Effects of Yucca shidigera Extract and Soluble Protein on Performance of Cows and Concentrations of Urea Nitrogen in Plasma and Milk

Abstract

Twelve multiparous Holstein cows averaging 122 d postpartum were used in a replicated Latin square design with 21-d periods. Cows were fed diets containing either low or high soluble protein supplemented with 0 or 9 g/d of Yucca shidigera extract per cow. Dry matter intake and yields of milk, fat, 3.5% fat-corrected milk, and total solids were not affected by treatment. High soluble protein increased percentages of fat and total solids in milk but decreased percentages of crude protein and true protein in milk. Yucca shidigera extract did not affect percentages or yields of milk components, ruminal NH3 N, or urea N in milk or plasma. High soluble protein tended to increase both ruminal pH and concentrations of ruminal NH3 N. Yucca shidigera extract did not affect ruminal pH or NH3 N. High soluble protein increased concentrations of urea N in plasma and milk when both were measured by enzymatic assay, but differences in milk urea N measured by mid infrared reflectance spectroscopy were not significant. Neither Yucca shidigera extract nor increased ruminally undegradable protein was beneficial in this trial when fed to cows milking 30 to 35 kg/d. Concentrations of urea N in milk as measured by mid infrared reflectance spectroscopy were higher than those measured by enzymatic assay, but measurements by mid infrared reflectance spectroscopy were not as sensitive to treatment differences as were measurements by enzymatic assay.

The effect and mode of action of saponins on the microbial populations and fermentation in the rumen and ruminant production

“…There are reports that milk yields and the composition of milk from moderate-or high-yielding cows (20 -30 kg/d) are not improved by inclusion of Yucca or Quillaja extract in diets containing 10 to 20 % crude protein (25,29,30,36,37,40,42) . Even supplementation of diets containing less than 10 % protein with Yucca saponins (0·1 g/kg) did not affect milk production (119) .…”

“…Sapindus saponaria (27) and Yucca extract (42) included in concentrate diets did not significantly reduce rumen ammonia concentrations, although it should be noted that the Yucca extract did not affect rumen protozoal numbers either. In studies with dairy cows, inclusion of sarsaponins up to 77 parts per million (ppm) of diet (29,33) , 9 g/d (36) , 8 g/d (40) and 10 g of Yucca whole plant (equivalent to 0·6 g saponins/kg DM) or 10 g Quillaja whole plant (equivalent to 0·3 g saponins/kg DM) (25) did not influence ammonia concentrations in the rumen, probably due to low concentrations of saponins inclusion in the diets. Valdez et al (29) and Hess et al (27) have reported that by decreasing protozoal numbers slightly, saponins increased bacterial numbers, which may explain why saponin treatments are not always associated with reduced rumen ammonia concentrations.…”

“…Additionally, the glycofractions of saponins are known to bind ammonia when concentrations of ammonia are low and when a high dose of saponins is added (44) . This might improve N efficiency by maintaining adequate rumen ammonia (trapping of rumen ammonia when ammonia concentrations are high after feeding and then slowly releasing it with the degradation of the glycofraction and desaturation of ammonia binding) for use during microbial protein synthesis when ammonia concentrations decrease (36,40) . However, it has been shown that this ammonia binding appears to be negligible at ammonia concentrations typical of the rumen (44) .…”

Microbial protein and blood parameters of goats fed with licury cake

“…This parameter is positively correlated with the ingestion of nitrogen by the animal (ROSELER et. al., 1993;HENNESSY et al, 1995;VALADARES et al, 1997;MOSCARDINI et al, 1998;CANNAS et al, 1998;WILSON;OVERTON;CLARK, 1998). Thus, the decrease in the levels of urea-N in the blood may be related to the modification of the fractionation of the nitrogen compounds in the diets due to the inclusion of the licury cake (Table 4); the reduction of the protein fraction A and a rapid degradability and increase of the fractions B3 and C, which are slow degrading and not degradable, respectively, was observed.…”

Balanço de nitrogênio e estimativas de perdas endógenas em vacas lactantes alimentadas com dietas contendo palma forrageira e teores crescentes de uréia e mandioca

“…Segundo Clark et al (1992), a disponibilidade de energia e N são fatores limitantes para o crescimento microbiano. De acordo com Kauffman e St-Pierre (2001), com aumento de amônia ruminal, ocorre aumento da concentração sanguínea de uréia e , conseqüentemente, sua difusão para o leite, ou seja, a uréia ao ser sintetizada no fígado é transportada para o sangue (filtrada no rim e excretada na urina ou reciclada para o rúmen) e glândula mamária (excretada no leite) (Wilson et al, 1998), o que é coerente com a maior concentração de NUP obtida (Tabela 5).…”