Factors Affecting Milk Flow Traits in Dairy Cows: Results of a Field Study

Abstract

The study of milk flow curves provides useful information for enhancing milking efficiency and protecting udder health by adapting milking machine and milking procedures to the physiological requirements of the cow. The aim of this experiment was to investigate, using field data, the relationships among traits of the milk flow curves, their sources of variation, and milking performances in terms of milk production, machine-on time, and udder health. A total of 2,486 milk flow curves of the whole udder were collected in 82 Italian Holstein-Friesian dairy herds in the Lombardy region of Italy. Approximately one-third (35.1%) of milk flow curves were classified as bimodal. Most flow characteristics were influenced by lactation number, days in milk, and peak flow but also strongly affected by premilking operations. Proper udder preparation, including forestripping and predipping, resulted in better milking performances compared with poor preparation, with greater milk yield per milking, shorter milking time, and lesser bimodality. Premilking delay time, between the start of teat stimulation and cup attachment, affected milking time significantly: The shortest milking time was obtained for a range of delay time between 1 and 60 s. As the delay time increased, the percentage of bimodality dropped significantly. Increasing the number of clusters per operator led to greater percentages of bimodal curves. The greater somatic cell count of cows with bimodal curves supports the hypothesis of the negative effect of bimodality on udder health and indicates the importance of avoiding its occurrence using proper pre-milking procedures.

Comparison of the effects of quarter-individual and conventional milking systems on milkability traits

“…of both systems were used according to the indication of the manufacturers and were not changed during the trial period. Sandrucci et al (2007) ascertained a HMF of 3.8±1.2 kg/min which was in agreement with the findings of the present study. Higher values of HMF with 4.49 kg/min and DMG with 2.84 kg/min, in comparison with our study, were found by Strapák et al (2009) at nearly the same level of MGG (15.63 kg).…”

“…The results showed that the milk letdown started earlier at the trial group milked quarter-individually. Sandrucci et al (2007) described a short tAN (0.89±0.47 min) that showed a wide variability similar to the present results for cows milked conventionally. Pre-stimulation positively influences the parameters of milk flow and therefore the efficiency of milk removal (Tančin et al 2007a).…”

“…In comparison with multiparous cows, the mammary gland is usually characterized by a smaller total milk yield (MGG) (Pfeilsticker et al 1996). They show a lower tPL and higher percentage of bimodal curves (Dodenhoff et al 1999, Sandrucci et al 2007. Bimodal milk flow curves imply a non-continuous milk flow at the beginning of milking.…”

“…During milking, milkability is described by milk flow traits which provide useful information about the efficiency and adequacy of milk release, milking process and milking machine settings (Zucali et al 2009). Among other things, the shape of milk flow curves is affected by milking conditions (Rittershaus et al 2002, Sandrucci et al 2007. Tančin et al (2006) reported that morning or evening milking significantly influenced all measured milk flow traits because of different milking intervals.…”

Management factors and cow traits influencing milk somatic cell counts and teat hyperkeratosis during different seasons

“…Furthermore, pre-milking preparation is essential to obtain a continuous and rapid milk removal of cisternal and alveolar milk and to avoid prolongation of milking time with consequent risk for udder health (Sandrucci et al, 2007) and teat-end callosity development (Neijenhuis et al, 2000).…”