Nutritional regulation of milk constituent synthesis and its manipulation

Author(s):  
D E Beever ◽  
G.E. Lobley ◽  
M.A. Lomax ◽  
J.C. MacRae ◽  
J.D. Sutton

Several important reasons have contributed to the current interest in manipulating the composition of cows milk, particularly the ratio of milk protein to fat. Current market forces are still influenced with the introduction of production quotas on milk volume which occurred in the mid 80's. This led to a payment scheme based on the sale of milk solids, whilst the more recent introduction of a quota on milk fat sales has provided a major disincentive to overproduce milk fat and specifically milk with a high fat content. Most recently, the pricing structure of milk was changed, with the reward for lactose being removed and replaced by an increased price differential between protein and fat. Thus to the dairy farmer, other than those producing Channel Island milk, increasing the protein content of milk appears the only option with which to increase the ex-farm gate value of the product. At the same time, consumer choice continues to have a major impact on the demand for milk and milk products and the increasing sales of semi-skimmed milk is one consequence of the Nation's concern regarding over-consumption of fats, especially those of animal origin.

1986 ◽  
Vol 43 (1) ◽  
pp. 27-36 ◽  
Author(s):  
J. B. Moran

ABSTRACTTwo experiments are described in which dairy cows in early lactation were individually offered ad libitum complete diets containing firstly rolled barley, wheat or oats comprising proportionately 0·6 of the total dry matter (DM) and seeondly, whole oats, rolled oats or whole oats soaked in sodium hydroxide comprising proportionately 0·5 of the total DM. Organic-matter (OM) digestibility was measured using chromium III oxide as an external faecal marker and production of milk, milk fat and milk protein were monitored. Rumen digestion rates of each grain type were measured in sacco using non-lactating cows.In the first experiment, voluntary DM intakes did not differ between diets, OM digestibilities were, in decreasing order, wheat > barley > oats, and faecal starch concentrations were, in decreasing order, barley > wheat > oats. Cows given oats produced the most milk and milk fat while cows given wheat produced the most milk protein. Digested OM was used most efficiently by cows given oats and their greater productivity was attributed partly to higher levels of dietary fibre and lipid.In the second experiment, cows fed alkali-treated oats had higher (though non-significant) DM intakes and produced the most milk, milk fat and milk protein. Excretion rates of whole grain from cows given treated or untreated whole oats did not differ, but grain weight loss in transit through the gut was higher with the alkali-treated grain. Food intakes and yields of milk and milk solids were similar in cows given either whole untreated or coarsely rolled oats.


2007 ◽  
Vol 47 (5) ◽  
pp. 502 ◽  
Author(s):  
S. C. García ◽  
M. Pedernera ◽  
W. J. Fulkerson ◽  
A. Horadagoda ◽  
K. Nandra

A grazing experiment involving 50 lactating Holstein–Friesian dairy cows was conducted to test the hypothesis that feeding concentrates (range 3–7 kg as fed/cow.day; average 5 kg/cow.day) to grazing cows based on individual (I) cow requirements would increase milk solids yield in comparison to fixed rate (F) allocation to the whole herd (average 5 kg/cow.day for all cows). The experiment comprised two sequential periods that differed only in the way maize silage was offered to cows (either 100% on a feed pad at night or 75% on a feed pad at night, with 25% in a paddock in the morning). Intake of individual cows was estimated using the 13C and n-alkanes method. The rumen degradability of the feeds (lucerne pasture, maize silage and commercial dairy pellets) was measured in parallel, using six rumen-fistulated sheep. Compared with cows in the F group, milk yield and milk fat yield for the I cows increased (P < 0.05) by 3.0 and 11.1%, respectively. As neither milk protein content nor milk protein yield was affected (P > 0.05) by treatment, total milk solids yield (milk fat plus milk protein) was 7.0% higher (P < 0.05) for I cows than for F cows. The increase in milk fat yield was presumably associated with an improved diet nutrient balance in the I cows, as indicated by a significant correlation between fibre intake and milk fat yield for cows in the I group but not for cows in the F group. This is also supported by the results of the rumen degradability of the feeds. In this study, higher-producing cows compensated for their higher requirements by increasing intake of maize silage, rather than pasture, as the former was the less restricted feed on offer. This highlights the importance of offering at least one feed to cows in a less restricted way, in order to enable high-producing cows in the herd to compensate for their higher intake requirements. In conclusion, under the conditions of the present study, feeding concentrates to cows based on individual cow requirements increased milk solids yield at no extra cost.


1995 ◽  
Vol 1995 ◽  
pp. 168-168
Author(s):  
E Smoler ◽  
D E Beever ◽  
M A Lomax ◽  
D J Humphries ◽  
G Perrott ◽  
...  

With the current production targets and pricing structures prevailing within the UK dairy industry, the incentives for the dairy farmer are to maximise milk protein content whilst controlling the yield of milk and milk fat widiin individual farm quotas. Manipulation of milk fat content by nutritional means is relatively easy, but increasing die protein content of milk by similar means is more difficult and certainly less predictable. Increasing the crude protein content of the diet will invariably stimulate the synthesis of milk protein, but tiiese changes are often associated with a parallel increase in milk volume, such mat milk protein content shows little change. In contrast, several studies have shown mat changing the nature and amount of carbohydrate in the diet can substantially improve milk protein content; Krohn et al., (1985), Roberts & Martindale, (1990), Yan & Roberts (1992, 1993) and Phipps et al (1993). At the same time, the increased use of caustic treated wheat (soda grain) on U.K dairy farms has in part been associated with consistent improvements which have been observed in milk protein content. The primary aim of this study was to consider the effect of replacing part or all of the concentrate portion of grass silage fed cows with alternative carbohydrate rich feeds on me yield of milk and milk constituents. The second objective was to compare the use of soda grain with a 50:50 mixture of rolled wheat and sugarbeet feed on dairy cow performance.


2015 ◽  
Vol 82 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Eleni Tsiplakou ◽  
Emmanouil Flemetakis ◽  
Evangelia-Diamanto Kouri ◽  
George Karalias ◽  
Kyriaki Sotirakoglou ◽  
...  

Milk protein synthesis in the mammary gland involves expression of six major milk protein genes whose nutritional regulation remains poorly defined. In this study, the effect of long term under- and over-feeding on the expression of αs1-casein: CSN1S1, αs2-casein: CSN1S2, β-casein: CSN2, κ-casein: CSN3, α-lactalbumin: LALBA and β-lactoglobulin: BLG gene in sheep mammary tissue (MT) was examined. Twenty-four lactating dairy sheep, at 90–98 d in milk, were divided into three groups and fed the same ration, for 60 d, in quantities which met 70% (underfeeding), 100% (control) and 130% (overfeeding) of their energy and crude protein requirements. The results showed a significant reduction on mRNA of CSN1S1, CSN1S2, CSN2 and BLG gene in the MT of underfed sheep compared with the overfed ones and a significant reduction in CSN3 and LALBA gene expression compared with the respective control animals. Significant positive correlations were observed between the mRNA levels of milk proteins’ genes with the milk protein yield and milk yield respectively. In conclusion, the feeding level and consequently the nutrients availability, affected the milk protein yield and milk volume by altering the CSN1S1, CSN1S2, CSN2, CSN3, LALBA and BLG gene expression involved in their metabolic pathways.


2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Johannes Haedrich ◽  
Claudia Stumpf ◽  
Michael S. Denison

Abstract Background Persistent organic pollutants (POPs) such as dioxins, dioxin-like chemicals and non-dioxin-like PCBs causing adverse effects to human health bio-accumulate through the food web due to their affinity for adipose tissues. Foods of animal origin are therefore the main contributors to human dietary exposure. The European Union’s (EU) food safety policy requires checking of a wide range of samples for compliance with legal limits on a regular basis. Several methods of varying efficiency are applied by official control laboratories for extraction of the different classes of lipids and associated POPs, bound to animal tissue and animal products in varying degrees, sometimes leading to discrepancies especially in fresh weight based analytical results. Results Starting from Smedes’ lipid extraction from marine tissue, we optimized the extraction efficiency for both lipids and lipophilic pollutants, abandoning the time-consuming centrifugation step. The resulting modified Smedes extraction (MSE) method was validated based on multiple analyses of a large number of real-world samples, matrix calibration and performance assessment in proficiency testing utilizing both instrumental and bioanalytical methodologies. Intermediate precision in 12 different foods was below 3% in chicken eggs, egg powder, animal fat, fish, fish oil, poultry, whole milk, milk fat and milk powder, and below 5% in bovine meat, liver, and infant food. In comparison to Twisselmann hot extraction, results presented here show an increased efficiency of MSE by + 25% for bovine liver, + 14% for chicken eggs, + 13% for poultry meat, + 12% for fish, 8% for bovine meat, and 6% for infant food. Conclusions For the first time, a fast and reliable routine method is available that enables the analyst to reproducibly extract "total" lipids from any EU-regulated food sample of animal origin within 6 to 8 min. Increased efficiency translates into a considerable increase in both lipid and wet weight-based analytical results measured for associated POPs, reducing the risk of false non-compliant results. Compared to a 4 h Twisselmann extraction, the extraction of 1000 samples using MSE would result in annual savings of about 250 h or 32 working days. Our MSE procedure contributes to the European Commission's objective of harmonizing analytical results across the EU generated according to Commission Regulation (EU) 2017/644.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 842
Author(s):  
Ramūnas Antanaitis ◽  
Vida Juozaitienė ◽  
Dovilė Malašauskienė ◽  
Mindaugas Televičius ◽  
Mingaudas Urbutis ◽  
...  

The aim of our study was to determine how the ease of calving of cows may influence changes in lactose concentration and other milk components and whether these two factors correlate with each other. To achieve this, we compared data of calving ease scores and average percentage of in-line registered milk lactose and other milk components. A total of 4723 dairy cows from nine dairy farms were studied. The cows were from the second to the fourth lactation. All cows were classified according to the calving ease: group 1 (score 1)—no problems; group 2 (score 2)—slight problems; group 3 (score 3)—needed assistance; group 4 (score 4)—considerable force or extreme difficulty. Based on the data from the milking robots, during complete lactation we recorded milk indicators: milk yield MY (kg/day), milk fat (MF), milk protein (MP), lactose (ML), milk fat/lactose ratio (MF/ML), milk protein/lactose ratio (MP/ML), milk urea (MU), and milk electrical conductivity (EC) of all quarters of the udder. According to the results, we found that cows that had no calving difficulties, also had higher milk lactose concentration. ML > 4.7% was found in 58.8% of cows without calving problems. Cows with more severe calving problems had higher risk of mastitis (SCC and EC). Our data indicates that more productive cows have more calving problems compared to less productive ones.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1247
Author(s):  
Xin Wu ◽  
Shuai Huang ◽  
Jinfeng Huang ◽  
Peng Peng ◽  
Yanan Liu ◽  
...  

The rumen contains abundant microorganisms that aid in the digestion of lignocellulosic feed and are associated with host phenotype traits. Cows with extremely high milk protein and fat percentages (HPF; n = 3) and low milk protein and fat percentages (LPF; n = 3) were selected from 4000 lactating Holstein cows under the same nutritional and management conditions. We found that the total concentration of volatile fatty acids, acetate, butyrate, and propionate in the rumen fluid was significantly higher in the HPF group than in the LPF group. Moreover, we identified 38 most abundant species displaying differential richness between the two groups, in which Prevotella accounted for 68.8% of the species, with the highest abundance in the HPF group. Functional annotation based on the Kyoto Encyclopedia of Gene and Genome (KEGG), evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG), and Carbohydrate-Active enzymes (CAZy) databases showed that the significantly more abundant species in the HPF group are enriched in carbohydrate, amino acid, pyruvate, insulin, and lipid metabolism and transportation. Furthermore, Spearman’s rank correlation analysis revealed that specific microbial taxa (mainly the Prevotella species and Neocallimastix californiae) are positively correlated with total volatile fatty acids (VFA). Collectively, we found that the HPF group was enriched with several Prevotella species related to the total VFA, acetate, and amino acid synthesis. Thereby, these fulfilled the host’s needs for energy, fat, and rumen microbial protein, which can be used for increased biosynthesis of milk fat and milk protein. Our findings provide novel information for elucidation of the regulatory mechanism of the rumen in the formation of milk composition.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 610
Author(s):  
Ramūnas Antanaitis ◽  
Vida Juozaitienė ◽  
Gediminas Urbonavičius ◽  
Dovilė Malašauskienė ◽  
Mindaugas Televičius ◽  
...  

In this study we hypothesized that the lameness of early lactation dairy cows would have an impact on inline biomarkers, such as rumination time (RT), milk fat (%), milk protein (%), milk fat/protein ratio (F/P), milk lactose (L, %), milk electrical conductivity of all udder quarters, body weight (BW), temperature of reticulorumen content (TRR), pH of reticulorumen content (pH), and walking activity (activity). All 30 lame cows (LCs) used in this experiment had a score of 3–4, identified according to the standard procedure of Sprecher et al.. The 30 healthy cows (HC) showed a lameness score of one. RT, milk fat, MY, milk protein, F/P, L, milk electrical conductivity of all udder quarters, and BW were registered using Lely Astronaut® A3 milking robots each time the cow was being milked. The TRR, cow activity, and pH of the contents of each cow’s reticulorumen were registered using specific smaXtec boluses. The study lasted a total of 28 days. Days “−14” to “−1” denote the days of the experimental period before the onset of clinical signs of lameness (day “0”), and days “1” to “13” indicate the period after the start of treatment. We found that from the ninth day before the diagnosis of laminitis until the end of our study, LCs had higher milk electrical conductivity in all udder quarters, and higher milk fat to protein ratios. On the 3rd day before the onset of clinical signs of the disease until the day of diagnosis, the milk fat of the LC group was reduced. The activity of the LCs decreased sharply from the second day to the first day after treatment. RT in the HC group tended to decrease during the experiment. pH in LCs also increased on the day of the appearance of clinical signs.


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