Effect of different types of silage on milk production of dairy cows

Accepted 05 August 2018 Online release 30 August 2018 The experiment was carried out in a village called Digholgao under Muktagacha upazila of Mymensingh BD to investigate the effect of different types of silage on milk production . Twelve milking cows (age 5-6 years, live weight 450±5 kg) divided into 4 groups each having 3 animals were used in the experiment They were assigned randomly to 4 dietary treatments: T0 = Basal diet + napier grass and maize fodder, T1= Basal diet + napier whole silage, T2= Basal diet + napier chopped silage, T3= Basal diet + maize silage. Basal diet was composed of rice straw, wheat bran, rice polish, mustard oil cake, DCP powder, salt and mineral mixture. All the animals of this experiment were offered ad libitum clean water. The design of experiment was completely randomized design. A feeding trial of 90 days duration was conducted on 12 dairy cows of mild lactation stage. The everyday milk production of those cows was recorded in a record book. The physico-chemical characteristics of different types of silages showed that maize and napier chopped silages were having similar P, colour, aroma, texture and temperature which were within the normal range of good quality silage. However, the silage of napier whole grass was having relatively poor quality characteristics compared to those of the other silages. The DM content of maize silage, napier chopped and whole silage were 18.47, 19.13 and 17.89% respectively. The P of maize silage, napier chopped and napier whole silage were 4.26, 4.27 and 5.26 respectively. The CP contents of maize silage (9.16%) and napier chopped silage (8.96%) were almost similar and higher than napier whole silage (7.03%). Meanwhile, the ADF content of napier whole silage (57.40%) was higher than maize silage (45.66%) and napier chopped (53.60%). The ammonia nitrogen (NH3-N) content of maize silage (9.20%) and napier chopped silage (9.85%) were almost similar and higher than napier whole silage (7.57%). Meanwhile, the total volatile fatty acids (TVFAs) content of maize silage, napier chopped and whole silage were 11.75%, 11.40% and 10.20% respectively. The average milk production (L/d) of maize, napier chopped and napier whole grass silage fed dairy cows were 18.94, 17.82 and 16.79 respectively. On the other hand, the control group or only mixed green grass fed dairy cows produce on average 14.73 litres milk per day. Milk yield of all the silage fed animal groups have given significantly (p<0.01) higher yields than that of the control group of animals. Among the silage supplemented groups the animals of maize silage group gave significantly (p<0.01) higher milk yield than that of napier whole grass silage group of animals but non-significantly higher yield than that of napier chopped silage group. The average milk production (L/d) of the 90 days feeding trial period for maize silage, napier chopped silage, napier whole grass silage and control diets were found as 18.94, 17.82, 16.79 and 14.73 respectively. Here all the silage fed groups of animals gave significantly (p<0.01) higher milk yield than that of the animals fed control ration. However, maize silage showed significantly better yield of milk compared to other silages. It was also found that milk yield was increased 28.59%, 20.96% and 13.97% of maize, napier chopped and napier whole silage fed cows, respectively over the control group. Based on the findings in respect of physical characteristics, chemical composition, pH, ammonia nitrogen (NH3-N), total volatile fatty acids (TVFAs) of silages and effect of silage on milk production of dairy cows it may be concluded that maize or chopped napier silage can be an effective alternative to green fodder during the period of fodder scarcity for continuing the milk production of dairy cows. Feeding silage to dairy cows increase milk production compared to fresh grass. Maize can produce better silage for increasing milk production compared to napier silage. Chopping napier grass before ensiling can give slightly better quality silage than whole napier grass. Keyword