The events that occur in the last weeks of pregnancy and the first weeks of breastfeeding largely determine the success rate of a breastfeeding period.
Extensive epidemiological studies show that dairy cows are more susceptible to diseases in the first month or two of lactation. With the start of lactation, the need for nutrients increases significantly if the animal still does not have the capacity to consume high amounts of feed. Therefore, cows rapidly move large amounts of body tissues for consumption, and body weight loss in the first month after calving often exceeds 40 to 50 kg. Cows that have a higher body score, at the same time as their appetite decreases, are prone to more invasion of adipose tissue to meet the needs of the animal. Posture management during previous lactation is the key to minimizing damage during subsequent lactation.
The common point between all animal diseases is the inflammatory response. Inflammation reduces the consumption of dry matter and increases the risk of contracting diseases and jeopardizing production. Therefore, the management and feeding of dairy cows is very important for the success of the course.
- Time in the transfer group and the risk of disease in early breastfeeding
Diseases are common in early lactation and are often associated with bacterial infections or tissue trauma from childbirth. Approximately 30–40% of dairy cows are diagnosed with a clinical disease in the first three to eight weeks of lactation (Santos et al., 2010; Ribeiro et al., 2016), and typically 75% of these diseases occur in the first three weeks after lactation. Childbirth happens. Illnesses in early lactation are more costly because they disrupt the rest of the lactation period. A case of mastitis at 20 days postpartum costs more than the same case at 200 days postpartum.
Transfer programs should be designed to reduce the risk of disease transmission
Cows should remain in the group for three to four weeks before calving. Vieira-Neto et al. (2021) cows that spent three to four weeks in the prenatal group had the lowest disease risk, produced the most milk, and had the highest pregnancy rates.
Basic common aspects of diseases
It is understandable why production and reproduction are impaired in cows suffering from clinical disease, although the cellular mechanisms are not always well understood.
In all studied species, the consequence of the disease is appetite suppression. The exact reason for the reduction in consumption is not fully understood, but it may be related to the control of nutrients needed for growth of pathogens during infection or a way to limit nutrients needed for an inflammatory response, which is usually triggered by the activation of the immune system. Associated trauma, trauma, or infection. (Brown and Bradford, 2021).
In addition, diseases often change the way nutrients are used, and changes in nutrient partitioning affect milk synthesis. For example, the activation of the immune system by lipopolysaccharides or LPS leads to hypoglycemia (Kvidera et al., 2017).
Elevation of plasma glucose by intravenous glucose injection was proposed as a method to quantify the glucose requirement for immune system activation. Based on that scenario, the authors showed that when the immune system is acutely activated by LPS, approximately 1 kg of intravenously infused glucose is required to maintain plasma glucose concentrations (Kvidera et al., 2017).
Beef calves exposed to bacterially contaminated trachea showed a major change in nutrient utilization by splanchnic tissues (Burciaga-Robles, 2009). The flow of effusive substances throughout the viscera and the amount of discharge from the liver were measured and calculated with catheters placed in the portal vein, hepatic vein, mesenteric vein, and artery. They showed that induction of inflammation greatly increased nutrient utilization by the liver.
Under these conditions, the use of essential and non-essential amino acids by the liver increased significantly, and such effects increase the calculated nutrient requirements for animal maintenance.
In dairy cows, induction of mild endometrial inflammation at 37 days postpartum reduced dry matter intake and milk production and compromised pregnancy rate (Husnain et al., 2023a).
Altogether, the combined effects of the disease on tissue integrity and function, release of pro-inflammatory molecules, altered nutrient partitioning, hyperthermia, and exacerbation of negative nutrient balance in relation to subsequent production and reproduction in dairy cows.
Manage body condition and stimulate dry matter intake
The degree of fatness of cows during the dry period or when entering the transfer period is one of the influencing factors on the amount of tissue loss in early lactation. Cows that have a high body score during the dry season have more tissue transfer (lipomobilization) in early lactation. Large epidemiological studies have clearly shown that cows with a high body score consume less dry matter and are more likely to decrease body score and suffer from postpartum diseases (Rosh et al., 2013).
It is possible that due to high lipomobilization in cows with high body score, increased liver signals suppress appetite and reduce feed consumption (Allen and Bradford, 2012).
These effects can be more pronounced in cows that have consumed a diet with high fermentable energy in early lactation. (Allen and Bradford, 2012).
Cows with more lipomobilization are less susceptible to any artificial insemination and there is an increased risk of pregnancy loss in them (Santos et al. 2010).
Therefore, the management of nutrition and the body score of the animal during the period of lactation until transfer is very important for the success of the next period of lactation (Freek et al. 2022).
Give transition period cows a diet that reduces the risk of diseases
One of the important goals in the ration of cows during the transition period is to reduce the risk of disease. Supplying the required energy and avoiding the increase of body fat in pre-calving cows are among the important goals of pre-calving rations (Drakli and Cardoso, 2014). Adequate supply of forage neutral detergent fiber (NDF), especially with sources that are physically involved in stimulating chewing and rumen filling can be effective and reduce the risk of milk displacement in early lactation. Dairy cows in the first weeks of lactation They are highly susceptible to fatty liver disease. Excessive accumulation of hepatic triglyceride (fat) is associated with reduced health and production performance of dairy cows (Arshad and Santos, 2022). Cows in the transition period with a high body score are more likely to suffer from fatty liver in early lactation than other cows. Therefore, body score management and diets that limit lipomobilization can reduce fatty liver. In addition, some nutrients in the transition period can affect the fatty liver of cows that were under negative energy balance (Arshad et al., 2023).
Choline is added to the diet of transitioning cattle due to its benefits for production and health (Arshad et al., 2020).
Feeding choline protected from the rumen reduced the accumulation of triglycerides in the liver (fatty liver) due to the transfer of adipose tissue to the liver. When protected choline is added to the feed throughout the transition period, it reduces the risk of certain diseases and increases the production of energy-modified milk.
As with the importance of preventing fat-related disorders, prevention of mineral-related disorders is also one of the most important issues in transition period cattle diets.
Hypocalcemia is a common problem in postpartum dairy cows. Cows with clinical and subclinical hypocalcemia have several problems, the reduction of dry matter consumption, impaired immune response and increased risk of uterine diseases are among the complications of this problem. One of the ways to reduce hypocalcemia is to change the mineral composition of prenatal diet by limiting the intake of sodium, potassium and phosphorus and increasing the intake of chloride and magnesium.
Such diets affect the acid-base status of prepartum cows, lowering prepartum blood phosphate and increasing magnesium supply, making cows less prone to clinical and subclinical hypocalcemia (Santos et al. 2019).
Feeding antenatal acidogenic diets not only reduces the risk of hypocalcemia, but also reduces the risk of retained placenta and metritis. Parturient cows fed acidogenic diets before parturition had increased milk and fat-modified milk production in subsequent lactations (Santos et al. 2019).
meet the nutritional needs of the cow
The ration of cows waiting to give birth should be able to meet the needs of the animals, so the consumption of this group should be measured daily and the ration should be adjusted based on their intake.
Cows with the first stomach have less feed consumption compared to the cows with multiple stomachs, which leads to a decrease in the supply of metabolizable amino acids to the cattle with the first stomach. In addition, cows in the first abdomen need more metabolizable amino acids for the growth of mammary tissue, for these reasons, more attention should be paid to meeting the needs of animals in the first abdomen for amino acids (NASEM Dairy Cattle, 2021).
Forage quality is very important
During the dry season, it is very important to consume quality fodder to maintain the capacity of the rumen and prevent the increase of fat tissue in the animal’s body. Excessive feeding of energy in the form of easy-to-digest carbohydrates leads to an increase in the weight (mainly body fat) of livestock and is significantly related to the intensification of the decrease in dry matter consumption in the last days of pregnancy (Drakli and Cardoso 2014).
Cows that suffer from a significant reduction in dry matter intake in the last week of pregnancy, eat less in early lactation and suffer from ketosis and displacement of teats, and this issue will be the basis of other diseases. Supplying adequate forage NDF is important to maintain rumen fill and ensure rumination during this period. A common practice has been to incorporate straw or less digestible forages into transition diets (Drakli and Cardoso, 2014).
fat supplement
Increasing dietary fat from 2.5 to 3 percent of dry matter to 4 to 4.5 percent, with the help of fat supplements, improves pregnancy per insemination and reduces open days (Rodney et al., 2015).
The mechanisms of reproductive improvement are multiple, effects on follicle growth, progesterone secretion by the corpus luteum, improvement in fertilization and embryo quality, changes in endometrial function, and increased pregnancy retention (Santos et al., 2008).
A common misconception is that the reproductive benefits of fatty acid intake in early lactation are attributed to improved energy balance. The addition of fat supplements rarely affects energy balance in early lactation, and reproductive benefits are observed regardless of changes in body weight or energy balance (Santos et al., 2008; Rodney et al., 2015). However, the effects on reproduction vary with the type of fatty acid fed, and usually unsaturated fatty acids are more beneficial for reproduction.