Machine milking parameters for Murciano-Granadina breed goats

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

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.

Physiological Aspects of Milk Somatic Cell Count in Small Ruminants—A Review

The aim of this review was to focus on the physiological aspects of milk somatic cell count (SCC) in small ruminants (SM). The SCC is an important component naturally present in milk and is generally used as an indicator of milk quality and udder health in milk producing ruminants. SCC contains the following cells: polymorphonuclear neutrophils (PMN), macrophages, lymphocytes, and many milk epithelial (MEC) cells, cell fragments, and cytoplasmic particles/vesicles. PMN (40–80%) represent the major cell type in milk in healthy uninfected goats, whereas the macrophages (45–88%) are the major cell type in sheep’s milk. However, dairy goats and sheep have an apocrine secretory system that produces cytoplasmic cellular particles/vesicles and large numbers of cell fragments, resulting in the physiological SCC limit being exceeded. It is obvious that the SCC level in milk of SM can be affected by various influencing factors, such as milk fraction, breed, stage of lactation, parity, type of birth, milking system, and others. An increase in the SCC above the physiological level not only indicates an udder or general health problem but reduces milk production, changes the milk composition, and hence affects milk processing. Moreover, the milking machine plays an important role in maintaining udder health in SM and stable SCC at physiological levels in the milk obtained. So far, there are no healthy or pathological physiological SCC levels defined in SM milk. Furthermore, a differential cell count (DCC) or even a high resolution DCC (HRDCC), which were recently developed for cattle milk, could also help in SM to gain deeper insight into the immunology of the mammary gland and find biomarkers to assess udder health. In conclusion, SCC is an indication of udder health or exposure of the udder to infectious agents or mechanical stress and should therefore always be considered a warning sign.

Effect of Vacuum Level and Pulsation Parameters on Milking Efficiency and Animal Welfare of Murciano-Granadina Goats Milked in Mid-Line and Low-Line Milking Machines

Simple Summary

In recent years, several studies have been carried out to optimize milking efficiency in Murciano-Granadina goats, but to our knowledge there are no experiments combining different milking parameters (system vacuum, pulsation rate and pulsator ratio) in two different height level milking machines. In two short experiments, testing different combinations of the parameters mentioned, milk fractioning, milking efficiency, teat end status and animal welfare were analyzed. Results showed that the height of the milking machine pipes can have an influence on which parameters are most optimal for milking efficiency and animal welfare in the milking of Murciano-Granadina goats.

Abstract

The Murciano-Granadina goat breed has been described as a slow milking breed. As milking machine parameters can affect milk extraction in terms of yield and time employed, two experiments of one-month duration were performed with 88 goats in Latin square design to find the best combination of these parameters. One of them was carried out in a mid-line milking machine and one in a low-line milking machine. For each of them, two vacuum levels (36 and 40 kPa), two pulsation rates (90 and 120 cycles/min) and two pulsator ratios (50 and 60%) were used and milking efficiency, sanitary status of the mammary gland, milk cortisol, and teat end status were evaluated. Results showed that in milking machines installed in mid- and low-line, the use of 40 kPa system vacuum, 60% pulsator ratio and 90 or 120 cycles/min pulsation rate achieved optimum milking fractioning and efficiency. In the case of low-level milking machines, a similar combination with 36 kPa not only showed worse milking fractioning values, but also provided better values of teat end status and cortisol level.

Influence of milking units and working vacuum level on the mechanical milking of goats

The objectives of this study were to evaluate and compare the effect of working vacuum levels (35 and 44 kPa) and liners dimensions (mouthpiece lip diameter and overall length, 20–185 and 22–170 mm) on the main milking characteristics of goats. The results highlight that both the working vacuum level and the liner dimension have influenced the milk flow curve parameters. The maximum variations were found for peak flow rate, which increased significantly with liner dimensions of 20–185 mm at a working vacuum level of 44 kPa as well as average milk flow rate and for plateau phase duration. The incorrect adoption of operative parameters and unsuitable milking machine components, might affect the performance of the mechanical milking and negatively affecting animal productions and welfare.

Automatic Prestimulation on Dairy Goats: Milking Efficiency and Teat-End Status

Simple Summary

In the literature reviewed, there were no studies about how automatic mechanical stimulation affects milking efficiency and teat-end status in dairy goats. Three experiments were performed at the onset, middle, and end of lactation on Murciano-Granadina goats. In each experiment, milking with and without previous mechanical stimulation was tested. Milk fractioning, milking time, milk flows, and teat-end status assessed by ultrasonography and vacuum levels in the short milk tubes and short pulsation tubes were registered. Results showed that, conversely to dairy cows, investing in equipment for performing mechanical prestimulation in dairy goats is not needed, as it did not offer any advantage regarding the above mentioned variables.

Abstract

Experiments carried out in dairy cows show that mechanical stimulation prior to milking offers a good release of oxytocin without involving changes in milk yield or a reduction of the milking time. The objective of the present study was to evaluate the effect of automatic prestimulation on milk fractioning, milking duration and milk flows, teat-end status, and vacuum levels at the short milk tubes and in the pulsation tubes of dairy goats. With this aim, three experiments in Latin square design were developed employing goats in different moments of the lactation: one of them at the onset of lactation, one at mid-lactation, and the last at the end of lactation. Two treatments were tested: milking with a mechanical prestimulation of 300 ppm for a 20-s period and milking without prestimulation. Results showed that prestimulation at the end of lactation showed slightly lower average milk flow (kg/min) values (0.53 ± 0.02 vs. 0.60 ± 0.02; p = 0.03) and lower maximum vacuum level values (Kpa) in the pulsation tubes (27.08 ± 0.15 vs. 39.48 ± 0.25; p < 0.01). No other differences were found in the variables related to milking efficiency or teat-end status in the three experiments carried out.