• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.6
• /
• pp.806-811
• /
• 2002

A 90 d study was designed to investigate the effects of rumen undegradable protein (RUP) and a mixture of Cu, Zn and Mn proteinate (CZMP) on milk yield and composition and ovarian functions during rainy months. Twenty four Holstein${\times}$ indigenous cows in their 2nd and 3rd lactation were randomly allocated to total mixed rations (TMR) containing soy bean meal (SBM) as a source of rumen degradable protein (RDP), SBM plus CZMP, and formalin treated SBM (FSBM) as a source of RUP. Maximum and minimum temperature humidity index during the experimental period were 83.6-84.7 and 75.4-76.1. There were no differences (p>0.05) in intakes of dry matter, crude protein and net energy and in contents of butterfat, lactose and minerals. Cows on TMR containing FSBM not only lost less weight (-278, -467 and -433 g/d) with more intake of RUP (0.92, 0.58 and 0.59 kg/d) but also produced more milk (19.27, 18.23 and 18.13 kg/d) and 4% fat corrected milk (18.57, 17.57 and 17.51 kg/d) with more protein (3.06, 2.81 and 2.80%), solids-not-fat (8.69, 8.38 and 8.38%) and less milk urea N (9.3, 15.4 and 15.0 mg/dl) compared with those on TMR containing SBM and SBM+CZMP, respectively (p<0.01). However, cows on TMR containing SBM and SBM+CZMP did not differ in these respects (p>0.05). Whereas incidence of cystic ovaries at 20 and 90 d pospartum was less (p<0.01) in cows on TMR containing SBM+CZMP (37.3 and 12.5%) than those on TMR containing SBM (62.5 and 25%), it was nil for cows on TMR containing FSBM. Cows in all three group differed (p<0.01) from each other for the recurrence of first observed estrus with those on TMR containing FSBM having least days (22, 36 and 47 d) compared with their counterpart on TMR containing SBM+CZMP and SBM, repectively. The results suggest that RUP is one of the limiting factors affecting milk yield and its composition and ovarian functions during early lactation of dairy cows in the tropics.

• Journal of Animal Science and Technology
• /
• v.56 no.4
• /
• pp.14.1-14.7
• /
• 2014

Two trials were conducted to evaluate the influence of supplemental urea withdrawal on characteristics of digestion (Trial 1) and growth performance (Trial 2) of feedlot cattle during the last 40 days on feed. Treatments consisted of a steam-flaked corn-based finishing diet supplemented with urea to provide urea fermentation potential (UFP) of 0, 0.6, and 1.2%. In Trial 1, six Holstein steers ($160{\pm}10kg$) with cannulas in the rumen and proximal duodenum were used in a replicated $3{\times}3$ Latin square experiment. Decreasing supplemental urea decreased (linear effect, $P{\leq}0.05$) ruminal OM digestion. This effect was mediated by decreases (linear effect, $P{\leq}0.05$) in ruminal digestibility of NDF and N. Passage of non-ammonia and microbial N (MN) to the small intestine decreased (linear effect, P = 0.04) with decreasing dietary urea level. Total tract digestion of OM (linear effect, P = 0.06), NDF (linear effect, P = 0.07), N (linear effect, P = 0.04) and dietary DE (linear effect, P = 0.05) decreased with decreasing urea level. Treatment effects on total tract starch digestion, although numerically small, likewise tended (linear effect, P = 0.11) to decrease with decreasing urea level. Decreased fiber digestion accounted for 51% of the variation in OM digestion. Ruminal pH was not affected by treatments averaging 5.82. Decreasing urea level decreased (linear effect, $P{\leq}0.05$) ruminal N-NH and blood urea nitrogen. In Trial 2, 90 crossbred steers ($468kg{\pm}8$), were used in a 40 d feeding trial (5 steers/pen, 6 pens/treatment) to evaluate treatment effects on final-phase growth performance. Decreasing urea level did not affect DMI, but decreased (linear effect, $P{\leq}0.03$) ADG, gain efficiency, and dietary NE. It is concluded that in addition to effects on metabolizable amino acid flow to the small intestine, depriving cattle of otherwise ruminally degradable N (RDP) during the late finishing phase may negatively impact site and extent of digestion of OM, depressing ADG, gain efficiency, and dietary NE.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.7
• /
• pp.970-973
• /
• 2001

An experiment was carried out to assess the effect of feeding concentrate mixtures varying in bypass protein levels with urea-treated or untreated grass on the performance of twelve Red Kandhari calves (14 months of age and 78.15 kg body weight) for a period of 75 days. Dry grass was treated with 4 percent urea solution and ensiled for 30 days. The CP ($N{\times}6.25$) content in urea treated grass increased from 3.96 to 8.89 percent. Two iso-caloric and iso-nitrogenous concentrate mixtures (CM-I and CM-II) varying in RDP to UDP ratio viz., 65:35 and 55.45 were prepared. The calves in control group ($T_1$) were fed concentrate mixture-I with ad libitum untreated dry grass and those in experimental group ($T_2$) were fed concentrate mixture-II with ad libitum urea treated dry grass. The dry matter consumption in group $T_2$ was significantly (p<0.01) higher as compared to group $T_1$. The total DMI in $T_1$ and $T_2$ was 146.92 and 166.95 kg respectively, whereas the DMI per day and per 100 kg body weight was 1.94 and 2.22 and 1.90 and 2.35 kg, respectively. The average total gain in body weight (kg) and average daily gain (g) of calves in $T_2$ was significantly (p<0.01) higher as compared to those in $T_1$ the values being 28.66, 18.33 and 382.16, 244.44, respectively. Feed efficiency in terms of kg DM per kg gain in body weight was significantly (p<0.01) lower in group $T_1$ than in $T_2$. The cost of feed per kg gain in body weight for $T_2$ and $T_1$ group was Rs. 21.14, 28.22, respectively. The digestibility coefficients of DM, CP, EE, CF, NFE, NDF and ADF were 59.60, 57.50, 53.00, 65.04, 45.82, 48.48, 52.48 and 55.73 for $T_1$ group. The coressponding values were 68.78, 67.80, 59.83, 71.41, 49.93, 53.37 and 57.81, respectively for $T_2$ group. The digestibility coefficients for all the proximate principles in $T_2$ were significantly (p<0.01) higher as compared to $T_1$. However, NDF and ADF digestibilities were not significantly different. Nutritive value determined in terms of DCP and TDN for The experimental ration was significantly (p<0.01) higher than control ration, the values being 7.32 and 47.34 and 9.39 and 52.40% respectively. The blood urea nitrogen levels at 0, 3 and 6 h interval after feeding were significantly (p<0.01) lower in calves fed experiment ration as compared to control. The overall results indicated that in Red Kandhari calves an optimum growth can be economically achieved by feeding 4 percent urea treated dry and mature grass as basal roughage supplemented with a concentrate mixture containing 20 percent CP, 70% TDN and 45% UDP/bypass protein.