Protein nutrition of dairy cows receiving grass silage diets. Effects on silage intake and milk production of postruminal supplements of casein or soya-protein isolate and the effects of intravenous infusions of a mixture of methionine, phenylalanine and tryptophan

1992 ◽  
Vol 58 (3) ◽  
pp. 307-314 ◽  
Author(s):  
Jai-Jun Choung ◽  
David G Chamberlain
Author(s):  
Jai-Jun Choung ◽  
David G. Chamberlain

When the proteins are given direct into the abomasum of dairy cows receiving diets based on grass silage, casein produces much greater responses of milk production than do equivalent amounts of soya-protein (Choung and Chamberlain 1991a, b). However, the cause of these differences of response is not known. In feeding trials, supplementation of silage diets containing soya bean meal with rumen-protected forms of the amino acids thought to be most limiting, methionine and lysine, has been without effect (Girdler et al 1988).


Author(s):  
Jai-Jun Choung ◽  
David G. Chamberlain

When different protein sources are infused direct into the abomasum of the dairy cow, the pattern of utilization of the amino acid-N supplied might be expected to be influenced by the amino acid composition of the infused protein. This suggestion was examined in a nitrogen-balance study with lactating cows.


1993 ◽  
Vol 60 (2) ◽  
pp. 133-138 ◽  
Author(s):  
Jai-Jun Choung ◽  
David G. Chamberlain

SummarySix lactating dairy cows receiving a diet of grass silage and barley were given the following treatments as infusions into the abomasum, in a replicated 3 × 3 Latin square with 10 d periods: sodium caseinate (C), an enzymic hydrolysate of casein (CH) and soya-protein isolate (SPI). The C and CH treatments supplied ~ 185 g/d and the SPI treatment ~ 160 g/d of amino acids. Milk yield was similar for all treatments. Yields of milk protsein were 605, 604 and 582 (P > 0·05) g/d for C, CH and SPI respectively. For C, CH and SPI respectively, concentrations (g/kg) of fat were 39·6, 45·7 and 41·9 and yields (g/d) of fat were 790, 931 and 827; values for CH were significantly (P < 0·01) higher than for either of the other treatments. It is concluded that the form in which amino acid residues of casein are supplied to the abomasum (protein v. peptide–amino acid mixtures) can influence the partition of use of nutrients between body tissues and the mammary gland.


2017 ◽  
Vol 84 (3) ◽  
pp. 240-247 ◽  
Author(s):  
Ruairi P McDonnell ◽  
Martin vH Staines

This research paper describes the effect of partially replacing wheat with maize grain and canola meal on milk production and body condition changes in early lactation Holstein-Friesian dairy cows consuming a grass silage-based diet over an 83-d period. Two groups of 39 cows were stratified for age, parity, historical milk yield and days in milk (DIM), and offered one of two treatment diets. The first treatment (CON) reflected a typical diet used by Western Australian dairy producers in summer and comprised (kg DM/cow per d); 8 kg of annual ryegrass silage, 6 kg of crushed wheat (provided once daily in a mixed ration), 3·6 kg of crushed lupins (provided in the milking parlour in two daily portions) and ad libitum lucerne haylage. The second treatment diet (COMP) was identical except the 6 kg of crushed wheat was replaced by 6 kg of a more complex concentrate mix (27% crushed wheat, 34% maize grain and 37% canola meal). Lucerne haylage was provided independently in the paddock to all cows, and no pasture was available throughout the experiment. The COMP group had a greater mean overall daily intake (22·5vs20·4 kg DM/cow) and a higher energy corrected milk (ECM) yield (29·2vs27·1 kg/cow;P= 0·047) than the CON cows. The difference in overall intake was caused by a higher daily intake of lucerne haylage in COMP cows (4·5vs2·3 kg DM/cow). The CON group had a higher concentration of milk fat (42·1vs39·3 g/kg;P= 0·029) than COMP cows. Milk protein yield was greater in COMP cows (P< 0·021); however, milk fat yield was unaffected by treatment. It is concluded that partially replacing wheat with canola meal and maize grain in a grass silage-based diet increases voluntary DMI of conserved forage and consequently yields of ECM and milk protein.


Author(s):  
F.P. O'Mara ◽  
J.J. Murphy ◽  
M. Rath

Milk protein synthesis may be limited by amino acid (AA) flow to the duodenum. This can be increased by increasing the flow of microbial AA's or undegraded feed AA's. This experiment was carried out to determine the effect on milk production and nutrient flows at the duodenum of including fishmeal (120g/kg) in the supplement to grass silage at two levels of supplement feeding.The treatments, arranged in a 2x2 factorial, were 1.) 3.5 kg/day of 0% fishmeal supplement (L-UDP), 2.) 7 kg/day of L-UDP, 3.) 3.5 kg/day of 12% fishmeal supplement (H-UDP), and 4.) 7 kg/day of H-UDP. Supplements were fed to 3 6 Friesian cows in a 4x4 multiple Latin-square trial with three week periods to determine production responses, and to four ruminally and duodenally cannulated cows to determine rumen fermentation and nutrient flows. Flows were determined by the dual marker technique of Faichney (1975) using cobalt-EDTA and ytterbium acetate as liquid and solid phase markers respectively. Purines were used as the bacterial marker (Zinn and Owens, 1986). Degradability of the feeds was measured in 3 other cows using the small bag technique described by De Boer et al. (1987).


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