Exploratory investigation of animal- and environment-related factors influencing colostrum intake patterns within the first 24 h postpartum in dam-bound rearing systems

Introduction: An adequate intake of colostrum is essential for neonatal calves, as it plays a critical role in the devel- opment of the immune system and supports growth during the early stages of life [1]. In conventional rearing systems, colostrum is administered via bottle or bucket feeding to monitor the amount consumed. In contrast, dam-rearing systems present challenges in monitoring colostrum consumption at the udder, as intake is influenced by a variety of factors dependent on both the calf and the dam [2; 3]. This study examined the influence of various animal- and envi- ronmental factors on the colostrum intake patterns within the first 24 h postpartum (pp) in dam-bound rearing systems. The objective was to identify key determinants that contribute to the success of the suckling process. Methods: The study was conducted on the TUM experimental farm Veitshof and included 13 Brown Swiss cows (primiparous n = 4; multiparous n = 9) and their calves. After birth, all calves remained with their dams. Cow-related data included an evaluation of the birth process using a dystocia scoring system ranging from normal to difficult births, as well as the duration of parturition and parity. Additionally, udder anatomy was assessed using 15 quantitative mea- surement points and 3 qualitative scorings, based on breed-specific exterior traits for Brown Swiss cows. Colostrum was sampled after birth and Brix was measured using a refractometer. Maternal and calf behavior (16 behavioral aspects) related to the colostrum intake pattern were analyzed using video recordings and a structured observation protocol, focusing on interactions that influence the calf’s ability to access and consume colostrum. Searching time reflected the time from birth until the calf successfully located the udder, while suckling duration indicated the time span of apparent milk intake. Human assistance served as an indicator of management intervention, and calf activity summarized locomotion (standing and walking). Maternal licking events were considered a proxy for dam–calf care by the cow. Calf-related data comprised birth weight and 20 anatomical body measurements, such as withers height, sacrum height, etc., which were recorded immediately after birth. Environmental data included continuous monitoring of ambient temperature and relative humidity. Statistical analysis was performed using RStudio 4.4.2 (R Core Team, Vienna, Austria). Descriptive statistics and Spearman correlation coefficients were calculated to identify key factors influencing the colostrum intake patterns within the first 24 h pp. Results: Within the first 24 h pp, calves spent on average 40.12 ± 4.98 min searching for the udder and 30.36 ± 7.32 min suckling. The average number of suckling events was 19 ± 3 in the first 24 h pp. Three calves required human assistance to successfully access milk from the udder within the first 24 h pp. Correlation analysis revealed that udder searching time was associated with calf activity and lying (r = 0.53 vs. -0.40, p ≤ 0.05), the number of maternal licking events (r = 0.36, p ≤ 0.05), and udder depth (r = 0.24, p ≤ 0.05). Regarding total suckling duration, correlations were found with calf activity (r = 0.37, p ≤ 0.05), parity of the dam (r = -0.29, p ≤ 0.05), and teat length (r = -0.23, p ≤ 0.05). Suckling duration and events were positively (r = 0.98, p ≤ 0.05) correlated. Udder searching time showed no or only weak (r ≤ 0.16) correlations with environmental variables. Conclusions: Multifactorial aspects, such as calf vitality, maternal behavior, and udder conformation influenced the success of colostrum intake (searching time and suckling duration) in dam-bound rearing systems. Calves require substantial time to locate and access the udder. These results highlight the importance of monitoring and supporting early calf-dam interactions, and warrant confirmation through further research. Bibliographical references [1] Hammon, H. M., Liermann, W., Frieten, D., and Koch, C. (2020). Review: Importance of colostrum supply and milk feeding inten- sity on gastrointestinal and systemic development in calves. Animal. 14(S1), 133-143. https://doi.org/10.1017/S1751731119003148 [2] Barrier, A. C., Haskell, M. J., Birch, S., Bagnall, A., Bell, D. J., Dickinson, J., Macrae, A. I., and Dwyer, C. M. (2013). The impact of dystocia on dairy calf health, welfare, performance and survival. Vet. J. 195: 86–90. https://doi.org/10.1016/j.tvjl.2012.07.031 [3] Metz, J. (1984). Behaviour and state of health of cows and calves kept together or separately in the post-partum period. Proc. Int. Congr. Appl. Ethol. 16, 385–394     «

Introduction: An adequate intake of colostrum is essential for neonatal calves, as it plays a critical role in the devel- opment of the immune system and supports growth during the early stages of life [1]. In conventional rearing systems, colostrum is administered via bottle or bucket feeding to monitor the amount consumed. In contrast, dam-rearing systems present challenges in monitoring colostrum consumption at the udder, as intake is influenced by a variety of factors dependent on both t...     »