Abstract: This study was carried out to evaluate using different levels of guar korma meal as a source of protein in rations of lactating buffalo cows. Thirty animals were chosen and divided into six similar groups (5 in each). Animals were at the 2nd season of lactation and assigned to receive guar korma meal at the rate of 0,3.3,6.7, 10.0, 13.3 and 16.7% to cover 0,10,20,30,40 and 50% from protein content of concentrate feed mixture (CFM) of rations A,B,C,O,E and F, respectively. Experimental rations consisted of CFM, berseem hay (RH) and wheat straw (WS) with rate 60:25:10, respectively.
Feeding trial lasted 240 days, during which six digestibility trials were carried out to determine digestibility coefficients and nutritive values. Samples of blood and rumen liquor were taken to measure some parameters. In addition, feed cost and economical efficiency were conducted.
The results obtained can be summarize as follows:
Increasing guar korma meal level in the experimental rations tended to slightly increase total OM intake (Kg/h) with little increase in DM, CP and EE but somewhat decrease of OM contents of calculated composition of experimental rations.
Experimental rations containing guar korma meal (rations E and F) significantly (P < 0.05) increased DM, OM, CP, EE and CF digestibility coefficients. The highest digestibility coefficients were recorded with ration F (containing 16.7% guar korma), recording 85.20, 93.15, 74.25, 70.82 and 65.16% for OM, OM, CP, EE and CF, respectively. Feeding values as TDN (%), DCP (%) and DE (Meal/Kg OM) were significantly (P < 0.05) higher with increasing guar korma meal in experimental rations. Ration F (containg 16.7% guar korma) had the highest feeding values, being 71.03%, 10.15% and 3.13Mca1/Kg DM for TDN, DCP and DE, respectively.
Average milk production as actual milk yields were 8.15,8.24,8.28,8.75,9.03 and 9.80 kg/hid versus 8.07,8.10,8.12,8.47,8.63 and 9.26 Kg 7% FCM with animals fed rations A,B,C,O,E and F, respectively. The significant (P < 0.05) differences in milk production were not found in rations containing guar korma up to 10%, but increasing level of guar karma in experimental rations (rations E and F) tended to significantly increase milk production. Average milk composition such as fat, protein, TS and SNF percentages significantly (P < 0.05) decreased with increasing guar korma level in rations, but lactose percentage showed significant(P < 0.05) increase. Also, the yields of the previous items showed significant higher or lower owing to different amounts of milk yields and their percentages.
. Average daily feed unit intake increased with increasing guar korma level in experimental rations. Animals fed ration F (containing 16.7% guar korma) had the highest feed unit intake expressed as DM, TDN and DCP, being 10.768, 7.649 and 1.093 kg, respectively. Animals fed ration (F) showed the best feed utilization efficiency expressed as kg DM, TDN or DCP/kg milk yield, being 1.099, 0.781 and
0.112kg, respectively The same previous trend was observed with feed efficiency expressed as Kg DM and TDN/Kg 7% FCM for ration (F) being 1.163 and 0.826 Kg, respectively.
Averages of daily feed cost/Kg milk yield were 2.609, 2.534, 2.522, 2.416, 2.316 and 2.106 LE for rations A,B,C,O,E and F,respectively. Corresponding values expressed as feed cost/Kg 7% FCM were 2.635, 2.578, 2.572, 2.496, 2.423 and 2.229 LE showing the lowest cost was recorded with ration (F) which contained 16.7% guar ~orma meal. In the same trend, the highest net revenue was recorded with animals fed ration (F). Moreover, net revenue per kg actual milk or 7% FCM yield was also the highest with ration (F), being 3.894 and 4.121 LE, respectively.
In addition, animals fed ration (F) had the highest economical efficiency (2.85) with improvement reach into 23.91 %.
Averages of some blood parameters such as protein concentration and its components, liver and kidney function values were at the normal range. Moreover, some rumen parameters were also at the same normal range.
From these results, it could be concluded that, guar korma meal can be used as a source of protein in ration formulation of lactating buffalo-cows. Incorporation of guar korma at the rate of 16.7% in concentrate feed mixture to cover 50% of protein content of CFM gave the highest digestibility for all nutrients, feeding values and milk production. Moreover, animals fed ration (F) containing 16.7% guar korma showed the best feed utilization efficiency and the lowest feed cost per kg actual milk or 7% FCM yield with the highest net revenue and economical efficiency.
Key words: Guar korma meal- buffalo cows - milk production.
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