Oxen wagon train in South Africa.
Anyone who has had to muck out a barn knows what a nasty chore it is. When you maintain farm animals, you can expect to clean up manure, shovel feed, and other undesirable tasks. In the old days, when people needed animals to plow and to grind, there was no choice. The effort was amply repaid, however. The labor of the oxen and horses greatly multiplied productivity. The point of this proverb is that to get results we often have to put up with inconveniences.
The story of our salvation is a story of Christ putting up with inconveniences. There was the inconvenience of leaving his throne in heaven. There were the inconveniences of poverty, cold, hunger, overwork, tiredness, misunderstanding, vilification, and crucifixion. He endured all these things to demonstrate what it means to have absolute obedience to God the Father. His inconvenience resulted in our salvation and much multiplication of fruit.