Processing Whole Cottonseed Moderates Fatty Acid Metabolism and Improves Performance by Dairy Cows

Abstract

Pelleting cottonseed (CS) improves handling characteristics. Our objectives were to determine whether increasing the particle size of the CS pellet or dilution of a smaller pellet with delinted CS would limit the rate of CS oil release to optimize digestibility of fatty acids (FA) and fiber while maintaining milk fat production. In a 5 x 5 Latin square design with 3-wk periods, 5 rumen-cannulated cows were fed 1) control with CS hulls (CSH) and CS meal plus tallow and Ca soaps of FA, 2) whole CS (WCS), 3) small CS pellets (SP; 0.44-cm die diameter), 4) larger CS pellets (LP; 0.52-cm die diameter), or 5) a blend of 1/2 SP plus 1/2 partially delinted CS (SPD). Diets contained 39.6% concentrate, 14.4% CS, and 46% forage (40:60, alfalfa hay:corn silage) on a DM basis and were balanced to have similar concentrations of CS protein, CS fiber, and total fat. In a production trial, dietary treatments were 1) WCS control, 2) LP, 3) SPD, and 4) SPD fed at 90%. Sixty cows averaging 105 d in milk were fed the WCS diet for 2 wk and then assigned to one of the 4 diets for 12 wk. Total tract digestibility of NDF was unaffected, but N digestibility was lower for SPD than for other treatments. Fatty acid digestibility was higher for SP and LP (82.6 and 82.3%) than for CSH or SPD treatments (78.8 and 75.3%), and WCS was intermediate (81.1%). The trans-11 C18:1 from cows fed SP and LP (6.58 and 6.24% of total milk FA) was greater than that from cows fed CSH, WCS, and SPD (3.23, 3.79, and 3.97%). The trans-10 C18:1 in milk fat from SP and LP (0.508 and 0.511%) was higher than that in WCS and SPD diets (0.316 and 0.295%); CSH was intermediate (0.429%). Using passage rates estimated from the NRC, disappearance of total FA in situ was estimated to be 17.7, 44.2, 46.6, and 35.0% for WCS, SP, LP, and SPD, respectively. In the production trial, a diet x week interaction was explained by a trend for progressively greater milk production for SPD and SPD90 than for WCS or LP. Milk fat was lower for LP (2.74%) and SPD90 (2.85%) than for WCS or SPD (3.07 and 3.08%). The fat yield was lower for LP than for SPD (1.09 and 1.30 kg/d); WCS and SPD90 were intermediate (1.23 and 1.21 kg/d). Although having a lower FA digestibility, SPD appeared to minimize negative effects of free oil from SP in the rumen, explaining higher DMI and milk production compared with WCS or LP.

Effect of processing whole cottonseed on yield and composition of milk in dairy cows

“…These results were consistent with other reports (Dhiman et al, 1999;Moreira et al, 2004;Reveneau et al, 2005).…”

“…However, we observed that the milk protein was increased when cows were fed delinted and extruded WCS (P<0.05), which was consistent with some previous reports (Mabjeesh et al, 2000;Reveneau et al, 2005). This can be explained that microbial protein synthesis was improved when cows were fed processing WCS, resulting in an increase of protein fl ow in the small intestine.…”

“…Previous studies showed that supplement of linted WCS, delinted WCS (Moreira et al, 2004;Reveneau et al, 2005) or extruded WCS (Dhiman et al, 1999) also had no effect on milk fat.…”

“…Mabjeesh et al (2000) demonstrated that feeding roasted delinted WCS was more effective in creasing milk fat content of cis9, trans11-CLA than feeding linted WCS. Reveneau et al (2005) concluded that feeding small WCS pellets was more effective in increasing milk fat content of cis9, trans11-CLA than feeding large WCS pellets. Dhiman et al (1999) found that milk fat content of cis9, trans11-CLA was increased in the extruded WCS treatment compared with control.…”

Effect of processing whole cottonseed on nutrient digestibility and ruminal fermentation in dairy cows

“…There was a trend that diets supplemented with extruded WCS could increase NDF digestibility (P<0.1). This result was in agreement with previous reports (Pires et al, 1997;Reveneau et al, 2005;Sullivan et al, 2005). The decrease in nutrient solubility and degradability of extruded WCS may increase passage of fi bre of WCS origin to the abomasum.…”