Abstract

The study aimed to investigate the principal breeding factors influencing milk yield and reproduction in the Red Chittagong cattle (RCC). Retrospective records of a total of 20 dairy cows from the 1st to the 2nd parities were collected from the record sheet from January 2020 to June 2022. Results indicated that birth weight of the RCC was 7.5 higher (P=0.023) in parity 2 when compared with parity 1. Accordingly, total milk yield per lactation was 10.2 higher (P=0.004) in parity 2 in comparison with parity 1. Age at first service was 34.7 higher (P=0.001) in parity 2 compared with parity 1. Accordingly, age at first conception was 38.3 higher (P=0.001) in parity 2 compared with parity 1. The dry period was 22.8 higher (P=0.001) in parity 1 compared with parity 2. Age at first service was 18.3 higher (P=0.014) in natural service (NS) compared with artificial insemination (AI). Age at first conception was 16.5 higher (P=0.023) in NS compared with AI. Post-partum period was 11.9 higher (P=0.008) in AI compared with NS. Days open was 8.9 higher (P=0.018) in AI compared with NS. Calving interval was 2.9 higher (P=0.006) in AI compared with NS. An increased probability of infertility was associated with NS compared with AI. Birth weight of the calf and dry period of the dam were negatively correlated while live weight and post-partum period of the dam were positively correlated milk yield at the expense of reproductive health. A decreased probability of milk fever, mastitis, metritis and infertility was associated with increased milk yield. Principal component analysis revealed that days open, calving interval and service per conception were the principal eigenvectors determining performance of RCC. Overall, RCC performed better in the 2nd parity compared with the 1st parity. Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/. © The Author(s) 2024