In the calf world we talk a lot about average daily gain and the effects that better gains early on in life have on lifetime production. Although gains early on in life are important and do affect productivity, much of the growth and development affecting lifetime productivity may be taking place in utero, even before the calf is even born.

In Utero

Fetal growth and development are profoundly influenced by the in-utero environment. In humans approximately 20% of stunting has in-utero origins. Growth deficits in-utero are associated with maternal or placental inflammation and infection. This suggests that there may be a role that the microbiome plays in fetal growth and development. It is also very likely that these same mechanisms come into play when we talk about neonatal calf growth and development.

In the United States, and likely many other countries, poor intrauterine environments may occur due to: 1) malnutrition, 2) insufficient energy supply, 3) heat stress or other stressors, 4) overweight mother cows. Each of these stressors influences the nutritional status of the dam as well as her microbial population. In turn affecting the growth and development of the fetus.

A poor uterine environment during the first trimester can have significant impacts on the development of the mammary gland, ovaries, and development of homeostatic mechanisms in the liver and pancreas. Proper development of these organs is critical for future lifetime milk production, heart, lung, pancreatic, kidney, and placental health. Other performance outcomes influenced by intrauterine growth are the development of the small intestine and muscle, weaning weight, and reproductive performance.

Establishment of Gut Microbiota

Vaginal delivery plays a key role in colonizing the calf with beneficial microbiota at birth. Typically, vaginal microbiota is dominated by one of four Lactobacillus species. These bacteria are swallowed by calf and colonization of the digestive tract begins. Other bacteria are also ingested by the calf as it enters a new environment. These bacteria are not always helpful. It is important to provide the calf with a clean area to be born so that harmful bacteria do not outcompete the beneficial ones during colonization of the digestive tract.

Colostrum is important not just for passive transfer of IgG, but also for the colonization of the gut. Bacterial composition of colostrum can be highly important for microbial colonization as fresh colostrum contains Lactobacillus, Bifidobacterium, Escherichia, Staphylococcus, Coliforms, and Streptococcus. Additionally, colostrum contains certain oligosaccharides that serve as substances for growth of the establishing bacterial community and for preventing pathogens from binding to the intestinal epithelial cells.

As the calf continues to grow and transition to dry feed the composition of gut microbiota continues to shift until the calf becomes a fully functioning ruminant.  Although the rumen provides a home for a diversity of bacteria, the lower digestive tract still proves to be a very important player in digestion and the immune system.

Immunity

Early development of gut microbiota is thought to be very important for the proper development of the immune system. Dynamic interactions between gut microbes and the innate and adaptive immune systems of the calf play vital roles in promoting intestinal homeostasis and inhibiting inflammation.

Gut microbiotas metabolize proteins and complex carbohydrates, synthesize vitamins, and produce a large amount of metabolic products that mediate communication between the gut epithelial and immune cells. Gut dysbiosis can also dysregulate immune responses, cause inflammation, and oxidative stress.

Management Factors Influencing Gut Colonization

We have come to know so much about the effects that gut microbiota have on the immune system. There is still much to learn, but here are some key takeaways that you can easily apply on your farm today.

1. Manage stress and inflammation in pregnant and transition cows. Provide proper nutrition and modulate the gut environment and the immune system with a direct fed microbial. (Achieve)

2. Not every calving is perfect. Calves experiencing a difficult birth, or that did not get adequate colostrum are good candidates to receive supplemented levels of lactobacillus. (Sync)

3. Every calf gets adequate amounts of high-quality colostrum and transition milk if possible.

4. Clean calving pen to prevent inoculation of harmful bacteria.

5. Avoid using oral antibiotics if possible. Turn to products that bind and remove pathogens instead. (Surveillance)

6. Provide the calf with appropriate starter feed and fresh water.

Sources:

Hang BPT, Wredle E, Dicksved J. Analysis of the developing gut microbiota in young dairy calves-impact of colostrum microbiota and gut disturbances. Trop Anim Health Prod. 2020 Dec 28;53(1):50. doi: 10.1007/s11250-020-02535-9. PMID: 33369699; PMCID: PMC7769786.

Malmuthuge, N. Effect of Early-Life Microbial Interventions on Health and Immunity. Lethbridge Research and Development Centre, 2018.

Schoonmaker, J. Effect of Maternal Nutrition on Calf Health and Growth. Purdue University, 2013.

(PDF) Effect of maternal nutrition on calf health and growth (researchgate.net)

Written by: Mariah Gull, M.S.

Calving is a stressful event for both the cow and the calf. Management practices that minimize stress and support immune function are crucial during this event. The first few days postpartum are the most critical days in the life of a dairy cow. Proper nutrition and management during this time is important to maintain immunity, prevent metabolic disorders, and achieve high milk production throughout lactation.

Metabolic Disorders

A metabolic disorder is a result of a disruption in the cow’s internal biochemical processes. These disorders are often caused by an imbalance of minerals in the blood or improper rumen pH. Cows that experience a metabolic disorder are less productive and more likely to encounter a secondary disorder such as; ketosis, mastitis, retained placenta and uterine prolapse.

Rumen Acidosis

Cause: Acidosis is caused by a drop of pH in the rumen. Signs of rumen acidosis include; going off feed, slug feeding, depressed milk fat, diarrhea, laminitis, and a high incidence of displaced abomasum. Acidosis is often caused by poor bunk management or low-quality ration forage.

Low rumen pH is often common in fresh cows as their intakes increase or decrease dramatically, or as they change to a new ration higher in fermentable carbohydrate. This low rumen pH makes the fresh cow more likely to experience acidosis than cows later in lactation.

Prevention: Properly balance diets for energy, and provide smooth transitions from the close-up ration, to the fresh cow ration, and on to the high cow ration. It is also a good idea to offer rumen buffers free choice and/or in the ration.

Milk Fever

Cause: Milk Fever is a result of hypocalcemia (low blood calcium). Typically, cows will experience hypocalcemia post calving because of increased demand for calcium as the cow produces more milk. In some cases, the change is more drastic and hypocalcemia is severe enough to lead to clinical milk fever.

This sudden demand for calcium must be accommodated by absorption from the gut or resorption (mobilization) from bone. When calcium supplied from both gut absorption and bone mobilization is not adequate, then milk fever is the result.

Prevention: Consider feeding a negative DCAD diet in the close-up period, and ensure the fresh cow diet is properly balanced. It is also common to supply the cow with an oral calcium supplement at calving as a preventative measure.

Displaced Abomasum

Cause: A displaced abomasum (DA) usually occurs within the first month after calving,

and may be a primary or secondary condition. The abomasum migrates to the left or right side, and the gut may become twisted and create a partial blockage of the digestive tract. Fresh cows with low dry matter intake, or those whose ration is changed abruptly are more at risk of a DA.

Prevention: Maintain adequate daily dry matter intake, and blood acid-base balance. Watch for any symptoms of milk fever and promptly treat with intravenous calcium if needed.

Ketosis

Cause: Ketosis occurs when the cow experiences a negative energy balance and the body mobilizes large amounts of adipose (fat) tissue. Fat mobilization is accompanied by high blood serum concentrations of non-esterified fatty acids (NEFAs), a large portion of which are directed to ketone synthesis in the liver. Resulting in high concentrations of NEFAs and ketones, and low concentrations of glucose in the cow.

Prevention: Manage body condition in late lactation, heavy cows are more likely to experience ketosis at freshening. Encourage DMI during the close-up and fresh cow periods, and balance rations for both adequate energy and fiber to promote rumen health. Consider including supplements such as; niacin, calcium propionate, sodium propionate, propylene glycol, and rumen-protected choline, during the close-up period as they may help prevent and manage ketosis.

There are many different metabolic diseases that fresh cows are at risk for. One thing that they all have in common is that to prevent them from occurring cows need properly balanced rations and we have to keep the cow eating! If the close-up ration is adequately balanced and the fresh cow ration mirrors the high cow ration, fresh cows should experience a relatively smooth transition.

However, there are additional supplements to consider when promoting gut health to keep cows eating and also to support to the immune system through transition. Yeast, probiotics, and chelated minerals have all been shown to promote optimum rumen function and improve overall cow health. One supplement that has all the bases covered is Achieve.

Achieve contains:

• Multiple strains of live yeast that provide a rich nutrient source for rumen microbes.

• Viable lactobacillus probiotics aid in stabilizing rumen pH and helping to prevent acidosis.

• Bacillus subtilis to produce large quantities of digestive enzymes and compete with pathogenic bacteria.

• Digestive enzymes that stimulate fiber-digestion, stabilize rumen pH, and reduce heat stress.

• Mannan-oligosaccharide prevents pathogenic colonization in the GI tract.

• Yucca schidigera modifies ruminal fermentation by altering select microorganism ratios. Resulting in reduction of rumen ammonia and high blood urea levels. Which in turn has been show to improve milk production and conception rates in dairy cattle.

• Immune Positioning System (IPS) a blend of biologically active polysaccharides and polypeptides. IPS nutritionally assists cows in balancing cellular function, reducing gut inflammation, and supporting the immune system.

Visit with your veterinarian and nutritionist about any management improvements, or ration adjusts that may aid in reducing metabolic disease in your transition cows.

Written by: Mariah Gull, M.S.