A reference milk system for instrumental measurement of milk fat and protein

1988 ◽  
Vol 55 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Timothy Clarke

SummaryA reference milk system (Clarke system) using primary reference milks made from preserved natural bovine milks (PNM) and standard reconstituted milk (SRM) has been developed to enable accurate calibration of milk analysing instruments. The PNM have values of 2, 3, 4, 5 and 6% fat and 3·5, 2·7, 3·4, 4·2 and 3·3% protein respectively and can be stored for 4 months without detectable change in fat or protein content. The above reference milk system utilizes SRM as a secondary reference milk to enable regular checking of the stability of the instrument calibration during routine testing (e.g. after every 100 samples). Over several months seven laboratories using 13 fat-testing instruments and seven protein-testing instruments achieved high levels of accuracy in weekly calibrations (coefficient of variation 1·1%) when they used the reference milk system and adhered to the prescribed calibration criteria.

1983 ◽  
Vol 36 (1) ◽  
pp. 59-68 ◽  
Author(s):  
W. G. Hill ◽  
M. R. Edwards ◽  
M.-K. A. Ahmed ◽  
R. Thompson

ABSTRACTAnalyses of variance were conducted on first lactation milk, fat and protein production records in England and Wales of daughters of British Friesian sires. Herds were split on milk yield into high and low levels of mean production and, in subsequent analyses, into high and low levels of within herd variance and coefficient of variation using all first lactation records. Data were then extracted on daughters of 798 young sires undergoing progeny test and on 118 widely used proven sires to generate connections. Least squares analyses were conducted within levels and genetic correlations estimated from the covariance of sire effects. W ith data split on mean yield, the heritability of milk yield was 0·24 at the low level and 0·30 at the high level, that of log transformed yield being 0·25 and 0·35 respectively.With data split on variance the corresponding figures were 0·24, 0·30, 0·27 and 0·36 respectively, and when split on coefficient of variation, 0·22,0·26,0·26 and 0·32. There were similar increases for fat and protein yield, proportionately smaller increases for fat and protein content.Genetic correlations were close to 1·0 between high and low levels for all traits on all criteria of data splitting. As a consequence progeny testing of bulls is rather more accurate at high mean or variance of production levels and data can be combined optimally without scaling. Cows of the highest predicted value using an index will be found in high variance herds.


2021 ◽  
Vol 937 (2) ◽  
pp. 022122
Author(s):  
A Ashiev ◽  
K Habibullin ◽  
N Kravchenko

Abstract The purpose of the research was to identify samples of the collection of peas with a high and stable protein content in the grain, as a starting material in breeding for grain quality. Of the 130 studied samples of the collection of peas, which had at least 25.0% of the protein content in the grain, on average over the years of research, only 13 samples had a protein content of at least 25.0%. The highest minimum protein content was observed in the Russian-bred OMK-3 sample, which had an indicator of 26.1%. For the rest, the minimum value was from 25.0 to 25.3%. The maximum protein content over the years of research in pea samples was from 25.8 to 29.7%, of which samples 193/73 (Ukraine) (29.7%), OMK-3 (Russia) (29.5%), NS-01-68 (Bulgaria) (29.1%), B-887 (Russia) (28.7%) and Orel-330 (Russia) (28.7%). The average value of the coefficient of variation for varieties, characterizing intravarietal variability, was 6.8% on average for the collection, with the lowest value being 1.2% and the highest value being 15.9%. In the 13 isolated samples, the intravarietal variability was lower than the average for the collection as a whole (1.2-6.6%), except for sample 193/73 (Russia), for which it was 7.3%. This sample has the highest average and maximum protein content in the years of research. The selected 13 samples from the pea collection are of breeding value as initial parental forms in the direction of increasing the protein content in the pea grain and enhancing the stability of this indicator.


Author(s):  
A. Zheltikov ◽  
N. Kostomakhin ◽  
D. Adushinov ◽  
O. Zaiko ◽  
V. Dementev ◽  
...  

The characteristic of milk productivity of cows of Holstein and Simmental breeds in LLC “Sibirskaya Niva” in the Maslyaninsky district in the Novosibirsk region has been given. It has been revealed that under the natural and climatic environments of the Western Siberia, when creating favorable conditions for feeding and housing for cows of Holstein and Simmental breeds have sufficiently high milk productivity. It has been found that Holstein first-calf heifers surpassed their Simmental herdmates by 959 kg in milk yield for the first 305 days of lactation under the same conditions of housing and feeding, by 3,1 kg in daily milk yield, by 38,2 kg in milk fat yield, and by 28,3 kg in milk protein yield (P < 0,001). There were no statistically significant differences between animals of Holstein and Simmental breeds in terms of fat and protein content in milk, which amounted to 3,94 and 2,96 % in Holstein breed and 3,97 and 2,98 % in Simmental breed, respectively. Both breeds have shown high milk productivity during the first 3 lactations. Thus, the milk yield of Holstein cows for the first 3 lactation was 6475–9290 kg, Simmental cows it was 5516–7680 kg, fat content was 3,93–3,99 and 3,96–3,97 %, respectively. The protein content in the milk of cows of both breeds did not exceed 3,0 %. High variability has been found in milk yield, yield of milk fat and protein, the coefficient of milk content and duration of lactation, the lowest in the content of protein and fat in milk and live weight. The correlation coefficients between the fat and protein content in milk were generally positive, but did not exceed 0,28. Therefore, breeding in the herd of cows in LLC “Sibirskaya Niva” have to be conducted not only by fat content, but also by protein content in milk.


1982 ◽  
Vol 49 (1) ◽  
pp. 25-28 ◽  
Author(s):  
David G. Chamberlain ◽  
Phillip C. Thomas

SUMMARYEight cows in mid lactation and receiving a diet of perennial ryegrass silage and barley (70:30 on a DM basis) were given intravenous supplements of l-methionine (8 g/d). The methionine treatment had no significant effect on milk yield, protein content or lactose content, but increased milk fat content and yield by approximately 10% (P < 0·05).


1990 ◽  
Vol 38 (3B) ◽  
pp. 487-498
Author(s):  
H. de Visser ◽  
P.L. van der Togt ◽  
S. Tamminga

A feeding trial was carried out with 64 multiparous dairy cows, in which the effect of type of carbohydrate in concentrate mixtures (starch vs. cell wall constituents) and differences in rumen degradation (fast vs. slow) on feed intake and milk yield were studied. The experiment started immediately after parturition and lasted for 15 wk. The basal diet, which comprised 75% of the total DM intake, consisted of wilted grass silage, maize silage and concentrates. The remaining part of the diet consisted of barley (B), maize (M), pressed ensiled beet pulp (P) or moist ensiled maize bran (MB). All diets were given as totally mixed rations. Total intake of DM and net energy did not differ between diets, but differences were found in energy partition. There was a tendency for cows given diet B to show increased liveweight gain, while cows given P mobilized more body reserves compared with the other treatments. Milk yield did not differ between diets, but milk fat content was higher for diet P. Milk protein content was higher for diets B and M compared with P and MB. The lower protein content of the milk of treatment P can be explained by a longer period of negative energy balance, while the lower milk protein in cows given diet MB probably resulted from reduced microbial protein synthesis. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2020 ◽  
Vol 36 (4) ◽  
pp. 417-426
Author(s):  
Dragan Niksic ◽  
Vlada Pantelic ◽  
Dusica Ostojic-Andric ◽  
Predrag Perisic ◽  
Ljiljana Samolovac ◽  
...  

In order to examine the variability of production performance traits (lactation duration, milk yield for the whole lactation, milk yield in standard lactation, milk fat content, milk fat yield in standard lactation, protein content and yield in standard lactation), 954 cows, domestic and imported Simmental populations, were included in the study, with a total of 3641 completed lactations. Cows were located in the area of Toplica district, reared on individual farming households (tied system) and on the farm with intensive farming (free system). Based on the rearing method and origin, animals were divided into four groups: Group 1 (domestic animals reared by individual agricultural producers on individual farming households); Group 2 (imported animals reared by individual agricultural producers on individual farming households); Group 3 (domestic animals reared on the farm) and Group 4 (imported animals reared on the farm). The fourth group of studied cows showed the highest yield and protein content, while the cows of the third group had the longest lactation and the highest milk fat content. All production performance traits varied highly significantly (p?0.001) under the influence of the combined factor of housing/rearing method and origin.


Author(s):  
N. Kosyachenko ◽  
Marina Abramova ◽  
M. Lapina

Abstract. Aim. The study of the influence of crossbriding on the growth and development of heifers and subsequent productive and reproductive qualities of cows on the first lactation. Methods. Using statistical methods, correlation analysis and ANOVA for evaluated genetic indicators of economic-valuable traits of dairy cattle. In particular was studied live weight of heifers from birth to 18 months, first insemination age and first fecundation age, live weight at fecundation, frequency of insemination, first calving age, days open, live weight at first lactation, milk yield for 305 days (kg), fat (%, kg) and protein (%, kg) in milk. Results. Relationship between productive indicators and the genotype of the animal is established. When assessing the strength of the influence of the factor «blood on the Holstein breed» it was found that the greatest impact can be traced at the age of 6 and 18 months, and is respectively 12.7 % and 17.1 %.The reproductive qualities of the first-calf cows decreased with the increase percent of blood in the Holstein breed. Evaluation of the impact of crossbreeding on milk production at first lactation has revealed significant strong influence on milk yield for 305 days of first lactation, and related signs the amount of milk fat and protein. According to qualitative indicators, the low influence of the Holstein blood fraction was found, while to a greater extent on the fat content than on the protein content in milk. Evaluation of phenotypic and genotypic correlations of milk yield and quality components of milk revealed average negative phenotypic and low negative genotypic correlation in all groups. The exception was in heifers of Yaroslavl breed with percent of Holstein blood less than 50 %, in which the relationship of yield x protein was positive. The relationship between milk yield and fat and protein content in milk has the opposite moderate character and strength. Practical significance. Studies was established that breeding of animals of Holstein and Yaroslavl breeds in one herd allows to receive an optimum ratio of milk production with optimal percentage fat and protein. For this herd among animals of the improved genotypes of the Yaroslavl breed, the use of genotypes with a percent of blood in the Holstein breed from 75.1 % to 87.6 % is optimal, which should be taken into account when selecting bulls to the breeding program.


Author(s):  
Ewa Czerniawska-Piątkowska ◽  
Maciej Szewczuk ◽  
H. Kamieniecki ◽  
M. Adamski ◽  
A. Bruś ◽  
...  

The general aim of the present work was to compare dairy performance and some reproductive parameters of Holstein-Friesian (HF) cows imported from Sweden as an in-calf heifers, and their age mates in Poland. The animals were kept freely on the deep litter on the farm owned by Agro-company “Witkowo” and feeding was based on TMR (total mixed ration) system during whole year. All ration’s ingredients (bulky feed, concentrate, miscellaneous additives) were mixed and fed as all-mash. The feed ration depended from the physiological condition of a cow and it was composed of corn and grass ensilage, mash concentrate, crushed corn meal, brewer’s grains and beet pulp.Cows imported from Sweden as in-calf heifers obtained higher milk, fat and protein yield in both lactations comparing to home cows. Significant statistical differences were observed for kg of milk, kg of protein, for FCM (P<0.01) and for kg of fat (P<0.05) in 2nd lactation. Fat and protein content in milk was in average higher for home cows (P<0.01). Big differences (P<0.01) were observed in SBT (proportion of protein to fat content) and RTB (difference between concentration of fat and protein) at imported cows in 2nd lactation. As far as reproduction parameters (gestation interval, calving interval, insemination index) are concerned was cows from Sweden better too. Heifers from Sweden calved earlier. The usage of high genetic potential of imported cows is possible only with providing them optimum living conditions suitable to their needs.


2019 ◽  
Author(s):  
Venkat Krishnan Sundaram ◽  
Nirmal Kumar Sampathkumar ◽  
Charbel Massaad ◽  
Julien Grenier

AbstractMultiple statistical approaches have been proposed to validate reference genes in qPCR assays. However, conflicting results from these statistical methods pose a major hurdle in the choice of the best reference genes. Indeed, as their respective approaches to calculating reference gene stability is different, their suitability has to be tested for a given experimental setting. In this study, the stability of 10 candidate reference genes (Actb, Gapdh, Tbp, Sdha, Pgk1, Ppia, Rpl13a, Hsp60, Mrpl10, Rps26) was assessed using four common statistical approaches (GeNorm, NormFinder, Coefficient of Variation analysis and Pairwise ΔCt method) in a longitudinal setting. We used the development of the cerebellum and the spinal cord of mice as a model to assess the suitability of these statistical methods for reference gene validation. GeNorm and the Pairwise ΔCt were found to be ill suited due to a fundamental assumption in their stability calculations. Whereas, NormFinder and Coefficient of Variation analysis fare better provided they are used complementarily. We therefore devised a workflow combining these two methods for validating reference genes in developmental studies. This workflow proves to be more robust than any of the methods used individually.


Author(s):  
Martin Skýpala ◽  
Gustav Chládek

Milk yield varies during lactation, following what is termed a lactation curve. ŽIŽLAVSKÝ and MIKŠÍK (1988) recorded changes in milk yield within a day, too. TEPLÝ et al. (1979) a KOUŘIMSKÁ et al. (2007) published variation within a day ± 1.10 kg in milk yield, ± 0.75 % in milk fat content and ± 0.20 % in milk protein content. Milk yield of cows can be expressed in many different ways, for instance, in kilograms per lactation or in kilograms per day. A practical parameter describing milk production is milk yield (kg) per milking.The object of experiment were 12 cows of Holstein cattle on the first lactation from the 100-day of lactation to 200-day of lactation. The samples of milk were collected from January to May 2007, once a month from the morning and evening milking (milking interval 12 h ± 15 min.). The following parameters were monitored: milk production – milk yield (kg), milk protein production (kg), milk fat production (kg); milk composition – milk protein content (%), milk fat content (%), lactose content (%), milk solids-not-fat content (%), milk total solids content (%); technological properties of milk – ti­tra­tab­le acidity (SH), active acidity (pH), rennet coagulation time (s), quality of curd (class) and somatic cell count as a parameter of udder health.Highly significant differences were found (P < 0.01) between morning milk yield (15.7 kg) and evening milk yield (13.8 kg), between morning milk protein production (0.51 kg) and evening milk protein production (0.45 kg) and between evening milk fat content (4.41 %) and morning milk fat content (3.95 %). A significant difference (P < 0.05) was found between morning milk total solids content (12.62 %) and evening milk total solids content (12.07 %). No significant differences were found between morning (M) and evening (E) values of the remaining parameters: milk fat production (M 0.62 kg; E 0.60 kg), milk protein content (M 3.24 %; E 3.27 %), milk lactose content (M 4.78 %; E 4.86 %), milk solids-not-fat content (M 7.69 %; E 7.71 %), somatic cell count (M 80 000/1 mL; E 101 000/1 mL), titratable aci­di­ty (M 7.75 SH; E 7.64 SH), active acidity (M pH 6.58; E pH 6.61), rennet coagulation time (M 189 s.; E 191 s.), quality of curd (M 1.60 class; E 1.57 class).


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