STRAIGHT FROM THE HORSES MOUTH

Duane A. Lienemann

 UNL Extension Educator,
Webster County
January 19, 2012 Edition
I just got a note from my daughter that her calving season has begun and I thought, wow that is a little early, but then I thought about it and we are coming up on the end of January already. I know that a lot of heifers are bred early to give them more time to recover before the next breeding cycle and a lot of AI calves usually arrive a little earlier than the traditional pasture bred cattle. Either way “the season” is upon us!
I always loved calving season when I had my cows. I will have to admit that I didn’t really enjoy checking those cows in the dead of a seriously cold night like the old Dr. Pepper commercial, 10-2 &4, which most likely was referring to the middle of the day. But what I did like is seeing that newborn literally come to life and marveling at how quickly they could get up and find their first meal. Yes, I felt I had to help some of the “dumb” or slow ones, but then I wonder sometimes who really was the dumb one. There still is nothing like the feeling of your planning, hard work, care and nervous anticipation come to fruition. Even better is when the grass starts greening up, the days get longer and warmer and you can see a whole herd of little bovines with their tails up in the air racing each other with nervous mothers looking on. Now when you take them to pasture and they timidly get off the trailer and then immediately look for mom when they see the large expanse before them. That was a little humorous to me. I guess in reality all kids are kind of the same.
I even experimented with feed timing to affect when calves were born. I found that the easiest and most practical method of inhibiting nighttime calving seemed to be by feeding cows at night. I always wondered why, and as I understand it, the physiological mechanism is really unknown, but some hormonal effect may be involved. Rumen motility studies indicate the frequency of rumen contractions falls a few hours before parturition. Intraruminal pressure begins to fall in the last 2 weeks of gestation, with a more rapid decline during calving. The theory is that night feeding causes those intraruminal pressures to rise at night and decline in the daytime. Now that sounds pretty scientific. My take was always that I didn’t really want to do much on a full stomach after a smorgasbord, so why would it be different for cows. I do know that it seemed to work on a high percentage, but I still did the late night checking. I guess I didn’t trust that intraruminal stuff.
That all leads me to a little research I want to report on. With calving season rapidly approaching for spring-calving cows, I believe that nutrition becomes the most critical. Research has shown that a cow’s body condition at calving is a good indicator of her ability to cycle and breed back in a timely manner. But given the high price of high-quality hay in many areas, producers might be looking for ways to boost the nutritional value of lower-quality feeds such as wheat straw. Depending on local availability, by-product feeds such as beet pulp or distillers’ grains could fit the bill, based on University of Nebraska research. I know we have several farmers in Webster and Adams County already doing this.
The researchers conducted two experiments to evaluate feeding wheat straw supplemented with distillers’ grains or distillers’ grains and beet pulp, compared with feeding alfalfa hay to late-gestation cows. For the first experiment, the researchers prepared a high-moisture combination of 30 percent wet distillers’ grains plus solubles (WDGS) and 70 percent ground wheat straw three months ahead of the test and stored the feed in agricultural bags. They randomly sorted 40 pregnant cows into eight five-head pens, with half of the pens receiving the mixed feed and the other half receiving ground alfalfa hay. They limit-fed both groups for 77 days, with the diets formulated to meet the cows’ energy needs.
They ended the experiment two weeks prior to calving and measured initial and ending body weights, initial and ending body condition score (BCS) and calf birth weights. In this trial, average weight gain over the 77 days for cows receiving the wheat straw-WDGS mix was167 pounds compared with 144 pounds for the group receiving alfalfa hay. Change in BCS and calf weights did not differ between the groups, and the researchers concluded the stored mix of 30 percent DDGS and 70 percent wheat straw can maintain body weight and BCS in gestating cows.
In the second experiment, the researchers sorted 57 cows into pens receiving one of three rations: 1) Ground alfalfa hay; 2) 30 % DGS and 70% wheat straw; and 3) 20% WDGS, 20 % beet pulp and 60% wheat straw. In this case, all the rations were mixed and fed fresh, rather than mixed and stored like in the first trial. The researchers limit-fed each treatment group for 84 days, with rations formulated to meet the cows’ energy needs. They ended the experiment four weeks before calving and measured initial and ending body weights, body weight change, BCS change and calf birth weights.
Weight gains for the cows on the alfalfa treatment averaged 66 pounds compared with 147 for those on the WDGS-wheat straw diet and 162 pounds for those on the WDGS-beet pulp-wheat straw diet. Average BCS scores for cows on the alfalfa diet were 5.3, and cows in this group lost an average of 0.4 BCS through the course of the trial. Cows in the WDGS and beet pulp groups finished the trial at BCS 5.7 and 5.8 respectively, and maintained BCS through the trial. The researchers conclude that cows in late gestation will maintain body weight and BCS when limit-fed WDGS and beet pulp mixed with wheat straw to meet their energy requirements and may have some advantages in weight gain.
You can go to 2012 UNL Beef Report for more. Whatever you do, the main thing is to see to the nutrition of those cows as they near the end of their third trimester. I believe that it is a critical management tool. Good luck and good calving!
The preceding information comes from the research and personal observations of the writer which may or may not reflect the views of UNL or UNL Extension. For more further information on these or other topics contact D. A. Lienemann, UNL Extension Educator for Webster County in Red Cloud, (402) 746-3417 or email to: dlienemann2@unl.edu or go to the !website at: http://www.webster.unl.edu/me