Manipulation of milk protein content in dairy cows

In Practice ◽  
1996 ◽  
Vol 18 (4) ◽  
pp. 163-167 ◽  
Author(s):  
Tom Chamberlan
Author(s):  
A Gavelis ◽  
V. Þilaitis ◽  
A Juozaitis ◽  
V. Juozaitienë ◽  
G. Urbonavièius ◽  
...  

The aim of this study was to evaluate relationship between milk progesterone concentration (P4) and milk traits at the start of estrus time and 12h after start of the estrus in dairy cows. The 96 milk samples of 48 Lithuanian dairy cows without reproduction disorders and 90–100 days after calving were evaluated. Cows were classified into two groups based on milk yield per day: less than 30 kg (n=20) and e”30 kg (n=28). Data were categorized by milk fat and protein content at the start estrus and 12h after start of estrus to evaluate relationship between P4 and milk traits examined. P4 at estrus time in dairy cows was significantly positively correlated with milk yield (P less than 0.001), whereas it was negatively correlated with milk protein (P less than 0.05-P less than 0.01) and fat at 12h after start of estrus. Dairy cows with F/P from 1.0 to 1.5 had the lowest P4 in milk. Results of the pregnancy in dairy cows were related with lower P4 and milk yield level (P less than 0.001), higher milk fat (P less than 0.05) and milk protein content (P less than 0.001). These cows had 1.90 times lower prevalence of the signs of subclinical ketosis (P less than 0.05) at estrus time when compared with non-pregnant cows. As a result, it was clearly demonstrated that P4 in dairy cows can help to evaluate and improve the reproductive properties of cows.


1997 ◽  
Vol 1997 ◽  
pp. 10-10
Author(s):  
R.D. Allison ◽  
P.C. Garnsworthy

Rumen inert fats are often included in dairy rations to increase the metabolisable energy (ME) supply whilst maintaining rumen function. Protected fat supplements have been shown to increase milk yields and fat content but with an associated and undesirable reduction in protein content. A reduced intake of rumen available energy (FME) may limit the microbial protein yield and so reduce the supply of amino acids to the mammary gland. Lactose supplements have been shown to increase the flow of microbial protein to the intestines (Chamberlain et al, 1993) and to reduce the effect of protected fats on milk protein content during early lactation (Garnsworthy, 1996). A trial was conducted to determine whether lactose supplementation could reduce the effects of protected fats on milk protein content during mid lactation.


1996 ◽  
Vol 1996 ◽  
pp. 88-88
Author(s):  
J A Metcalf ◽  
L A Crompton ◽  
F R C Backwell ◽  
B J Bequette ◽  
M A Lomax ◽  
...  

Previous work by this group (Metcalf et al 1996) has shown that milk protein concentration can be increased by jugular infusion of different mixtures of amino acids (AA). The current experiment was designed in part to investigate which groups of AA had the greatest effect in stimulating milk protein content.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
H. Zhou ◽  
L. Cheng ◽  
W. Azimu ◽  
S. Hodge ◽  
G. R. Edwards ◽  
...  

1996 ◽  
Vol 1996 ◽  
pp. 88-88
Author(s):  
J A Metcalf ◽  
L A Crompton ◽  
F R C Backwell ◽  
B J Bequette ◽  
M A Lomax ◽  
...  

Previous work by this group (Metcalf et al 1996) has shown that milk protein concentration can be increased by jugular infusion of different mixtures of amino acids (AA). The current experiment was designed in part to investigate which groups of AA had the greatest effect in stimulating milk protein content.


1999 ◽  
Vol 66 (4) ◽  
pp. 475-487 ◽  
Author(s):  
ZYGMUNT M. KOWALSKI ◽  
PAWEŁ M. PISULEWSKI ◽  
MAURO SPANGHERO

The objective of this study was to determine the effects of supplementing the diets of dairy cows with Ca soaps of rapeseed fatty acids (CSRFA) and rumen-protected (RP) methionine on their milk yield and composition, including milk protein fractions and fatty acids. Twelve Polish Red Lowland cows were used in a complete balanced two period changeover experiment. The four treatment diets were a control consisting of a total mixed ration of grass silage and concentrates, and the total mixed ration supplemented with RP methionine, CSRFA or RP methionine plus CSRFA. Dry matter intake was not affected by diet. Milk yield increased when cows were given the diet with CSRFA, but supplementation of diets with RP methionine did not affect milk yield. Milk protein content, but not milk protein yield, decreased when CSRFA was given. The addition of RP methionine to the control diet and the CSRFA diet produced similar increases in the milk protein content. Supplementation of the diet with CSRFA significantly changed the milk fatty acid profile: the proportions of 10:0, 12:0, 14:0, 15:0 and 16:0 in milk fat decreased, but those of 18:0 and cis-18:1 increased. We conclude that CSRFA can be used in practical dairy diets to increase milk yield and manipulate its fatty acid composition.


1999 ◽  
Vol 1999 ◽  
pp. 87-87
Author(s):  
J.Alderson ◽  
B.J. Bequette ◽  
M.A. Lomax

The current pricing structure of the UK milk industry considers milk quality with higher premiums paid for milk protein content than for fat. Attempts to alter milk protein content by feeding extra protein(Bequette et al.,1998) or infusing amino acids(AA) in dairy cows has not always given consistent results. The present study is the first in a series where the objective is to use explants prepared from rat mammary glands to start identifying which AA may be (limiting) most important in regulating milk protein synthesis. Such information could be useful to identify specific AA which should be supplemented in the diet of the cow.


Animals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 442 ◽  
Author(s):  
Tao Wang ◽  
Seung Woo Jeon ◽  
U Suk Jung ◽  
Min Jeong Kim ◽  
Hong Gu Lee

This study aimed to explore genes associated with milk protein content in dairy cows and their relationships with l-leucine. Ten primiparous Holstein cows (93.8 ± 11.56 milking days) fed the same diet were divided into two groups depending on their milk protein contents (group High, 3.34 ± 0.10%; and group Low, 2.86 ± 0.05%). Milk epithelial cells (MECs) were isolated from the collected morning milk and differentially expressed proteins in MECs were explored by two-dimensional gel electrophoresis (2-DE). Then, the mRNA expression of these proteins was detected by real time PCR in MAC-T cells incubated with three different media named positive control (PC), negative control (NC), and l-leucine depletion (NO-leu). Results showed that ten proteins were differentially expressed in MECs from cows in group High. They included seven down-regulated ones (heat shock protein beta-1 (HSPB1), 78 kDa glucose-regulated protein (GRP-78), l-lactate dehydrogenase B chain (LDH-B), malate dehydrogenase, cytoplasmic (MDH1), annexin I (ANXA1), cytokeratin-7 (CK-7), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH)), and three up-regulated ones (prohibitin (PHB), beta casein (CSN2), and alpha S1 casein (CSN1S1)). When l-leucine was depleted from the medium, not only proteins content was lowered (p < 0.05), but also the LDH-B mRNA expression was decreased in MAC-T cells (p < 0.05). In conclusion, LDH-B is negatively associated with the milk protein content of dairy cows and has a positive association with l-leucine.


1989 ◽  
Vol 29 (3) ◽  
pp. 309 ◽  
Author(s):  
SC Valentine ◽  
BD Bartsch

Friesian cows in early lactation were fed 3.5 or 7.0 kg DM daily of either hammermilled lupin grain, hammermilled oaten grain or whole oaten grain as supplements to a pasture-based diet. Milk production and composition and the amount and composition of whole oaten grain excreted in the faeces were measured. There were no significant differences between treatments in the yields of milk, fat or protein. There was a tendency towards lower milk fat content in milk from cows fed 7.0 kg DM daily of the hammermilled grains. Differences between grain types were not significant for all production parameters except milk protein content. Protein content was significantly (P<0.01) higher in milk from cows fed hammermilled and whole oaten grain compared with that from cows fed lupin grain. Yield of milk fat was significantly (P<0.05) higher and ratio of milk protein to fat significantly (P < 0.05) lower for cows fed 3.5 kg DM of grain than for those fed 7.0 kg DM of grain. There was a significant (P< 0.05) interaction between grain type and grain level for the ratio of protein to fat in the milk. Cows excreted 24% of the whole oaten grain at both levels of grain fed and there were no significant differences in composition of the whole oaten grain fed or excreted in the faeces. There was no benefit to production either from feeding hammermilled lupin grain compared with hammermilled or whole oaten grain or from feeding 7.0 compared with 3.5 kg DM daily of grain to cows grazing pasture.


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