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Hazarganji Chiltan National Park in Balochistan, Pakistan was established in 1980 and the protected area was further extended in 1998. Large area of this mountain is still open for unmanaged human disturbances such as collection of wood for fuel purpose and livestock grazing. Removal of vegetation of rangelands has a significant negative impact on soil organic matter (SOM). This research evaluates litter decomposition in three sites of Hazarganji Chiltan mountain with varying history of human disturbances (unprotected site, young protected site and old protected site). Twigs of Pistacia khinjuk with approximately equal weight and length were placed in litter bags of mesh size 2 mm and were buried in 0-5 cm depth in three sites in January. Half of the twigs of each site received rain simulation in April, August, October, November and January while the other half of the twigs were subjected under natural conditions for 15 months. Twigs from each plot of each treatment of each site were collected from soil after every rain simulation in the previous month of experiment and were processed for weight loss assessment. Results showed that weight loss of twigs by decomposition was significantly higher in the soil of unprotected site as compared to other two sites and there was no difference between rain simulation and control treatments except that loss of weight of twigs of unprotected site was higher under control than rain simulation condition. To confirm that SOM was the major controlling factor for the decomposition of litter decay, soils of each site were collected and burned to remove SOM; thereafter, burned soil samples were mixed with homogenous powder of oven-dried native plants, incubated for 6 months and were provided with dissolved organic matter of the soils of each site. Results showed that there was no difference in the decomposition of litter between soils under controlled laboratory condition, which confirmed that SOM was a major controlling factor for the litter decay in soil under field conditions. The pyrosequencing analysis of the DNA of soils collected from three sites revealed the presence of bacterial species Thermovum composti.
Imran Khan; Shamim Gul; Sarfraz Ahmad; Gul Bano Rehman; Agha Waqar Yunus; Iram Gul; Imran Ali; Ali Akbar; Muhammad Islam. Litter decay in rangeland sites with varying history of human disturbance: a study with Hazargangi Chiltan mountain. Journal of Mountain Science 2020, 17, 898 -906.
AMA StyleImran Khan, Shamim Gul, Sarfraz Ahmad, Gul Bano Rehman, Agha Waqar Yunus, Iram Gul, Imran Ali, Ali Akbar, Muhammad Islam. Litter decay in rangeland sites with varying history of human disturbance: a study with Hazargangi Chiltan mountain. Journal of Mountain Science. 2020; 17 (4):898-906.
Chicago/Turabian StyleImran Khan; Shamim Gul; Sarfraz Ahmad; Gul Bano Rehman; Agha Waqar Yunus; Iram Gul; Imran Ali; Ali Akbar; Muhammad Islam. 2020. "Litter decay in rangeland sites with varying history of human disturbance: a study with Hazargangi Chiltan mountain." Journal of Mountain Science 17, no. 4: 898-906.
Aflatoxin M1 contamination of milk in Pakistan, like many developing countries, is poorly understood. The present study was therefore conducted to determine AFM1 contamination of milk and its contributory factors in Pakistan. We sampled milk and feedstuffs from 450 peri-urban dairy farms in seven major cities following a cross-sectional study design. Analysis of milk using ELISA revealed high contamination with an overall average of 3164.5 ng of AFM1/L, and significant differences (p < 0.001) between cities. The milk sampled from Gilgit, in northern hilly areas, had an average AFM1 level of 92.5 ng/L. Milk from other cities had 3529.7 ng/L average contamination, with only 5.7% samples qualifying the maximum tolerable limit of 500 ng of AFM1/L. Heavy mean aflatoxin contamination was found in bakery waste (724.6 μg/kg), and cottonseed cake (600.8 μg/kg). Rest of the other feedstuffs had moderate to low mean aflatoxin contamination, ranging from 66.0 μg/kg in maize stover to 3.4 μg/kg in wheat bran. The mean aflatoxin level in commercial dairy concentrates was 32.7 µg/kg. About 80% of the total aflatoxin intake of dairy animals was contributed by cottonseed cake alone due to its high aflatoxin contamination and proportion in dairy rations. On-farm storage time of oilseed cakes varied (p < 0.01) in different cities but was not associated with aflatoxin contamination. The exceptionally high AFM1 contamination suggests that milk from peri-urban dairy farms is a serious public health threat in Pakistan. This situation can be mitigated by reducing aflatoxin contamination in cottonseed cake and promoting the use of commercial concentrates and other feedstuffs with low contamination.
Agha Waqar Yunus; Aman Ullah; Johanna Frida Lindahl; Zahid Anwar; Atta Ullah; Sharjeel Saif; Mubarak Ali; Aamer Bin Zahur; Hamid Irshad; Shahbaz Javaid; Nida Imtiaz; Umer Farooq; Aitzaz Ahsan; Zahida Fatima; Avais Ahmed Hashmi; Babar Hilal Ahmad Abbasi; Zubair Bari; Ihsan Ullah Khan; Mohammed Nawaz Mohammed Ibrahim. Aflatoxin Contamination of Milk Produced in Peri-urban Farms of Pakistan: Prevalence and Contributory Factors. Frontiers in Microbiology 2020, 11, 159 .
AMA StyleAgha Waqar Yunus, Aman Ullah, Johanna Frida Lindahl, Zahid Anwar, Atta Ullah, Sharjeel Saif, Mubarak Ali, Aamer Bin Zahur, Hamid Irshad, Shahbaz Javaid, Nida Imtiaz, Umer Farooq, Aitzaz Ahsan, Zahida Fatima, Avais Ahmed Hashmi, Babar Hilal Ahmad Abbasi, Zubair Bari, Ihsan Ullah Khan, Mohammed Nawaz Mohammed Ibrahim. Aflatoxin Contamination of Milk Produced in Peri-urban Farms of Pakistan: Prevalence and Contributory Factors. Frontiers in Microbiology. 2020; 11 ():159.
Chicago/Turabian StyleAgha Waqar Yunus; Aman Ullah; Johanna Frida Lindahl; Zahid Anwar; Atta Ullah; Sharjeel Saif; Mubarak Ali; Aamer Bin Zahur; Hamid Irshad; Shahbaz Javaid; Nida Imtiaz; Umer Farooq; Aitzaz Ahsan; Zahida Fatima; Avais Ahmed Hashmi; Babar Hilal Ahmad Abbasi; Zubair Bari; Ihsan Ullah Khan; Mohammed Nawaz Mohammed Ibrahim. 2020. "Aflatoxin Contamination of Milk Produced in Peri-urban Farms of Pakistan: Prevalence and Contributory Factors." Frontiers in Microbiology 11, no. : 159.
A longitudinal one-year study was conducted to determine aflatoxin M1 levels in different types of milk marketed in Pakistan. Processed and raw liquid milk from 21 sources, two milk powder and six tea whitener brands were sampled on monthly basis from Islamabad. The aflatoxin M1 levels in liquid milk were lower (p < 0.05) in summer (April to July) compared with the levels in winter (January, November and December). The mean aflatoxin M1 levels were 254.9, 939.5, and 1535.0 ng/L in UHT, pasteurized, and raw milk, respectively (differing at p < 0.001). The mean toxin level in powdered milk after reconstitution was 522.1 ng/L. Overall, 12.9, 41.0, 91.9 and 50.0% of the UHT, pasteurized, raw and powdered milk samples, respectively, exceeded the Codex maximum tolerable limit of 500 ng of aflatoxin M1/L. It was estimated that consumers of raw and processed milk were exposed to 11.9 and 4.5 ng aflatoxin M1, respectively, per kg of body weight daily. The study indicates potential aflatoxin M1 exposure risks for the consumers of raw milk in the country. The levels of the toxin though comparatively lower in milk powder, requires attention as this type of milk is consumed by infants.
Agha Waqar Yunus; Nida Imtiaz; Haider Khan; Mohammed Nawaz Mohammed Ibrahim; Yusuf Zafar. Aflatoxin Contamination of Milk Marketed in Pakistan: A Longitudinal Study. Toxins 2019, 11, 110 .
AMA StyleAgha Waqar Yunus, Nida Imtiaz, Haider Khan, Mohammed Nawaz Mohammed Ibrahim, Yusuf Zafar. Aflatoxin Contamination of Milk Marketed in Pakistan: A Longitudinal Study. Toxins. 2019; 11 (2):110.
Chicago/Turabian StyleAgha Waqar Yunus; Nida Imtiaz; Haider Khan; Mohammed Nawaz Mohammed Ibrahim; Yusuf Zafar. 2019. "Aflatoxin Contamination of Milk Marketed in Pakistan: A Longitudinal Study." Toxins 11, no. 2: 110.
Cottonseed cake in South East Asia has been associated with health issues in ruminants in the recent years. The present study was carried out to investigate the health issues associated with cottonseed cake feeding in dairy animals in Pakistan. All the cake samples were confirmed to be from early maturing cotton varieties (maturing prior to or during Monsoon). A survey of the resource persons indicated that the feeding problems with cottonseed cake appeared after 4–5 months of post-production storage. All the cake samples had heavy bacterial counts, and contaminated with over a dozen different fungal genera. Screening for toxins revealed co-contamination with toxic levels of nearly a dozen mycotoxins including aflatoxin B1 + B2 (556 to 5574 ppb), ochratoxin A + B (47 to 2335 ppb), cyclopiazonic acid (1090 to 6706 ppb), equisetin (2226 to 12672 ppb), rubrofusarin (81 to 1125), tenuazonic acid (549 to 9882 ppb), 3-nitropropionic acid (111 to 1032 ppb), and citrinin (29 to 359 ppb). Two buffalo calves in a diagnostic feed trial also showed signs of complex toxicity. These results indicate that inappropriate processing and storage of the cake, in the typical conditions of the subcontinent, could be the main contributory factors regarding the low quality of cottonseed cake.
Agha W. Yunus; Michael Sulyok; Josef Böhm. Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems. Toxins 2015, 7, 2188 -2197.
AMA StyleAgha W. Yunus, Michael Sulyok, Josef Böhm. Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems. Toxins. 2015; 7 (6):2188-2197.
Chicago/Turabian StyleAgha W. Yunus; Michael Sulyok; Josef Böhm. 2015. "Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems." Toxins 7, no. 6: 2188-2197.
The purpose of this study was to observe the effects of low doses of aflatoxin B1 (AFB1) on responses to common vaccines and levels of serum cations in broilers. Male broilers at 7 d of age were fed control (no AFB1), a 75 µg of AFB1/kg (75 ppb of AFB1) diet, or a 750 µg of AFB1/kg (750 ppb of AFB1) diet. The 750 ppb of AFB1 diet resulted in a temporary increase in ELISA titers against Newcastle disease virus (P = 0.014) and infectious bursal disease virus (P = 0.005) during wk 2 and 4 of exposure, respectively, compared with the control diet. Conversely, lower (P ≤ 0.01) serum protein concentrations were found in broilers under the 750 ppb AFB1 diet during wk 2 and 4. During wk 2 of exposure, lower serum levels of potassium were noted in birds under both the 75 (P = 0.037) and 750 ppb (P = 0.000) AFB1 diets compared with those under the control diet. During wk 5, higher serum magnesium (P = 0.004), and sodium (P = 0.000) under the 750 ppb AFB1 diet were found compared with the control diet. These data indicate that low dietary levels of AFB1 can temporarily increase or decrease the studied serological variables in broilers depending upon the stage of exposure.
A. W. Yunus; J. Böhm. Temporary modulation of responses to common vaccines and serum cation status in broilers during exposure to low doses of aflatoxin B1. Poultry Science 2013, 92, 2899 -2903.
AMA StyleA. W. Yunus, J. Böhm. Temporary modulation of responses to common vaccines and serum cation status in broilers during exposure to low doses of aflatoxin B1. Poultry Science. 2013; 92 (11):2899-2903.
Chicago/Turabian StyleA. W. Yunus; J. Böhm. 2013. "Temporary modulation of responses to common vaccines and serum cation status in broilers during exposure to low doses of aflatoxin B1." Poultry Science 92, no. 11: 2899-2903.
The present experiment was carried out to investigate if levels of serum cations in broilers are modulated differently at various stages of exposure to deoxynivalenol (DON). Male broiler chicks at 7 days of age were fed a basal diet (0.27 mg of DON; 0.01 mg of zearalenone/kg), or either a low DON diet (1.68 mg of DON; 0.15 mg of zearalenone/kg) or a high DON diet (12.21 mg of DON; 1.09 mg of zearalenone/kg) produced using extracts from Fusarium graminearum cultures. Blood samples from the birds were collected during weeks 2, 4, and 5 of exposure. The high DON diet resulted in lower serum calcium levels compared to the basal diet at all the 3 sampling stages, while the low DON diet resulted in lower serum calcium levels only during weeks 2 and 5. Serum potassium levels were reduced under both the DON diets during weeks 2 and 5, while no diet-associated changes were found for serum levels of magnesium, sodium, and zinc. Under the present experimental conditions, the serum levels of calcium were consistently modulated in the broilers exposed to the DON-contaminated diets. The modulation of serum levels of potassium was, however, dependent upon the stage of exposure to DON.
Agha Waqar Yunus; Josef Böhm. Serum cation profile of broilers at various stages of exposure to deoxynivalenol. Mycotoxin Research 2013, 29, 113 -117.
AMA StyleAgha Waqar Yunus, Josef Böhm. Serum cation profile of broilers at various stages of exposure to deoxynivalenol. Mycotoxin Research. 2013; 29 (2):113-117.
Chicago/Turabian StyleAgha Waqar Yunus; Josef Böhm. 2013. "Serum cation profile of broilers at various stages of exposure to deoxynivalenol." Mycotoxin Research 29, no. 2: 113-117.
The present investigations were conducted to test the effects of T-2 toxin on electrophysiological variables of jejunal epithelium of chicken. Jejunal segments of broilers were monitored in Ussing chambers in the presence of T-2 toxin at the levels of 0 (negative control), 0 (methanol/vehicle control), 0.1, 1, 5, and 10 μg/ml of buffer. T-2 toxin did not affect basal values of short circuit current (Isc), transmural potential difference, or tissue conductivity in the jejunal epithelium. T-2 toxin also did not statistically affect glucose-induced electrophysiological variables during the first 3 min of glucose induction. Compared to the vehicle control, the ouabain-sensitive Isc was negatively affected (P = 0.008) only under 5 μg of T-2 toxin/ml. Increasing levels of T-2 toxin negatively affected the ouabain-sensitive Isc in a cubic (P = 0.007) fashion. These data indicate that acute exposure to moderate levels of T-2 toxin may progressively impair the cation gradient across the jejunal epithelium.
Agha Waqar Yunus; Susan Kröger; Alexander Tichy; Jürgen Zentek; Josef Böhm. Electrophysiological response of chicken’s jejunal epithelium to increasing levels of T-2 toxin. Mycotoxin Research 2012, 29, 23 -27.
AMA StyleAgha Waqar Yunus, Susan Kröger, Alexander Tichy, Jürgen Zentek, Josef Böhm. Electrophysiological response of chicken’s jejunal epithelium to increasing levels of T-2 toxin. Mycotoxin Research. 2012; 29 (1):23-27.
Chicago/Turabian StyleAgha Waqar Yunus; Susan Kröger; Alexander Tichy; Jürgen Zentek; Josef Böhm. 2012. "Electrophysiological response of chicken’s jejunal epithelium to increasing levels of T-2 toxin." Mycotoxin Research 29, no. 1: 23-27.
Deoxynivalenol (DON) has been recently documented to deteriorate intestinal morphology in chickens at dietary doses that are regarded as safe for this species. The present trial was conducted to explore the significance of these morphological changes in relation to intestinal absorptive functionality and DON metabolism. Ross broilers at 7 d of age were fed either a basal diet (0.265 ± 0.048 mg of DON/kg; 0.013 ± 0.001 mg of zearalenone/kg), a low DON diet (1.68 mg of DON/kg; 0.145 ± 0.007 mg of zearalenone/kg), or a high DON diet (12.209 ± 1.149 mg of DON/kg; 1.094 ± 0.244 mg of zearalenone/kg). The DON diets (to variable degrees) progressively decreased the relative density (weight:length) of the small intestine with increasing exposure length, which could be correlated with a decrease in villus height in the small intestine. Short circuit current of the jejunal epithelium, reflecting transport function of the epithelium per unit area, was reduced (P = 0.001) in the birds fed the high DON diet. The increasing dietary level of DON linearly (P = 0.035) increased the length of the jejunum in wk 4 of exposure, resulting in conservation of macronutrient retention. Upon challenging the birds with a fixed amount of DON after wk 5 of exposure, higher (P ≤ 0.033) amounts of DON and the detoxification metabolite (de-epoxy-DON) were found at 5 h postchallenge in the guts of birds raised on the DON diets. The increasing level of previous exposure to DON linearly (P = 0.040) decreased the plasma level of DON in the birds at 1 h postchallenge. The amounts of zearalenone and its analogs in the gut and plasma also followed a trend similar to that for DON. These data suggest that intestines in chickens may adapt to a chronic DON challenge by morphological and functional modifications. The birds having previous exposure to Fusarium mycotoxins showed moderate detoxification coupled with reduced transfer of the mycotoxins to systemic circulation. Some metabolites of zearalenone found in this study were previously unknown for chickens.
A. W. Yunus; A. Blajet-Kosicka; R. Kosicki; M. Z. Khan; H. Rehman; J. Böhm. Deoxynivalenol as a contaminant of broiler feed: Intestinal development, absorptive functionality, and metabolism of the mycotoxin. Poultry Science 2012, 91, 852 -861.
AMA StyleA. W. Yunus, A. Blajet-Kosicka, R. Kosicki, M. Z. Khan, H. Rehman, J. Böhm. Deoxynivalenol as a contaminant of broiler feed: Intestinal development, absorptive functionality, and metabolism of the mycotoxin. Poultry Science. 2012; 91 (4):852-861.
Chicago/Turabian StyleA. W. Yunus; A. Blajet-Kosicka; R. Kosicki; M. Z. Khan; H. Rehman; J. Böhm. 2012. "Deoxynivalenol as a contaminant of broiler feed: Intestinal development, absorptive functionality, and metabolism of the mycotoxin." Poultry Science 91, no. 4: 852-861.
Recent data suggest that Fusarium trichothecenes may reduce broiler performance at levels previously thought not to affect this variable in chickens. In the present study, we investigated the effects of deoxynivalenol (DON), a type-B trichothecene, on broilers. Male broilers at 7 d of age were fed either a basal diet (0.265 ± 0.048 mg of DON; 0.013 ± 0.001 mg of zearalenone/kg), a low DON diet (1.68 mg of DON/kg; 0.145 ± 0.007 mg of zearalenone/kg), or a high DON diet (12.209 ± 1.149 mg of DON/kg; 1.094 ± 0.244 mg of zearalenone/kg). Increasing levels of DON decreased the weekly weight gain linearly (P ≤ 0.041) during the first 3 wk of exposure; there were no significant differences in the weight gain of the birds after wk 3. With increasing levels of DON, the titers against Newcastle disease virus increased linearly during wk 2 (P = 0.022) and wk 4 (P = 0.033) of exposure, whereas the titers against infectious bronchitis virus decreased linearly (P = 0.006) during wk 5 of exposure. The serum protein concentration increased linearly (P = 0.017) during wk 2 and quadratically (P = 0.002) during wk 4 of exposure. Under these experimental conditions, the performance and vaccine response of the broilers were modulated to varying degrees at concentrations of DON that are currently permitted (up to 5 mg/kg of diet) in many countries. Further studies are therefore required to clarify the implications of these results on the welfare of chickens.
A. W. Yunus; K. Ghareeb; Magdalena Twarużek; Jan Grajewski; J. Böhm. Deoxynivalenol as a contaminant of broiler feed: Effects on bird performance and response to common vaccines. Poultry Science 2012, 91, 844 -851.
AMA StyleA. W. Yunus, K. Ghareeb, Magdalena Twarużek, Jan Grajewski, J. Böhm. Deoxynivalenol as a contaminant of broiler feed: Effects on bird performance and response to common vaccines. Poultry Science. 2012; 91 (4):844-851.
Chicago/Turabian StyleA. W. Yunus; K. Ghareeb; Magdalena Twarużek; Jan Grajewski; J. Böhm. 2012. "Deoxynivalenol as a contaminant of broiler feed: Effects on bird performance and response to common vaccines." Poultry Science 91, no. 4: 844-851.
Aflatoxin B1 is a common contaminant of poultry feeds in tropical and subtropical climates. Research during the last five decades has well established the negative effects of the mycotoxin on health of poultry. However, the last ten years of relevant data have accentuated the potential of low levels of aflatoxin B1 to deteriorate broiler performance. In this regard, any attempt to establish a dose-effect relationship between aflatoxin B1 level and broiler performance is also complicated due to differences in types of broilers and length of exposure to the mycotoxin in different studies. Contrary to the prevalent notion regarding literature saturation with respect to aflatoxicosis of chicken, many areas of aflatoxicosis still need to be explored. Literature regarding effects of the mycotoxin on the gastrointestinal tract in this regard is particular scanty and non-conclusive. In addition to these issues, the metabolism of aflatoxin B1 and recently proposed hypotheses regarding biphasic effects of the mycotoxin in broilers are briefly discussed.
Agha W. Yunus; Ebrahim Razzazi-Fazeli; Josef Bohm. Aflatoxin B1 in Affecting Broiler’s Performance, Immunity, and Gastrointestinal Tract: A Review of History and Contemporary Issues. Toxins 2011, 3, 566 -590.
AMA StyleAgha W. Yunus, Ebrahim Razzazi-Fazeli, Josef Bohm. Aflatoxin B1 in Affecting Broiler’s Performance, Immunity, and Gastrointestinal Tract: A Review of History and Contemporary Issues. Toxins. 2011; 3 (6):566-590.
Chicago/Turabian StyleAgha W. Yunus; Ebrahim Razzazi-Fazeli; Josef Bohm. 2011. "Aflatoxin B1 in Affecting Broiler’s Performance, Immunity, and Gastrointestinal Tract: A Review of History and Contemporary Issues." Toxins 3, no. 6: 566-590.