Undegradable Protein Supplementation to Early-Lactation Dairy Cows in Grazing Conditions

Abstract

To determine the production responses to rumen undegradable protein (RUP) feeding in grazing conditions, we fed 18 multiparous Holstein cows concentrates containing either soybean meal (SBM) or blood meal (BM) during the first 8 wk of lactation. One cow from the SBM treatment was removed because of mastitis. Six additional dairy cows in late lactation fitted with ruminal cannula were used to evaluate the rumen environment and the in situ crude protein (CP) degradability of concentrates. On a dry matter (DM) basis, concentrates contained SBM (33%) or BM (13%), corn grain (64 and 84% for SBM and BM, respectively) and a mineral-vitamin complex (3%). Concentrates were offered at a rate of 6.6 kg/d per cow and herbage allowance averaged 31 kg/d of DM per cow. The BM reduced ruminal ammonia-N levels and had no effect on ruminal pH and molar volatile fatty acid concentration. The degradable fraction (63.59 vs. 22.46%) and the rate of disappearance of the CP (9.68 vs. 1.69%/h) were greater for the SBM compared with the BM concentrate. Cows fed the BM concentrate produced more milk (29.3 vs. 24.9 kg/d) and more milk protein (0.85 vs. 0.74 kg/d) than did those fed the SBM concentrate. Milk fat yield and percentages of milk fat, lactose and protein were not affected. Forage DMI was increased by BM (17.19 vs. 13.17 kg/d per cow). The in vivo responsiveness to lipolytic stimuli were increased by BM but enhanced body weight loss or higher plasma nonesterified fatty acids concentration were not observed. Results indicated that a concentrate with a high RUP content increased milk and milk protein yields when spring pasture was the sole forage. The highest milk yield was more likely caused by increased DM than by enhanced body lipid mobilization.

Effect of by-pass protein supplements on milk production of dairy cattle

“…The higher milk yield in bypass protein supplemented cows may be due to increased supply of amino acids for absorption in small intestine. Similar results of increased milk yield fed with by-pass protein were presented by (Kunju et al,1990;Kumar et al, 2006).Similarly, Chaturvedi et al (2001), Schor (2001), Garg et al (2002a), Garg et al (2003b) and Mishra et al (2006) recorded significantly higher average milk yield in cows due to supplementation of bypass protein. Milk composition: Average milk fat percentage for groups T 0 , T 1 and T 2 was 5.52, 5.55 and 4.47%, respectively.…”

Reducing dietary protein in dairy cow diets: implications for nitrogen utilization, milk production, welfare and fertility

“…Tissue, body fat/protein mobilisation A decrease in dietary protein supply in early lactation is associated with an increase in the responsiveness of adipose tissue to anti-lipolytic stimuli such as insulin, and decrease in the responsiveness to lipolytic stimuli such as epinephrine (Cadórniga and López Díaz, 1995;Schor and Gagliostro, 2001). It would therefore be anticipated that decreasing tissue amino acid supply should be translated into a net decrease in body fat mobilisation.…”

“…An analysis of data from studies (i.e. Jones and Garnsworthy, 1988;Cadórniga and López Díaz, 1995;Garcia-Bojalil et al, 1998;Hongerholt and Muller 1998;Bach et al, 2000;Westwood et al, 2000;Schor and Gagliostro, 2001;Davidson et al, 2003) that have examined the influence of DUP level within the same dietary protein concentration have also failed to find a consistent relationship (geometric means for plasma NEFA: 255 v. 310 µeq/l for Low v. High DUP respectively; P = 0.158). The effects of protein supply on body tissue mobilisation are, however, confounded by dietary factors (e.g.…”

Advances in Soybean and Soybean By-Products in Monogastric Nutrition and Health

“…In one study, isoleucine availability was found to be only 39%, compared to 59% or better for all other essential amino acids (Gaylord and Rawles, 2003). Researchers have studied blood meal as a viable protein supplement in many species including beef cattle (Rangngang et al, 1997), dairy cattle (Schor and Gagliostro, 2001), nursing swine (DeRouchey et al, 2002), sheep (Hoaglund et al, 1992) and poultry (Tyus et al, 2009). …”