MILKABILITY OF COWS - RELATIONSHIPS WITH CERTAIN TEAT CHARACTERISTICS

Relationships between certain teat characteristics and milkability wer e studied in 30 French Friesian black and white cows. Milking characte ristics were recorded separately for each quarter Using relatively sim ple equipment, pressures and suctions of several types were applied in order to determine certain elastic properties of the teat tip. Milkin g times and flow rates were higher for the hindquarters than for the f orequarters (P < 0.001). This was due to the antero-posterior disequil ibrium as 60% of the milk was stored in the hindquarters. In addition, some results showed that rear-teats were easier to milk than fore-tea ts. The vacuum and pressure required to open the teat canal and observ e the beginning of milk flow were lower than for front teats. The stre tchability of the teat canals was also higher (P < 0.001). Teats that were easy to milk had thin walls and a teat canal surrounded by a smal l volume of elastic tissue. Consequently, milking times were decreased and milk flow rates increased. Using experimental equipment (ie the v acuometer), the correlation between the maximum milk flow rate and the milk volume extracted when a constant vacuum was maintained for 20 s beneath the teat reached + 0.75. Consequently, use of the vacuometer m ight provide a practical testing method for assessment of milk flow ra te. The equipment was easy to handle under farm conditions and the mea surements were made rapidly (20-30 cows/h).