Cattle, sheep, deer and similar livestock are known as ruminants. As a group, ruminants share the characteristics of mammals, with an even number of toes, which swallow and rechew their food. This re-chewing or rumination is the characteristic that gave rise to their name. The process of rumination allows these animals to consume high-fiber forage that cannot be eaten by humans or other non-ruminant animals.
Ruminants have a four-part stomach, which includes the gizzard, rumen, hijab, and larynx. These animals generally eat quickly with minimal chewing. After the food is swallowed, the food enters the anus, which is shared with the rumen. The rumen is the largest part of the 4-part stomach and is used as a reservoir for mixing feed and a place for microbial fermentation and absorption of nutrients. Combined, the rumen and rumen of an adult dairy cow can hold about 50 gallons of relatively digested forage.
During rumination, the morsel is brought up again, re-chewed, and re-swallowed. Chewing during rumination is slower and more continuous than when eating. During the chewing process, cows also produce a lot of saliva, which contains large amounts of bicarbonate. Saliva in the rumen acts as a buffer that reduces the level of acidity. Therefore, rumination helps maintain stable conditions in the rumen environment, which is good for fiber digestibility. Good rumination also reduces the chance of subclinical acidosis in the rumen, a condition that can lead to reduced milk fat.
The process of rumination reduces the size of food particles, allowing them to move from the rumen to the rumen. As feed passes through the colostrum, water is absorbed, reducing the volume of material reaching the teat. The udder, which is known as the true stomach, produces acid and digestive enzymes, similar to the stomach of non-ruminant animals, before it enters the lower parts of the digestive tract for further digestion, absorption and finally excretion from the body to further break down the food. it helps.
The amount of time that livestock ruminate is influenced by the species, breed, physical and chemical properties of the diet, health conditions, feed intake, and production level. It has been shown that approximately one-third of the variation in rumination time in dairy cows is related to feed intake, and two of the most important dietary factors are starch and NDF.
Rumination can occur at any time during the day, but generally has a diurnal pattern, with cows ruminating mostly at night and after feeding times. Rumination often occurs when cows are resting, which makes it essential that cows have adequate and comfortable space to rest. A dairy cow ruminates on average between 7 and 8 hours a day. Rumination time during the day is divided into several meals, each meal lasting from a few minutes to more than an hour. Each bite is chewed for 30 to 70 seconds before being swallowed.
Attention to the relationship between the behavior, health and production of dairy cows is increasing, especially since more automated equipment is now available to monitor the behavior of dairy cows. These technologies can provide many possibilities to check the correct and repeatable behavioral parameters of dairy cows. It is possible to monitor the health status of cows by using the data collected automatically and by means of them to evaluate the executive operations of cattle management.
In recent studies, the monitoring of rumination behavior of cows has been in the center of much attention. The status of cow rumination behavior is of interest because the amount of rumination is related to several different factors and the act of rumination plays a large role in the digestive process of dairy cows.
If the rancher walks through the herd and sees at least 40% of the cows ruminating, this amount of cow rumination behavior indicates that the herd is healthy in terms of rumen performance and that cow rumination management has been done correctly.
There is evidence that supports this amount of rumination (40% rumination). In a group of healthy cows, on average, 40% rumination is observed during the day. In addition, in a study, it was observed that during the induction of rumen acidosis, about 10% less cows ruminated at the peak of rumination time. In a recent study, it was shown that based on the rumination behavior of newborn cows with problems such as metritis, Mastitis, breast displacement and ketosis (subclinical and clinical) are diagnosed. All these cows showed a reduction in rumination time compared to healthy cows, allowing them to be detected before the disease develops and shows clinical signs.
Producers, consultants and veterinarians have long recognized the importance of rumination as an indicator of animal health and performance. In the past, visual observation of rumination activity was the only method available to measure this activity in the field to assess rumen health. For example, 40 percent or more of the entire herd should be ruminating at any one time, which is considered an indicator of the health of rumen performance in the entire herd. However, this method is time-consuming and only allows for herd-level monitoring, whereas individual ruminant data can help producers identify animals that need more attention. In addition, this method of visual observation suffers from inconsistencies between different observers and the time of day used by the observers to observe the herd. Rumination is affected by daily activities on the farm such as feeding, time of day (eg night or day). For these reasons, although visual observation of cows to assess rumination activity is a good estimate of cow comfort and health at the herd level, this method cannot provide an accurate description of individual cow rumination.
Currently, several companies have commercially designed rumination evaluation systems. These rumination sensors are usually combined with activity measuring devices, ear-rings or neck collars, which are used to help manage reproductive activity in dairy herds. For systems that are commonly used in America, these devices also use pedometers to measure small changes in animal position and movement to determine rumination time, or audio systems that record chewing behavior. Less commonly, some rumination assessment systems use bolus placed in the rumen or a pressure sensor placed in the muzzle. Many of these systems are able to distinguish eating behavior from ruminating behavior, and in addition to ruminating time, some also report eating time.
Regardless of where the sensors are installed on the animal’s body or in which part of the stall (free stall, tie stall, pasture), these devices have been found to be effective in investigating rumination behavior. Many independent studies have confirmed the accuracy and precision of the main systems on the market, and universities are increasingly using this technology as a tool to measure rumination time in research studies.
Reproduction and health of cows during the transition period
The transition period of dairy cows, often defined as three weeks before to three weeks after calving, is a challenging time for the health and performance of dairy cows. Metabolic and reproductive health are issues related to the transition period, with udder displacement, ketosis, and retained placentas being common reasons for early removal of cows from the herd.
Many researches have investigated the possibility of using information obtained from activity and rumination monitoring systems as a tool to check the health status of cows during the transition period with the aim of early detection and prevention of cow health problems during the transition period. These studies all showed that pre-calving rumination time was shorter for cows that became sick after calving (stillbirth, placental abruption, udder displacement, ketosis, metritis) compared to cows that did not have health problems. For example, one study found that cows that underwent udder displacement after calving had reduced rumination activity time earlier than 12 days before calving compared to cows that did not have health problems.
A study at the University of Pennsylvania found that pre-calving activity and rumination data could be used to help ranchers identify cows that are likely to be sick or removed from the herd. This early warning can give farmers the chance to choose appropriate management methods for these animals, which will allow the animals to better deal with the problems of the transition period, and therefore, reduce the likelihood that they will suffer and or be removed from the herd to reduce.
Although less rumination time has been associated with postpartum health problems in pre-calving cows, nearly all pre-calving cows experience a severe reduction in rumination. This sharp reduction in rumination time generally starts 6 hours before calving and is associated with a reduction in eating time and a reduction in dry matter intake. This sharp reduction in rumination time can be used as an indicator of the time of delivery.
The Heat Stress Index (THI) combines temperature and relative humidity to better describe a cow’s environmental conditions and is used to determine when animals are under heat stress. A THI index above 68 is known as mild heat stress in dairy cows. The literature suggests that daily rumination time decreases by 6 minutes per day for each unit increase in THI above 60 for high-producing Holstein cows in a Southern Pennsylvania Ty stall. A German study showed that rumination time per day for cows in naturally ventilated free stalls decreased when the THI reached above 52.
These studies showed that cows may experience heat stress before the THI reaches 68. Late lactation and older high producing cows may be more sensitive to high THI than other cows. Other management factors, such as housing type, ration and water availability, also affect when animals begin to experience heat stress. Access to information from evaluation of rumination in herds may help farmers to determine heat stress at the herd level and change management practices before milk production and reproduction are negatively affected.
A cow’s rumination time per day during estrus has been shown to decrease from baseline. Rumination time begins to decrease on the day before estrus, and is at its lowest on the day of estrus. On the day before estrus and on the day of estrus, cows’ rumination decreases by more than one hour from the base rumination level. Rumination returns to baseline the day after estrus. In combination with information from animal activity, reduced rumination can be used to determine when to inoculate.
In an academic study, it was observed that when cows experience severe pain along with clinical mastitis, it immediately decreases the amount of rumination behavior of the cow, although in many of these cases, the decrease in the amount of cow rumination behavior is related to the reduction of animal feed consumption. Yes, but in many cases, the decrease in animal feed consumption actually happens after the decrease in the amount of rumination.
4 positive effects that evaluate rumination electrically
1- early diagnosis:
Rumination examination is a useful tool for examining sick cattle before clinical signs appear. For example: a study at Cornell University showed that ketosis can be detected 1.5 days earlier with rumination. The sooner ketosis treatment is done, the better the outcome. Rumination monitoring also helps you detect and react to acute situations.
Cows usually ruminate many times during the day. It is rare for a cow to stop ruminating for a few hours or for a long time. If this does not happen, they are probably suffering from an acute disease such as milk fever. In this situation, the electronic cow monitoring system can send a disease alert so the rancher can react immediately before the cows suffer serious disease consequences.
2- Faster response of newborn cows:
The health status of cows in the first days after calving ensures their health and production throughout the lactation period. The results showed that cows with low feed intake in the first days of lactation may suffer from severe health problems such as metritis or ketosis, and their milk production or future reproduction will be reduced.
3- Greater flexibility in treatment:
Rumination information allows the rancher to consult with his herd veterinarians to review veterinary protocols, and to select the least expensive treatment and surgery based on the information obtained.
4- Increasing the ability to follow up treatment:
Another benefit of electronic monitoring is the ability to monitor the response of cows to treatment. As the cow begins to recover, rumination begins to return to its normal level before milk production recovers.
If the treatment is successful, rumination should increase sharply in 10 to 12 hours. If rumination remains at the same level or decreases further after treatment, it is a good sign that the treatment has not worked, and the farmer should find an alternative treatment.
Overall, these topics tell us that monitoring cow rumination behavior is very important, not only to determine a problem, but also to detect a change in the cow before other symptoms appear.