Neurophysiology of Milk Ejection and Prestimulation in Dairy Buffaloes

Abstract

The present review aims to integrate the anatomical characteristics of the mammary gland and the neurophysiology of milk ejection to understand the milking capacity of the water buffalo. Since one of the main uses of this species is milk production, this article will analyze the controversies on the use of oxytocin as a stimulant during milking as well as the existing alternatives that farmers apply to promote correct stimulation during milk letdown. According to the available literature, the efficiency of the milking process, the quality of the milk, and the health of the animals are elements that require the consideration of species-specific characteristics to enhance the performance of buffaloes. The incorporation of technological innovations and competitive strategies could contribute to a better understanding of water buffalo in the milk industry.

Keywords: Bubalus bubalis; anatomy; calving; lactation curve; mammary gland.

Figure 1

The methodology applied in this manuscript with the selection and exclusion criteria focused on fulfilling the objective of this manuscript.

Figure 2

Anatomy of the water buffalo’s mammary gland. Sagittal cut of a mammary complex showing the system of lobules with their alveolar glands, enlarged alveolar glands, excretion ducts, and milk storage area.

Figure 3

The neurophysiology of milk ejection in dairy buffalo cow. Tactile stimulation of the MG is transformed into nerve impulses that are transmitted by the inguinal nerve to the inguinal ring, which continues as the genitofemoral nerve whose roots enter lumbar pair 3° and 4° (L3, L4), reaching the ganglion of the dorsal root (DRG). There, the impulses are modulated and transferred by the ascending pathway to the cerebral nuclei of the hypothalamus (PVN, SON) and then to neurohypophysis for oxytocin (Ox) synthesis. After its release, oxytocin is stored in the neurohypophysis and later secreted into the bloodstream where it reaches the Ox receptors in the MG and contracts alveolar tissue cells to trigger milk ejection. MPOA: medial preoptic area; PVN: paraventricular nucleus; SON: supraoptic nucleus.

Figure 4

Presence of the calf during milking, a factor identified as a positive visual, tactile, and auditory stimulus for adequate milk ejection in buffalo cows (Bubalus bubalis).

Figure 5

Manual and auditory stimulation during milking in dairy buffalo cows (Bubalus bubalis). (A) Manual stimulation by the milker in the form of massages to foster adequate milk ejection. (B) Presence of the calf to provide tactile and auditory stimulation prior to milking.

Figure 6

Mechanical milking in dairy buffaloes. (A) A mechanical milking station with a free liner for the standing calf serves as tactile stimulation for oxytocin secretion and milk ejection. (B) Mechanical milking station with standing calf support where tactile, auditory, and visual stimulation is allowed as well as feeders with ad libitum feed. (C) Adapted mechanical milking with space for breeding for the support and stimulation of milk ejection. (D) Mechanical milking parlor adapted to the characteristics of the water buffalo with the presence of feeders and without specific space for calves.

Figure 7

Positive and negative effects of oxytocin on buffalo milk production as reported in various studies as well as its principal uses as a tool during and after birth and in the milking process, with impacts on the characteristics of the composition of milk and its production. For example, mastitis processes can be detected with the help of non-invasive tools such as infrared thermography devices that can detect changes in the superficial temperature due to the inflammatory process of the MG. OXR: oxytocin receptors; PMN: polymorphonuclear cells; ROS: reactive oxygen species.