The team of researchers created a software program that they dubbed "Google Translate for cows" to get a better idea of what the animals are saying when they moo. They did this by listening to Holstein-Fresian heifers, a European breed, mooing into a microphone and analyzing their pitch.
They also found that each animal retains its own distinct moo and can give cues in different situations to maintain contact with the rest of the herd. They are said to be able to express excitement, arousal, engagement, and distress as well.
Cattle can produce vocalizations with frequencies over 1,000 Hz, which are likely to occur during arousal. It has been hypothesized that high-frequency calls should contain more individual information than low-frequency ones due to their propagation over long distances.
"We found that cattle vocal individuality is relatively stable across different emotionally loaded farming contexts," lead author Alexandra Green said.
The findings could help farmers keep their cattle healthy by understanding their moods and translating their individual sounds.
This is not the first study that has looked into communication between cows. An earlier study found that mother cows and their offspring communicate by maintaining the individuality of their lowing – the low, deep sound cattle make. The new study, however, confirms that cows maintain their individual mooing through their lives, even as they natter among themselves. (Related: Calves have conversations with their mothers: cows are intelligent, conscious animals.)
The scientists recorded hundreds of "moos" from 13 heifers for the study using acoustic analyses programs. The calls were collected during different situations. Green and her team put the cows in heat, gave them food, deprived them of food and separated them from the herd.
Using acoustic analyses programs, the researchers found that cows maintained their individual vocal cues, and it is likely that they recognize other members of the herd through these calls.
They found that dairy cows tend to communicate with each other all the time, and their moos become more sonorous when they talk about happy things like food. But when they are moaning about the weather, their moos tend to pitch lower.
"Cows are gregarious, social animals. In one sense it isn’t surprising they assert their individual identity throughout their life and not just during mother-calf imprinting. But this is the first time scientists have been able to analyze voice to have conclusive evidence of this trait." Green said.
The findings also align with previous observations that indicate cattle herds have observable hierarchies. They experience long-term effects when separated from their mothers at an early age, and learn better when they have friends around. Because of these indications, it makes sense that the animals could use vocal cues to recognize other herd members.
The findings suggest that farmers should integrate the knowledge of individual cow voices into their farming routines to tune into the emotional state of their cattle, and therefore, improve animal welfare, especially during a time where cow welfare is severely compromised by mass farming practices. In the dairy industry, herd sizes are getting bigger, and farmers need to find more novel ways to look at cow welfare.
"By understanding these vocal characteristics, farmers will be able to recognize individual animals in the herd that might require individual attention."
Read more unusual facts about animals at WeirdScienceNews.com.