Different aspects of lactation persistency in dairy cows

Abstract

Lactation persistency (cow’s ability to maintain milk production after reaching its peak) is a very important economic characteristic in the dairy cattle production system. Different definition and functions for describing and measuring of this trait were proposed by researchers. The random regression model using Legendre polynomial was one of the common and effective methodologies for evaluation of persistency in the last decade. Several factors affecting persistency such as different characteristics of lactation curve, environment factors, reproduction traits and health status of the dairy cow. Based on different studies the heritability of this trait was low to medium and negative or positive amount of genetic correlation between persistency and total milk yield in dairy cattle is attributed to persistency measures and method of data analysis. Persistency is related with low and later peak yield and selecting cows for peak yield will improve persistency and lactation curve traits. Analysis of relationships between persistency and other functional traits show signs that genetic improvement for persistency is possible and favorable. Different aspects and relationships of persistency with various lactation and other functional traits in dairy cows are reviewed in this article.

Optimal value for the exponential term of Wilmink's function according to current Holstein lactation curves in Japan

“…From 1991 to 2018, lactation persistency increased from 93 to 95 for first lactation, from 88 to 89 for second lactation, from 85 to 88 for third lactation, from 86 to 88 for fourth lactation, and from 85 to 89 for fifth lactation. Lactation persistency tended to improve with increasing test year and was particularly high for the first lactation (Figure 4), similar to results from a previous study (Mahdi et al, 2019). The association between delayed peak lactation and increased lactation persistency is consistent with previous reports (Muir et al, 2004).…”

“…The association between delayed peak lactation and increased lactation persistency is consistent with previous reports (Muir et al, 2004). The decrease in lactation persistency with increasing parity reflects the moderate to large positive correlation between peak milk‐yield day and persistency (Mahdi et al, 2019). Milk yield in early lactation might result somewhat lower lactation persistency, because of the negative genetic correlation (−0.09) between these traits (Farhangfar & Rowlinson, 2007).…”

Prediction of persistency for day 305 of lactation at the moment of the insemination decision

“…In the current study, we only included cow and herd information in the prediction models that was available through the MmmooOgle herd management software. As persistency is a heritable trait and could be a target for selection ( 33 , 51 , 52 ) others have tried adding its breeding value to prediction models, though with little success ( 53 ). It’s worth noting that the heritability of persistency varies, influenced by factors like the definition of persistency, the breed, and the parity of the cows, with heritability values spanning the range of 0.01–0.33 ( 34 , 52 , 54 ).…”

Investigating lactation curve characteristics of dairy cows

“…Вона має більш високі значення у тварин, які мають нижчі надої та пізніше досягають пікового рівня молочної продуктивності. Проведений аналіз зв'язків між сталістю лактаційної кривої корів та іншими функціональними ознаками їхньої молочної продуктивності показав, що генетичне вдосконалення цього показника можливе та сприятливе для селекційного процесу (Torshizi et al, 2019). Оцінки коефіцієнту успадковування (h 2 ) параметру сталості лактаційної кривої корів голштинської породи протягом перших трьох лактацій мали тенденцію до зниження, головним чином через зростання величини залишкової дисперсії, і складали 0,17, 0,16 та 0,14, відповідно.…”