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Understanding the magnitude and impact of dietary pesticide exposures is a concern for some consumers. However, the ability of consumers to obtain and understand state-of-the-science information about how pesticides are regulated and how dietary exposure limits are set can be limited by the complicated nature of the regulations coupled with an abundance of sources seeking to cast doubt on the reliability of those regulations. Indeed, these regulations are sometimes not well understood within health care professions. As such, the objective of this review is to provide a historical perspective as to how modern pesticides were developed, current trends in pesticide use and regulation, and measures taken to reduce the risk of pesticide use to the consumer. Throughout the review, we provide specific examples for some of the concepts as they apply to glyphosate-a pesticide commonly used by both farmers and consumers. In addition, we describe current efforts to monitor pesticide use. We are confident that this succinct, yet thorough, review of this topic will be of interest to myriad researchers, public health experts, and health practitioners as they help communicate information about making healthful and sustainable food choices to the public.

Background: Although animal studies have shown that exposure to glyphosate (a commonly used herbicide) does not result in glyphosate bioaccumulation in tissues, to our knowledge there are no published data on whether it is detectable in human milk and therefore consumed by breastfed infants., Objective: We sought to determine whether glyphosate and its metabolite aminomethylphosphonic acid (AMPA) could be detected in milk and urine produced by lactating women and, if so, to quantify typical consumption by breastfed infants., Design: We collected milk (n = 41) and urine (n = 40) samples from healthy lactating women living in and around Moscow, Idaho and Pullman, Washington. Milk and urine samples were analyzed for glyphosate and AMPA with the use of highly sensitive liquid chromatography-tandem mass spectrometry methods validated for and optimized to each sample matrix., Results: Our milk assay, which was sensitive down to 1 μg/L for both analytes, detected neither glyphosate nor AMPA in any milk sample. Mean ± SD glyphosate and AMPA concentrations in urine were 0.28 ± 0.38 and 0.30 ± 0.33 μg/L, respectively. Because of the complex nature of milk matrixes, these samples required more dilution before analysis than did urine, thus decreasing the sensitivity of the assay in milk compared with urine. No difference was found in urine glyphosate and AMPA concentrations between subjects consuming organic compared with conventionally grown foods or between women living on or near a farm/ranch and those living in an urban or suburban nonfarming area., Conclusions: Our data provide evidence that glyphosate and AMPA are not detectable in milk produced by women living in this region of the US Pacific Northwest. By extension, our results therefore suggest that dietary glyphosate exposure is not a health concern for breastfed infants. This study was registered at clinicaltrials.gov as NCT02670278., (© 2016 American Society for Nutrition.)

Background: The benefits of omega-3 (n-3) long-chain polyunsaturated fatty acids to heart health are well established. Stearidonic acid (SDA, 18:4n-3) may contribute to these benefits., Objective: The objective was to evaluate the ability of SDA-containing soybean oil to increase the omega-3 index [erythrocyte eicosapentaenoic acid (EPA) + docosahexaenoic acid, as a percentage of total fatty acids] and to affect other cardiovascular disease risk markers compared with EPA and regular soy oil (control)., Design: This was a randomized, placebo-controlled, double-blind multicenter study in which 252 overweight subjects were randomly assigned to 1 of 3 treatments for 12 wk: 1 g encapsulated soybean oil/d plus 14.7 g liquid soybean oil/d to be mixed in food (control group), 1 g encapsulated EPA/d plus 14.7 g liquid soybean oil/d (EPA group), and 1 g encapsulated soybean oil/d plus 14.7 g liquid SDA-enriched soybean oil/d, providing 4.2 g SDA (SDA group). Subjects consumed treatment oils in exchange for other oils in their diet., Results: The mean (±SE) baseline omega-3 index was similar between treatments, but after 12 wk of treatment values for this index were 4.15 ± 0.12%, 4.84 ± 0.13%, and 4.69 ± 0.15% for control, EPA, and SDA groups, respectively. Values for the EPA and SDA groups were greater than those for control subjects in the intent-to-treat population (P < 0.001 and P = 0.006, respectively). No adverse treatment-related effects of SDA-enriched soybean oil were reported., Conclusions: SDA-enriched soybean oil increased the omega-3 index by raising erythrocyte EPA concentrations. SDA-enriched soybean oil is a land-based n-3 fatty acid that is a sustainable approach to increasing tissue concentrations of long-chain polyunsaturated n-3 fatty acids.

Animal feeding studies were conducted with rats, broiler chickens, catfish and dairy cows as part of a safety assessment program for a soybean variety genetically modified to tolerate in-season application of glyphosate. These studies were designed to compare the feeding value (wholesomeness) of two lines of glyphosate-tolerant soybeans (GTS) to the feeding value of the parental cultivar from which they were derived. Processed GTS meal was incorporated into the diets at the same concentrations as used commercially; diary cows were fed 10 g/100 g cracked soybeans in the diet, a level that is on the high end of what is normally fed commercially. In a separate study, laboratory rats were fed 5 and 10 g unprocessed soybean meal 100 g diet. The study durations were 4 wk (rats and dairy cows), 6 wk (broilers) and 10 wk (catfish). Growth, feed conversion (rats, catfish, broilers), fillet composition (catfish), and breast muscle and fat pad weights (broilers) were compared for animals fed the parental and GTS lines. Milk production, milk composition, rumen fermentation and nitrogen digestibility were also compared for dairy cows. In all studies, measured variables were similar for animals fed both GTS lines and the parental line, indicating that the feeding value of the two GTS lines is comparable to that of the parental line. These studies support detailed compositional analysis of the GTS seeds, which showed no meaningful differences between the parental and GTS lines in the concentrations of important nutrients and antinutrients. They also confirmed the results of other studies that demonstrated the safety of the introduced protein, a bacterial 5-enolpyruvyl-shikimate-3-phosphate synthase from Agrobacterium sp. strain CP4.

Somatotropins increase nitrogen retention, decrease carcass fat and increase lean/fat ratio in growing ruminants and swine. However, responses are much more variable in growing ruminants. Maintenance requirements in both ruminants and swine are increased slightly with somatotropin treatment in conjunction with increased lean mass. This is associated with increases in partial efficiency of protein accretion, resulting in increased efficiency of growth. Additional information is required to accurately assess effects of somatotropin on nutrient requirements for growing ruminants and swine. Future studies should target degradable and nondegradable protein requirements for growing ruminants and the impact of somatotropin on these requirements; definition of dose, pattern and formulation of somatotropin for both ruminants and swine and interaction of somatotropin with other factors affecting feed intake in swine and ruminants.

Six Holstein cows were used in a complete block design to examine effects of period of lactation and somatotropin (bST) administration on concentrations of insulin, insulin-like growth factors (IGF-I, IGF-II), and IGF-binding protein 2 (IGFBP-2). During late lactation, the dry period and the subsequent early lactation, cows received injections of NaHCO3 buffer for 5 d and bST for 7 d. Cows were in positive energy and protein balances during late lactation and the dry period and in slight negative balances during early lactation. Basal insulin concentrations were highest in late lactation (170 pmol/L), whereas bST concentrations were higher in early lactation (0.6 micrograms/L). Insulin was increased by bST in the dry period (255 pmol/L) and late lactation (149 pmol/L) but not in early lactation (14 pmol/L), probably because of greater availability of glucose during positive nutrient balance. Basal IGF-I was lowest in early lactation (63.6 micrograms/L) but was increased by bST during all periods. The IGF-I response to bST administration was lower during early lactation (74.1 micrograms/L) compared with late lactation (123.6 micrograms/L) and dry period (146.0 micrograms/L). The IGF-II concentrations were not affected by period of lactation of bST administration but IGF-II tended to be higher during bST administration when cows were dry. Concentration of IGFBP-2 was higher during early lactation when cows were in negative nutrient balance (479.5 micrograms/L) than during the dry period (289.2 micrograms/L) and was decreased with bST. These data support a role of insulin and IGF in regulation of milk production. Availability of nutrients may be involved in regulating these hormones, particularly during bST treatment.

Holstein calves were used to investigate the effects of immunization procedures against somatostatin (SRIF) on growth and concentrations of somatotropin in plasma. In Trial 1, eight heifers 37 weeks of age were inoculated with cyclic-SRIF conjugated to human alpha-globulin. Final body weight, average daily gain, and measurements of body size were not significantly different between control and SRIF-immunized calves. Apparent total tract nutrient digestibilities and efficiency of feed utilization also were not significantly different between treatments. Plasma concentrations of somatotropin were increased and plasma concentrations of urea nitrogen were decreased in calves immunized against SRIF compared to controls, but these mean differences were not significant. In Trial 2, eleven bull calves seven weeks of age were inoculated with cyclic-SRIF conjugated to keyhole limpet hemocyanin. Calves immunized against SRIF had larger average daily gains (P less than .06) than did control calves. Body size, efficiency of feed utilization, and concentrations of somatotropin in plasma were not significantly different for SRIF immunized calves and control calves. Urea nitrogen in plasma was lower (P less than .04) for calves immunized against somatostatin than for control calves. Data indicate that Holstein calves can produce auto-antibodies against SRIF; however, additional research will be required before such immunization techniques can be effectively used to improve weight gains in cattle.

The effectiveness of an encapsulated rumen-protected methionine compound (RPMet) for delivering methionine postruminally and its effect on plasma amino acid concentrations, milk production and milk composition were evaluated. Thirty multiparous Holstein cows in early lactation were randomly assigned to five levels of RPMet. RPMet was supplied at 0, 550, 1100, 1650 or 3300 mg/kg of concentrate resulting in an intake of 0, 6.9, 12.9, 19.6 or 40.2 g of supplemental DL-methionine/day for each cow. The basal diet was alfalfa-bromegrass hay and a 15.8% crude protein corn- and soybean meal-based concentrate mixture. The experiment was divided into pretreatment and treatment periods, each consisting of 21 days. Feed intake and milk production were measured daily, milk composition weekly and plasma amino acid concentrations twice daily on days 17 and 20 of the pretreatment period and on days 4, 10 and 21 of the treatment period. RPMet was effective in delivering methionine postruminally, which increased concentrations of methionine in plasma. Dry matter intake, milk production, milk composition and body weight were not significantly affected by RPMet.