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Geographic variation in tissue accumulation of endocrine disrupting compounds (EDCs) in grazing sheep
2011
Rhind, S.M. | Kyle, C.E. | Mackie, C. | Yates, K. | Duff, E.I.
Muscle tissue was collected from ewes and lambs derived from farms throughout Scotland and sample concentrations of five endocrine disrupting compound groups were determined. Farms of origin were categorised according to geographic region. There were few statistically-significant differences with region or distance from cities. However, the magnitude of the difference between the highest and lowest mean values in ewe muscle from different regions exceeded 30% for 13 of the 15 compounds that were consistently detected in muscle, with animals derived from the industrialised region having the highest mean values for 11 of the 13 compounds. A less marked trend was apparent in the lamb muscle (8 of 13 highest were in the industrialised region). The physiological effects of such small differences in exposure to mixtures of pollutants remain to be determined.
Show more [+] Less [-]Have Meteorological Conditions Reduced NO2 Concentrations from Local Emission Sources in Gothenburg?
2011
Tang, Lin | Rayner, David | Haeger-Eugensson, Marie
The risks of exceeding EU limit values for NO2 concentrations have increased in many European cities, and compliance depends strongly on meteorological conditions. This study focuses on meteorological conditions and their influences on urban background NO2 concentrations in the city of Gothenburg for 1999–2008. The relations between observed NO2 concentrations and meteorological conditions are constructed using two modelling approaches: multiple linear regression and synoptic regression. Both approaches assume no trends in emissions over the study period. The multiple linear regression model is established on observed local meteorological variables. The synoptic-regression model first groups days according to synoptic conditions using Lamb Weather Types and then uses linear regression on each group separately. A model comparison shows that linear regression model and synoptic-regression model perform satisfactory. The synoptic-regression model gives higher explained variance (R 2) against observations during the calibration years (1999–2007), in particular for the morning peak and afternoon–evening peak concentrations, but the improvement in the validation period is weak. The annual mean NO2 variations, and their trends during the study period, were assessed using the synoptic-regression model. The synoptic-regression model is able to explain 54%, 42% and 80% of the annual variability of daily mean, morning peak and afternoon–evening peak NO2 concentrations, respectively. The observed and modelled annual means of the daily mean and morning/afternoon–evening peak NO2 concentrations show decreasing trends from 1999 to 2008. All trends, except the trend in annual-average observed morning peak NO2 are statistically significant. The presence of trends in the modelled NO2 concentrations—even though emissions are assumed to be constant—leads us to conclude that weather and climate alone are responsible for a substantial fraction of the recent declines in observed NO2 concentrations in Gothenburg. Favourable meteorological conditions may have mitigated increases in local NO2 emissions during 1999 to 2008.
Show more [+] Less [-]Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs
2016
Alhidary, I. A. | Abdelrahman, M. M. | Khan, R. U.
Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.
Show more [+] Less [-]Effect of calcium lignosulfonate supplementation on metabolic profiles of confined lambs
2018
Silva, Maria Luiza França | de Carvalho, Gleidson Giordano Pinto | Silva, Robério Rodrigues | da Silva Magalhães, Tamires | Viana, Pablo Teixeira | de Almeida Rufino, Luana Marta | Santos, Aracele Vieira | Azevedo, José Augusto Gomes | Júnior, José Esler Freitas | de Oliveira Nascimento, Camila | Eiras, Carlos Emanuel
This study aimed to evaluate the effect of calcium lignosulfonate associated with whole cottonseed in high-concentrate diets for sheep. Eight Dorper crossbred sheep with an average live weight of 42.5 ± 1.70 kg were assigned to two 4 × 4 Latin squares. The following experimental diets were evaluated: control diet (without calcium lignosulfonate) and diets with inclusion of 50, 100, and 150 g of calcium lignosulfonate/kg fresh matter. Diets were composed of soybean meal, ground corn, and whole cottonseed. Feed intake, digestibility, metabolic characteristics, and feeding behavior were evaluated. The intake of nutritional components did not show significant differences as a function of the lignosulfonate levels in the diet; however, the increase in calcium lignosulfonate levels linearly decreased the dry matter digestibility. Rumen ammonia nitrogen concentrations decreased linearly as the lignosulfonate levels in the diets were increased. There was no effect of lignosulfonate levels on blood parameters or feeding behavior of the animals. The use of lignosulfonate associated with cottonseed decreases the digestibility of dry matter and the concentration of rumen ammonia nitrogen, but does not change the intake of nutritional components, the blood parameters, or the feeding behavior of sheep.
Show more [+] Less [-]Effects of prepartum sustained-release trace elements ruminal bolus on performance, colustrum composition and blood metabolites in Najdi ewes
2017
Abdelrahman, Mutassim M. | Aljumaah, Riyadh S. | Khan, Rifat Ullah
The aim of this study was to determine the effect of the supplementation of slow release bolus of selenium (Se), copper (Cu), zinc (Zn), cobalt (Co), phosphorous (P), manganese (Mn), and iodine (I) at late gestation (60 day prepartum) on performance of Najdi ewes and their newborn. Twenty Najdi ewes at late gestation were randomly selected from a herd raised under an intensive system and equally divided into two groups (control and treated). Blood samples were collected from ewes and newborns at parturition. Body weights of newborns were taken at birth, 30 and 60 days. A significant (P < 0.05) increase in Cu and Co in blood of dams treated with boluses with an increase (P < 0.05) in blood P, Zn, Cu, Co, and Se of their newborn lambs were observed. Creatinine and triglyceride were significantly (P < 0.05) low in treated newborn while urea was significantly (P < 0.05) high in the same group. In dams, significantly (P < 0.05) low concentration of triglyceride was observed. Body weight of lambs from treated group at 30 days was significantly (P < 0.05) higher when compared with the control. In conclusion, bolus of trace minerals at late gestation improved some mineral status of ewes and the newborns with higher body weight.
Show more [+] Less [-]Assessment of intake of copper and lead by sheep grazing on a shooting range for small arms: a case study
2019
Johnsen, Ida Vaa | Mariussen, Espen | Voie, Øyvind
The Norwegian Armed Forces’ shooting ranges contain contamination by metals such as lead (Pb) and copper (Cu) and are often used as grazing pastures for livestock. To determine whether the sheep were at risk from grazing at a shooting range in Nord-Trøndelag (the Leksdalen shooting field), a study was conducted wherein the aim was to determine the amount of soil the sheep were eating, the accumulation of Cu and Pb in the livers of lambs grazing on the shooting ranges, and the accumulation of Pb and Cu in the grass. The grazing behavior of the sheep was mapped using GPS tracking and wildlife cameras. Soil, grass, feces, and liver samples were collected. All the samples were analyzed for Pb, Cu, and molybdenum (Mo), and soil and feces were also analyzed for titanium (Ti). Mean concentrations in grass, soil, feces, and liver was 41–7189, 1.3–29, 4–5, and 0.3 mg/kg Pb, respectively, and 42–580, 4.2–11.9, 19–23, and 273 mg/kg Cu, respectively. The soil ingestion rate was calculated using Ti in feces and soil. From these results, the theoretical dose of Cu and Pb ingested by grazing sheep was calculated. The soil ingestion rate was found to be 0.1–0.4%, significantly lower than the soil ingestion rate of 5–30% usually used for sheep. Little or no accumulation of Cu and Pb in the grass was found. There was no difference between the metal concentrations in the washed and unwashed grass. According to the calculated dose, the sheep were at little or no risk of acute or chronic Pb and Cu poisoning from grazing on the Leksdalen shooting range. The analysis of liver samples showed that lambs grazing on the shooting range did not have higher levels of Cu or Pb than lambs grazing elsewhere. None of the lambs had concentrations of Cu or Pb in their livers indicating poisoning.
Show more [+] Less [-]Bentonite supplementation can improve performance and fermentation parameters of chronic lead-exposed lambs
2017
Azadbakht, S. | Khadem, A. A. | Norouzian, M. A.
Two experiments were conducted to investigate the effect of supplemental bentonite on performance, blood, and fermentation characteristics in Zandi lambs. In experiment 1, 20 Zandi male lambs (initial BW, 17.5 ± 1.6 kg and 110 ± 5 days old) were randomly assigned into four groups of five animals in each. The experimental treatments were (1) control (no Pb and bentonite), (2) 15 mg/kg DM Pb as Pb acetate and no bentonite, (3) 15 mg/kg DM Pb as Pb acetate and 1.5% bentonite, and (4) 15 mg/kg DM Pb as Pb acetate and 3% bentonite. The dietary treatments had no significant effect on dry matter intake of experimental lambs. Feed required per unit of weight gain was more (P < 0.05) in lead-exposed lambs in group 2 compared to the control and bentonite supplemented groups. Serum glucose, urea nitrogen, cholesterol, HDL, and LDL concentrations was similar among the treatments. In experiment 2, an in vitro gas production technique was used to evaluate the effects of bentonite supplementation on the gas production parameters of lead-polluted diets. The rate and amount of gas production was higher for bentonite supplemented groups (P < 0.01). Asymptotic gas production (b), metabolizable energy, and concentration of short chain fatty acids were lower (P < 0.05) for lead-polluted non-supplemented diet (group 2) as compared to the bentonite supplemented and control groups. It was concluded that bentonite supplementation favorably modified ruminal fermentation pattern and improved feed conversion ratio in growing lead-exposed lambs.
Show more [+] Less [-]Assessing the protective effect of bentonite against lead toxicity in growing lambs
2017
Azadbakht, Samira | Norouzian, Mohammad Ali | Khadem, Ali Akbar
The objective of the present experiment was to investigate the effect of bentonite supplementation in lead (Pb)-exposed lambs on serum Pb, Ca, P, Cu, Zn, and Fe concentrations, blood hematological parameters, and hepatic enzymes. Twenty Zandi male lambs (initial BW, 17.5 ± 1.6 kg) were randomly assigned to one of the four treatments: (1) control (no Pb or bentonite), (2) 15 mg/kg DM Pb as Pb acetate with no bentonite, (3) 15 mg/kg DM Pb as Pb acetate with 1.5% bentonite, and (4) 15 mg/kg DM Pb as Pb acetate with 3% bentonite. The experiment lasted after 90 days. Lead intake resulted in a decrease (P < 0.05) in serum Fe and an increase in serum Pb, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities (P < 0.05). Bentonite supplementation at 1.5 or 3% of DM decreased blood Pb concentration (P < 0.01) in lambs fed diets containing Pb and reduced (P < 0.05) blood concentration of Cu and Zn compared to control group (P < 0.01). However, the hematological parameters were not affected by any of the treatments. Our results showed that the dietary supplementation of bentonite could protect lambs against lead toxicity.
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