Effects of milk protein genetic variants on milk yield and composition

1984 ◽  
Vol 51 (4) ◽  
pp. 531-546 ◽  
Author(s):  
Douglas M. McLean ◽  
E. R. Bruce Graham ◽  
Raul W. Ponzoni ◽  
Hugh A. McKenzie

SummaryEffects of genetic variants of the milk proteins, αs1-casein, β-casein, κ-casein and β-lactoglobulin (βlg), on milk yield and composition, particularly the protein composition, were investigated in milk samples from 289 Jersey and 249 Friesian cows in eight commercial herds.Milk protein genotypes had no significant effect on yields over a complete lactation of milk and fat, but significant differences in fat content were detected for β-casein (B, A1B, A2 > A1A2) and βlg (B, AB > A) variants. Significant differences between β-lg variants were also found with total solids (B, AB > A), casein (B, AB > A), whey protein (A > AB > B) and βlg (A > AB, AC > B > BC) concentrations. Casein genotypes were not significantly different in total protein and casein concentrations but many differences were found in casein composition. αs1-Casein variants significantly affected αs1-casein (BC > B) and κ-casein (B > BC) concentrations. β-Casein variants affected concentration and proportion of β-casein (A1B, A2B > A1, A1A2, A2, B), αs1-casein (A1, A2 > B) and κ-casein (B > A2) and concentration of whey protein (A1 > most other β-casein variants). κ-Casein variants affected concentration and proportion of κ-casein (B > AB > A), proportion of αs1-casein (A > AB > B) and concentration of βlg (A > AB, B) and α-lactalbumin (A, AB > B). Differences in milk composition were found between breeds, herds and ages, and with stage of lactation. The potential use of milk protein genotypes as an aid in dairy cattle breeding is discussed.

2013 ◽  
Vol 4 (3) ◽  
pp. 612-617 ◽  
Author(s):  
H. Bovenhuis ◽  
M. H. P. W. Visker ◽  
A. Lundén

The suitability of milk for specific dairy products might be improved by changing milk fat or milk protein composition. In the RobustMilk project, we showed that milk fat composition is determined by genetic factors. In addition, recent studies indicate that milk protein composition is strongly affected by genetic factors. This suggests that there are opportunities to change milk composition by means of selective breeding. Traditional selection is based on large-scale phenotyping and not all analytical methods are suited for this purpose. The RobustMilk project team has shown that several fatty acids can be predicted on the basis of IR spectra. Accuracy of predicting individual milk proteins based on IR spectra is low. In addition to phenotypic records, selection might be based on genotypic information. DGAT1 and SCD1 genotypes are strongly associated with fat composition. β-Lactoglobulin, β-casein and κ-casein protein variants are strongly associated with protein composition. We conclude that tools are now available for changing detailed milk fat or milk protein composition by means of selective breeding.


1983 ◽  
Vol 63 (4) ◽  
pp. 751-761 ◽  
Author(s):  
I. MONDRAGON ◽  
J. W. WILTON ◽  
O. B. ALLEN ◽  
H. SONG

Yield and composition of milk was measured on 270 cows with up to three parities each. Several combinations of breeds were included with all first parity females nursing Angus-sired calves and second and third parity females nursing Simmental-sired calves. Milk yields and compositions were obtained at 6, 14 and 22 wk postcalving. Yields were measured by both calf-nursing and machine-milking techniques. Milk yields were similar throughout lactation in first parity but declined over stages of lactation in parities two and three. No interactions between breed group of cow and stage of lactation were found. Milk fat percentages were found to be highest in early lactation, while protein percentages increased during lactation and lactose percentages remained constant. Milk yields increased from first to second parity, but were similar for second and third parities. Composition of milk was similar in all parities. Cows classified as being of dairy breeding had the highest milk yields, Jersey crosses were intermediate, while Charolais, British breeds and their crosses were lower and similar in milk yield. Jersey crosses were highest in milk fat percentage. Milk yield estimates were higher for the calf-nursing method than for the machine-milking method. Estimated repeatabilities of total milk yield, milk fat percent, milk protein percent and milk lactose percent were 0.40, 0.36, 0.58 and 0.52, respectively. Milk yields had a significant positive effect on weaning weights of calves. The inclusion of either milk fat percent or milk protein percent as covariates did not increase the percent of variation explained in weaning weights. Key words: Milk yield, beef weaning weights, milk composition, repeatabilities


2021 ◽  
Vol 12 (6) ◽  
pp. 2605-2616
Author(s):  
Teresa Francis Wegrzyn ◽  
Alejandra Acevedo-Fani ◽  
Simon M. Loveday ◽  
Harjinder Singh

The gastric digestion behaviours of blended protein beverages containing different ratios of casein, whey protein and soya protein that were heat-treated at 60 °C or 80 °C were investigated using an in vitro dynamic human gastric simulator.


2016 ◽  
Vol 19 (1-2) ◽  
pp. 50-65
Author(s):  
MA Baset ◽  
KS Huque ◽  
NR Sarker ◽  
MM Hossain ◽  
MN Islam

A total of 160 cows, 10 cows in each of native (local cow) and crossbred (local × Holstein Friesian) origins differing in lactation were used in 2×2×2×2 factorial experiment using Randomized Block Design (RBD) to evaluate milk yield and composition of cows considering regions (good & poor feed base region), seasons (dry: Nov.–Feb. 2009 & wet: Jun.–Oct. 2009), genotypes and lactation. A “good and/or poor feed base” region was classified based on the availability of quantity and quality roughages throughout the year. The study revealed that the daily milk yield and 4% FCM of cows under good feed base condition were 6.76 and 6.49 kg, respectively and under poor feed base condition were 3.67 and 3.31 kg, respectively. Feed base region did not affect on milk fat and it was observed that the milk protein, lactose, solids-not-fat (SNF), minerals and total solids under good feed base condition were 37.9, 54.9, 100.9, 6.3 and 140.6 g/kg, respectively, whereas, under poor feed base condition the values were 36.3, 52.9, 98.0, 6.1 and 135.2 g/kg, respectively. Season did not affect milk yield and composition except minerals (6.5 g/kg vs. 5.9 g/kg). Genotypes significantly (p?0.01) influenced daily milk yield, the milk protein and minerals. Lactation did not affect milk yield and the milk protein, but influenced the fat, lactose, SNF, minerals and total solids. The interaction of feed base regions and seasons significantly (p?0.01) influenced milk yield and the milk fat and SNF. The milk protein and lactose was influenced by the interaction of feed bases region, seasons and lactation. Milk yield negatively correlated with fat per cent. The percentage of fat significantly (p?0.01) correlated with protein, lactose, SNF, and minerals %. The percentage protein correlated with lactose, SNF and minerals. Lactose % significantly (p?0.01) correlated with SNF%. It may be concluded that milk yield and composition depends on feed base region, genotype and lactation of cows. Season did not influence milk yield and the composition. Milk yield negatively correlated with the percentage of fat, protein, lactose, SNF and milk composition strongly correlated with each other.Bangladesh J. of Livestock Res. 19(1-2): 50-65, Jan-Dec 2012


2003 ◽  
Vol 76 (3) ◽  
pp. 439-454 ◽  
Author(s):  
H. J. Sayers ◽  
C. S. Mayne ◽  
C. G. Bartram

AbstractA study was undertaken to examine the effect of level and type of supplement and changes in the chemical composition of herbage through the grazing season on herbage intake, animal performance and rumen characteristics with high-yielding dairy cows. Thirty-two high genetic merit dairy cows were allocated to one of four treatments in a two-phase change-over design experiment. The four treatments involved offering either high-fibre (HF) or high-starch (HS) supplements at either 5 or 10 kg dry matter (DM) per day. Animals rotationally grazed perennial ryegrass swards offered a daily herbage allowance of 23 kg DM. High levels of animal performance were maintained throughout the study with mean milk yields over the 21-week experimental period of 35·5 and 37·2 kg per cow per day on the 5- and 10-kg treatments respectively. Supplement type had no significant effect on herbage intake. Increasing the level of supplementation reduced herbage intake by 0·49 and 0·46 kg herbage DM per kg supplement DM and increased milk yield, with a milk yield response of 0·55 and 0·65 kg/kg supplement DM offered in phases 1 and 2. Supplement type had no significant effect on milk yield and milk butterfat content. However, in both phases 1 and 2, milk protein content was significantly higher with cows offered the HS supplement compared with the HF supplement, this being particularly evident at the higher level of supplementation. Supplement type also had marked effects on milk protein composition. These results indicate that high levels of performance can be achieved with dairy cows on grazed pasture with moderate levels of supplementation.


PEDIATRICS ◽  
1983 ◽  
Vol 71 (2) ◽  
pp. 268-271 ◽  
Author(s):  
Iréne Jakobsson ◽  
Tor Lindberg

Sixty-six mothers of 66 breast-fed infants with infantile colic were put on a diet free from cow's milk. The colic disappeared in 35 infants; it reappeared on at least two challenges (cow's milk to mother) in 23 infants (35%). A double-blind crossover trial with cow's milk whey protein was performed in 16 of these 23 mothers and infants. Six infants had to be taken out of the study for various reasons; of the remaining ten infants, nine reacted with colic after their mothers' intake of whey protein-containing capsules. Sequential analysis showed a high correlation between infantile colic in breast-fed infants and their mothers' consumption of cow's milk protein. A diet free of cow's milk is suggested for the mothers as a first trial of treatment of infantile colic in breast-fed infants.


2020 ◽  
Vol 65 (No. 2) ◽  
pp. 41-50
Author(s):  
Lucia Mačuhová ◽  
Vladimír Tančin ◽  
Juliana Mačuhová

Milking frequency is the main factor regulating milk yield and milk quality if feeding, welfare, health, and environmental conditions are adequate. Milk yield and composition are substantially influenced by breed, and consequently the breed has an impact on both factors at a different frequency of milking. Further, the size of cisternal compartment plays an important role in accommodating secreted milk between milkings. Thus, ewes with large cisterns (i.e. large cisternal area, high cisternal milk percentage, and delayed tight junction opening during milk stasis) adapt themselves better to longer milking intervals than ewes with a small cistern. The increase of milking frequency from two to three times a day can lead to an increase of milk yield in the range of 3 to 36%. On the other hand, the reduction of milking frequency from twice to once a day can decrease milk yield from 9 to 67%. Two milkings per week could be omitted with no negative effects on milk yield, milk composition, and somatic cell count in ewes with large cisterns. However, besides the breed and cistern storage capacity, the results in literature show that the effects of milking frequency on milk yield and milk composition can vary according to the stage of lactation, individual animal, production level, practice of stripping, and duration of changed frequency. The right use of different milking frequency strategies can result in increased milk yield or in significant savings in labour and time spent in the milking parlour with negligible or no negative effects on milk yield and composition.


2001 ◽  
Vol 2001 ◽  
pp. 192-192
Author(s):  
R.E. Lawson ◽  
A.R. Moss ◽  
C. Rymer ◽  
J.S. Blake

Mansbridge (1995) reported that replacing ground wheat with a mix of ground wheat and maize grain increased milk protein concentration, which led the authors to speculate that increased inclusion of maize grain increased rumen by-pass starch. Indeed, de Visseret al(1990) reported that feeding less rapidly degradable starches has led to increased milk protein concentration.The objective of this study was to examine the effects of starch concentration and source on feed intake, milk yield and milk composition of dairy cows.


Author(s):  
Henk Bovenhuis

Several studies have shown milk protein genetic variants to be associated with manufacturing properties of milk. The main findings were that κ-casein genetic variants affect renneting time of milk and βlactoglobulin genetic variants are associated with casein number (reviewed by Grosclaude, 1988). There are reports also of associations between milk protein genetic variants and milk production traits. Results from these studies indicate that κ-casein genotypes are associated with protein content and βlactoglobulin genotypes are related to fat content (reviewed by Bovenhuis et al., 1992). Therefore, κ-casein and βlactoglobulin genotypes might be of value as selection criteria. The aim of the present study was to quantify the potential effects of selection for κ-casein and β-lactoglobulin genotypes by using stochastic simulation of a closed adult MOET nucleus breeding scheme.


1992 ◽  
Vol 54 (1) ◽  
pp. 15-21 ◽  
Author(s):  
S. A. Okantah

AbstractDaily partial milk yield of Sanga cows in 13 smallholder agropastoralist herds at two locations on the Accra Plains was recorded through monthly sampling. Estimates of mean daily partial milk yield and milk composition were computed from 1266 observations. The unadjusted mean daily partial milk yield was 875 (s.e. 11) g. The composition of milk: total solids (TS), fat (F) and solid-not-fat (SNF) were 131 (s.e. 14), 41 (s.e. 11) and 90 (s.e. 7) g/kg respectively. Least squares estimate of mean daily partial milk yield were 808·2 and 462·4 g with average s.e. of 41·8 for wet and dry season respectively. The wet and dry season differences in daily partial milk yield, TS and F were highly significant (P < 0·01). Seasonal difference in SNF was not significant.Herd difference in partial milk yield, TS, F and SNF were highly significant (P < 0·02). There were no significant effects of location on daily partial milk yield and SNF, although location effects on F and TS were significant (P < 0·05). The highest milk yield was observed in cows in third lactation and the lowest in cows in seventh lactation (P < 0·01). Daily partial milk yield peaked in the 3rd month of lactation. On average, lactation length was 210 to 240 days. Both linear and quadratic effects of stage of lactation were highly significant (P < 0·01). Lactation curve parameters for partially milked cows were also estimated. The implications of the results for milk production in sub-Saharan Africa were discussed.


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