Effects of Rubber Seed Kernel Fermented with Yeast on Feed Utilization, Rumen Fermentation and Microbial Protein Synthesis in Dairy Heifers
, Thanaporn Ouppamong 2, Pichad Khejornsart 3, Anusorn Cherdthong 4, Metha Wanapat 4, Sineenart Polyorach 5, Chatchai Kaewpila 2, Sungchhang Kang 6 and Pongsatorn Gunun 2,*
Round 1
Reviewer 1 Report
Abstract and introduction were presented correctly, as well as the methodological part, although it may be worth describing the scope of the analyzes in more detail.
Line 23-26 (abstract): „Yeast-fermented rubber seed kernel (YERSEK) was substituted for soybean meal in ruminant diets and was shown to reduce feed costs. To evaluate the effect of YERSEK on feed intake, digestibility, rumen fermentation and microbial protein synthesis in dairy heifers”, I suggest to remove the part: „...and was shown to reduce feed costs”, because it is already an effect, so maybe in conclusions . New wording: „The sentence „Yeast-fermented rubber seed kernel (YERSEK) was substituted for soybean meal in ruminant diets to evaluate the effect of YERSEK on feed intake, digestibility, rumen fermentation and microbial protein synthesis in dairy heifers”.
Line 55: some mess with parentheses, similarly in line 76 and 87-90, and on in the text.
Line 64-67: why repeat three times „in the rumen”? Once, at the end of the sentence, is enough.
The first sentence in subchapter 3.2 is unnecessary, it is a repetition of the table title, a reference to the table can be included in the next sentence. Similarly in section 3.3 and 3.4.
The results were described in just a few sentences, including repeated table titles. The small amount of text did not allow the all tables to be included in this part of the work.
Line 210 (discussion): values from table 2 are presented here, maybe in the results chapter?
Line 219: „The CP content increase in YERSEK in this study could be estimated using the following formula…”, maybe in the methodical part?
Line 288 (conclusions): where the value of 107g/kgDM comes from, it is not visible in the tables and in the text.
In the discussion, reference was made to only a few issues presented in the cited literature, no more complete explanation of the obtained values was undertaken.
The work requires the indicated corrections and additions, which will allow to decide whether to publish it.
Author Response
Responses to Reviewer:
Reviewer: 1
Comments and Suggestions for Authors
Abstract and introduction were presented correctly, as well as the methodological part, although it may be worth describing the scope of the analyzes in more detail.
Line 23-26 (abstract): „Yeast-fermented rubber seed kernel (YERSEK) was substituted for soybean meal in ruminant diets and was shown to reduce feed costs. To evaluate the effect of YERSEK on feed intake, digestibility, rumen fermentation and microbial protein synthesis in dairy heifers”, I suggest to remove the part: „...and was shown to reduce feed costs”, because it is already an effect, so maybe in conclusions . New wording: „The sentence „Yeast-fermented rubber seed kernel (YERSEK) was substituted for soybean meal in ruminant diets to evaluate the effect of YERSEK on feed intake, digestibility, rumen fermentation and microbial protein synthesis in dairy heifers”.
-Line 23-25: Already changed, please see in text.
Line 55: some mess with parentheses, similarly in line 76 and 87-90, and on in the text.
-Line 39 and 83-91: Already changed, please see in text.
Line 64-67: why repeat three times „in the rumen”? Once, at the end of the sentence, is enough.
The first sentence in subchapter 3.2 is unnecessary, it is a repetition of the table title, a reference to the table can be included in the next sentence. Similarly in section 3.3 and 3.4.
The results were described in just a few sentences, including repeated table titles. The small amount of text did not allow the all tables to be included in this part of the work.
-Line 64-66: Already changed to “It is known to stimulate the growth of fiber digesting bacteria, stabilize rumen pH by stimulating the population of lactate-utilizing bacteria, support the proliferation of other microorganisms [7,8] and may also increase microbial protein synthesis in the rumen.”, please see in text.
Line 210 (discussion): values from table 2 are presented here, maybe in the results chapter?
-Line 172-173: Already changed to “The RSK contained CP at 212 g/kg DM, while the YERSEK product contained CP at 336 g/kg DM, an increase in CP of 124 g/kg DM. “, please see in text.
Line 219: The CP content increase in YERSEK in this study could be estimated using the following formula…”, maybe in the methodical part?
-Line 93-97: Already changed, please see in text.
Line 288 (conclusions): where the value of 107g/kgDM comes from, it is not visible in the tables and in the text.
-Already deleted, please see in text.
In the discussion, reference was made to only a few issues presented in the cited literature, no more complete explanation of the obtained values was undertaken.
The work requires the indicated corrections and additions, which will allow to decide whether to publish it.
-I already add reference in the discussion section, please see in text.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Line 181 to 183: “Increasing levels of YERSEK supplementation meant the DM intake of rice straw and total intake was decreased linearly (p < 0.05), the EE intake was increased linearly (p < 0.01), but the intake of NDF and ADF was decreased linearly (P > 0.05)”. Replace to: Increasing levels of YERSEK supplementation meant the DM intake of rice straw and total intake was decreased linearly (p < 0.05), the EE intake was increased linearly (p < 0.01), but the intake of NDF and ADF was decreased linearly (P < 0.05).
Line 184 to 185: “Increasing levels of YERSEK did not change the digestibility of DM, OM, CP, NDF and ADF (p > 0.05), except for the digestibility of EE (p < 0.01)”. Include information about the effects of YERSEK inclusion in the EE digestibility.
Line 196 to 198: “The direct count of bacterial, protozoal and fungal zoospores population was not significantly different between treatments of increasing 197 YERSEK supplementation (p > 0.05) as shown in Table 5”. Replace t: The direct count of bacterial, protozoal and fungal 196 zoospores population was not significantly different among treatments of increasing YERSEK supplementation (p > 0.05) as shown in Table 5.
Considering the information’s of Line 93: “Final product is stored in plastic bag for mixing in the concentrate” and Table 02, Line 186. Were the data referring to the chemical composition of YERSEK, the results of chemical analyses carried out on samples collected after the preparation of the mixtures, or were they from samples evaluated throughout the experimental period?
Considering the description of YERSEK production (Line 85 to 93), justify the information: “The reduction in NDF and ADF content of YERSEK could be due to the secretion of various enzymes, which degraded the hemicellulose and cellulose”. Line 224 to 225”. YERSEK production took place in a short time, the product is dried and stored. Explain how enzymatic activities that promote a reduction in the fibrous fraction contents can occur in this condition. What is the dry matter content of YERSEK ?
Line 287: Conclusion: “Inclusion of YERSEK affected the digestible nutrient intake levels, rumen fermentation and microbial protein synthesis? Data from Table 01 support the discussion about the chemical composition of diets, mainly crude protein and gross energy associated to the intake of nutrients, CP and gross and digestible energy are important to explain your results.
Comments for author File: Comments.pdf
Author Response
Reviewer: 2
Comments and Suggestions for Authors
Line 181 to 183: “Increasing levels of YERSEK supplementation meant the DM intake of rice straw and total intake was decreased linearly (p < 0.05), the EE intake was increased linearly (p < 0.01), but the intake of NDF and ADF was decreased linearly (P > 0.05)”. Replace to: Increasing levels of YERSEK supplementation meant the DM intake of rice straw and total intake was decreased linearly (p < 0.05), the EE intake was increased linearly (p < 0.01), but the intake of NDF and ADF was decreased linearly (P < 0.05).
-Line 176-178: Already changed, please see in text.
Line 184 to 185: “Increasing levels of YERSEK did not change the digestibility of DM, OM, CP, NDF and ADF (p > 0.05), except for the digestibility of EE (p < 0.01)”. Include information about the effects of YERSEK inclusion in the EE digestibility.
-Line 180-181: Already changed to “The EE digestibility were increased linearly (p < 0.01) with an increase of YERSEK in the diet and was highest when inclusion of YERSEK at 150 g/kg DM.”, please see in text.
Line 196 to 198: “The direct count of bacterial, protozoal and fungal zoospores population was not significantly different between treatments of increasing 197 YERSEK supplementation (p > 0.05) as shown in Table 5”. Replace t: The direct count of bacterial, protozoal and fungal 196 zoospores population was not significantly different among treatments of increasing YERSEK supplementation (p > 0.05) as shown in Table 5.
-Line 195-197: Already changed, please see in text.
Considering the information’s of Line 93: “Final product is stored in plastic bag for mixing in the concentrate” and Table 02, Line 186. Were the data referring to the chemical composition of YERSEK, the results of chemical analyses carried out on samples collected after the preparation of the mixtures, or were they from samples evaluated throughout the experimental period?
-Line 91-92: Already changed to “Final product is stored in plastic bag and analyzed for chemical content., please see in text.
Considering the description of YERSEK production (Line 85 to 93), justify the information: “The reduction in NDF and ADF content of YERSEK could be due to the secretion of various enzymes, which degraded the hemicellulose and cellulose”. Line 224 to 225”. YERSEK production took place in a short time, the product is dried and stored. Explain how enzymatic activities that promote a reduction in the fibrous fraction contents can occur in this condition. What is the dry matter content of YERSEK ?
-Line 210-214: Already changed to “The reduction in the NDF and ADF content of YERSEK could be due to two possible reasons. Firstly, the ingredients including yeast, sugars, molasses and urea for transformation of RSK to YERSEK were reduce in fiber content, resulting in a dilution of NDF and ADF contents in YERSEK. Secondly, the secretion of various enzymes by yeasts and natural cellulase-producting microbes might degrade the hemicellulose and cellulose of YERSEK.”, please see in text.
Line 287: Conclusion: “Inclusion of YERSEK affected the digestible nutrient intake levels, rumen fermentation and microbial protein synthesis? Data from Table 01 support the discussion about the chemical composition of diets, mainly crude protein and gross energy associated to the intake of nutrients, CP and gross and digestible energy are important to explain your results.
-Line 231-237: Already changed to “This study also demonstrated that the inclusion of YERSEK in concentrate diets decreased the intake of DM, NDF and ADF. It has often been observed that the negative effect of fat on intake could be due to a low palatability of added fat [29,30,31], so levels of unsaturated fatty acids in YERSEK could be affected by the rice straw intake in dairy heifers. In addition, increasing levels of YERSEK in concentrate increased EE content from 8 to 72 g/kg DM and GE from 16.1 to 17.3 MJ/kg DM. Therefore, it was expected that YERSEK would increase energy supply and nutrient availability and also reduce fiber intake in the current study.”, please see in text.
Author Response File: Author Response.pdf
