Optimal Parameters to Milk Murciano-Granadina Goats in Mid and Low-Line Milking Parlours

SIMPLE SUMMARY: There were not long-term studies in the literature reviewed on how machine milking parameters (pulsation rate, pulsation ratio and system vacuum) affect milk production, milk composition, animal welfare and udder health throughout the lactation of Murciano-Granadina goats. After previous experiments developed in short term by this research group, the aim of the present experiments was to test during one entire lactation duration the best combination of system vacuum and pulsation parameters using two types of milking parlours, one with low-line pipes and the other with mid-line pipes to obtain optimal values of milking duration, milk yield, animal welfare and udder health. The results confirmed that the optimal parameters to milk Murciano-Granadina goats are different in mid-line milking parlours and in low-line milking parlours. The milking parameters must be correctly programmed to achieve optimal milking efficiency and milk quality values, enhancing the animals’ sanitary status and farm profitability. The conclusions of this project have established work guidelines for small ruminants’ farmers and technicians to improve milk quantity, milk quality and animal welfare. ABSTRACT: Recent short-term studies on Murciano-Granadina goats have established that the optimal parameters to set up the milking machines are different according to the milk pipes height. Two groups of 52 fresh goats each were employed in 2 different experiments to confirm during an entire lactation period the best combinations of system vacuum pulsation rate and pulsator ratio in low-line and mid-line milking parlours. The experiment performed in the low-line milking parlour included one group milked with 40 KPa vacuum system level, 90 puls/min pulsation rate and 60/40 pulsation and a second group milked with 38 KPa vacuum system level, 90 puls/min pulsation rate and 60/40 pulsation ratio. The experiment carried out in mid-line included one group milked with 40 KPa vacuum system level, 90 puls/min pulsation rate and 60/40 pulsation ratio and a second group milked with 40 KPa vacuum system level, 120 puls/min pulsation rate and 60/40 pulsation ratio. Variables studied included milking efficiency, milk composition, cortisol, SCC and intramammary infections, teat-end oedema after milking and vacuum dynamics during milking. Considering the results of an entire lactation period, it was confirmed that when milking in mid-line, the combination of 40 KPa system vacuum, 90 cycles/min pulsation rate and 60/40 pulsator ratio showed optimal results of the above-mentioned variables. On the other hand, the use of 40 KPa in a low-line system increased the milk cortisol values (0.34 ± 0.1 vs. 0.44 ± 0.1 ng/mL) without any other advantage. Thus, the recommendation is to use a combination of 38 KPa system vacuum, 90 cycles/min pulsation rate and 60/40 pulsator ratio to enhance animal welfare.