Floristic evidence for alternative biome states in tropical Africa.

The idea that tropical forest and savanna are alternative states is crucial to how we manage these biomes and predict their future under global change. Large-scale empirical evidence for alternative stable states is limited, however, and comes mostly from the multimodal distribution of structural aspects of vegetation. These approaches have been criticized, as structure alone cannot separate out wetter savannas from drier forests for example, and there are also technical challenges to mapping vegetation structure in unbiased ways. Here, we develop an alternative approach to delimit the climatic envelope of the two biomes in Africa using tree species lists gathered for a large number of forest and savanna sites distributed across the continent. Our analyses confirm extensive climatic overlap of forest and savanna, supporting the alternative stable states hypothesis for Africa, and this result is corroborated by paleoecological evidence. Further, we find the two biomes to have highly divergent tree species compositions and to represent alternative compositional states. This allowed us to classify tree species as forest vs. savanna specialists, with some generalist species that span both biomes. In conjunction with georeferenced herbarium records, we mapped the forest and savanna distributions across Africa and quantified their environmental limits, which are primarily related to precipitation and seasonality, with a secondary contribution of fire. These results are important for the ongoing efforts to restore African ecosystems, which depend on accurate biome maps to set appropriate targets for the restored states but also provide empirical evidence for broad-scale bistability.

The experience with colorectal cancer screening in the Czech Republic: the detection at earlier stages and improved clinical outcomes.

OBJECTIVES: Colorectal cancer (CRC) remains a major health burden. Although screening is recommended and considered beneficial, further data on its positive effects are needed for worldwide implementation. STUDY DESIGN: The aim of our national multicentre prospective observational study was to reveal and document clinicopathological differences in CRC diagnosed by screening and presented by disease symptoms as well as assess the efficiency of the screening programme in the Czech Republic. METHODS: Between March 2013 and September 2015, a total of 265 patients were enrolled in 12 gastroenterology centres across the Czech Republic. Patients were divided into screening and symptomatic groups and compared for pathology status and clinical characteristics. Screening was defined as a primary screening colonoscopy or a colonoscopy after a positive faecal occult blood test in an average-risk population. RESULTS: The distribution of CRC stages was significantly (statistically and clinically) favourable in the screening group (predominance of stages 0, I and II) compared with the non-screening group (P < 0.001). The presence of distant and local metastases was significantly less frequent in the screening group than in the symptomatic group (P < 0.001). Patients in the screening group had a higher probability of radical surgery (R0) than those diagnosed based on symptoms (P < 0.001). Systemic palliative treatment was indicated in two patients in the screening group compared with 23 patients in the non-screening group (P = 0.018). CONCLUSION: CRC diagnosed by screening disclosed less advanced clinicopathological characteristics and results in patients with a higher probability of radical surgery (R0) than diagnoses established based on symptoms, with subsequent management differing accordingly between both groups. These results advocate the implementation of a suitable worldwide screening programme.

Perfectionism discrepancy and falling short of the ideal self: Investigating drinking motives and impaired control on the road to alcohol-related problems.

Self-Discrepancy Theory (Higgins, 1987) predicts that the difference between the ideal and the actual self will be associated with impaired-control-over-drinking (IC; dysregulated drinking beyond one's own limits) as well as alcohol-related-problems. According to Slaney et al. (2001) perfectionism is a multi-faceted personality trait which represents both adaptive (e.g. high-standards) and maladaptive (e.g. discrepancy) aspects. In particular, discrepancy has been associated with poorer coping approaches, which may suggest a Self-Medication route to IC. Yet, to date, no one has examined whether drinking-motives (e.g., social, enhancement, coping and conformity) mediate the relations between discrepancy and high standards and alcohol-outcomes such as IC. We used a structural equation model to test indirect associations of discrepancy and high-standards to both heavy-episodic-drinking and alcohol-related-problems through the mediating mechanisms of drinking-motives and IC. Results supported the distinction between discrepancy and high-standards consistent with the Self-Medication Hypothesis (Hersh & Hussong, 2009). Discrepancy was associated with poorer alcohol-outcomes through greater coping-motives, conformity-motives and IC. In contrast, higher-standards were associated with fewer alcohol-outcomes through less coping-motives, conformity-motives, and IC. This study illustrates the importance of personality factors such as discrepancy in the development of problematic alcohol-use suggesting that it might be a good target for intervention.

Narcissism and Devaluing Others: An Exploration of Impaired Control Over Drinking as a Mediating Mechanism of Alcohol-Related Problems.

Devaluing or diminishing the worth of others is how many individuals destroy their relationships, such as by drinking beyond limits at inappropriate times and letting others down. Impaired control over drinking (IC) reflects consuming alcohol beyond predetermined limits. This investigation sought to determine whether facets of vulnerable narcissism (e.g., entitlement-rage, hiding-the-self, contingent-self-esteem, and devaluing) or narcissistic grandiosity (e.g. grandiose-fantasy, self-sacrificing-for-self-enhancement, and exploitativeness) were directly related to IC and indirectly related to drinking outcomes. We examined a path model of 759 university student drinkers. Our results show that while grandiose-fantasy (i.e., desire for special recognition) was negatively linked to IC, devaluing was positively linked to IC. In addition, men scored higher on exploitativeness (i.e., interpersonally manipulative for personal gain) than women. We conducted mediational analysis with asymmetric confidence intervals and a bias-corrected bootstrap technique. Mediational tests showed that higher levels of grandiose-fantasy were indirectly related to fewer alcohol-related problems through less IC and less heavy-episodic drinking. In contrast, higher levels of devaluing were indirectly related to more alcohol-related problems through more IC and heavy-episodic-drinking. Our results suggest that targeting thought processes in which people with Alcohol Use Disorders (AUDs) are actively devaluing others may be a good target for therapeutic intervention.

Short communication: Field study to investigate the associations between herd-level risk factors for milk fat depression and bulk tank milk fat percent in dairy herds feeding monensin.

Fat is the most variable milk component, and maintaining milk fat continues to be a challenge on commercial dairy farms. Our objectives were to establish associations between herd-level risk factors for milk fat depression and bulk tank milk fat content in commercial dairy herds feeding monensin. Seventy-nine Holstein commercial dairy herds in the northeast and Upper Midwest United States were enrolled in an observational study. Data were collected on herd characteristics, total mixed ration (TMR) samples, all component silage samples, and bulk tank milk samples. The unconditional univariable association of each explanatory variable and bulk tank milk fat percentage was evaluated using simple linear regression and multivariable regression models. Milk fat content of trans-10 C18:1 had an exponentially negative relationship to herd milk fat percentage. In general, milk fat content of fatty acids synthesized de novo in the mammary gland were positively related to herd milk fat, and the content of several trans-C18:1 fatty acids, which would be products of alternate pathways of ruminal biohydrogenation, were negatively related to herd milk fat. Variables related to TMR composition did not have univariable relationships with herd milk fat percentage. Herds that had >49.8% of the TMR particles on the middle screen of the Penn State particle separator had higher milk fat percentage than those with ≤49.8%, and herds with >54.0% of TMR particles in the bottom pan had lower milk fat percentage than herds with ≤54.0%. Dietary content of monounsaturated fatty acids (C16:1 and C18:1) had negative relationships with herd milk fat percentage; however, no single diet component accounted for more than 11% of the variation in herd-level milk fat percentage. Univariable monensin dose was not associated with herd milk fat percentage. The relative lack of significant univariate relationships with herd-level milk fat suggests many factors contribute to milk fat content, and herds experiencing low milk fat will need to examine many potential risk factors when working to troubleshoot this challenge.

A 100-Year Review: Regulation of nutrient partitioning to support lactation.

We have seen remarkable advances in animal productivity in the last 75 years, with annual milk yield per cow increasing over 4-fold and no evidence of nearing a plateau. Because of these gains in productive efficiency, there have been dramatic reductions in resource inputs and the carbon footprint per unit of milk produced. The primary source for the historic gains relates to animal variation in nutrient partitioning. The regulation of nutrient use for productive functions has the overall goal of maintaining the cow's well-being regardless of the physiological or environmental challenges. From a conceptual standpoint, it involves both acute homeostatic controls operating on a minute-by-minute basis and chronic homeorhetic controls operating on a long-term basis to provide orchestrated adaptations that coordinate tissues and body processes. This endocrine regulation is mediated by changes in circulating anabolic and catabolic hormones, hormone membrane receptors and intracellular signaling pathways. The coordination of tissues and physiological systems includes a plethora of hormones, but insulin and somatotropin are 2 key regulators of nutrient trafficking. Herein, we review the advances in our understanding of both conceptual and actual regulation of nutrient partitioning in support of milk synthesis and identify examples of the challenges and future opportunities in dairy science.

Sex-biased dispersal creates spatial genetic structure in a parthenogenetic ant with a dependent-lineage reproductive system.

Reproduction and dispersal are key aspects of species life history that influence spatial genetic structure in populations. Several ant species in the genus Cataglyphis have evolved a unique breeding system in which new reproductives (that is, queens and males) are produced asexually by parthenogenesis; in contrast, non-reproductives (that is, workers) are produced via sexual reproduction by mates from distinct genetic lineages. We investigated how these two coexisting reproductive methods affect population-level spatial genetic structure using the ant Cataglyphis mauritanica as a model. We obtained genotypes for queens and their male mates from 338 colonies, and we found that the two lineages present in the study population occurred with equal frequency. Furthermore, analysis of spatial genetic structure revealed strong sex-biased dispersal. Because queens were produced by parthenogenesis and because they dispersed over short distances, there was an extreme level of spatial structuring: a mosaic of patches composed of clonal queens was formed. Males, on the other hand, dispersed over several hundred metres and, thus, across patches, ensuring successful interlineage mating.

TRIENNIAL LACTATION SYMPOSIUM/BOLFA:Historical perspectives of lactation biology in the late 20th and early 21st centuries.

The latter half of the 20th century and the early portion of the 21st century will be recognized as the "Golden Age" of lactation biology. This period corresponded with the rise of systemic, metabolomic, molecular, and genomic biology. It includes the discovery of the structure of DNA and ends with the sequencing of the complete genomes of humans and all major domestic animal species including the dairy cow. This included the ability to identify polymorphisms in the nucleic acid sequence, which can be tied to specific differences in cellular, tissue, and animal performance. Before this period, classical work using endocrine ablation and replacement studies identified the mammary gland as an endocrine-dependent organ. In the early 1960s, the development of RIA and radioreceptor assays permitted the study of the relationship between endocrine patterns and mammary function. The ability to measure nucleic acid content of tissues opened the door to study of the factors regulating mammary growth. The development of high-speed centrifugation in the 1960s allowed separation of specific cell organelles and their membranes. The development of transmission and scanning electron microscopy permitted the study of the relationship between structure and function in the mammary secretory cell. The availability of radiolabeled metabolites provided the opportunity to investigate the metabolic pathways and their regulation. The development of concepts regarding the coordination of metabolism to support lactation integrated our understanding of nutrient partitioning and homeostasis. The ability to produce recombinant molecules and organisms permitted enhancement of lactation in farm animal species and the production of milk containing proteins of value to human medicine. These discoveries and others contributed to vastly increased dairy farm productivity in the United States and worldwide. This review will include the discussion of the centers of excellence and scientists who labored in these fields to produce the harvest of knowledge we enjoy today.

Short communication: Milk fat depression induced by conjugated linoleic acid and a high-oil and low-fiber diet occurs equally across the day in Holstein cows.

Recently, a circadian rhythm of milk and milk component synthesis has been characterized that is partially dependent on the timing of feed intake. Our objective was to determine if inhibition of milk fat synthesis during diet-induced milk fat depression occurred to a higher degree during certain phases of the day. A retrospective analysis was conducted on 2 experiments that induced milk fat depression while milking cows 3 times per day at equal intervals. The response at each milking was analyzed using mixed model ANOVA with repeated measures. In experiment 1, nine multiparous Holstein cows were arranged in a 3×3 Latin square design, and treatments were control, 3-d intravenous infusion of 10 g/d of trans-10,cis-12 conjugated linoleic acid (CLA), and a low-forage and high-fat diet for 10 d. In experiment 2, ten multiparous ruminally cannulated cows were arranged in a replicated design and milk samples were collected during a control period or after 5 d of abomasal infusion of 10 g/d of CLA. The daily pattern of milk fat concentration and yield did not differ between treatments in either experiment. In experiment 1, an effect was found of treatment and milking time on milk fat concentration and yield. Similarly, in experiment 2, main effects were found of treatment and milking time on milk fat concentration and an effect of treatment, but no effect of milking time on milk fat yield. Milk fat percent was increased from 3.41 to 4.06% and 3.25 to 3.48% from the morning to the afternoon milking in experiments 1 and 2, respectively. Additionally, milk fatty acid profile, including trans intermediates, was changed over the day in experiment 1, but the magnitude of the changes were small and the pattern did not differ among treatments. A daily rhythm of milk fat concentration and yield was observed in cows milked 3 times a day, but milk fat depression decreases milk fat yield equally over the day.

Short communication: effect of trans-10,cis-12 conjugated linoleic acid on activation of lipogenic transcription factors in bovine mammary epithelial cells.

The objective of this study was to examine the effect of trans-10,cis-12 conjugated linoleic acid (t10c12CLA) on the activation of transcription factors that potentially regulate lipid synthesis in a bovine mammary epithelial cell line (MAC-T). Cells were transfected with luciferase reporter constructs containing sterol response element (SRE and SRE complex) for sterol regulatory element binding protein-1, peroxisome proliferator response element for peroxisome proliferator-activated receptor γ, or liver X receptor response element for liver X receptor. Different concentrations of t10c12CLA (0, 25, 50, 75, or 100µM) were applied to cells to determine the activation of transcription factors. The influence of t10c12CLA bond structure on transcription factor activation was also investigated by treating cells with different 18:1 fatty acid isomers (trans-10 18:1 or cis-12 18:1) at 100µM. Cells were harvested for luciferase assay after 24h of treatment. Compared with linoleic acid and cis-9,trans-11 CLA controls, the SRE reporters had significantly lower activity in t10c12CLA-treated cells at 50 and 75µM for SRE complex and SRE, respectively. Lower SRE and SRE complex activation was observed in t10c12CLA treatment at 25, 50, and 75µM compared with 0µM. The peroxisome proliferator response element and liver X receptor response element reporters did not respond differently between the t10c12CLA treatment and controls. Compared with t10c12CLA, both trans-10 18:1 and cis-12 18:1 increased the activities of SRE and SRE complex reporters by 1.3- to 4.2-fold. In conclusion, t10c12CLA has an inhibitory role in lipogenic transcription factor activation of SRE, and this negative effect is due to the conjugation of trans-10 and cis-12 double bonds in the fatty acid. Furthermore, we found no support for a regulatory role of response elements for peroxisome proliferator-activated receptor γ or liver X receptor in the t10c12CLA inhibition of mammary lipid synthesis.

Update on human health concerns of recombinant bovine somatotropin use in dairy cows.

The 20 yr of commercial use of recombinant bovine somatotropin (rbST) in the United States provide the backdrop for reviewing the outcome of use on human health issues by the upcoming 78th meeting of the Joint Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) Expert Committee on Food Additives. These results and further advancements in scientific knowledge indicate there are no new human health issues related to the use of rbST by the dairy industry. Use of rbST has no effect on the micro- and macrocomposition of milk. Also, no evidence exists that rbST use has increased human exposure to antibiotic residues in milk. Concerns that IGF-I present in milk could have biological effects on humans have been allayed by studies showing that oral consumption of IGF-I by humans has little or no biological activity. Additionally, concentrations of IGF-I in digestive tract fluids of humans far exceed any IGF-I consumed when drinking milk. Furthermore, chronic supplementation of cows with rbST does not increase concentrations of milk IGF-I outside the range typically observed for effects of farm, parity, or stage of lactation. Use of rbST has not affected expression of retroviruses in cattle or posed an increased risk to human health from retroviruses in cattle. Furthermore, risk for development of type 1 or type 2 diabetes has not increased in children or adults consuming milk and dairy products from rbST-supplemented cows. Overall, milk and dairy products provide essential nutrients and related benefits in health maintenance and the prevention of chronic diseases.

Conjugated linoleic acid-induced milk fat depression in lactating ewes is accompanied by reduced expression of mammary genes involved in lipid synthesis.

Conjugated linoleic acids (CLA) are produced during rumen biohydrogenation and exert a range of biological effects. The trans-10,cis-12 CLA isomer is a potent inhibitor of milk fat synthesis in lactating dairy cows and some aspects of the mechanism have been established. Conjugated linoleic acid-induced milk fat depression has also been observed in small ruminants and our objective was to examine the molecular mechanism in lactating ewes. Multiparous lactating ewes were fed a basal ration (0.55:0.45 concentrate-to-forage ratio; dry matter basis) and randomly allocated to 2 dietary CLA levels (n=8 ewes/treatment). Treatments were zero CLA (control) or 15 g/d of lipid-encapsulated CLA supplement containing cis-9,trans-11 and trans-10,cis-12 CLA isomers in equal proportions. Treatments were fed for 10 wk and the CLA supplement provided 1.5 g of trans-10,cis-12/d. No treatment effects were observed on milk yield or milk composition for protein or lactose at wk 10 of the study. In contrast, CLA treatment significantly decreased both milk fat percentage and milk fat yield (g/d) by about 23%. The de novo synthesized fatty acids (FA; C16) was increased (10%) for the CLA treatment. In agreement with the reduced de novo FA synthesis, mRNA abundance of acetyl-coenzyme A carboxylase α, FA synthase, stearoyl-CoA desaturase 1, and glycerol-3-phosphate acyltransferase 6 decreased by 25 to 40% in the CLA-treated group. Conjugated linoleic acid treatment did not significantly reduce the mRNA abundance of enzymes involved in NADPH production, but the mRNA abundance for sterol regulatory element-binding factor 1 and insulin-induced gene 1, genes involved in regulation of transcription of lipogenic enzymes, was decreased by almost 30 and 55%, respectively, with CLA treatment. Furthermore, mRNA abundance of lipoprotein lipase decreased by almost 40% due to CLA treatment. In conclusion, the mechanism for CLA-induced milk fat depression in lactating ewes involved the sterol regulatory element-binding protein transcription factor family and a coordinated downregulation in transcript abundance for lipogenic enzymes involved in mammary lipid synthesis.

Effect of linoleic acid and dietary vitamin E supplementation on sustained conjugated linoleic acid production in milk fat from dairy cows.

Conjugated linoleic acid (CLA; cis-9,trans-11 18:2), a bioactive fatty acid (FA) found in milk and dairy products, has potential human health benefits due to its anticarcinogenic and antiatherogenic properties. Conjugated linoleic acid concentrations in milk fat can be markedly increased by dietary manipulation; however, high levels of CLA are difficult to sustain as rumen biohydrogenation shifts and milk fat depression (MFD) is often induced. Our objective was to feed a typical Northeastern corn-based diet and investigate whether vitamin E and soybean oil supplementation would sustain an enhanced milk fat CLA content while avoiding MFD. Holstein cows (n=48) were assigned to a completely randomized block design with repeated measures for 28 d and received 1 of 4 dietary treatments: (1) control (CON), (2) 10,000 IU of vitamin E/d (VE), (3) 2.5% soybean oil (SO), and (4) 2.5% soybean oil plus 10,000 IU of vitamin E/d (SO-VE). A 2-wk pretreatment control diet served as the covariate. Milk fat percentage was reduced by both high-oil diets (3.53, 3.56, 2.94, and 2.92% for CON, VE, SO, and SO-VE), whereas milk yield increased significantly for the SO-VE diet only, thus partially mitigating MFD by oil feeding. Milk protein percentage was higher for cows fed the SO diet (3.04, 3.05, 3.28, and 3.03% for CON, VE, SO, and SO-VE), implying that nutrient partitioning or ruminal supply of microbial protein was altered in response to the reduction in milk fat. Milk fat concentration of CLA more than doubled in cows fed the diets supplemented with soybean oil, with concurrent increases in trans-10 18:1 and trans-11 18:1 FA. Moreover, milk fat from cows fed the 2 soybean oil diets had 39.1% less de novo synthesized FA and 33.8% more long-chain preformed FA, and vitamin E had no effect on milk fat composition. Overall, dietary supplements of soybean oil caused a reduction in milk fat percentage and a shift in FA composition characteristic of MFD. Supplementing diets with vitamin E did not overcome the oil-induced reduction in milk fat percentage or changes in FA profile, but partially mitigated the reduction in fat yield by increasing milk yield.

Porcine somatotropin alters insulin response in growing pigs by reducing insulin sensitivity rather than changing responsiveness.

Exogenous porcine somatotropin (pST) treatment consistently improves growth performance and reduces fat deposition in pigs, and it is hypothesized that one component of the mechanism is through altering the sensitivity and/or responsiveness to insulin. Therefore, a study was conducted to investigate the effect of pST treatment on whole-body glucose metabolism in response to varying doses of insulin. Eight barrows were surgically prepared with indwelling catheters and randomly assigned to one of two treatment groups (0 or 120 µg pST/kg BW · d) for 13 d. Whole-body glucose kinetics were measured during infusion of [6-(3)H]-glucose under basal conditions and during hyperinsulinemic-euglycemic clamps at various insulin infusion rates (7, 28, and 140, and 14, 70, and 280 ng insulin/kg BW · min) and alterations in the dose-response parameters were calculated with nonlinear regression. Treatment with pST increased basal plasma concentrations of glucose (36%; P = 0.005), insulin (276%; P = 0.001), and NEFAs (177%; P = 0.01) and decreased the rate of glucose disappearance (-59%; P = 0.001). The responsiveness (maximum response) for steady state glucose infusion rate to maintain glycemia was not altered by pST (112 vs 106 µmol/min · kg; P = 0.78), whereas the sensitivity (effective dose at 50% of maximum response) was increased almost 7-fold (1.3 vs 8.7 ng/mL; P = 0.027). Similar responses were observed for rate of glucose disappearance and insulin-dependent glucose utilization. Therefore, pST-induced insulin resistance with regard to whole-body glucose uptake is due to a reduced sensitivity to insulin, rather than a change in responsiveness.

An unprotected conjugated linoleic acid supplement decreases milk production and secretion of milk components in grazing dairy ewes.

Feeding conjugated linoleic acid (CLA) in a rumen-inert form to dairy ewes has been shown to increase milk production, alter milk composition, and increase the milk fat CLA content. However, few studies have tested ruminally unprotected CLA sources. The objective of this study was to evaluate the effects of an unprotected CLA supplement (29.8% of cis-9,trans-11 and 29.9% of trans-10,cis-12 isomers as methyl esters) on milk yield and composition of dairy ewes. Twenty-four lactating Lacaune ewes were used in a crossover design and received 2 dietary treatments: (1) control: basal diet containing no supplemental lipid and (2) basal diet plus CLA (30 g/d). The CLA supplement was mixed into the concentrate and fed in 2 equal meals after morning and afternoon milkings. Each experimental period consisted of 21 d: 7 d for adaptation and 14 d for data collection. The CLA supplement decreased milk fat content and yield by 31.3 and 38.0%, respectively. Milk yield and secretion of milk lactose and protein were decreased by 8.0, 9.8, and 5.6%, respectively. On the other hand, milk protein content and linear SCC score were 1.8 and 17.7% higher in ewes fed the CLA supplement. The concentration of milk fatty acids originating from de novo synthesis (C16) was increased by 22.6% in ewes fed the CLA supplement. The CLA supplement decreased C14:1/C14:0, C16:1/C16:0, and C18:1/C18:0 desaturase indexes by 25, 18.7, and 0.1%, respectively, but increased the cis-9,trans-11 CLA/trans-11 C18:1 ratio by 8.6%. The concentrations of trans-10,cis-12 CLA and cis-9,trans-11 CLA in milk fat was 309 and 33.4% higher in ewes fed CLA. Pronounced milk fat depression coupled with the deleterious effects on milk yield, milk SCC, and secretion of all milk solids observed in ewes fed an unprotected CLA supplement is likely to be associated with high doses of trans-10,cis-12 CLA reaching the mammary gland, corroborating previous results obtained with dairy cows.

Effect of a supplement containing trans-10,cis-12 conjugated linoleic acid on the performance of dairy ewes fed 2 levels of metabolizable protein and at a restricted energy intake.

Trans-10,cis-12 conjugated linoleic acid (CLA) inhibits milk fat synthesis in dairy ewes, but the effects under varying dietary metabolizable protein (MP) levels when energy-limited diets are fed have not been examined. The objectives of the study were to evaluate the response of lactating dairy ewes to CLA supplementation when fed diets limited in metabolizable energy (ME) and with either a low or high MP content. Twelve multiparous ewes in early lactation were randomly allocated to 1 of 4 dietary treatments: a high MP (110% of daily MP requirement) or low MP (93% of daily MP requirement) diet unsupplemented or supplemented with a lipid-encapsulated CLA to provide 2.4 g/d of trans-10,cis-12 CLA, in each of 4 periods of 25 d each in a 4×4 Latin square design. All diets were restricted to supply each ewe with 4.6 Mcal of ME/d (equivalent to 75% of ME requirement). Supplementation with CLA decreased milk fat percentage and yield by 33% and 24%, respectively, and increased milk, milk protein, and lactose yields by 16, 13, and 17%, respectively. Feeding the high MP diet increased the yields of milk, fat, protein, and lactose by 18, 15, 19, and 16%, respectively. Milk fat content of trans-10,cis-12 CLA (g/100g) was 0.09 and <0.01 for the CLA-supplemented and unsupplemented ewes, respectively. Ewes supplemented with CLA had a reduced yield (mmol/d) of fatty acids of C16, although the effect was greatest for C16. Plasma urea concentrations were lowest in ewes supplemented with CLA compared with those unsupplemented (6.5 vs. 7.4 mmol/L, respectively) and receiving low compared with high MP diets (5.6 vs. 8.3 mmol/L, respectively). In conclusion, dairy ewes fed energy-limited diets and supplemented with CLA repartitioned nutrients to increase yields of milk, protein, and lactose, with the response to CLA supplementation and additional MP intake being additive.

Characterization of the acute lactational response to trans-10, cis-12 conjugated linoleic acid.

Trans-10, cis-12 conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis in the dairy cow. The decrease in milk fat yield during abomasal infusion of CLA reaches a nadir after 3 to 5 d. The acute responses to CLA were evaluated using 4 cows in a crossover design. Cows were milked with the aid of oxytocin every 4h from -28 to 80h and every 6h from 86 to 116h relative to the initiation of abomasal CLA infusion. An initial priming dose of 7.5g of CLA was given at time zero followed by infusion of 2.5g every 4h for 72h. Plasma CLA reached a near-steady-state concentration by 4h, and initial plasma enrichments were greatest in the triglyceride and nonesterified fatty acid fractions. Milk CLA concentration peaked at 6h and reached steady state by 22h. At termination of the infusion, decreases in milk CLA concentration and yield and plasma CLA concentration were best fit by a reciprocal-linear function. Milk fat percentage decreased progressively after 2h and was significant by 14h. Milk fatty acid profile was initially unchanged, but between 18 and 36h after initiation of the CLA dose the proportions of fatty acids progressively shifted, resulting in an increase in fatty acids >C16 and a decrease in fatty acids

Branched chain fatty acid content of United States retail cow's milk and implications for dietary intake.

Branched chain fatty acids (BCFA) have recently been shown to be a major component of the normal human newborn gastrointestinal tract and have long been known to be a component of human milk. Ruminant food products are major sources of fat in the American diet, but there are no studies of milkfat BCFA content in retail milk. We report here the profile and concentrations of BCFA in a representative sampling of retail milk in the 48 contiguous United States (US), and their estimated intake in the American diet. Conventionally produced whole fluid milk samples were obtained from 56 processing plants across the contiguous 48 states. Retail milk samples contain exclusively iso- and anteiso-BCFA with 14-18 carbons. BCFA were 2.05 ± 0.14%, w/w of milkfat fatty acids (mean ± SD), and anteiso-BCFA comprised more than half this total. Based on these data and USDA food availability data, the average per capita BCFA intake of Americans is estimated to be about 220 mg/d from dairy; if current dietary recommendations were followed, BCFA intake would be about 400 mg/d. Adding intake from beef consumption, these estimates rise to approximately 400 and 575 mg/d, respectively. These results indicate that BCFA intake is a substantial fraction of daily fat intake, in amounts exceeding those of many bioactive fatty acids.

Improving oral health in Pakistan using dental hygienists.

This paper reviews the healthcare system, available dental care, and oral health status of people in Pakistan. Considering the enormous unmet oral health needs, the insufficient supply of dental professionals and the current unstructured dental hygiene curriculum in Pakistan, a mission, vision, and goals for professional dental hygiene in Pakistan is recommended. The authors offer recommendations for competency-based dental hygiene education and practice, professional credentialing, a practice act, and a dental hygiene scope of practice to promote the health, welfare, and quality of life of the Pakistani people. Specifically, the authors recommend increasing the number of quality dental hygiene programs, establishing the dental hygienist as a primary care provider of oral health services, enhancing current dental hygiene curriculum, and establishing a dental hygiene council with responsibility for educational requirements and regulation of dental hygienists in Pakistan.

Survey of the fatty acid composition of retail milk in the United States including regional and seasonal variations.

Consumers are increasingly aware that food components have the potential to influence human health maintenance and disease prevention, and dietary fatty acids (FA) have been of special interest. It has been 25 years since the last survey of US milk FA composition, and during this interval substantial changes in dairy rations have occurred, including increased use of total mixed rations and byproduct feeds as well as the routine use of lipid and FA supplements. Furthermore, analytical procedures have improved allowing greater detail in the routine analysis of FA, especially trans FA. Our objective was to survey US milk fat and determine its FA composition. We obtained samples of fluid milk from 56 milk processing plants across the US every 3 mo for one year to capture seasonal and geographical variations. Processing plants were selected based on the criteria that they represented 50% or more of the fluid milk produced in that area. An overall summary of the milk fat analysis indicated that saturated fatty acids comprised 63.7% of total milk FA with palmitic and stearic acids representing the majority (44.1 and 18.3% of total saturated fatty acids, respectively). Unsaturated fatty acids were 33.2% of total milk FA with oleic acid predominating (71.0% of total unsaturated fatty acids). These values are comparable to those of the previous survey in 1984, considering differences in analytical techniques. Trans FA represented 3.2% of total FA, with vaccenic acid being the major trans isomer (46.5% of total trans FA). Cis-9, trans-11 18:2 conjugated linoleic acid represented 0.55% total milk FA, and the major n-3 FA (linolenic acid, 18:3) composed 0.38%. Analyses for seasonal and regional effects indicated statistical differences for some FA, but these were minor from an overall human nutrition perspective as the FA profile for all samples were numerically similar. Overall, the present study provides a valuable database for current FA composition of US fluid milk, and results demonstrate that the milk fatty acid profile is remarkably consistent across geographic regions and seasons from the perspective of human dietary intake of milk fat.