M N Hossain, M M Mia, M A Baset and M M H Khan
Journal of Sylhet Agricultural University, 2016, Volume 3, Number 2; Pages: 159-172
This in vitro experiment was aimed to estimate the amount of methane emission and degradability of different types of roughage and concentrate feed from the crossbred dairy cows. Ten feed ingredients were used in this experiment; rice straw (Oryza sativa), napier grass (Pennisetum purpureum) and german grass (Echinochloa polystachya) were grouped as roughages and rice polish (Oryza sativa), wheat bran (Triticum aestivum) and broken rice (Oryza sativa) as energy rich concentrates and red lentil (Lens culinaris), grass pea (Lathyrus sativus), mung bean (Vigna radiata) and mustard oil cake (Brassica nigra) as protein rich concentrates according to their nutrient composition. Rumen fluids from 3 crossbred dairy cows (Local×Holstein Friesian) with average body weight of 300±20 kg were collected from them just after slaughtering. Buffered rumen fluid was incubated at 39±0.5°C temperature. A completely randomize design was followed to assess the in vitro degradability after 72 h incubation, gas production at 0, 3, 6, 12, 24, 36, 48, 72 h and methane emission at 24, 48 and 72 h of incubation. Significant differences were observed (P<0.001) among the in vitro dry matter degradability (IVDMD), in vitro organic matter degradability (IVOMD), gas and methane production. Among the roughages IVDMD and methane production was significantly higher (P<0.001) in german grass (72.08% and 110.56 ml g-1 DM) and lower in rich straw (42.66% and 12.45 ml g-1 DM) while among the energy rich concentrates they were significantly higher (P<0.001) in broken rice (83.72% and 76.33 ml g-1 DM) and lower in rich polish (38.87% and 23.56 ml g-1 DM). Beside this significantly higher (P<0.001) IVDMD and methane emission were observed in Grass peas (87.49% and 54.11 ml g-1 DM) and were lower mustard oil cake (67.89% and 49.78 ml g-1 DM) among the protein rich concentrates. Methane emission was negatively correlated with the level of crude protein and ether extract and was positively correlated with the level of nitrogen-free extract. It may be concluded that nitrogen-free extract plays important role in increasing methane emission from crossbred dairy cows whereas crude fiber and ether extract plays important role to abate.
Keywords: in vitro, feed ingredients, methane emission, dairy cows
M T Islam, N Z Shoshe, M T Islam, M M R Howlader and M S Islam
Journal of Sylhet Agricultural University, 2014, Volume 1, Number 2; Pages: 155-159
The study was carried out to investigate productive and reproductive performances of crossbreds and indigenous dairy cows. A total of 200 dairy cows belonging to 10 farms of Sylhet district were selected randomly of which 50 cows were Holstein Friesian cross, 50 cows were Sahiwal cross, 50 cows were Sindhi cross and 50 were indigenous breed. The highest average milk yields day -1 cow -1 and total lactation yield cow -1 was observed in Holstein Friesian cross (9.82±2.92; 2899.13±1280.52 liter) followed by Sahiwal cross (6.13±2.85, 1773.60±1107.68 liter), Sindhi cross (4.35±1.12; 1127.24±342.32 liter) and indigenous cows (2.41±0.72; 541.42±144.71 liter). The lactation period (days) of crossbreds dairy cows was significantly (p<0.01) higher than native indigenous cows. The postpartum heat period and calving to first service were highest in Sindhi cross and indigenous cows. The age at first calving (months) was almost similar in different crossbred cows but significantly (p<0.01) higher in indigenous cows. Considering all the parameters studied, Holstein Friesian cross showed better performance followed by Sahiwal cross, Sindhi cross and indigenous cows.
Keywords: Crossbreds, dairy cows, indigenous, productive and reproductive performance