methodology introduced here can be adopted in other regions to improve sustainability by reducing water, energy, and environmental impacts of grazing dairy farms, while maximizing the farm profit and productions.

Capillary Electrophoresis Analysis of Bovine Milk Oligosaccharides Permits an Assessment of the Influence of Diet and the Discovery of Nine Abundant Sulfated Analogues.

Bovine milk oligosaccharides (BMOs), like their analogues in human milk, have important prebiotic functions. Environmental factors have previously been linked to variation in BMO structures, and thus to test the hypothesis that the bovine diet may lead to these changes in relative BMO abundances, a rapid capillary electrophoresis (CE)-based work flow was developed to profile the BMOs extracted from the milk of cows fed distinctly different diets. Over the first week of lactation, few significant differences were observed between the different diet groups, with the dominant changes being clearly linked to lactation period. CE analyses indicated the presence of ten unusually anionic BMOs, which were predicted to be phosphorylated and sulfated species. Nine unique sulfated BMOs were detected by high-resolution accurate mass spectrometry, none of which have been previously described in bovine milk. The biosynthesis of these was in direct competition with 3'-sialyllactose, the most abundant BMO in bovine milk.

Dairy cow breed interacts with stocking rate in temperate pasture-based dairy production systems.

Economic optimum stocking rates for grazing dairy systems have been defined by accounting for the pasture production potential of the farm [t of dry matter (DM)/ha], the amount of feed imported from outside the farm (t of DM/ha), and the size of the cow (kg). These variables were combined into the comparative stocking rate [CSR; kg of body weight (BW)/t of feed DM available] measure. However, CSR assumes no effect of cow genetics beyond BW, and there is increasing evidence of within-breed differences in residual feed intake and between-breed differences in the gross efficiency with which cows use metabolizable energy for milk production. A multiyear production system experiment was established to determine whether Jersey (J) and Holstein-Friesian (HF) breeds performed similarly at the same CSR. Fifty-nine J cows and 51 HF cows were randomly allocated to 1 of 2 CSR in a 2 × 2 factorial arrangement; systems were designed to have a CSR of either 80 or 100 kg of BW/t of feed DM (J-CSR80, J-CSR100, HF-CSR80, and HF-CSR100 treatment groups). Data were analyzed for consistency of farmlet response over years using ANOVA procedures, with year and farmlet as fixed effects and the interaction of farmlet with year as a random effect. The collated biological data and financial data extracted from a national economic database were used to model the financial performance for the different breed and CSR treatments. On average, annual and individual season pasture DM production was greater for the J farmlets and was less in the CSR100 treatment; however, the effect of CSR was primarily driven by a large decline in pasture DM production in the HF-CSR100 treatment (breed × CSR interaction). This interaction in feed availability resulted in a breed × CSR interaction for the per-cow and per-hectare milk production variables, with HF cows producing more milk and milk components per cow in the CSR80 treatment but the same amount as the J cows in the CSR100 treatment. On a per-hectare basis, HF cows produced the same amount of 4% fat-corrected milk and lactose as J cows in the CSR80 treatment, but less fat; at CSR100, J cows produced more 4% fat-corrected milk, fat, and protein per hectare than HF cows. Our results support a greater gross efficiency for use of metabolizable energy by the J cow; 11% less total metabolizable energy was required to produce 1 kg of fat and protein at a system level. Economic modeling indicated that profitability of both breeds was less at CSR100, but the decline in profitability with increasing stocking rate was much greater in the HF breed. Holstein-Friesian cows were more profitable at CSR80 but were less profitable at CSR100.