Current research illustrates that the addition of MOS to birds at different week interval have a positive effect on feed intake. Results showed that birds fed with feed T6 (800g/ton of MOS) consumed significantly highest average FI than negative and positive control group. Similar outcomes were observed by Zakeri and Kashefi (2011) as supplementation of MOS during 1st week of age has greater feed intake then the control group. In the same way, Iji et al. (2001) revealed that addition of MOS to diet enhanced the FI of birds as compared to the control group. In contrast, Abdelwahid et al. (2017) and Koc et al. (2010) observed that MOS supplemented had no difference on FI.
It was observed that addition of MOS to birds feed at different week interval had a positive effect on average weekly weight gain. Same outcomes were found by Abdelwahid et al. (2017), as he observed that supplementation of MOS at 0.2% significantly increased the BWG in broiler chicks during 0-21 days of age. Similarly, Shahir et al. (2014) found that MOS supplemented group showed better WG than control group and probiotic group for 1-21 days. In contrast, according to the study of Abdelwahid et al. (2017) and Koc et al. (2010) no significant difference was observed in WG during 1-21 days of age between MOS supplemented and positive control group.
The present study showed that the supplementation of MOS to birds at different week interval had a positive effect on weekly FCR. The results of Bozkurt et al. (2008) were similar to this study, they observed better FCR in MOS added group than all other groups (negative control, positive control with AGP and dextran oligosaccharide) during 0-21 days of age. Similarly, results of Koc et al. (2010) were also in line to our study, as they recorded the better FCR in MOS supplemented group. However, results presented in the study of Abdelwahid et al. (2017) contrasted with our study as they reported that there was no significant improvement in FCR due to supplementation of MOS.
Supplementation of MOS significantly affected the length of intestinal sections. At the end of trial, birds supplemented with T2 group have highest length of duodenum followed by T4. Similar results were found by Padihari et al. (2014) as they observed that addition of MOS at a level of 500g/ton significantly increased the duodenum length as compared to negative and positive control groups. Supplementation of MOS didn’t show any effect on jejunum length (Dimitroglou et al. 2010; Padihari et al. 2014).
Addition of MOS to broiler chick feed significantly affected the histomorphology of jejunum and ilium. At the end of trial, birds of group T3 and T6 showed significantly highest villus height in jejunum. In the same way, Mostafa et al. (2015) found that supplementation of MOS had positive effect on villus height in jejunum and ilium. In contrast to our results, Abudabos et al. (2015) observed that supplementation of MOS had no significant effect on villus height in jejunum. Supplementation of MOS has no effect on villus height and crypt depth in ilium. In contrast to our results, Biswas et al. (2018) found that addition of MOS to basal diet had significant effect on crypt depth in ilium. Supplementation of MOS at different inclusion rates had no effect on number of goblet cell per villus but these results were significantly superior and inferior to negative and positive control groups, respectively. In contrast to our result Baurhoo et al. (2009) found that MOS had significantly affected the goblet cell number.
Supplementation of MOS significantly affected the antibody titer against NDV. Birds fed on T6 and T5 showed highest antibody titer against NDV. Lowest values for titer were found in negative control group. Similar results were also published by Shahir et al. (2014) as they observed that MOS supplemented group gained higher antibody titer against NDV as compared to control group but lower than probiotic group. Results of Muhammad et al. (2020) were also similar to our study they recorded that MOS supplemented group has significantly higher antibody titer against NDV as than control group but lower than probiotic group. Similar results were also found by Waqas et al. (2019) as MOS supplemented group showed higher antibody titer against NDV as compared to control group.