Effect of Molasses Supplementation on the Production of Lactating Dairy Cows Fed Diets Based on Alfalfa and Corn Silage

Abstract

Adding sugar to the diet has been reported to improve production in dairy cows. In each of 2 trials, 48 lactating Holsteins (8 with ruminal cannulas) were fed covariate diets for 2 wk, blocked by days in milk into 12 groups of 4, and then randomly assigned to diets based on alfalfa silage containing 4 levels of dried molasses (trial 1) or liquid molasses (trial 2). In both studies, production data were collected for 8 wk, ruminal samples were taken in wk 4 and 8, and statistical models were used that included covariate means and block. In trial 1, experimental diets contained 18% CP and 0, 4, 8, or 12% dried molasses with 2.6, 4.2, 5.6, or 7.2% total sugar. With increasing sugar, there was a linear increase in dry matter intake (DMI), and digestibility of dry matter (DM) and organic matter (OM), but no effect on yield of milk or protein. This resulted in linear decreases in fat-corrected milk (FCM)/DMI and milk N/N-intake. There was a linear decrease in urinary N with increasing sugar, and quadratic effects on milk fat content, yield of fat and FCM, and ruminal ammonia. Mean optimum from these quadratic responses was 4.8% total sugar in these diets. In trial 2, experimental diets contained 15.6% crude protein (CP) and 0, 3, 6, or 9% liquid molasses with 2.6, 4.9, 7.4, or 10.0% total sugar, respectively. Again, there were linear declines in FCM/DMI and milk N/N-intake with increasing sugar, but quadratic responses for DMI, yield of milk, protein, and SNF, digestibility of neutral detergent fiber and acid detergent fiber, milk urea, urinary excretion of purine derivatives, and ruminal ammonia. Mean optimum from all quadratic responses in this trial was 6.3% total sugar. An estimate of an overall optimum, based on yield of fat and FCM (trial 1) and yield of milk, protein, and SNF (trial 2), was 5.0% total sugar, equivalent to adding 2.4% sugar to the basal diets. Feeding more than 6% total sugar appeared to depress production.

Replacing maize grain with dried citrus pulp in a concentrate feed for Jersey cows grazing ryegrass pasture

“…A higher mean ruminal pH with fewer and shorter dips below pH 6.0 would promote cellulolytic bacteria activity, increasing the degradability of pasture (Calsamiglia et al, 2002;Jacobs, 2014). Earlier results of the effect of increasing sugar and pectin content on NDF degradability of roughages varied, with some studies finding no improvement (Penner & Oba, 2009) and others finding linear and quadratic effects (Broderick & Radloff, 2004;Broderick et al, 2008). Previous in vitro studies found that the use of molasses as a substrate increased the DM degradability of ryegrass pasture.…”

The soybean molasses in diets for dairy cows

“…Martel et al (2011) substituted the corn grain with sugarcane molasses and determined the increase of ruminal pH value (5.73 : 5.87). Broderick and Radloff (2004) found that increase in the content of sugar beet molasses in ration DM for lactating cows (from 3 to 9 %) leads to higher ruminal pH value (5.90 : 6.06).…”

“…Vallimont (2004) reported that increased rate of readily degradable fractions of carbohydrates in rumen can positively affect the synthesis of microbial protein and milk yield. An optimal portion for molasses in diets for lactating cows is up to 3 % DM which has a positive effect on milk yield (Broderick and Radloff, 2004). These authors investigated the effects of molasses supplementation in the concentrations of 0, 3, 6 and 9 % DM where obtained milk yields were 43.6, 45.5, 44.0 and 42.4 kg/day, respectively.…”

“…A partial replacement of starch with sugars in the nutrition of high yielding dairy cows can often enhance the DM ration intake (Gao and Oba, 2015;Broderick and Radloff, 2004;Penner and Oba, 2009), the yield of energy-corrected milk (Gao and Oba, 2015) and the yield of milk fat (Penner and Oba, 2009). …”

Cinética de degradação ruminal de silagem de capim-elefante com diferentes níveis de jaca e raspa de mandioca

“…Estudos nos quais foram avaliadas as inclusões de carboidratos solúveis na forma de sacarose e melaço, demonstraram melhorias na degradação da fração fibrosa das silagens de milho e alfafa, e foram relacionadas com o aumento da eficiência de uso do nitrogênio e consequentemente com o aumento da síntese de proteína microbiana, pois o aumento no consumo de energia oriunda dos açucares promoveu aumento na eficiência da síntese microbiana (BRODERICK et al, 2004(BRODERICK et al, , 2008.…”