Global contributions of milk to nutrient supplies and greenhouse gas emissions.

Globally, ruminant production systems used to synthesize meat and milk differ tremendously in terms of their efficiency, productivity, and environmental impacts. Regardless of this variability, milk has been repeatedly identified as an essential source of nutrients for humans. The objective of this work was to characterize global contributions of fluid milk to human food and nutrient supplies, greenhouse gas emissions, and water withdrawal. Data were leveraged from the United Nations Food and Agriculture Organization to estimate global supplies of agricultural products. Trade of agricultural products and waste of those products, along with use of human food for livestock feed were accounted for before estimating human nutrient supplies. The contributions of milk to human-edible nutrient supplies were then enumerated in terms of their proportion of total nutrients supplied by the agricultural system and in terms of the human population's requirement for that nutrient. We identified that fluid milk provides over 10% of consumable supplies of vitamin B12, vitamin A, riboflavin, and calcium available for humans globally. In terms of human nutrient requirements, milk provides sufficient vitamin B12 to meet the needs of over 60% of the global population, riboflavin to satisfy 50% of the population, and calcium and phosphorus for over 35% of the population. Compared with other foods, milk ranked among the highest in terms of nutrient-to-calorie ratio for numerous amino acids, phosphorus, calcium, and riboflavin. Conditional dependencies were identified between greenhouse gas emissions and ruminant milk and meat, but not between water withdrawal and milk production. When evaluating the trade-offs in nutrient use versus nutrient provision for producing milk or producing all ruminant products, the production of ruminants worldwide was associated with both net increases and net decreases of several key nutrients. Continued work focusing on strategies to reduce the environmental impact of milk production will improve the utility of milk for feeding the growing global population.

Global human-edible nutrient supplies, their sources, and correlations with agricultural environmental impact.

Food production, sustainable development, population growth, and agricultural environmental impacts are linked global problems that require complex solutions. Many efforts evaluating these challenges primarily evaluate dietary strategies designed for health and environmental objectives without considering the subsequent adaptations required by the global food supply. Here we use a complementary approach to summarize trends and variability in the current agricultural system in the context of the growing population and impending environmental challenges. Globally, agricultural systems produce sufficient nutrients to feed 10 billion people with the exception of Ca, DHA + EPA, vitamins B4, D, and E. In a network analysis, greenhouse gas emissions were conditionally dependent on ruminant meat and milk, while water use was conditionally dependent on vegetable and fruit production; however, supplies of most nutrients were also dependent on these same production categories, suggesting trade-offs between nutritional and environmental objectives. Future work should evaluate strategies to address these compromises (i.e., improving water use efficiency and reducing greenhouse gas emissions), to explore to what extent such compromises are biophysically essential or merely a product of the current agricultural system structures. Given the time-sensitive nature of population growth and environmental concerns, strategies to make more effective use of currently produced agricultural products will also be critical complementary strategies to sustainably feed the growing population which can work in concert with other agricultural-, diet- and policy-focused efforts.

Algorithm development for individualized precision feeding of supplemental top dresses to influence feed efficiency of dairy cattle.

Individualized, precision feeding of dairy cattle may contribute to profitable and sustainable dairy production. Feeding strategies targeted at optimizing efficiency of individual cows, rather than groups of animals with similar characteristics, is a logical goal of individualized precision feeding. However, algorithms designed to make feeding recommendations for specific animals are scarce. The objective of this study was to develop and test 2 algorithms designed to improve feed efficiency of individual cows by supplementing total mixed rations (TMR) with varying types and amounts of top-dressed feedstuffs. Twenty-four Holstein dairy cows were assigned to 1 of 3 treatment groups as follows: a control group fed a common TMR ad libitum, a group fed individually according to algorithm 1, and a group fed individually according to algorithm 2. Algorithm 1 used a mixed-model approach with feed efficiency as the response variable and automated measurements of production parameters and top-dress type as dependent variables. Cow was treated as a random effect, and cow by top-dress interactions were included if significant. Algorithm 2 grouped cows based on top-dress response efficiency structure using a principal components and k-means clustering. Both algorithms were trained over a 36-d experimental period immediately before testing, and were updated weekly during the 35-d testing period. Production performance responses for dry matter intake (DMI), milk yield, milk fat percentage and yield, milk protein percentage and yield, and feed efficiency were analyzed using a mixed-effects model with fixed effects for feeding algorithm, top dress, week, and the 2- and 3-way interactions among these variables. Milk protein percentage and feed efficiency were significantly affected by the 3-way interaction of top dress, algorithm, and week, and DMI tended to be affected by this 3-way interaction. Feeding algorithm did not affect milk yield, milk fat yield, or milk protein yield. However, feeding costs were reduced, and hence milk revenue increased on the algorithm-fed cows. The efficacy of feeding algorithms differed by top dress and time, and largely relied on DMI shifts to modulate feed efficiency. The net result, for the cumulative feeding groups, was that cows in the algorithm 1 and 2 groups earned over $0.45 and $0.70 more per head per day in comparison to cows on the TMR control, respectively. This study yielded 2 candidate approaches for efficiency-focused, individualized feeding recommendations. Refinement of algorithm selection, development, and training approaches are needed to maximize production parameters through individualized feeding.

Rumen fermentation and epithelial gene expression responses to diet ingredients designed to differ in ruminally degradable protein and fiber supplies.

Although numerous studies exist relating ruminal volatile fatty acid (VFA) concentrations to diet composition and animal performance, minimal information is available describing how VFA dynamics respond to diets within the context of the whole rumen environment. The objective of this study was to characterize how protein and fiber sources affect dry matter intake, rumen pH, fluid dynamics, fermentation parameters, and epithelial gene expression. Four diet treatments (soybean meal or heat-treated soybean meal and beet pulp or timothy hay) were delivered to 10 wethers. The soybean meals served as crude protein (CP) sources while the beet pulp and timothy hay represented neutral detergent fiber (NDF) sources. Feed intake, rumen pH, fluid pool size, and fluid passage rate were unaffected by treatment. Butyrate synthesis and absorption were greater on the beet pulp treatment whereas synthesis and absorption of other VFA remained unchanged. Both CP and NDF treatment effects were associated with numerous VFA interconversions. Expression levels of rumen epithelial genes were not altered by diet treatment. These results indicate that rumen VFA dynamics are altered by changes in dietary sources of nutrients but that intake, rumen environmental parameters, and the rumen epithelium may be less responsive to such changes.

Rumen volatile fatty acid molar proportions, rumen epithelial gene expression, and blood metabolite concentration responses to ruminally degradable starch and fiber supplies.

The objective of this work was to characterize rumen volatile fatty acid (VFA) concentrations, rumen epithelial gene expression, and blood metabolite responses to diets with different starch and fiber sources. Six ruminally cannulated yearling Holstein heifers (body weight = 330 ± 11.3 kg) were arranged in a partially replicated Latin square experiment with 4 treatments consisting of different starch [barley (BAR) or corn (CRN)] and fiber [timothy hay (TH) or beet pulp (BP)] sources. Treatments were arranged as a 2 × 2 factorial. Beet pulp and TH were used to create relative changes in apparent ruminal fiber disappearance, whereas CRN and BAR were used to create relative changes in apparent ruminal starch disappearance. Each period consisted of 3 d of diet adaptation and 15 d of dietary treatment. In situ disappearance of fiber and starch were estimated from bags incubated in the rumen from d 10 to 14. From d 15 to 17, rumen fluid was collected every hour from 0500 to 2300 h. Rumen fluid samples were pooled by animal/period and analyzed for pH and VFA concentrations. On d 18, 60 to 80 papillae were biopsied from the epithelium and preserved for gene expression analysis. On d 18, one blood sample per heifer was collected from the coccygeal vessel. In situ ruminal starch disappearance rate (7.30 to 8.72%/h for BAR vs. 7.61 to 10.5%/h for CRN) and the extent of fiber disappearance (22.2 to 33.4% of DM for TH vs. 34.4 to 38.7% of DM for BP) were affected by starch and fiber source, respectively. Analysis of VFA molar proportions showed a shift from propionate to acetate, and valerate to isovalerate on TH diets compared with BP. Corn diets favored propionate over butyrate in comparison to BAR diets. Corn diets also had higher molar proportions of valerate. Expression of 1 gene (SLC9A3) were increased in BP diets and 2 genes (BDH1 and SLC16A4) tended to be increased in TH diets. Plasma acetate demonstrated a tendency for a starch by fiber interaction with BAR-BP diets having the highest plasma acetate, but other metabolites measured were not significant. These results suggest that TH has the greatest effect on shifts in VFA molar proportions and epithelial transporters, but does not demonstrate shifts in blood metabolite concentrations.

Diastolic dysfunction is a feature of the antiphospholipid syndrome.

Recurrent thrombi, thrombocytopenia, pregnancy loss, and stroke in association with medium to high concentrations of anticardiolipin antibodies are well-recognized features of antiphospholipid syndrome. Cardiac manifestations of primary antiphospholipid syndrome (PAPS) also have been documented but involve structural and valvular heart disease. Diastolic dysfunction in PAPS has not been well described. Therefore, 10 patients with PAPS (nine women and one man) of mean age 30 +/- 7 years (range 20 to 46 years) and 10 healthy age-, sex-, weight-, and height-matched control subjects were studied by echocardiography. Anticardiolipin antibody concentrations of patients with PAPS were > 80 immunoglobulin G phospholipid units as determined by enzyme-linked immunosorbent assay. Doppler-derived parameters of left ventricular filling showed a significant association between PAPS and diastolic dysfunction compared with control, as evidenced by a decrease in peak early filling velocity (52 +/- 10 cm/sec vs 67 +/- 12 cm/sec; p < 0.01), a decrease in the ratio of peak early to peak atrial filling velocities (1.03 +/- 0.40 vs 1.52 +/- 0.28; p < 0.005), a decrease in the mean deceleration rate of early filling (338 +/- 75 cm/sec2 vs 590 +/- 227 cm/sec2; p < 0.005), and an increase in the percentage of atrial contribution to filling and deceleration time. Left ventricular mass, diastolic filling time, and heart rate did not differ between groups. Left ventricular systolic function was normal and ejection fraction did not differ between patients with PAPS and control subjects (63% +/- 2% vs 65% +/- 7%; p not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of cardiac valvular involvement in the primary antiphospholipid syndrome versus anticardiolipin-negative systemic lupus erythematosus.

Recurrent thrombosis and pregnancy loss are well-recognized features of the antiphospholipid syndrome. Uncertainty exists, however, as to whether other reported features of the antiphospholipid syndrome such as cardiac valvular vegetations are truly part of this disorder or more reflective of associated systemic lupus erythematosus (SLE). Several recent studies have concluded that patients with antiphospholipid antibodies have a higher risk of developing Libman-Sacks endocarditis. This study was performed to determine whether antiphospholipid antibodies are the only risk factors for cardiac valvular disease in patients with primary antiphospholipid syndrome (PAPS) or SLE. Ten patients with PAPS were matched with 20 patients with SLE and 20 healthy control subjects by sex. All participants were tested for anticardiolipin (aCL) antibodies by means of a standardized enzyme-linked immunosorbent assay technique, and all underwent two-dimensional and color-flow Doppler echocardiography. The echocardiograms were interpreted by two cardiologists blinded to the patients' underlying disease. Sixty percent of the PAPS group had cardiac valvular involvement compared with 40% of the SLE group (p = NS). We conclude that cardiac valvular vegetations are common both in aCL-negative patients with SLE and in patients with PAPS. This suggests that aCL antibodies either play no causative role or are not the only risk factors in the development of cardiac valvular vegetations.

The antiphospholipid syndrome: the clot thickens.

The "Antiphospholipid Syndrome" is a disorder that mainly affects young people. Recurrent venous or arterial thrombosis, recurrent fetal loss, and thrombocytopenia are the primary features. The diagnosis is established by the presence of the anticardiolipin (aCL) antibody or the lupus anticoagulant (LA). Treatment is symptomatic.

Upper extremity contractures in a patient with eosinophilia-myalgia syndrome.

L-tryptophan is an essential amino acid taken as an over-the-counter nutritional supplement for a variety of conditions including chronic pain, insomnia, and depression. In October 1989 several patients were reported having eosinophilia-myalgia syndrome (EMS) who had taken L-tryptophan in large doses. Little is known about the long-term outcomes of EMS. A patient with EMS who developed contractures of the upper extremities because of severe myalgias is discussed. Early aggressive rehabilitative intervention may prevent contractures in patients with EMS.