Short-term fasts increase levels of halogenated flame retardants in tissues of a wild incubating bird

Many species are adapted for fasting during parts of their life cycle. For species undergoing extreme fasts, lipid stores are mobilized and accumulated contaminants can be released to exert toxicological effects. However, it is unknown if short-term fasting events may have a similar effect. The objective of this study was to determine if short successive fasts are related to contaminant levels in liver and plasma of birds. In ring-billed gulls (Larus delawarensis), both members of the pair alternate between incubating the nest for several hours (during which they fast) and foraging, making them a useful model for examining this question. Birds were equipped with miniature data loggers recording time and GPS position for two days to determine the proportion and duration of time birds spent in these two activities. Liver and plasma samples were collected, and halogenated flame retardants (HFRs) (PBDEs and dechlorane plus) and organochlorines (OCs) (PCBs, DDTs, and chlordane-related compounds) were determined. Most birds (79%) exhibited plasma lipid content below 1%, indicating a likely fasted state, and plasma lipid percent declined with the number of hours spent at the nest site. The more time birds spent at their nest site, the higher were their plasma and liver concentrations of HFRs. However, body condition indices were unrelated to either the amount of time birds fasted at the nest site or contaminant levels, suggesting that lipid mobilization might not have been severe enough to affect overall body condition of birds and to explain the relationship between fasting and HFR concentrations. A similar relationship between fasting and OC levels was not observed, suggesting that different factors are affecting short-term temporal variations in concentrations of these two classes of contaminants. This study demonstrates that short fasts can be related to increased internal contaminant exposure in birds and that this may be a confounding factor in research and monitoring involving tissue concentrations of HFRs in wild birds. © 2015 Elsevier Inc

Polycyclic aromatic hydrocarbons contaminants in black-lip (pearl) oyster Pinctada margaritifera from Kish Island (Persian Gulf)

Twenty-four Black-lip Oysters (Pinctada margaritifera ) were collected in summer (July) 2004 from six coastal locations in Kish Island (Persian Gulf) and were analyzed at the analytical laboratory of Great Lakes Institute for Environmental Research at the University of Windsor according to the chemical analysis procedures which has been accredited by the Canadian Association for Environmental Analysis Laboratories (CAEAL). In order to obtain information on bioavailability of sixteen EPA priority polycyclic aromatic hydrocarbons (PAHs), concentration of 2 to 6-ring PAHs was determined for all samples with application of a gas chromatograph with a mass selective detector. Oysters from Big Coral site exhibited a wide range of total PAH concentration (1.07 to 77.66 ng/g wet weight). The lowest value (oysters from Foreigner’s Pelage) and highest values were 0.7 and 36.33 ng/g wet weight respectively. Comparison of the PAH concentrations in oysters with sediments collected from the same locations showed that the overall bioaccumulation has been performed through the movement of water-soluble lower molecular weight (LMW) PAHs to the oysters in the studied area

Effects of Optaflexx alone or in combination with BoVantage on the performance and carcass merit of finishing heifers

Beta agonists, including Optaflexx (Elanco Animal Health, Greenfield, IN), are now routinely fed to finishing cattle as a means of increasing carcass weight and efficiency of carcass weight gain during the final 20 to 42 days on feed. BoVantage, a product recently introduced by Kent Nutrition Group (Muscatine, IA) for use in feedlot cattle, has been observed to improve efficiency of gain late in the finishing phase. This study was conducted to determine if the actions of BoVantage and Optaflexx are synergistic

Initial heifer body composition has little impact on response to Zilmax

Using a growth promotant at the correct time of finishing is critical for maximizing profit potential. Previous studies have shown that zilpaterol-HCl (Zilmax; Intervet/ Schering-Plough Animal Health, Millsboro, DE) improves carcass characteristics. The objective of this study was to determine effects of prior body composition on subsequent changes in carcass weight, fatness, and muscle in heifers fed Zilmax so producers can introduce Zilmax at the level of finish that will result in the most desirable response. We hypothesized that fatter heifers use fat as the fuel for muscle growth

Supplemental Zinc Oxide Does Not Interact With Zilmax in Feedlot Steers

Zilmax (Merck Animal Health; Summit, NJ) is in a class of feed additives known as beta agonists and is designed to improve production efficiency in cattle when fed 20 days prior to harvest. Zilmax works by altering deposition of body tissue to more lean muscle than fat. Zinc is an essential mineral necessary for normal growth and development of all mammals. Zinc functions largely in enzymes involved in protein synthesis and carbohydrate metabolism along with many other biological reactions. The purpose of this study was to assess changes in blood components and to evaluate the interactive effects of zinc and Zilmax supplementation on growth and carcass characteristics of finishing steers

High moisture tempering of corn before flaking: effects on bacterial contamination from houseflies and fecal shedding in finishing cattle Broce, A.B.; Gordon, C.M.; Sindt, J.J.; Depenbusch, Brandon E.; Drouillard, James S.; Phebus, Randall K

Tempered and non-tempered steam-flaked corn samples along with total mixed rations containing either tempered or non-tempered steam-flaked corn were exposed to flies and the environment for 21 hours. Exposure to flies and the environment increased (P\u3c0.05) generic E. coli, non-E. coli coliforms, total coliforms, and total plate count for the steamflaked corn samples independent of tempering. Tempering corn before steam-flaking increased total plate counts. Exposure to the environment and flies did not significantly (P\u3e0.05) alter microbial counts of total mixed rations regardless of tempering (Table 1). Generic E. coli coliforms were greater in total mixed rations when the corn was tempered, both before and after exposure to flies and the environment (P\u3c0.05). Similarly, total microbial plate counts were higher in steam-flaked corn samples when the corn was tempered (P\u3c0.05). A significant increase in response to grain tempering was also noted in non-E. coli coliforms and total microbial plate counts for the total mixed ration samples after exposure (Table 1). Following the initial experiments, 96 finishing beef steers were used to evaluate the effects of tempering steam-flaked corn on acid-resistant E. coli and total fecal coliforms. On day 56 of the feeding period, fecal samples were collected and analyzed for total and acidresistant E. coli and coliforms. No significant treatment difference was observed in the total fecal coliforms (P\u3e0.05), but acid-resistant (pH 2) non-E. coli and total fecal coliforms (Table 2) were lower in feces of cattle fed the tempered grain than those fed non-tempered grain

Menthol Supplementation Has Minimal Effects on Blood Components from Holstein Steers

Menthol is a naturally occurring compound classified as an essential oil that gives plants of the Mentha species their characteristic minty aroma and flavor. Menthol is used as a cooling compound in products ranging from common cold medications to pesticides and has been found to have a wide range of biological activities in different systems within the body. More recently, menthol and other essential oils have been identified as potential alternatives to feed antibiotics and growth promotants. Menthol has been observed to directly affect κ-opioid receptors. Kappa opioid receptors are located in the central nervous system, with a high density found in the hypothalamus. Menthol has been hypothesized to be capable of binding to κ-opioid receptors in the hypothalamus, stimulating neuropeptides involved in the production and release of growth hormone and leading to increased insulin-like growth factor-1 concentration, thus increasing growth. The purpose of this experiment was to evaluate changes in blood metabolites when menthol was incorporated into the diets of steers

Effects of Growth-Promoting Technologies on Feedlot Performance and Carcass Characteristics of Crossbred Heifers

The use of growth-promoting technologies has become a common practice in the beef cattle industry as producers strive for efficient growth and greater lean deposition. Two common technologies include exogenous hormonal implants and beta-adrenergic agonists (β-AA). Combination implants containing estrogen and testosterone increase muscle mass by elevating protein synthesis and/or reducing protein degradation. The increase in protein synthesis allows the animal to produce more lean muscle tissue. Optaflexx (Elanco Animal Health, Greenfield, IN) is a popular β-AA that works as a repartitioning agent to redirect nutrients toward muscle deposition and away from adipose tissue production. The two technologies utilize separate pathways for muscle growth and can have additive results on efficiency and ultimate carcass characteristics. Feedlot heifer responses to growth-promoting technologies have been inconsistent and not as potent as those observed in steers. The objective of this study was to determine the effects of two growth-promoting programs on feedlot heifer performance and carcass composition

Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production

Citation: Van Bibber-Krueger, C. L., Miller, K. A., Aperce, C. C., Alvarado-Gilis, C. A., Higgins, J. J., & Drouillard, J. S. (2016). Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production. Journal of Animal Science, 94(3), 1170-1178. doi:10.2527/jas2015-8779Fifty-two Holstein steers (573 +/- 9.92 kg BW) were used to determine if oral administration of crystalline menthol would induce changes in endogenous secretions of IGF-1 and circulating concentrations of glucose, lactate, and plasma urea nitrogen (PUN). Steers were blocked by BW and assigned within block to treatment. Treatments consisted of 0, 0.003, 0.03, or 0.3% crystalline menthol (DM basis) added to the diet. Animals were housed in individual, partially covered pens equipped with feed bunks and automatic water fountains. On d 1 of the experiment, blood samples were obtained via jugular venipuncture at 0, 6, 12, 18, and 24 h after feeding. Treatment administration commenced on d 2, and blood samples were again drawn at 0, 6, 12, 18, and 24 h after feeding. This blood-sampling schedule was repeated on d 9, 16, 23, and 30. Plasma was analyzed for PUN, glucose, and lactate concentrations. Serum was used to analyze IGF-1 concentration. Body weights were measured on d 1, 9, 16, 23, and 30. To accompany the live animal phase, in vitro fermentations were performed using ruminal fluid cultures. Measurements included VFA concentrations and fermentative gas production for cultures containing crystalline menthol at 0, 0.003, 0.03, or 0.3% of substrate DM. Addition of menthol to the diet of steers resulted in a treatment x day interaction (P 0.21). In conclusion, menthol supplementation minimally affected blood parameters associated with growth or ruminal fermentative activity