The effect of fine grinding or sodium hydroxide treatment of wheat, offered as part of a concentrate supplement, on the performance of lactating dairy cows

Abstract

A study was conducted to examine the effect of fine grinding or sodium hydroxide treatment of wheat, and increasing concentrate food level, on milk production. Two concentrates based either on ground wheat (450 g/kg, GW) or sodium hydroxide treated wheat (500 g/kg, SW) were offered at four concentrate levels of 2-5, 5-0, 7-5 and 10-0 kg dry matter (DM) per day to 24 dairy cows in a three-period, change-over design experiment. On average, across all concentrate food levels, silage DM intake was significantly (P < 0-01) higher with the SW concentrates, reflecting a significantly lower silage substitution rate with SW relative to GW concentrates (P < 0-01). Milk yield was also significantly higher with the SW concentrates (P < 0-05), although marginal responses to increased concentrate food level were similar (P > 0-05). Milk protein concentration increased linearly with increasing concentrate food level (P < 0-001), with a significantly greater response with the GW relative to the SW concentrate (0-59 v. 0-24 g/kg (P < 0-05) increase per kg additional concentrate). However, milk protein concentration was also significantly lower with the GW concentrate at low food levels (P < 0-05). Milk fat concentrations were similar with the two concentrate types with significant reductions in milk fat concentration with increasing concentrate food level (P < 0-05). Blood urea (P < 0-001) and /5-hydroxybutyrate (P < 0-05) concentrations were significantly lower in animals offered the SW concentrate. Apparent digestibility coefficients were unaffected by either concentrate type or concentrate food level (P > 0-05), although modified acid-detergent fibre apparent digestibility was significantly reduced with increasing concentrate food level (P < 0-001). Results indicate that, at similar levels of concentrate feeding, silage intake and milk yield were significantly greater with SW compared with GW concentrates (P < 0-05 or greater). Increases in milk protein concentration with increasing concentrate food level were significantly greater with GW than with SW concentrates (P < 0-05).

A review of starch digestion in the lactating dairy cow and proposals for a mechanistic model: 1. Dietary starch characterisation and ruminal starch digestion

“…These data support the principal that total tract digestibility of starch is related more to ruminal (Figure 8) digestion than intestinal digestion. In a study investigating the use of NaOH (3.5%> NaOH per kg DM) treated wheat grain vs ground wheat, Mayne and Doherty (1996) reported no difference in the apparent digestibility of dry matter (DM) or organic matter (OM) between the two treatments for dairy cows. These data suggest that NaOH treatment has less effect on digestibility when used to treat sorghum than with the treatment of wheat.…”

“…Digestibility coefficients for wheat OM were 81% with both treatments (Mayne and Doherty, 1996). Krause et al (1998) determined the effects of the addition of fibrolytic enzymes to whole barley grain on digestion in four ruminally cannulated steers.…”

Comparison of rolled, NaOH treated and ensiled wheat grain in dairy cattle diets

“…Mayne and Doherty (1996) neither found differences in the energy values of grass silage based diets with GW or NaW, incorporated in the concentrate. No literature data were found on the energy value of EnW, but Kennelly et al (1988) found a comparable energy value for ensiled rolled HMB and rolled dry barley.…”

“…The data from literature on NaOH treated wheat (NaW) are also restricted and somewhat contradictive. Kung et al (1983) found negative effects of NaOH treated grain on the milking performance, whereas Sriskandarajah et al (1980) and Mayne and Doherty (1996) found higher milk yields and increased intake with NaW vs. rolled wheat (RW) and ground wheat (GW), respectively.…”