Investigation of Reciprocal Cross Effects in F2 Nellore–Angus Calves
Round 1
Reviewer 1 Report
In my opinion, this is an interesting paper with result highly transferable to the sector in tropical and subtropical latitude. Anyway, I would like to have in the literature papers in this context using as environmental creole resources such as Long Horn or Florida´s Cracker instead of zebu. It would be a way to save and disseminate the American local breeds maintaining a good meat quality in the cross-breed carcasses.
Very few technical criticisms are possible because this paper is excellently written, the design is correct, as the statistical analysis. Results are clear and consistent, and they are perfectly discussed. Conclusions are extremely applicable, and References are correctly updated.
Summarizing, this is a simple and concrete research which outputs are very important to the meat production sector, for this reason, I recommend the acceptance of the manuscript in its present form
Author Response
Thank you for your thorough review of the article.
We are very interested in Longhorn and Florida Cracker cattle, and their crosses. We have not evaluated any of these crosses with Angus or with Zebu. You are welcome to contact me in the future if you want to have more discussion.
Reviewer 2 Report
The ruminants-1852918 entitled "Investigation of Reciprocal Cross Effects in F2 Nellore-Angus Calves" is an interesting study and written well by the authors. The objectives of this study were to analyze calf performance traits and sex ratio frequencies in reciprocal Bos indicus-Bos taurus F2 Nellore-Angus calves (n = 539). The F2 calves were produced using reciprocal Angus-sired (AN) and Nellore-sired (NA) F1 sires and F1 dams, resulting in four F2 cross types. Calf weight traits were analyzed using mixed models. Deviations from 50% calf sex ratios were tested against expected binomial thresholds. Dam type influenced Julian birth date (P < 0.05) with calves from AN cows born 5 to 6 days earlier than calves from NA cows. Sire type and dam type affected birth weight (P < 0.05) with calves from NA parents about 2.5 kg heavier than those from AN parents; weaning weight did not differ for parent F1 type. However, an interaction between sire and dam types affected weaning weight (P = 0.038) where AN x AN calves were 5 to 8 kg lighter than other crosses. Sire type influenced calf sex distribution at birth (P = 0.036) and weaning (P = 0.026) with NA sires producing over 66% male calves. These results suggest birth weight reciprocal differences due to parental line of descent typically observed among F1 Bos indicus-Bos taurus crosses can persist in subsequent generations. However, the following points to be addressed to improve the quality of the manuscript：
For the assessment software and statistical methods used in the material approach, it is recommended to add relevant references.
Please check that the horizontal coordinates in Figure 1 are written correctly.
Author Response
Thank you for your thorough review of the article.
We did not cite the software package because the author guidelines (and other published manuscripts) for this journal state these in the materials and methods.
The caption and description for Figure 1 has been modified to explain the horizontal coordinates.
