The Effect of Corn Silage Particle Size and Cottonseed Hulls on Cows in Early Lactation

Abstract

The objective of this study was to evaluate the effects of reducing forage particle length (FPL) and the inclusion of cottonseed hulls (CSH) on intake, digestibility, chewing activity, and milk production of cows in early lactation. Sixteen multiparous cows averaging 17 ± 3 d in milk and 677 ± 58 kg BW were assigned to one of four 4 × 4 Latin squares. One square contained ruminally cannulated cows to evaluate effects of treatment on rumen fermentation and function. During each of the 23-d periods, cows were offered one of four total mixed rations that differed in particle length (long or short corn silage) and CSH inclusion rate (0 or 8% DM). Dietary treatments were: long no CSH (LGNH), long with CSH (LGH), short no CSH (SHNH), and short with CSH (SHH). Total physically effective NDF content, measured as percentage of NDF greater than 1.18 mm, was similar across diets, but mean particle length decreased with reducing FPL and inclusion of CSH. Dry matter intake was not significantly affected by FPL but was significantly increased with the inclusion of CSH. Decreasing FPL and the inclusion of CSH significantly increased neutral detergent fiber intake. Total chewing activity expressed as minutes per day was unaffected by FPL and the inclusion of CSH. Both eating and ruminating efficiency expressed as minutes per kilogram of neutral detergent fiber intake increased with increasing FPL and decreased with the inclusion of CSH. Milk production did not differ across treatments, but the inclusion of CSH significantly increased percent and yield of milk protein.Reducing FPL tended to reduce percentage milk fat but not yield. Mean ruminal pH was not affected by FPL but was highest on diets containing CSH, even though no treatment effects were observed on total VFA, acetate, or propionate concentration. These re- 2438sults indicate that corn silage FPL is a poor predictor of total chewing time and rumen pH but is useful in understanding factors affecting feeding behavior. In addition, the inclusion of CSH, resulted in increased rumination and mean rumen pH even though effects on VFA concentration were not observed. (Key words: forage particle length, rumination, and cottonseed hulls)Abbreviation key: CSH = cottonseed hulls, FPL = forage particle length, LG = long, LGH = long corn silage with cottonseed hulls, LGNH = long corn silage with no cottonseed hulls, NDFI = neutral detergent fiber intake, NFFS = nonforage fiber sources, peNDF = physically effective neutral detergent fiber, PSPS = Penn State Particle Separator, SH = short, SHH = short corn silage with with cottonseed hulls, SHNH = short corn silage with no cottonseed hulls, TC = total chewing activity, TNC = total nonstructural carbohydrate, X gm = geometric mean length.

The effect of partial replacement of corn silage on rumen degradability, milk production and composition in lactating primiparous dairy cows

“…In the current study, the daily mean ranged from 6.24 to 6.42 and from 4.00 to 4.50 for rumen pH and acetate/propio n a t e, respectively (Gencoglu and T u r k m e n , 2006). The percentages of milk fat in all diets were higher compared with those observed in other studies (Beauchemin et al, 2003;Kononoff and Heinrichs, 2003). In addition, these results are consistent with Mertens (1983) who reported that FCM yield was the greatest for cows fed diets based on AH, corn silage, or bermudagrass hay when dietary NDF content was 35% for each diet.…”

“…The requirement for peNDF of dairy cows was determined by Mertens (1997), who suggested that should be 22% of ration DM to maintain an average ruminal pH of 6.0 and 20% of ration DM to maintain the milk fat percentage of early to Midlactation Holstein cows at 3.4%. Based on measurements using the PSPS, several studies reported that increased intake of peNDF increased milk fat content (Yang et al, 2001;Kononoff and Heinrichs, 2003) and decreased milk protein content (Kononoff and Heinrichs, 2003), but others did not find any effects of peNDF on milk composition (Beauchemin et al, 2003;Kononoff et al, 2003b). Results obtained from the current study showed that cows fed with the CSW and CSWA diets had higher peNDF than CS and CSA (Table 2) but the peNDF did not affect the milk fat percentage.…”

Effects of different levels of physically effective fibers in diets for cows in early lactation

“…Soita et al (2005) reported that 99% of corn silage retained when 1.18 mm sieve was used, and there was no difference between long (19.1 mm) and short (9.5 mm) cut corn silage. Similarly, no difference in PEF was found for long (22.3 mm) and short (4.8 mm) cut corn silage in the study by Kononoff & Heinrichs (2003b). Yang & Beauchemin (2006a) determined greater range in PEF using original PSPS with two sieves, than those obtained using three sieves (range of 0.41-0.72 vs. 0.93 to 0.96, respectively) for three theoretical cut length of corn silage (28.6, 15.9 and 4.8 mm).…”

“…In this study, proportion of concentrate in the diets for different treatments was approximately 57% in DM basis. Reduced chop length of CS (Kononoff & Heinrichs, 2003b;Yang & Beauchemin, 2006a), and AH (Yang & Beauchemin, 2007) did not affect the dietary DM and NDF intake. It was discussed that the different dietary content of PENDF did not affect the rumen rate of digesta passage and thereby DM intake (Beauchemin & Yang, 2005).…”

“…In the recent study, dietary content of NDF and PENDF for all treatments were above the minimal requirements (25% for NDF, 19% for forage NDF on DM basis; NRC, 2001). Kononoff & Heinrichs (2003b) reported that highfiber coarse particles of CS were not consumed, and that sorting was the greatest in cows fed diet with longer forage particle length. This could explain the lower NDF intake in cows fed on the diets with longer forage particle length.…”