Leila Taherabadi; Farokh Kafilzadeh
Volume 25, Issue 2 , July 2023, , Pages 169-181
Abstract
Introduction: Increased livestock production can be achieved through the cultivation of high-quality forages with high-yielding capacity. Napier grass has been introduced to all tropical and subtropical areas of the world and is used as a forage crop with high potential productivity in terms of annual ...
Read More
Introduction: Increased livestock production can be achieved through the cultivation of high-quality forages with high-yielding capacity. Napier grass has been introduced to all tropical and subtropical areas of the world and is used as a forage crop with high potential productivity in terms of annual dry matter yield. However, both dry matter yield and nutritional quality of this grass have been affected by different cutting interval. This grass has been neither grown nor studied as a source of forage for ruminant nutrition in Iran.This research was conducted to identify the appropriate cutting interval for Napier grass to produce the maximum nutritive value and yield.
Material and methods: Napier grass was cultivated in a complete randomised block design with three replicates. During the growth season, the cutting intervals were 16-20, 24-28, 43 d or 136 d after planting to corresponding cutting heights of 50, 100, 150 and 300 cm. Hence, from each plot 6, 4, 2, or 1 cuts were harvested, respectively. Cell wall fractions, organic matter, and crude protein of Napier grass from different cuts were determined. Dry matter and organic matter digestibility and in-vitro ruminal fermentation kinetics of the forages were also determined. Biomass production of Napier grass under different cutting interval programs was also assessed.
Results and Discussion: The highest yield of dry matter of Napier grass (25.1 tons per hectare) was observed when only one cut was harvested at the end of vegetative stage (height of 300 cm). The digestibility of organic matter (OMD) ranged from 60 to 70 % in all treatments and the highest OMD was observed at the height of 50 cm. The maximum dry matter and digestible organic matter per hectare (15.9 and 14.2 tons, respectively) was produced when forage was harvested in one cut at the height of 300 cm. There was no difference in the yield of digestible dry matter and digestible organic matter of the forage harvested at the height of 50 and 100 cm. The concentration of crude protein in forages from different cuts ranged from 7.1 to 14.2 % and neutral detergent fiber ranged 65.7 to 76.2 %. The highest concentration of crude protein and the lowest cell wall components were observed at the height of 50 cm. The lowest and the highest gas production potential and fractional rate of gas production were observed at the cutting height of 300 cm and 50 cm, respectively.
Conclusion: The present study showed that it is possible to obtain higher quality of Napier grass by shortening the harvesting intervals. However, this resulted in a pronounce decrease in the yield of organic matter and digestible dry matter yield per hectare. The highest organic matter and digestible dry matter per hectare was produced when Napier grass was harvested only once (136 d after planting and height of 300 cm) at the end of vegetative stage.
mansour Dehghani; Ahmad Afzalzadeh; Mohammad Ali Norouzian
Volume 23, Issue 2 , July 2021, , Pages 191-200
Abstract
The present study was conducted to evaluate the effect of urea treatment of wheat straw and sugarcane bagasse on chemical composition, lag time and ruminal degradability parameters of dry matter (DM) and neutral detergent fiber (NDF) by nylon bag technique. The chemical composition and degradability ...
Read More
The present study was conducted to evaluate the effect of urea treatment of wheat straw and sugarcane bagasse on chemical composition, lag time and ruminal degradability parameters of dry matter (DM) and neutral detergent fiber (NDF) by nylon bag technique. The chemical composition and degradability parameters of unprocessed samples and processed samples with five percent urea were determined using three mature rumen-fistulated Holstein dairy cows (with initial body weight of 615±15 kg and three lactation number). Urea treatment decreased DM and NDF degradation lag time of processed wheat straw (P<0.05); however it had no effect on DM and NDF degradation lag time of sugarcane bagasse. The urea treatment resulted to increase in DM and NDF degradability rate of processed wheat straw (P<0.05), but had no effect on DM and NDF degradability rate of sugarcane bagasse. The potentially degradable fraction of DM and NDF of both experimental materials were increased by treatment (P<0.05). The effective degradability of DM and NDF of experimental roughages increased (P<0.05) after urea treatment from 35.69 and 21.69 to 44.04 and 29.12 percent, respectively for wheat straw and from 18.88 and 15.65 to 23.92 and 19.52 percent, respectively for sugarcane bagasse. According to the results of this experiment, urea treatment of roughages-feeds, especially wheat straw improves degradability of DM and NDF.
Hossien Bayatani; Mohammad Ali Norouzian; Ahmad Afzalzadeh
Volume 21, Issue 2 , July 2019, , Pages 209-221
Abstract
The aim of this research was to study the feeding value of Lactuca Serriola at different harvesting stages and comparison of different models for prediction of its lag time. The forage was cut at tow growing stages before and after bloom and chemical composition, degradability and gas production parameters ...
Read More
The aim of this research was to study the feeding value of Lactuca Serriola at different harvesting stages and comparison of different models for prediction of its lag time. The forage was cut at tow growing stages before and after bloom and chemical composition, degradability and gas production parameters were compared with alfalfa hay. Also lag time of experimental forages was determined. The crud protein and NFC concentration were the lowest and NDF and ADF content were the highest after bloom compared with alfalfa hay (p<0.05). potentially digestible fraction (b) of DM increased by enhancement of the growing stage od Lactuca Serriola (p<0.05). effective degradability (ED) and gas production potential before bloom stage were significantly higher than the other experimental forages (p<0.05). Results obtained from prediction of lag time showed that the lag timewas the highest before bloom of Lactuca Serriola (p<0.05). In conclusion, Lactuca Serriola ( before bloom) could be considered as a good potential forage source in ruminant nutrition.
Mostafa Lotfy; farid shariatmadari; Hamed Ahmadi; Mohsen Sharafi
Volume 21, Issue 2 , July 2019, , Pages 223-232
Abstract
The purpose of this study was to develop multiple linear regression (MLR) model to predict the nitrogen-corrected true metabolizable energy (TMEn) value of wheat bran. The amount of crude fat, ash, crude protein, crude fiber (all used as % of DM) and TMEn (Kcal/kg DM) were measured in 25 wheat bran samples ...
Read More
The purpose of this study was to develop multiple linear regression (MLR) model to predict the nitrogen-corrected true metabolizable energy (TMEn) value of wheat bran. The amount of crude fat, ash, crude protein, crude fiber (all used as % of DM) and TMEn (Kcal/kg DM) were measured in 25 wheat bran samples with 4 replicates. The force-fed method has been used to estimate TMEn and excreta were collected for 48 h. There were significant (P < 0.001) differences in chemical composition and TMEn of wheat bran samples. The average crude fat, ash, crude protein, crude fiber and TMEn content of samples was determined to be 4.80, 5.68, 16.23, 8.60 (all used as % of DM) and 2062 (Kcal/kg DM), respectively. The calculated MLR model to predict the TMEn value (Kcal/kg) based on chemical composition (% of DM) was obtained as follows: TMEn = 2364 + (19×crude protein) + (46.1×crude fat) – (63×crude fiber) – (51.1×ash). The R2 value revealed that developed model could accurately predict the TMEn of wheat bran samples (R2=0.82). Crude fat and crude protein had a positive effect on TMEn, while ash and crude fiber had a negative impact on TMEn. The sensitivity analysis on the model indicated that dietary crude fiber (%) is the most important variable in the TMEn, followed by dietary ash, crude fat and crude protein. The results suggest that the MLR model may be used to accurately estimate the TMEn value of wheat bran from its corresponding chemical composition.