What does the drought of 2022 mean for lactating pairs in the spring of 2023?
As of February, Nebraska remains in drought conditions despite much of the state receiving significant snowfall in December and January (https://droughtmonitor.unl.edu/). The soil moisture profile is in a deficit due to months of below normal precipitation the last couple of years, which will have an impact on grass growth this spring.
Range Ecologists are Recommending Delayed Turn Out
Range ecologists are recommending delayed turn out to give the grass a chance to recover from the hard hitting drought conditions of last summer. Producers who choose to delay turn out need to feed a diet that meets the needs of the cow for lactation, for returning to estrus, and if turn out is delayed more than a month, the nutritional needs of the calf beyond milk consumption.
Total Digestible Nutrients (TDN) Requirements Increase over 50% from Late Gestation to Peak Lactation
The energy requirements (typically measured as TDN in cow diets) increase over 50% from late gestation when the fetus is rapidly growing, to peak lactation, which is generally 8 weeks postpartum. Additionally, a cow must rebreed within 85 days to stay on a 365-d calving interval. In a normal year, lush green grass would exceed the nutrient needs for the lactating cow and make the return to estrus in a timely manner very likely. In a confinement situation, the diet fed must meet those requirements.
Saving the Best Hay and Increasing the Winter Protein Supplement – Does that Meet Her Needs?
If a producer fed 28 lb (as fed basis) of high quality hay (58% TDN; 13% CP) and 3.5 lb of 20% protein cubes to a 1400 lb lactating cow, the cow’s protein needs would likely be met, but the energy provided would fall short, causing the cow to lose weight. The cold winter coupled with many inches of snow cover across most of Nebraska has made it difficult for cows to maintain body condition over the winter. Therefore, using extra body condition as an energy source while deferring grazing may not be an option for some cows.
Total Mixed Ration (TMR) Option
If producers have a way to grind, mix, and feed a TMR, this can be a viable option. University of Nebraska Extension Beef Team personnel can assist producers with developing specific rations with the commodities they have. However, an example diet for a lactating 1400 lb cow would include 19 lb of residue or poor quality hay, 17 lb of silage, 26 lb of wet distillers grains and a mineral package (per cow on an as fed basis). This diet meets the needs of the cows, but is a little bit limiting in dry matter intake to reduce costs, so producers will want to provide at least 2.5-3 ft of bunk space per pair to provide all cows and calves an equal chance at the feed, as calves will come to feed with the cows.
Consuming Feed in Addition to Milk is Critical for Rumen Development in the Calf
If grazing were deferred until June, a March-born calf would be three months old by the time grazing was available. This calf would likely be eating at least 1% of its body weight in forage on a dry matter basis. Therefore, a 300 lb calf would eat about 6 lb (as fed basis) of the example TMR above in addition to milk from the cow. Another option producers might consider is providing a creep gate to allow the calf access to their own TMR in a different pen, or a creep feeder in which they provided a commercial creep feed. Feed costs need to be evaluated as pelleted and bagged feeds tend to be more expensive than mixing a diet from bulk commodities on site.
Other Considerations for the Confined Calf
Confined calves are likely exposed to a higher pathogen load than grazing calves. Therefore, another advantage to a creep gate into their own pen is that it allows them space away from the cows, which can reduce pathogen exposure. Another advantage is that it allows the producer to offer the calves their own water source designed so that they can always reach the water level. A windbreak or shelter may also be provided.
Producers who are planning to confine pairs to defer grazing may want to consult with their local veterinarian to develop a herd health protocol and a nutritionist or beef focused extension personnel to develop diets with available commodities appropriate for confined pairs.