Within a properly balanced diet, four key feed ingredients and strategies can help improve reproductive success:

• Dietary Anion-Cation Difference (DCAD)
• Metabolizable protein (MP)
• Refined Functional Carbohydrates™ (RFCs™)
• Essential Fatty Acids (EFAs)

Individually and combined, these feed ingredients work to promote cow health and productivity, which directly affect reproductive efficiency. Here’s how these factors help nutritionally support your dairy’s reproductive program.

1. Formulate Rations for Proper DCAD levels Before and After Calving

Feeding a negative DCAD diet (-8 to -12 meq/100g ration dry matter) for the three weeks prior to calving improves cow health and performance in the following lactation.

Research¹ published in 2015 demonstrated that:

• Feeding the ration with negative DCAD levels reduced (P<0.05) the prevalence of subclinical hypocalcemia at day zero and one day in milk (20.0 percent and 34.3 percent) compared with the ration with positive DCAD levels (69.3 percent and 76.5 percent) on day zero and day one in milk.
• Incidence of clinical hypocalcemia (milk fever) was 0 percent in the ration with negative DCAD levels compared with 23.1 percent for the ration with positive DCAD levels (P<0.05).

Two 2018 meta-analyses^2,3 further illustrate how prepartum negative-DCAD rations improve calcium metabolism around calving, reduce the risk of milk fever and uterine diseases, and foster lactation performance.

 

Ration DCAD strategies must change following calving

Feeding a ration formulated for positive DCAD postcalving also benefits cow health and performance.

Achieving positive DCAD status can help neutralize blood acid load caused by high milk production, ketone development and free fatty acids from body fat mobilization.

Increasing the potassium component of DCAD will help replace what is lost through increased milk production, as well as assist cows in better dealing with heat stress.

Aim for a dietary potassium level of at least 1.7 percent of the total dry matter during non-heat-stress periods, and to at least 2 percent immediately before and during heat-stress periods of the year.

Postpartum ration DCAD levels depend on lactation stage. Recommendations are:

• +35 to +45 meq/100g ration dry matter for high producing cows
• +30 to +35 meq/100g ration dry matter for mid-lactation cows producing less than 85 pounds of milk
• +25 to +30 meq/100g ration dry matter for late-lactation cows

Keep in mind that seasonality and climate can affect feedstuff DCAD levels. Test silage and other feed ingredients regularly with wet chemistry analysis to ensure ration accuracy—so that proper levels of DCAD are being fed at all times.

 

2. Factor in MP

Focusing on DCAD levels alone—without accounting for MP—does not result in optimal rations or optimal animal performance. When you omit MP from consideration, you’re missing an opportunity to enhance cow health and production.

MP matters because it is the true protein that is digested post-ruminally, and the amino acids that are the components of protein and are absorbed by the small intestine.

Absorbed amino acids are used for the synthesis of proteins that are essential for an animal’s growth, body condition maintenance, reproduction and milk production as well as supporting fetal growth. These are vitally important tasks and help explain why proper nutrition in the transition period helps lay the groundwork for a successful next lactation.

If dry cows do not receive enough MP, they will break down muscle and other protein sources in the body.⁴ It’s important to remember that early-lactation cows are unable to consume sufficient protein to meet the mammary and non-mammary amino acid requirements.

• Therefore, formulate prefresh diets to supply about 1,100 – 1,200 grams per day of MP.

When cows receive adequate levels of MP during this timeframe, you’ll see benefits after calving. Research⁴ shows that MP fed in the close-up period was positively related to milk protein yield in early lactation as long as cows were fed more than 75 percent of their MP requirement in early lactation.

 

3. Embrace RFCs

RFCs have been shown to have a positive effect on dairy cow health and performance. This is due in large part to RFCs’ ability to counteract mycotoxins and agglutinate harmful bacteria in the gastrointestinal tract that can impede immune function.

This is an important element, because mycotoxins have been associated with several factors that reduce performance including irregular estrous cycles, embryonic mortalities, pregnant cows showing estrus and decreased conception rates. When animals are fighting off a health challenge—whether locally or systemically—it affects the energy available for other biological processes, including cyclicity and pregnancy retention.

In addition, immune suppression caused by mycotoxins can be reversed by beta 1,3/1,6 glucans and mannans present in RFCs, allowing the cow to further protect itself against bacterial pathogens. Plus, nutrient uptake is maintained, leading to better feed efficiency and animal performance.

 

4. Use EFAs to Enhance Reproductive Performance

Omega-3 and Omega-6 Essential Fatty Acids (EFAs) are one of the nutrition solutions that have been identified to increase dairy cow reproductive performance and immune function. EFAs aid in several significant biological functions, including:

Data from five on-farm trials⁵ conducted across the country illustrate the positive health impacts that can be obtained by adding Omega-3 and Omega-6 Essential Fatty Acids (EFAs) to pre- and postpartum cow diets during the transition period. 

Results showed that transition and prebreeding diets enhanced with these EFAs:

• Resulted in 64 percent fewer embryonic deaths
• Improved reproductive performance
• Conception rate improved an average of 9.1 percent
• Pregnancy rate increased an average of 11.5 percent

The upward trend in cow health and immune function from adding Omega-3 and Omega-6 EFAs to pre- and postpartum rations shows the positive impact this key feed ingredient has on cow health, reproductive performance and potential profitability regardless of location or management style.

University trials also indicate that adding Omega-3 and Omega-6 EFAs to transition cow rations improved immune function. Data^6,7 show a 37 percent reduction of endometritis, a serious threat to reproductive performance.

Of course, optimal pregnancy rate and reproductive success take efforts from all areas of the dairy. Work with your on-farm team, as well as your veterinarian and nutritionist to identify opportunities for improvements.

Use these nutritional tools as part of an overall reproductive management strategy to help you achieve the outcomes you seek—optimal cow health, reproductive performance and potential profitability.

 

1 Martinez N, Rodney R, Santos RM, Greco LF, Bisinotto RS, Ribeiro ES, Hernandez LL, Nelson CD, Block E, Lean IJ, Santos JEP.  Effects of feeding diets differing in dietary cation-anion difference (DCAD) and source of vitamin D on Ca status, health and lactation performance in Holstein cows. 2015 American Dairy Science Annual Meeting Abstract # 704. Available at: http://m.jtmtg.org/abs/t/64388 

2 Lean IJ, Santos JEP, Block E, Golder H. 2018. Effects of prepartum dietary cation anion difference intake on production and health of dairy cows: A meta-analysis. J Dairy Sci (submitted)

3 Santos JEP, Lean IJ, Golder H, Block E. 2018. Meta-analysis of the effects of prepartum dietary cation-anion difference on performance and health of dairy. J. Dairy Sci. (submitted)

4 Dann, H. Are your dry cows getting enough metabolizable protein? Miner Institute Farm Report. Available at: http://whminer.com/fr_13_02_03.html. Accessed April 7, 2018.

5 Pankowski J, Noble J, Brennan P, Jarrett G, Block E. Effects of ruminally inert essential fatty acids on postpartum immune-related functions and productivity in lactating dairy cattle. Abstract #659 presented at: ADSA-ASAS Joint Annual Meeting, July 8 – 12, 2013; Indianapolis, Indiana. Data on file.

6 Bowen AJ. The Effects of Dietary Linoleic and Linolenic Acids on Reproductive Performance in Holstein Cows. [Master’s thesis].

Department of Animal Sciences, University of Arizona; 2008.

7 Jones B, Fish RD, Martin A, Duff GC, Ax RL. Effects of Supplemental Linoleic and Linolenic Acids on Reproduction in Holstein Cows. Prof Anim Sci 2008;24:500-505.