Heat stress (HS), one of the major problems of tropical and subtropical countries, adversely affects the production performance of poultry. Keeping this in view, the present study was designed to investigate some of the biological markers of HS in broilers as modulated by dietary supplementation of mannan-oligosaccharide (MOS) and a Lactobacillus-based probiotic (LBP), either alone or in combination. Two hundred fifty 1-d-old-chicks were randomly divided into 5 groups. From d 22, the birds were either kept at the thermoneutral zone (TN) or exposed to HS to the conclusion of study, d 42. Birds were fed either a corn-based basal diet (TN and HS groups) or the same diet supplemented with 0.5% MOS (HS-MOS group), 0.1% LBP (HS-LBP group), or their combination. Birds were immunized against Newcastle disease virus on d 4 (intraocular; live attenuated) and d 20 (drinking water; live attenuated) and infectious bursal disease virus on d 8 (intraocular; live intermediate strain) and d 24 (drinking water; live attenuated). Birds were killed on d 42 to collect serum for determination of cortisol, thyroid hormones, cholesterol, C-reactive protein, and postvaccinal antibody titers. Results revealed that dietary supplementations decreased (P < 0.05) the serum cortisol and cholesterol concentrations and increased (P < 0.05) thyroxine concentration compared with the HS group without affecting triiodothyronine concentration. The percentage of the C-reactive protein-positive birds was higher (P < 0.05) in the HS group compared with the TN group. Dietary supplementations improved humoral immunity against Newcastle disease virus and infectious bursal disease virus during HS. In conclusion, dietary supplementation of either MOS or LBP alone or in combination can reduce some of the detrimental effects of HS in broilers.

This study was intended to explore the oxidative status of broilers under cyclic heat stress (HS) as modulated by supplementation of mannan-oligosaccharides (MOS) and a probiotic mixture (PM). Two hundred fifty 1-d-old chicks were randomly divided into 5 groups. From d 22, birds were either kept in a thermoneutral zone (TN; 26.7°C for 24 h/d) or subjected to HS (35 ± 1.1°C and 75 ± 5% RH for 8 h/d from 1000 to 1800 h) to the conclusion of the study on d 42. Birds were fed either a corn-based diet (TN and HS groups) or the same diet supplemented with 0.5% MOS (HS-MOS group), 0.1% PM (HS-PM group), or their combination as a symbiotic (SYN; HS-SYN group). On d 42, birds were killed by cervical dislocation to collect serum for the determination of total oxidants, total antioxidants, paraoxonase, arylesterase, ceruloplasmin, aspartate aminotransferase, alanine aminotransferase, and trace minerals. Heat stress increased (P < 0.05) total oxidants and total antioxidants and decreased (P < 0.05) paraoxonase and arylesterase, with no change in ceruloplasmin, aspartate aminotransferase, and alanine aminotransferase activities. Dietary supplementation decreased (P < 0.05) total oxidants and total antioxidants, with no effect on the activities of other enzymes. Heat stress did not influence serum copper, zinc, and manganese concentrations of birds when compared with those in the TN group. However, MOS increased (P < 0.05) concentrations of all the trace minerals, whereas SYN increased (P < 0.05) concentrations of only zinc and copper. It was concluded that MOS or PM supplementation, alone or as a SYN, may reduce some of the detrimental effects of HS, whereas MOS alone or as a SYN may improve the absorption of trace minerals.

No abstract

BackgroundThe impact of drug selection pressure on the overall genetic diversity of parasitic nematode populations in the field is poorly understood. In this study, we address this issue for the small ruminant parasite Haemonchus contortus in the Punjab, Pakistan. This region provides an opportunity to compare H. contortus populations that have been subjected to a prolonged period of frequent benzimidazole drug treatments on government farms with parasite populations that have been exposed to little or no drug treatment in neighbouring pastoral herds.MethodsAdult H. contortus worms were collected from the abomasa of small ruminants from three government farms frequently using benzimidazole drugs, and closed to animal movement, for over 30 years and also from from eighteen pastoral herds subject to minimal drug selection. The frequency of three known benzimidazole resistance associated mutations was determined in each parasite population. For the seven parasite populations in which resistance mutations were found, the diversity, geographical distribution and phylogenetic relationships of isotype-1 β-tubulin benzimidazole resistance haplotypes were determined. In addition, the genetic diversity of the parasite populations on the three government farms were compared with those from four pastoral herds.ResultsThe F200Y (TAC) resistance mutation was present at a very high frequency in H. contortus populations from government herds, but not from pastoral herds, consistent with their respective drug selection histories. Population genetic analysis, using a panel of microsatellite markers, revealed that there was little genetic differentiation among the parasite populations with no significant difference in the overall genetic diversity between government and pastoral herds. In addition, sequence analysis of the isotype-1 β-tubulin locus revealed multiple F200Y (TAC) haplotypes demonstrating soft selective sweeps even in government herds with little or no contemporary parasite migration.ConclusionsThe results suggest that, although the frequent drug treatment used on government farms has selected for a high frequency of benzimidazole resistance mutations, there has been little or no reduction in the overall genetic diversity of the selected parasite populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1624-0) contains supplementary material, which is available to authorized users.

Parasites reside inside or outside their hosts and get host nutrition and blood. Here, we have emphasized economic losses in cattle caused by parasitic diseases due to ecto- and endo- parasites (flies, ticks, mites and helminths). We have outlined different methods/models including economic evaluation techniques and dynamic analysis as a major class, used for the calculation of economic losses caused by parasites in cattle. According to already conducted studies, a decrease in production is mentioned in quantity and percentage while financial losses are expressed in the form of account with respect to per head, herd or for the specific study area. The parasites cause the reduced production and financial losses due to control, treatment and mortality costs. We calculated the average decrease in milk production and organ condemnation as 1.16 L animal-1 day-1 and 12.95%, respectively, from overall cattle parasitic infections. Moreover, the average calculated financial and percentage losses were US$ 50.67 animal-1 year-1 and 17.94%, respectively. Economically important parasitic diseases mentioned here are caused by specific spp. of protozoans and helminths according to data collected from the literature. Protozoan diseases include tick-borne diseases, coccidiosis, neosporosis, trypanosomiasis and cryptosporidiosis. Losses due to tick-borne infections were encountered for decreased milk production, mortality, treatment and control. Losses from coccidiosis were due to decreased weight gain, treatment costs and mortality. While abortion losses were encountered in neosporosis. Trypanosomiasis caused losses due to a decrease in milk yield. Moreover, only diagnostic (conventional or molecular techniques) cost was taken into account for cryptosporidiosis. Economically important nematode parasites are Oesophagostomum spp., Cooperia spp., Trichostrongylus spp., Strongyloides spp., Ostertagia spp. and Haemonchus placei. Due to the zoonotic importance of echinococcosis, Echinococcus granulosus is the most economically important cestode parasite. Losses caused by echinococcosis were due to organ condemnation, carcass weight loss and decreases hide value, milk production and fecundity. While, fascioliasis is one of the most economically important trematodal disease, which causes cirrhosis of the liver due to parasite migration, and thus, the organ becomes inedible. So, it would be helpful for farmers and researchers to approach these methods/models for calculation of parasitic losses and should adopt suitable measures to avoid long-term economic losses.

No abstract

No abstract

No abstract