Ketosis in cattle diagnosis, treatment and prevention

06/02/2023

In the past thirty years, milk production of dairy cows has doubled in most countries. The direction of nutrients to the udder immediately after calving has been the basis for successful breeding towards higher milk yield, but there is a large variation in the adaptative responses of individual cows toward energy and nutrient shortages. High milk yields pose a metabolic challenge for the cows, which may result in a decrease in the immune response, reproductive performance and milk quality, as well as cow welfare. Cows with higher milk production are more likely to suffer from ketosis [2], or hyperketonaemia, a metabolic state characterized by elevated concentrations of ketone bodies in the blood that diffuse to different body fluids: β-hydroxybutyrate (BHB) can be found in blood and milk, acetoacetate in urine, and acetone in breath Ketosis occurs mainly postpartum, at the start of lactation, due to a negative energy balance. In that period, the feed consumption, and therefore the energy intake, of the cows do not meet the demands of the high milk production. To compensate for this shortage, the cow breaks down her own body fat, forming ketone bodies. The body can process small quantities of these ketone bodies, but in the case of glucose deficiency, oxaloacetate is extracted from the tricarboxylic acid (TCA) which leads to an excess of acetyl-Co, causing the formation of more ketone bodies, leading to ketosis. First and second-parity cows are less prone to ketosis because they are less at risk of a negative energy balance. These cows produce less milk and their liver is less fatty
Under normal conditions, ketone bodies are produced by the rumen epithelium from fatty acids in the diet, especially butyrate [6]. Ketone bodies are also produced in the liver from fatty acids, which are mobilized in adipose tissue during negative energy balance. Ketone bodies are important sources of energy [8], especially during negative energy balance and low blood glucose concentrations. At the start of lactation, blood glucose concentration decreases as well as the insulin/glucagon ratio while the concentrations of BHB and non-esterified fatty acids (NEFAs) in the blood increase. The NEFAs are oxidized by β-oxidation, forming acetyl-CoA, which is used in the TCA cycle The excess of NEFAs results in an excess of acetyl-CoA that the TCA cycle cannot process, leading to ketogenesis. Acetoacetate is formed from acetyl-CoA and BHB and acetone from acetoacetate BHB is the major circulating ketone body in dairy cattle. Ketone bodies are released into the blood where they serve as an energy source for organs such as muscles, the brain, mammary glands, and the heart. In short, ketogenesis is a normal physiological process during fat mobilization, and ketone bodies are important energy sources, but an excess of ketone bodies due to ketogenesis can cause problems in the metabolic process. Risk factors for ketosis are a body condition score > 3.75 (on a scale from 1 to 5), multiple pregnancies, dry period > 70 days, locomotion problems, or claw health issues
Due to the negative energy balance during ketosis, the amount of energy available for other processes in the body is decreased and cows have an increased risk of uterine infection, mastitis, fatigue, and reduced fertility. Due to the reduced feed intake, there is a higher risk of abomasum displacement. Veterinary treatments, decreased milk production, a prolonged calving interval, and culling can result in high losses for ketotic cows, estimated at approximately 709 or 735 euros per case, and ranging from 64 to 1196 euros. In Europe, 16–23% of cows develop ketosis 2–15 days postpartum, with blood concentrations of BHB ≥ 1.2 mmol/L. In the Netherlands, 11.2 percent of dairy cows suffer from ketosis in the first months of lactation while the prevalence per farm varies from 0–80%
To detect ketosis at an early stage, ketone bodies can be measured. Several tests are used in practice, to determine BHB in blood, BHB in milk or acetoacetate in urine. Measuring acetone in breath is not yet common practice, partly because no sensors or tests are available yet for routine breath analysis in cows
The measurement of BHB in blood gives the most reliable results in the detection of ketone bodies because BHB is more stable than acetone or acetoacetate. BHB in the blood is therefore considered the gold standard for ketosis diagnosis . Therefore, in this study, we took blood samples, preferably from the jugular vein, the second choice being the coccygeal vein. Acetoacetate, acetone, and BHB are small molecules that do not bind to plasma proteins in the blood and therefore can end up in the preliminary urine. When the concentration of ketone bodies in the blood is low, almost all ketone bodies are resorbed in the kidneys. With high concentrations of ketone bodies in the blood, they are filtered out in the Bowman’s capsule, resulting in approximately 20% of the ketone bodies being excreted through the urine. Urine test strips measure acetoacetate in the urine, which is a reliable ketosis test and more reliable than milk tests Milk contains acetone, acetoacetate, and BHB. The concentration of ketone bodies in milk is about 50% of the total concentration of ketone bodies in the blood. The ketone bodies enter the milk via the blood capillaries surrounding the alveoli, which contain milk-forming cells. Ketone bodies can pass through the milk-forming cells into the milk sacks, and are transported with the milk to the milk atrium. Milk test strips measure BHB in milk, which has a strong correlation of 0.705 with BHB in blood, and therefore they are suitable for determining ketosis . Blood flows to the capillaries of the lungs, where it releases acetone into the alveoli, after which the air is exhaled. In an earlier study, it was shown that ketosis can be detected by analyzing exhaled air from cows. The acetone concentrations in blood correlated with concentrations of blood BHB (r = 0.81) and milk acetoacetate and acetone (r = 0.70). In another study, it was shown that acetone concentrations varied between 0 and 14 ppm. Ketotic cows showed higher acetone concentrations in breath, and it was concluded that breath analysis can be a non-invasive way of determining ketosis. Previous research indicated that the rise in acetone levels in breath occurs earlier than the rise in BHB in milk and acetoacetate in urine. This was also shown in another study, where acetone was the first rising ketone body in the blood
If acetone is indeed the first ketone body to rise in the blood, then acetone in breath might be a good indicator for early detection of rising ketone bodies and risk of ketosis. Through early detection, the cow can be treated in time to prevent a more serious course of disease [33]. However, breath analysis has not yet been compared to blood values. Testing ketosis in blood gives more reliable results than the ketosis test strips for milk and urine
The purpose of this study was to measure ketone bodies in the breath of cows at risk of ketosis just before and after calving and to compare the rise in ketone bodies in blood, urine, milk, and breath. The main research question is whether a rise in ketone bodies is shown in all body fluids and which measurement shows the rise first. If the concentration of acetone in breath increases at the same time or soon after the rise of BHB in blood, then breath analysis is a good alternative for the present ketosis tests. It is non-invasive and there are possibilities to automate the process. This can help the farmer with the early detection and treatment of ketosis, preventing a more serious course of the disease, and being beneficial for cow welfare, as well as for the technical and financial results of the farm.

22/09/2022

Symptoms of ketosis
Ketosis expresses in a number of ways including reduced milk yield, weight loss, reduced appetite, dull coat, breath/milk smelling of acetone (pear drops) and fever. Some cows also develop nervous signs including excessive salivation, licking and aggression.
Cows affected by subclinical ketosis (high blood serum ketone body concentrations without any of the observed clinical symptoms mentioned above) will be at increased risk of developing clinical ketosis and will also be more susceptible to displaced abomasum and reduced fertility. They may also suffer from reduced milk production. Cows with raised blood ketone levels may excrete ketones in urine and milk.

22/09/2022

Treatment of ketosis in dairy cattle
The initial aim of treatment is to restore the lack of glucose in the body. A quick-acting glucose supplement is required immediately, with follow-up treatment aimed at providing a long-term supply of glucose. Many of the long-acting corticosteroids have beneficial effects in ketosis as they help to break down muscle protein to produce glucose which immediately replenishes the depressed blood glucose levels.

22/09/2022

Risk factors of Ketosis
Insufficient ruminal production of propionic acid (the main precursor of glucose in ruminants) will result in hypoglycemia and worsen the situation. This can be caused by underfeeding or a reduced feed intake as a result of a suppressed appetite or lack of feed (quality, quantity and access). A lack of appetite is normal around calving but may be worsened in the early stages of a new lactation by a poor forage quality, sudden changes in diet or excessive weight at calving.
Other common risk factors for the onset of ketosis are:
wintry conditions (when the cow has to expend more energy to keep herself warm)
higher parity cows
milk fever (which reduces feed intake after calving)
cows which have experienced ketosis in the previous lactation
cows which had an increased 305-day milk yield in the previous lactation.
Silage with a high butyric acid loading can also promote the onset of ketosis. Silage containing high levels of butyric acid is also less palatable and will therefore be consumed in lower quantities, further exacerbating the energy imbalance.
Secondary ketosis is common and is the result of conditions such as displaced abomasum, mastitis and metritis causing a reduction in appetite during early lactation.
In areas of cobalt deficiency, ketosis may also be diagnosed in grazing cattle: rumen microbes need sufficient cobalt to enable the synthesis of vitamin B12, and it is also essential for adequate utilisation of propionic acid.
Ketosis is also common in dairy herds affected by liver fluke or fasciolosis.

22/09/2022

How does Ketosis occur?
A negative energy balance leads to the mobilization of free fatty acids and glycerol from the fat stores which are oxidized into products such as Acetyl-CoA. However, the liver cannot fully process all that Acetyl-CoA and the excess is therefore converted into, among other things, ketones – a process known as acetonaemia or ketosis.
Milk production places a significant burden on a dairy cow’s resources, with the majority of the energy required to produce large volumes of milk usually obtained from ingested feed and body reserves. However, when milk production increases rapidly during the early stages of a new lactation the energy taken in is often insufficient to meet the energy output required to reach peak milk production. As such the cow goes into a negative energy balance and can become more vulnerable to poor health, with any stresses that cause a further reduction in feed intake potentially leading to the additional health problems.

22/09/2022

Ketosis: prevention is better than cure
Milk production places a significant burden on a dairy cow’s resources, with the majority of the energy required to produce large volumes of milk usually obtained from ingested feed and body reserves. However, when milk production increases rapidly during the early stages of a new lactation the energy taken in is often insufficient to meet the energy output required to reach peak milk production. As such the cow goes into a negative energy balance and can become more vulnerable to poor health, with any stresses that cause a further reduction in feed intake potentially leading to the additional health problems.

22/09/2022

Treatment of Ketosis in Cattle
Oral administration (drench) of propylene glycol (250–400 g, PO, every 24 hours for 3–5 days) is the standard and most efficacious treatment
Additional therapy with bolus glucose treatment (500 mL of 50% dextrose solution, IV, as a single bolus) in neurologic cases and vitamin B12 (1.25 mg, IM, every 24 hours for 3 days) in cases that are also hypoglycemic is suggested
Treatment of ketosis is aimed at reestablishing normoglycemia and reducing serum ketone body concentrations. Bolus glucose treatment (500 mL of 50% dextrose solution, IV, as a single bolus) is also common. This solution is very hyperosmotic and, if administered perivascularly, results in severe tissue swelling and irritation, so care should be taken to ensure that it is given IV. Bolus glucose treatment generally results in a rapid temporary recovery, especially in cases occurring near peak lactation (type I ketosis). However, the effect frequently is transient, and relapses are common.
Dextrose administration is recommended for cases of nervous ketosis, but may not be necessary or even helpful for every ketosis case. Administration of glucocorticoids is not recommended as there is little evidence of benefit and some indication of harm.
Propylene glycol acts as a glucose precursor, and oral drenching (250–400 g [8–14 oz], PO, every 24 hours for 3–5 days) is effective as a ketosis treatment. Overdosing propylene glycol leads to CNS depression.
There is also support for the use of vitamin B12 (1.25 mg, IM, every 24 hours for 3 days) as an adjunct treatment with oral drenching of propylene glycol, particularly in ketotic cows that are also hypoglycemic. 1,2
Ketosis cases occurring within the first 1–2 weeks after calving (type II ketosis) frequently are more refractory to treatment than cases occurring nearer to peak lactation (type I ketosis). In many cases, a repeated 5-day course of oral drenching of propylene glycol often combined with vitamin B12 seems to resolve these refractory ketosis problems. However, some still remain clinically hyporectic. In these cases, some have suggested that a long-acting insulin preparation (150–200 U, IM, every 24 hours for 5 days) may be beneficial; however, there is little evidence to support this. Insulin suppresses both adipose mobilization and ketogenesis; it should be given in combination with glucose or a glucocorticoid to prevent hypoglycemia. Use of insulin in this manner is an extralabel, unapproved use.
Other therapies that may be of benefit in refractory ketosis cases are continuous IV glucose infusion and tube feeding. (Also see Fatty Liver Disease of Cattle.). In addition, limited research has demonstrated that reducing milking frequency from twice a day to once daily will reduce ketone body concentration and improve the chances of a cure, although at the expense of reduced milk production.

22/09/2022

Ketosis is a common and costly disease in dairy cattle, with both its clinical and subclinical forms associated with increased risk of other diseases and impaired production and reproduction.
Ketosis can be diagnosed with cowside blood, milk or urine tests; the most accurate method is blood measurement of BHB concentration.
Ketosis is treated with oral drenching of propylene glycol (300 g per cow, PO, every 24 hours for 3 days in mild cases and extended for 5 days in severe cases).

13/09/2022

Etiology and Pathogenesis of Ketosis in Cattle
The pathogenesis of bovine ketosis is incompletely understood; however, it requires the combination of intense adipose mobilization and a high glucose demand. Both of these conditions are present in early lactation, at which time negative energy balance leads to adipose mobilization, and milk synthesis creates a high glucose demand. Adipose mobilization is accompanied by high serum concentrations of nonesterified fatty acids (NEFAs). During periods of intense gluconeogenesis, a large portion of serum NEFAs is directed to ketone body synthesis in the liver. Thus, the clinicopathologic characterization of ketosis includes high serum concentrations of NEFAs and ketone bodies and low concentrations of glucose. In contrast to many other species, cattle with hyperketonemia do not have concurrent acidemia. The serum ketone bodies are acetone, acetoacetate, and beta-hydroxybutyrate (BHB).
Ketosis in Cattle
Pathogenesis of ketosis cases occurring in the immediate postpartum period is thought to differ slightly from that of cases occurring closer to the time of peak milk production.
Ketosis cases occurring close to the time of peak milk production (usually around 4–6 weeks after parturition) is sometimes described as type I ketosis. Ketosis at this time may be associated with underfed cattle experiencing a metabolic shortage of gluconeogenic precursors than with excessive fat mobilization.
Ketosis in the immediate postpartum period is sometimes described as type II ketosis. Such cases of ketosis in very early lactation (1–2 weeks postpartum) are usually associated with fatty liver. Both fatty liver and ketosis are probably part of a spectrum of conditions associated with intense fat mobilization in cattle.
The exact pathogenesis of the clinical signs is not known. They do not appear to be associated directly with serum concentrations of either glucose or ketone bodies. They may be due to metabolites of the ketone bodies.
Subclinical ketosis is defined as high serum ketone body concentrations without observed clinical signs. Subclinically affected cows are at increased risk of clinical (or more severe) ketosis, metritis, and displaced abomasum and are also less fertile than those with normal serum ketone body concentrations. Furthermore, they appear to have reduced milk production and are at increased risk of culling in early lactation.
Distinction between clinical and subclinical ketosis is unimportant in practical terms and may be difficult to determine without routine testing. Both are part of the same disease syndrome, with impacts increasing as ketone body concentrations increase. Determination of serum or whole blood BHB concentration is considered the best way to detect and monitor subclinical ketosis; however, urine or milk cowside tests can also be used in on-farm monitoring programs.
Concentrations >1.0 mmol/L (10.4 mg/dL) or 1.4 mmol/L (14.6 mg/dL) blood or serum BHB are considered diagnostic of subclinical ketosis. The standard threshold used for blood is 1.2 mmol/L (12.5 mg/dL), which corresponds to thresholds of 100 mcmol/L for milk, and 15 mg/dL (or "small" on a dipstick) for urine.
Given that ketosis is a costly disease and that treatment is efficacious, on-farm monitoring programs are cost-effective for most farms with moderate to higher prevalence. Two outcomes of monitoring programs are treatment of individual ketotic cows and evaluation of prevalence to determine effectiveness of prevention strategies at the herd level. Sudden or prolonged elevation in herd prevalence of ketosis indicates a herd-level problem and should prompt a review of nutritional and cow management.
Some farms use handheld BHB meters to test all cows in early lactation. Cows with subclinical ketosis are treated with oral drenching of propylene glycol. Such an approach is labor-intensive but has been demonstrated to reduce further disease occurrence in subclinically ketotic animals and to improve milk production in treated animals. Sound nutritional management procedures are also important. Routine milk ketone body tests are available in some countries from dairy herd improvement companies. These tests can be used to classify herd risk before considering on-farm testing programs, or as the sole source of monitoring in herds with very low prevalence (

13/09/2022

Prevention
Ketosis causes financial loss through lost production and treatment. It may be prevented by management strategies that maintain a good appetite and supply adequate feed to meet this appetite during the late dry period and immediately after calving. These strategies include:
feeding transition rations before calving that reduce the risk of milk fever, retained membranes and dystocia
feeding ample quantities of high-quality forages and concentrates after calving
avoiding having cows fat when they are calving.
It is also important to ensure that any health problems (calving difficulties, abomasal displacement, milk fever) are identified and treated as early as possible.

13/09/2022

Treatment
Treatment is best undertaken by your local veterinarian.
The aim of treatment is to:
correct the energy deficiency in the diet
reduce the production of ketones
maintain adequate dietary energy levels to prevent relapse.
Treatment may include:
Supplying adequate dietary requirements.
Intravenous glucose (if used as the sole treatment, relapses will occur). Also give repeated drenches of propylene glycol or glycerine.
Corticosteroids.
Gastric stimulants to increase appetite.
Supportive therapy.
Failure to respond to treatment within two days indicates that there may be another, underlying problem which should be identified Ketosis in cattle diagnosis, treatment and prevention

13/09/2022

Predisposing factors
Age - cows of any age may be affected but the disease appears more common in later lactations peaking at about the fourth lactation.
Body condition at calving - over fatness at calving has been associated with increased levels of ketosis.
Other diseases - secondary ketosis results frequently when conditions such as mastitis, retained placenta and milk fever have previously occurred.
Signs of the disease
In the more common wasting form, there is a decrease in appetite and milk yield. There is an associated loss of weight, firm faeces and the cow becomes depressed. With recovery there is a gradual return to normal milk production.
In the nervous form, affected cattle excessively lick and chew or grind their teeth. The cattle may also walk aimlessly and appear blind and become recumbent.
In sub-clinical ketosis, clinical signs are not seen but ketones are present in the milk and urine.
Diagnosis
A veterinary examination may be necessary to confirm the presence of the disease. Ketosis is characterised by a high blood ketone level and a low blood glucose level. A test is available which will detect the presence of ketones in the urine and this is a good guide as to the existence of the disease.

13/09/2022

Five types of the disease are recognised:
Primary underfeeding or starvation ketosis - feed quality inadequate.
Secondary underfeeding ketosis - inadequate feed intake due to another disease or condition.
Ketogenic or alimentary ketosis - from feeds high in ketogenic material.
Ketosis due to a specific nutritional deficiency - cobalt and possibly phosphorus deficiency have been suspected as causes.
Spontaneous ketosis - where causes are not able to be established.
Predisposing factors

13/09/2022

Cause
Ketosis may develop from poor diet or periods of stress such as cold, wet weather. It may also affect apparently well-fed cows producing very large volumes of milk. In pasture-fed cows the condition is usually seen when the grass is drying off and green feed is scarce.
The disease is relatively common in lactating cows in Australia but often goes unnoticed in its mild forms. The mortality rate in affected cattle is low and spontaneous recoveries occur in many cases. The disease is usually seen in early lactation (within the first 2 months after calving) and may cause significant production losses.

13/09/2022

Ketosis in cattle is associated with an inadequate supply of the nutrients necessary for the normal carbohydrate and fat metabolism that is seen mainly in times of high milk production in early lactation. The excessive ketone bodies in the bloodstream come from the breakdown of fat when the animal is forced to draw on its bodily reserves for energy. Although the metabolism of body fat provides energy for cows, the nervous system is dependent on glucose, and the ketones produced as a result of excessive fat metabolism can have toxic effects. The excess ketone bodies are eliminated in the urine, milk and breath of the animal.

31/08/2022

There are several benefits of estrus synchronization of beef cows. Regardless of when your calving season occurs, manipulating the reproductive process of your cow herd can result in shorter breeding and calving seasons. Accordingly, more calves born earlier in the calving season result in an older, heavier, more uniform calf crop when you wean.
Shortened calving seasons permit improvements in herd health and management such as timing of vaccinations and practices that add to calf value with less labor requirements (or at the very least concentrating labor efforts into a shorter time frame). Cows that are closer to the same stage of gestation can also be fed and grouped accordingly which facilitates a higher level of management.

25/07/2021

12/06/2021

Most fixed-time AI protocols utilized in the USA today are variations on the Ovsynch protocol e.g., Cosynch protocols are more commonly used in beef cattle because GnRH is administered at the same time as fixed-time AI, avoiding one trip through the chute.

Synchronization protocols involving the use of GnRH have been listed by the Beef Cattle Reproduction Leadership This is an excellent reference source put together by representatives from the AI and pharmaceutical industries, veterinarians, and reproductive physiologists from the Beef Reproduction Task Force. A GnRH-based protocol for fixed-time AI is illustrated in Figure 2.

The 5-day Cosynch protocol
A recent change to the Cosynch protocol is to shorten exposure to progesterone from 7 days to 5 days. One study showed that pregnancy rates were 11% higher in beef cows following a 5-day exposure with fixed-time AI along with the second GnRH at 72 hours after progesterone-releasing device removal compared to a 7-day exposure with fixed-time AI at 60 hours. The cause of the increased pregnancy rates was proposed to be due to a lengthened developmental period for the ovulatory follicle (proestrus) and higher estradiol levels at the time of AI. However, a disadvantage of the 5-day protocol is that because of the shorter interval between the first GnRH and the injection of prostaglandin, two injections of prostaglandin 6 to 8 hours apart are needed to ensure that the new corpus luteum is regressed. If ovulation to the first GnRH does not occur, then a second injection of prostaglandin is not needed.

More research is needed comparing 5-day protocols in beef cattle. One report showed that fixed-time AI at 56 hours in a 5-day Cosynch protocol resulted in 10.3% higher pregnancy rate than insemination at 72 hours, whereas, another showed that the pregnancy rates did not differ between 5-day and 7-day Cosynch protocols using only a single injection of prostaglandin when the progesterone-releasing device was removed. In that study, the use of the first GnRH in the 5-day Cosynch protocol did not seem to be necessary as pregnancy rates did not differ when it was not used. In heifers at least, the first GnRH seems to be necessary only when cyclicity is considered a problem. If heifers are cyclng the first GnRH can be omitted and a single administration of prostaglandin is all that is required to regress the original CL. This would be an enormous advantage in eliminating one trip through the chute.

Combined programs
There are numerous progesterone-based protocols that utilize either estradiol or GnRH to synchronize follicle wave emergence and ovulation. In Argentina, an estradiol-based protocol with shortened progestin exposure and a lengthened proestrus, named J-Synch, has been developed. Estradiol is administered at the time of insertion of a progesterone device to synchronize follicle growth. The progesterone device is removed and prostaglandin is administered on Day 6 and fixed-time AI is done along with the administration of GnRH 72 hours later (on Day 9). Use of a 6-day J-Synch protocol has resulted in higher pregnancy rates in heifers than the conventional 7- or 8-day estradiol-based protocol. Another study comparing protocols showed that pregnancy rates did not differ between groups of heifers regardless of the protocol used. The important issue is to understand the timing of ovulation relative to treatment. In cattle with a synchronized follicle wave and treatment with a progesterone-releasing device, ovulation will occur approximately 27 hours after GnRH treatment, or approximately 45 hours after estradiol treatment. Thus, the timing of AI must be adjusted according to when the final dose of either GnRH or estradiol is administered.

Management
Fertility in an AI program is a product of female fertility, semen fertility, inseminator skill and timing of AI. It is vitally important to realize that a deficiency in any one of these components, or sub-optimal performance in two or more of these components, will substantially decrease pregnancy rate.

Many synchronization programs have failed due to inadequate attention to detail. Estrus synchronization and AI typically compliment good management, but rarely replace it. Good management practices are necessary year-round, in addition to just prior to the breeding season. Good planning and communication, including written protocols and frequent consultations with your veterinarian, are essential.

Body condition and nutrition
The importance of body condition, postpartum interval, pubertal status and nutrition cannot be overemphasized. Heifers should be approximately 65 to 70% of expected mature weight and cows should be at least 50 days postpartum and both should be on an increasing plane of nutrition. However, exogenous progestins (MGA or progesterone-releasing devices) may induce cyclicity in prepuberal heifers or postpartum cows. Regardless, body condition scoring and appropriate nutrition are critically important.

Semen viability
Semen should be examined before use, or purchased from a reputable source and properly handled (including storage and thawing). If there is any question regarding semen viability, the semen should be examined prior to use.

Minimize stress
There must be adequate facilities for handling cattle and the stress associated with handling must be minimized; it is noteworthy that stress increases cortisol which can block LH release and impair or prevent ovulation.

Treat cattle in groups
To maintain consistent intervals between treatments and AI, it is important to treat and inseminate cattle in groups (spaced over the course of a day or on consecutive days). Generally, the number of animals scheduled should not be more than what can be inseminated in a 4-hour period of time. This also supports consistency in inseminator skill and prevents inseminator fatigue, which deserve as much consideration as the other components in the program.

Consult your Veterinarian
Implementation of a synchronization breeding program is best done in close consultation between the producer and the veterinarian. One should take into account resources, capabilities, intentions and breeding objectives in order to choose the most appropriate protocol.