The Deviation between Dairy Cow Metabolizable Energy Requirements and Pasture Supply on a Dairy Farm Using Proximal Hyperspectral Sensing

Round 1

Reviewer 1 Report

A paper comparing estimated and observed feed intake in pasture based dairy cow production, and comparing feed intake to estimated feed requirements for the cows. 
Very many components are taken into account in the calculations, making it a challenge to understand their complexity. I must admit that I am not a cow nutritionist, and that may explain my limited understanding of some parts of the paper.
Some more detail on how dairy cow registrations are done in New Zealand could be helpful for a foreign reader (how often individual cow milk production was registered and how and how often the 'vat' information was registered). Some of this is done in the Discussion, but could have been included in the Introduction and Material and Methods. (Why wasn't the amount of milk consumed by calves and excluded from the vat for treated/diseased cows corrected for ? - Confer the Discussion - .) 
Could the Discussion have been revised with more focus on the outstanding results of the study (- more 'marketing' of results - ) ? - The last part of the Discussion is more interesting than the first ...
When you find that the variation within cows is greater than between cows, do you consider that any measurement error etc would appear as within cows ?

Comments related to specific lines in the manuscript: 

I don't understand well what is 'opposite' in the pasture versus indoor TMR feeding (line 36 )

Consider rewriting:
Various energy feeding 60
systems are currently adopted in Europe (INRA [10]; AFRC [11]) and North America 61
(NRC [12]), being the AFRC [11] also widely used to estimate energy requirements of 62
grazing dairy cows in New Zealand.

Missing comma ;
while in 2017-18, rape (Brassica napus), maize silage (Zea mays), tapioca (Manihot esculenta) 97

Not consistant placing of spaces before/after +s (lines 155-156) :
Yt(c:y)= (β0P0+ β 1P1 + β 2P2+ β3P3) + (α0P0+ α1P1 + α2P2+ α3P3) +et(c:y) (3)

where x is the number of days after calving standardised to a maximum lactation length 163 ->
where x is a function of the number of days after calving standardised to a maximum lactation length 163

Why do you need to assume the cow was in the herd as said in 171-173 ?  I suppose there was a MY record for the cow if she was there ...

I am not in a position to verify equations (6) - (9) , but they seem a bit inconsistent : Why is km with a non-subscripted m, while the rest are subscripted ? 

There is a missing end bracket in equation 12 :
Fm= 1 (0.53 (LWd / 1.08)0.67 (12)  

How is FL calculated 'as a multiple of MEm' ? (line 214)

What does it mean that a 5% tolerance was considered ? :
The difference between herd MEt 217
estimated requirements and the ME supplied daily in the diet was calculated considering 218
a ±5% tolerance on the ME supply. 

The i and j in equation (23) should be switched to correspond to the following text.

Are cows assumed independent, or is for example genetic relationship considered ? (239-241)

What does SD per cow (in brackets)  for 'Milk vat' mean in Table 2 ? The mean is not a simple division by 260 (or 255) ... Maybe explain better how this was done in : 
descriptive statistics of milk in the vat calculated on a per cow basis are presented between brackets. 251

Possibly explain what 'Milk vat' implies in your context for people from other parts of the world ...

Is 'RPE' standard notation, or should it be explained (line 274) ? You define it in Figure 2 text. But is it clearly defined  ? I don't know exactly.

Table 3 : In the header T should be a subscript. 

Consider rewriting lines 416-419. It's hard to grasp :
On the other hand, the 416
ME measured in herbage represented, in average, 73% of the ME supplied in the diet of 417
cows, however, this figure was based on assumptions on the ME content of supplemen- 418
tary feeds which might have also led to error in the estimation of dietary ME supply. 

One 'in' too much ? :
feeding strategies in in pasture-based dairy farm systems. 455

Author Response

Dear Editor,

Please Find Responses to Reviewer 1 attached.

Kind regards

The Authors

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors,

The manuscript (agriculture- 1130972) presented for review is interesting and I think it needs a minor correction.

Authors, Please note and address the following comments:

Title: The title of the manuscript is very complicated, I suggest changing the title, but I haven’t any idea how to do it.

Abstract: The conclusions of the abstract are different from those of chapter Conclusion. I suggest unify it.

Results: I do not understand, what is mean N (samples) presented in Table 2. Data came from two production seasons (22 months), and from 260 (in the second season 255) cows. Average MY (milk yield; L/day) is 15.6 in the 2016-2017 production season (e.g. about  330 production days, 260 cows, N=2296), and 16.3 in the 2017-2018 production season (e.g. about 330 production days, 255 cows, N=1933). Probably I am wrong, but now in my opinion data does not result from all cows. Can the authors explain what N stands for? Below Table 2 is the explanation that N=number of samples. 

Conclusion

Could the authors indicate in Chapter Conclusion further directions for this kind of research?

References

Authors Please check the correctness of the citation of references by requirements of the Agriculture Journal. I have the impression that in some of the references authors didn't write properly.

Reviewer

Author Response

Dear Editor,

Please Find Responses to Reviewer 2 attached.

Kind regards

The Authors

Author Response File: Author Response.docx