Publicação
Influence of metabolic stress in bovine fetal development : an allometric study
| Resumo: | Dairy cows go through great metabolic change during the transition period, with several detrimental side effects on health and productivity. The possibility that the stress they undertake on the final phase of gestation can also influence the unborn calf or even have carryover effects that will impact him after birth is not one that should be ignored. The main goal of this study was to determine if calves born from metabolic stressed cows prioritized the development of vital organs, brain and heart specifically, over the development of the long bones, more precisely the radius-ulna and the metatarsus. Additionally, differences between countries, particularly environmental, were also considered as a possible aggravator of metabolic stress and, consequently, of allometric fetal development. For the purposes of this study, the head diameter and circumference (HD and HC, respectively), chest circumference (HG), forearm and metatarsal lengths (FL and ML, respectively), hip and shoulder width (HW and SW, respectively), height (WH) and diagonal length (DL) of 171 newborn Holstein Friesian calves from one farm in Portugal and two farms in Belgium were measured with callipers and a measuring tape. The dam’s milk production for the year (M305d), parity and gemelarity, as well as the season when the measurements were performed, were also registered. Measurement ratios (HC/ML, HC/FL, HD/ML, HD/FL, HG/ML and HG/FL) were used as an indicator of prenatal allometric growth and analysed against the data obtained from the mothers. Some significant correlations were evidenced (P<0.05) in the belgian calves, between the ratios with parity and season, demonstrating a tendency towards higher ratios with the increase of these two variables. However, the portuguese calves supported none of these results. This discrepancy obtained from the analysis of the portuguese and belgian calves, probably the result of an insufficient sample size, led us to believe that the conclusions drawn from this study are most likely premature and that further studies should be conducted in order to clarify them. Subsequently, the relation between metabolic stress and fetal development also remains unclear and should be the subject of further investigation. |
|---|---|
| Autores principais: | Goulão, João Pedro Pinto |
| Assunto: | Metabolic stress transition period negative energy balance dairy cattle allometry Stress metabólico período de transição balanço energético negativo vacas leiteiras alometria |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Dairy cows go through great metabolic change during the transition period, with several detrimental side effects on health and productivity. The possibility that the stress they undertake on the final phase of gestation can also influence the unborn calf or even have carryover effects that will impact him after birth is not one that should be ignored. The main goal of this study was to determine if calves born from metabolic stressed cows prioritized the development of vital organs, brain and heart specifically, over the development of the long bones, more precisely the radius-ulna and the metatarsus. Additionally, differences between countries, particularly environmental, were also considered as a possible aggravator of metabolic stress and, consequently, of allometric fetal development. For the purposes of this study, the head diameter and circumference (HD and HC, respectively), chest circumference (HG), forearm and metatarsal lengths (FL and ML, respectively), hip and shoulder width (HW and SW, respectively), height (WH) and diagonal length (DL) of 171 newborn Holstein Friesian calves from one farm in Portugal and two farms in Belgium were measured with callipers and a measuring tape. The dam’s milk production for the year (M305d), parity and gemelarity, as well as the season when the measurements were performed, were also registered. Measurement ratios (HC/ML, HC/FL, HD/ML, HD/FL, HG/ML and HG/FL) were used as an indicator of prenatal allometric growth and analysed against the data obtained from the mothers. Some significant correlations were evidenced (P<0.05) in the belgian calves, between the ratios with parity and season, demonstrating a tendency towards higher ratios with the increase of these two variables. However, the portuguese calves supported none of these results. This discrepancy obtained from the analysis of the portuguese and belgian calves, probably the result of an insufficient sample size, led us to believe that the conclusions drawn from this study are most likely premature and that further studies should be conducted in order to clarify them. Subsequently, the relation between metabolic stress and fetal development also remains unclear and should be the subject of further investigation. |
|---|