Whole Linted Cottonseeds and Chewing
Fiber, typically measured as neutral detergent fiber (NDF), is an essential component of the lactating cow's diet to obtain maximum dry matter and net energy of lactation (NEL) intake, to maintain normal rumen fermentation and milk fat percentage, and possibly to aid in the prevention of post-calving disorders (NRC, 1989). The NRC (1989) suggests that at least one third of the total diet dry matter should be long hay or its equivalent as medium to coarsely chopped silage or other forage. It recommends that the lactating dairy cow diet should contain a minimum of 25 to 28% NDF; 75% of the dietary NDF should be supplied from forage.
In low forage diets in which alfalfa was the sole forage, cottonseeds have been shown to have effectiveness values that vary quite remarkably.
| Feed | Standard | Effectiveness value |
| Short alfalfa | Long alfalfa | 76% |
| Cottonseed | Long alfalfa | 50% |
| Cottonseed | Short alfalfa | 127% |
| (Mooney and Allen, 1997) | ||
The short-cut and long-cut alfalfa haylages had mean particle sizes of 5.8 and 11.4 mm. Although 5.8 mm (less than 1/4 inch) seems small, the short-cut alfalfa haylage was still relatively long compared to other forages; the small size is explained by laboratory sieving methods that sort particles more by width than by length. Allen (1997) plotted chewing time against mean particle size; he noted that 3 mm was a major breakpoint below which chewing dropped precipitously and above which chewing time increased at a diminishing rate. From the table above, the range in effectiveness values within each category was quite small (i.e., low variation). Thus, only dietary interactions explain how the effectiveness value of cottonseeds was lower than short-cut alfalfa, when compared to long-cut alfalfa (50 versus 76%), but actually was higher when compared directly with short-cut alfalfa (127%). Recent work at OSU (Slater et al., 2000) documented the high effectiveness of whole cottonseeds in low forage diets.