The Effect of Feeding Management and Culling of Cows on the Lactation Curves and Milk Production of Primiparous Dairy Cows

Abstract

The study attempted to estimate the lactation curves of primiparous dairy cows in relation to their feeding management. Therefore, the first aim of the study was to determine and compare the lactation curves of primiparous dairy cows using Wood’s model and to estimate the association between the lactation curves and feeding management. The second objective was to investigate the effect of the culling rate on improvement in the milk yield of primiparous dairy herds. The study was conducted on four commercial dairy farms of Polish Holstein–Friesian cows using different feeding systems (TMR—total mixed ration and PMR—partial mixed ration) and management (T1—one TMR throughout lactation; P1—one PMR throughout lactation; T2 and T3—three feed periods such as FRESH, TMR I and TMR II according to days in milk). The data used for the study were obtained from monthly milk performance evaluations of 1662 primiparous cows conducted by the Polish Federation of Cattle Breeding and Dairy Farmers throughout the year 2015. Wood’s lactation model was used to plot curves for milk yield, fat and protein content, lactose content, and milk urea contents. The highest milk yield for the whole lactation and in the peak lactation phase was recorded for cows in herd T1. This herd reached peak lactation on day 105 of milking, with an average milk yield of 42.1 kg, which was about 5 kg more milk than in the other herds. The study showed that the culling of primiparous cows in herd T1 after 30, 60 and 90 days of lactation prevented a significant reduction in milk yield in a 305-day lactation. It also increased average milk production by 1586.9 kg per primiparous dairy cow.

Characteristics of Lactation Curve and Reproduction in Dairy Cattle

“…Similar estimates of heritability were obtained by Radjabalizadeh et al (2022). This is due to the fact that the lactation activity of cows is influenced by many environmental factors, primarily the feeding system (Różańska-Zawieja et al, 2021). Marumo et al (2022) proved the influence of temperature fluctuations indoors and outdoors on the lactation activity of cows.…”

How does reproduction account for dairy farm sustainability?

“…All breeds increased milk yield, especially Girolando (+79%) and Gyr cows (+73%). Fertility improvements ( Bragança and Zangirolamo, 2018 ), culling rate ( De Vries and Marcondes, 2020 ; Różańska-Zawieja et al, 2021 ), feeding management ( Różańska-Zawieja et al, 2021 ), mortality reduction ( Yanga and Jaja, 2021 ), and age to first calving ( Eastham et al, 2018 ) can explain these findings.…”

Lactation curve modelling in dairy production

“…Lactation curve modeling at cow level LCC serve as a crucial metric for evaluating milk production performance at the cow level and have diverse applications in various dairy research fields. They are intensely used in research related to feed composition and feeding systems (Chen et al, 2016;van Hoeij et al, 2017;Różańska-Zawieja et al, 2021). For instance, the effect of dietary energy source and dietary energy level on LCC were studied (van Hoeij et al, 2017).…”