Behavioral, productive, reproductive and thermoregulatory performance of lactating 3/4 and 7/8 Holstein/Gir cows

• Autor(a) principal: Ferro, Diogo Alves da Costa
• Data de Publicação: 2021
• Outros Autores: Ferro, Rafael Alves da Costa, Santos, Klayto José Gonçalves dos, Santos, Aracele Pinheiro Pales dos, Taveira, Rodrigo Zaiden, Silva, Bruna Paula Alves da, Gontijo, Lídia Mendes de Aquino, Lopes, Juvenal Matheus da Cruz
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Semina. Ciências Agrárias (Online)
• Texto Completo: https://ojs.uel.br/revistas/uel/index.php/semagrarias/article/view/40378
• topic: Ambience; Dairy production; Thermotolerance.; Ambiência; Produção Leiteira; Termotolerância.

The aim of this study was to examine the behavioral, productive, reproductive and thermoregulatory performance of 3/4 and 7/8 Holstein/Gir (HG) dairy cows to identify which genetic composition suffers the least heat stress. A completely randomized design was adopted involving 20 multiparous, lactating crossbred cows from a dairy farm located in the municipality of Turvânia - GO, Brazil. During the experimental period, data on behavioral, productive, reproductive and thermoregulatory traits were collected every 15 days. Bioestat (5.0) statistical software was used for statistical analysis. The mean temperature-humidity index, ambient temperature and relative humidity obtained throughout the experimental period were 74.45, 30.51 ºC and 63.64%, respectively. In terms of reproductive performance, there was a significant difference (p < 0.05) between the genetic compositions for the time from calving to first service, with a longer period shown by the animals with greater Holstein breed genetic composition. Service period and calving interval differed significantly (p < 0.05) during the experimental period between the genetic compositions. A significant difference (p < 0.05) was also detected between the compositions for respiratory rate, with higher values observed in the animals with higher European genetic composition. Benezra thermal comfort index also differed significantly (p < 0.05), with the 7/8 HG animals showing a higher value. Lactating cows with a 7/8 HG genetic composition achieved better results in milk production, whereas those with 3/4 HG genetic composition showed superiority in milk fat composition and reproductive and thermoregulatory performance, indicating greater adaptation to the climatic conditions of the region.