Performance of Lactating Dairy Cows Fed Silage from Corn of Varying Maturities

Abstract

The deleterious effect of frost on corn harvested for silage was investigated with 30 lactating Holstein cows fed silages from corn harvested at the milk or dough stage, or after one, two, or five frosts. The fibrous components of the corn plant increased as maturity and dry matter content increased, whereas the mineral content tended to decrease. Dry matter intake and 4% fat-corrected milk increased as maturity of the silage increased up to the silage harvested after two frosts and then declined for the silage harvested after five frosts. Gross energy apparent digestibility decreased from 64.9% for milk stage silage to 60.6% for silage from corn harvested after five frosts. Partitioning of gross energy, nitrogen, calcium, phosphorus, potassium, and magnesium provided similar increasing trends in feed intake, utilization, and milk production from milk stage silage to that harvested after two frosts, then a decline of all measurements occurred with silage harvested after five frosts. Net energy for lactation was calculated for each silage from the observed digestible energy, from a regression equation used by the provincial feed evaluation laboratories, and from a recently published summative equation; the latter method appeared best.

Nutritive value of maize silage in relation to dairy cow performance and milk quality

“…A number of studies have shown that an increasing maturity of silage maize at harvest has a major effect on the DMI, milk yield and milk protein content of dairy cows . Summarizing data from 10 studies with 51 direct comparisons of maize silage, ensiled at different harvest maturity, on milk production and milk composition of dairy cows showed that the silage maize harvest maturity has a marked influence on the DMI, milk yield and milk protein content (Table ).…”

“…Remarkably, most of the change in starch/NDF ratio occurred early in the grain‐filling period, because the growth of the kernels and the accumulation of nutrients in the kernels are very rapid during the early grain‐filling period, and the rate declines with progressing maturity. Moreover, the DMI generally decreases with increasing moisture content of the forages . Erdman suggested that the DMI of high‐moisture silages is more likely limited by the fermentation end products, a lower pH and high NH 3 levels.…”

“…Adapted from: Bal et al , Buck et al , Cammell et al , Johnson et al , Huber et al , Keady et al , Khan et al , Phipps et al , Pierre et al and Warner et al …”

“…In Europe, but also in other parts of the world, silage maize is harvested at a wide range of maturities, with the whole‐crop DM content ranging from 250 to 450 g kg −1 fresh weight. The variation in maturity at ensiling during the grain filling period results in major changes in the content and composition of the carbohydrates (starch/neutral detergent fibre (NDF) ratio) in maize silages, affecting silage DMI, milk yield and milk composition of dairy cows . We summarized literature data to quantify the effect of silage maize harvest maturity on silage nutrient composition, digestibility and dairy cows' performance.…”

Influence of Glyphosate-Tolerant (event nk603) and Corn Rootworm Protected (event MON863) Corn Silage and Grain on Feed Consumption and Milk Production in Holstein Cattle

“…Average BW and BCS were unaffected by diet, but change in BW per period was negative for cows fed the GT diet. Previous research has shown small losses in BW when corn silage of greater than 40% DM was fed to lactating dairy cows (St-Pierre et al, 1987). 1 REF1 = Reference line 1 (Asgrow hybrid RX740), REF2 = reference line 2 (DEKALB hybrid DK647), CON = nontransgenic line (Asgrow hybrid RX670), CRW = corn rootworm protected line (event MON863).…”