Ensile Corn Silage Four-Six Months Before Feeding
For optimum starch and fiber digestibility, corn silage should be ensiled at least four months before it's fed, a recent study showed.
In another, quality appeared to plateau after about six months of ensiling.
The first study, by Cumberland Valley Analytical Services, Hagerstown, MD, and Paradox Nutrition, Chazy, NY, looked at samples submitted to the lab between January 2004 and February 2008.
Available starch was lower during October and November than during the rest of the year. NDF digestibility was highest in samples received from September through January. Titratable acidity was lowest and pH was highest from September to December. Lactic acid was lowest from September to December and acetic acid was lowest from September to February.
“These data suggest that at least four months are required for full fermentation of corn silage,” the researchers wrote.
In the other trial, by Vita Plus Corporation and Dairyland Laboratories, chopped corn was collected from incoming loads at two dairy farms. Silage from each farm was placed in 48 vacuum-sealed plastic bags, then four bags were removed monthly and frozen until analyzed for several digestibility parameters.
The researchers say changes in digestibility values appeared to plateau after six months of ensiling, with total-tract starch digestibility and ruminal NDF digestibility changing the most during that time.
Narrow Swaths Make Highest-Quality Hay
Alfalfa hay dries faster when laid in wide swaths instead of narrow ones, but a University of Idaho study showed that it isn't as high in quality.
The researchers compared the effects of wide vs. narrow swaths and morning vs. afternoon cutting on carbohydrate and protein digestion in sheep.
Daily intake of organic matter, NDF, ADF, hemicellulose, cellulose and total nonstructural carbohydrate (TNC) was higher for narrow swaths than for wide ones. Protein and TNC intakes were higher when alfalfa was cut in the afternoon rather than in the morning, say the researchers.
BMR Silage Helps Transition Cows
Cows fed brown midrib (BMR) instead of conventional corn silage for six weeks starting three weeks before calving produced more milk during the first 15 weeks of their lactations.
In the Cornell University study, prepartum rations contained 47% corn silage, 18% wheat straw, 7% alfalfa haylage and 28% concentrate. Post-calving rations included 40% corn silage, 15% alfalfa hay, 1% straw and 44% concentrate. The diets were formulated to keep all parameters the same except NDF digestibility, which is higher in BMR corn silage than in conventional silage.
Cut Bermudagrass Every 24-27 Days
Short cutting intervals provide excellent-quality Tifton-85 bermudagrass greenchop, but probably aren't the best option.
That's according to University of Florida researchers who cut the grass every 21, 24, 27 or 35 days in 2007, leaving 2.76” or 5.5” of stubble. The number of cuttings ranged from six for 21-day intervals to three for the 35-day schedule.
Cutting height did not affect nutritive value of the harvested forage, the researchers report. Crude protein and digestibility were highest with 21-day cutting and lowest at 35 days.
The 24- and 27-day cutting intervals provided the best compromise between quality, yield and other factors, they add.
Fenugreek Can't Match Alfalfa's Feeding Value
An annual legume seen as a possible emergency replacement for winterkilled alfalfa didn't cut the mustard in a University of Alberta study.
Haylages made from two varieties of fenugreek were compared with each other and with alfalfa haylage as part of TMRs for dairy cows. All were fed in 40%-haylage, 10%-barley silage and 50%-concentrate rations.
“Our results suggest that, although the digestibility of the fenugreek diets was equivalent to that of the alfalfa diet, fenugreek haylage has a lower feeding value than alfalfa for lactating dairy cows due in part to lower dry matter intake, resulting in lower milk yield,” the researchers reported. The lower intake was attributed to slower NDF digestion in fenugreek. One fenugreek variety had a longer rumen turnover time than the other, and both were longer than that of alfalfa.
Consider Adding Straw To Limit Heifer Intake
Adding straw to free-choice rations for growing heifers may be a suitable alternative to limit feeding as a way to control intake.
Scientists at the University of British Columbia and University of Guelph reached that conclusion after comparing three rations for Holstein heifers. The control diet contained 17% corn silage, 52% grass silage and 31% concentrate. The experimental rations were the control diet plus 10% or 20% straw.
Adding straw increased feeding time and reduced dry matter intake. Energy and nutrient requirements were sufficiently met with the control and 10%-straw diets.
The results suggest that adding a moderate amount of straw can target nutrient intake without negatively affecting feeding behavior or growth potential, say the researchers. Furthermore, free-choice feeding of a diluted diet provides increased opportunity for the animals to express their natural foraging behavior, they add.