Dietary molasses increases ruminal pH and enhances ruminal biohydrogenation during milk fat depression

Abstract

SummaryMolasses has long been used in animal feeds for palatability and as a binding agent to ensure uniform consumption of essential nutrients. Recent work with molasses in highly fermentable diets has revealed that molasses might offer additional benefits in dairy rations. Feeding highconcentrate diets increases the risk of milk fat depression by disrupting the normal pathway of fatty acid biohydrogenation in the rumen. Preliminary research conducted at Kansas State University and other universities has indicated that dietary sugars have the potential to increase milk fat synthesis during milk fat depression. In this study, we sought to understand the reasons for this beneficial effect of molasses on milk fat synthesis. Despite the fact that molasses provides readily fermentable sugar, replacing 5% of dietary corn grain with molasses increased ruminal pH, improved fatty acid biohydrogenation, and shifted the profile of fermentation acids in a manner suggesting that growth of fiber-digesting bacteria was improved. Results of several studies suggest that 5% dietary molasses can increase milk fat yield by 5 to 10%, and the current study indicates that this effect is driven by a stabilization of ruminal pH and biohydrogenation.

The soybean molasses in diets for dairy cows

“…Somewhat lower concentration of glucose observed in experimental group may be a consequence of consuming the diet in which existing ratio of carbohydrates fractions (with different rate of ruminal degradation) contributed to a change in molar concentration of volatile fatty acids, that could be a physiological prerequisite of a lower glycaemia. Partial substitution of starch by molasses sugars in lactating cows ration decreases molar proportion of propionate in rumen content (Martel et al, 2011) or it remains Results obtained in our research differ from the conclusions of Moloney et al (1994), who determined a lower concentration of glucose in blood of cows fed ration with higher content of starch in comparison with the cows fed molasses supplemented rations (3.44 : 3.55 mmol/L).…”

“…Cows fed rations containing more of disaccharides achieved higher milk yield in comparison with the cows fed rations with higher content of starch (Gao and Oba, 2015). The results of our research differ from the conclusions of Martel et al (2011) where corn grain was substituted by the sugarcane molasses in the rations for dairy cows in the quantity of 2.5 and 5 % DM and decrease of the milk yield by 1.9 and 5.6 % were found, respectively, with no significant effect on 4 % FCM yield. Siverson et al (2014) reported that increased content of sugarcane molasses in ration for lactating cows (from 2.9 to 5.8 % DM) had no positive effect on milk production (34.9 and 34.4 kg/day).…”

“…Improvement in the efficiency of utilization of consumed protein was 7.82 and 8.03 % for milk and 4 % FCM production (Table 4). Obtained results differ from the conclusions of Martel et al (2011) where corn grain was replaced by sugarcane molasses in the quantity of 2.5 and 5 % DM of ration for lactating cows with determined decreased efficiency of ration DM utilization by 2.9 and 5.8 %, and reduced efficiency of protein utilization by 3.04 and 4.97 %. Siverson et al (2014) evaluated the effect of using the sugarcane molasses in concentration of 0-5.8 % DM and determined no significant effect on feed conversion for milk production.…”

“…The cows fed with rations containing higher level of disaccharides had higher concentration and yield of milk protein compared to cows fed rations with higher content of starch (3.51 vs 3.46 %; 1.32 vs 1.28 kg/day), (Oba and Gao, 2015). On the contrary, Martel et al (2011) concluded that substituting the corn grain with sugar beet molasses in the quantity of 5 % DM of ration decreased protein milk yield by 0.05 kg/day but the effect on protein concentration (3.32 vs 3.31 %) was not observed.…”

Molasses : dampak negatif pada ruminansia

“…Hasil penelitian tersebut didukung oleh Wood (1990) dan Martel et al (2011) yang menyatakan bahwa pemberian molasses sampai dengan 5% dari jumlah pakan menyebabkan penurunan produksi susu. Hasil penelitian Ghedini et al (2016) juga menunjukkan penurunan produksi susu secara linier.…”