Effect of Using Slow-Release Urea on Milk Production and its Composition of Lactating Dairy Cows

Abstract

TWELVE lactating Holstein cows with live body weight from 550 to 680 kg averaging 600 ± 15 kg and at 1-4 of lactation seasons were used in Latin square design (3x3) with three treatments and three successive experimental periods. Cows in G1 were fed the basal ration consisted of (on DM basis) 57.7% concentrate feed mixture (CFM) + 24.7% corn silage (CS) + 17.6% alfalfa hay (AH) without supplementation and served as a control. While, in G2 and G3, 1 and 0.5 kg soybean meal was replaced by 125 and 62.5 g Optigen™ plus 2.710 and 1.355 kg corn silage/ head/ day, respectively. Results showed that the contents of DM, OM, CP, NFC and NFE in experimental rations tended to decrease, however, the contents of CF, NDF, ADF and ash tended to increase with increasing the level of Optigen supplementation. The digestibility coefficients of all nutrients and nutritive values were not significantly affected by Optigen supplementation. Average daily intake of total DM, TDN, CP, DCP, DE, ME and NEL were nearly similar for the different experimental rations. Moreover, average daily yield of actual milk and 4% FCM, milk composition, the concentrations of urea and urea-N in milk, the concentrations of urea-N and total protein in blood plasma, feed conversion ratio, daily feed cost, feed cost /kg milk and economic efficiency were not affected significantly (P>0.05) by Optigen supplementation. It could be concluded that optigen supplementation for lactating Holstein cows did not showed any significant effects on feed intake, digestibility, milk yield and composition along with feed conversion ratio and economic efficiency.

The impact of using slow-release urea instead of fast-release urea in feed on the milk production of Awassi sheep and some blood traits

“…Perhaps the reason for this increase is due to its association with improved feed conversion factor and protein utilization efficiency in the 4th treatment, which is due to the slow decomposition of Minogen. Due to the scarcity of research on the use of slow-release urea in sheep, research on dairy cows was directed, which is not consistent with the current study as recorded by several authors [13,[15][16][17][18][19][20], indicated that there were no significant differences in milk quantity produced. As Table (3) shows, the 4th treatment significantly increased (P≥0.05) in milk fat percentage, surpassing the rest of the treatments as it reached (3.463, 3.366, 3.866 and 4.326%), respectively.…”

“…Similar studies conducted in this field on cows pointed to results similar to this study. Some authors [16,17] observed a significant increase in cow's milk fat percentage when increasing the level of slow-release urea in their feeds, while it differed with the results of the study by many studies [13,15,[18][19][20][21][22], as they pointed out that there were no significant differences in cow's milk fat percentage when increasing the level of slow-release urea.…”

Effects of slow-release urea on in vitro rumen fermentation parameters, growth performance, nutrient digestibility and serum metabolites of beef cattle

“…The levels of serum ALP and glucose in sheep were unaffected until the dosage of urea phosphate was higher than 4% in the concentrate feed (Ji et al, 2017). Goulart et al (2013) observed that the concentration of γ-GGT, urea, and ALB were not differed in cows after feeding SRU diet and urea diet.…”

“…It is well known that SRU can be used as a substitute for protein feed in ruminants (Goulart et al, 2013;Inostroza, Shaver, Cabrera, & Tricárico, 2010;Highstreet, Robinson, Robison, & Garrett, 2010), but little information is available about its effect on serum immunity in beef cattle. The immune response is closely related to health of animals (Ingvartsen & Moyes, 2013).…”

“…The adverse effects of urea can be prevented by using SRU (Taylor-Edwards et al, 2009). Goulart et al (2013) found that SRU can effectively promote the utilization of degrading nitrogen by rumen microorganisms and enhance the ability of rumen microbe to synthesize protein, and SRU can be used as a better NPN feed.…”