This study aimed to evaluate the effects of different supplemental fat sources [soybean oil (SBO) as a source of n-6 fatty acid and fish oil (FO) as a source of n-3 fatty acids] in the starter feed of milk-fed dairy calves during the hot season. Forty Holstein calves (3 d of age; 39.67 kg of body weight; ten calves per group) were randomly assigned to the experimental treatments as follows: (1) starter feed supplemented with no fat source (CON), (2) starter feed supplemented with 3% SBO (DM basis), (3) starter feed supplemented with 3% FO (DM basis), and (4) starter feed supplemented with an equal mixture of SBO and FO (1.5% each, DM basis). The milk feeding schedule was constant for treatments and all calves were weaned on d 65 of age. Results show that calves had greater starter intake, average daily gain, and body length when fed SBO compared to other treatments. However, feed efficiency was increased and inflammatory indicators (tumor necrosis factor-alpha, serum amyloid A and haptoglobin) concentrations were reduced in the calves fed FO compared to the other treatments. In summary, it was revealed that SBO rich in n-6 FA improved starter intake and growth performance, while FO rich in n-3 FA could improve the immune function of calves. Due to the current experimental condition, an equal mixture of SBO and FO (1.5% each, DM basis) can be recommended to have an optimum growth performance and immune function while the calves are reared under the heat conditions.

This study was conducted to investigate the effects of supplementation of different fat sources in calf starters on growth performance, health, blood fatty acid profiles, and inflammatory markers during the cold season in dairy calves. A total of 48 Holstein calves (24 males and 24 females) were randomly assigned to 1 of 4 starter diets throughout the experiment (d 3 to 65): (1) no supplemented fat (CON), (2) 3% calcium-salts of soybean oil (Ca-SBO), (3) 3% calcium-salts of fish oil (Ca–FO), and (4) 3% mixture of Ca-SBO and Ca–FO (1.5% each, DM basis; MIX). Calves were given free access to starter feed and water and were raised individually in pens from 3 to 65 d of age. Calves fed Ca-SBO consumed a greater proportion of n-6 FA, while calves fed Ca–FO consumed a greater level of n-3 FA compared to the other dietary treatments. Fat supplementation increased the intake of linoleic acid, the major n-6 FA, with the greater intake observed in the Ca-SBO group compared to the other dietary treatments. Calves fed the Ca–FO and MIX diets consumed more long-chain n-3 FA than the other diets. In addition, calves fed Ca-SBO and Ca–FO diets consumed more starter feed and total dry matter than calves fed MIX and CON throughout the experiment (d 3 to 65). Calves fed Ca–FO had higher average daily gain throughout the trial (d 3 to 65) than the other treatment groups. Of all treatment groups, calves fed Ca–FO achieved the highest final body weight and showed the greatest feed efficiency. Random forest analysis revealed that eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid were the serum levels of FA most affected by the diets. The principal component analysis of blood FA profile, blood parameters, and inflammatory markers showed distinct differences between dietary treatments. Calves fed Ca-SBO had higher plasma concentrations of linoleic acid, while calves fed Ca–FO had higher plasma concentrations of long-chain n-3 polyunsaturated fatty acids (PUFA), such as EPA, docosapentaenoic acid (DPA), and DHA than the other treatment groups. Plasma inflammatory markers were lower in calves fed Ca–FO and higher in calves fed CON than in the other treatment groups. The Ca–FO group had lower levels of inflammatory markers, including serum amyloid A, tumor necrosis factor-alpha, Interferon-γ, haptoglobin, and interleukin-6 compared to the other experimental treatments. Also, the blood malondialdehyde levels, an indicator of oxidative stress, were lower in calves fed Ca–FO compared with calves fed the other treatment diets. In conclusion, the performance of preweaned dairy calves can be improved by adding fat to their starter feed under cold conditions. Overall, the type of fat in milk may affect growth and inflammation of dairy calves before weaning under cold conditions, with n-3 FA (Ca–FO) promoting growth and reducing inflammation more effectively than n-6 FA (Ca-SBO).

Context: Deoxynivalenol (DON) contamination of feedstuffs causes detrimental effects on animals and poultry. Dietary inclusion of microbial feed additives, such as probiotics and/or yeast, seems to be a useful approach for DON detoxification and reducing the toxin absorption from the gut. Aims: This study was conducted to evaluate the synergetic effects of a probiotic (Lactobacillus spp.), yeast (Saccharomyces cerevisiae) and mycotoxin detoxifier on performance, serum chemical parameters and immune status of broiler chickens fed a DON-contaminated diet. Methods: A total of 200 1-day-old female broilers (Hubbard®) were allocated to five dietary treatments with four replicates each in a completely randomised design. Experimental diets consisted of: (1) control diet (basal diet), (2) DON diet (basal diet contaminated with 10 mg/kg DON), (3) DON diet supplemented with 0.25% mycotoxin detoxifier (Mycofix® Plus), (4) DON diet supplemented with a combination of 0.4 g/kg probiotic and 1.5 g/kg yeast, and (5) DON diet supplemented with a combination of a probiotic, yeast and mycotoxin detoxifier. Key results: The results showed that the DON diet significantly increased the feed conversion ratio compared with mycotoxin detoxifier and control diets. Administration of 0.4 g/kg probiotic along with 1.5 g/kg yeast to a DON-contaminated diet caused a significant enhancement of dressing percentage, leg relative weight and aspartate aminotransferase enzyme activity. The DON-contaminated diet reduced total protein, albumin, triglyceride and cholesterol concentrations, but consumption of a probiotic, yeast and mycotoxin detoxifier improved the levels of these parameters. The DON-treated birds showed a reduction in haematocrit, haemoglobin, red blood cells and blood lymphocyte percentage in comparison with control levels. The inclusion of a combination of a probiotic and yeast along with mycotoxin detoxifier diminished the increased heterophil: lymphocyte ratio by DON administration. The antibody titre against Newcastle disease virus vaccine increased by inclusion of a probiotic, yeast and Mycofix. Conclusions: In summary, a combination of a probiotic and yeast along with mycotoxin detoxifier can improve the enzyme activity, immunity and haematological attributes, which are useful for DON-contaminated diet detoxification. Implications: Dietary supplementation with a probiotic, yeast and mycotoxin detoxifier could be used as an alternative to detoxification DON in broiler chickens.

High oxidative capacity of polyunsaturated fatty acid rich oils is the main problem with their dietary application. The main objectives of this study were to determine the effects of different encapsulants and oil loading levels on nutritive value, fatty acid profile, and oxidative stability of microencapsulated fish oil powders. Four types of wall materials [glucose syrup and maltodextrin based Maillard reaction products (MRP) or equivalent non-reacted physical blends (Non-MRP)] were used along with the three levels of oil loadings (oil to wall ratio of 1:2; 1:1; 2:1 as low, medium and high oil loadings). Emulsions and resulting microencapsules were tested for fatty acid content and stability if fatty acids over time. Additionally, different oxidative parameters were used to assess the oxidative stability of the microencapsules. Results showed that high oil loading significantly increased the mean particle size of emulsions and resultant powders and concomitantly reduced microencapsulation efficiency (ME) and yield of capsules in all of the tested wall materials. However, MRP exhibited better performance. Maillard reaction products showed better protection efficiency against oil oxidation relative to non-MRP. Nevertheless, two types of MRP encapsulants showed different proficiency and glucose syrup-MRP, provided more protection than Maltodextrin-MRP. Maillard reaction had a positive correlation with the stability properties of emulsions and resulting microcapsules. Our results showed that microencapsulation with Maillard reaction products could be used as an efficient way to protect fish oil from oxidation.

Context: Interest in studying heat stress (HS) has increased significantly due to the problems associated with increasing global warming. Heat stress has very destructive effects on the health and performance of livestock. Aims: Our objective was to investigate the effects of heat stress on in vivo and in vitro ruminal metabolism in fat-tailed Iranian sheep. Methods: Fourteen intact non-lactating and non-pregnant mature fat-tailed Makoei ewes (67.5 ± 2.5 kg BW) were kept indoors for 24 h/day and randomly assigned to HS (33.0–41.0°C and a temperature–humidity index (THI) of =83 for 24 h/day) or thermoneutral (TN; 24.5 ± 2.3°C and a THI of 66.1 ± 2.5) condition in two consecutive experimental periods. At the end of first experimental period, the animals in each group were exchanged with another group. The ewes were fed a total mixed ration two times a day, composed of lucerne hay (33%) and corn silage (1:2) to meet their maintenance metabolisable energy and protein requirements. Key results: HS ewes had lower dry-matter (DM) intake than did TN ewes (P < 0.05). HS increased the in vivo DM, organic matter (OM) and neutral detergent fiber digestibility (P < 0.05), but crude protein digestibility was not affected. Total volatile fatty acid concentration and pH were not affected by HS. However, propionate molar percentage was increased and N-NH3 concentration was decreased by HS. In vitro gas production of three different tested feeds was lower in rumen fluid collected from HS than that from TN group, but DM and OM digestibility and methane emission were decreased only in the case of Orchard grass (P < 0.05). Conclusions and implications: In general, HS had detrimental effects on DM intake and in vitro nutrient digestibility but increased in vivo nutrient digestibility, and changed microbial population.