Changes in daily energy amounts of main milk components (lactose, protein and fat) during the lactation of high-yielding dairy cows

Gáspárdy, András; Schwartz, Ziva; Zöldág, L.; Veresegyházy, T.; Fekete, S.

doi:10.1556/avet.52.2004.4.8

Cited by 11 publications

(10 citation statements)

References 5 publications

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“…In the present study, proportion of milk lactose was constant during the first 20 weeks of lactation, but tended to be higher on day 57 pp. These results coincide with data from Gáspárdy et al (2004) which show that lactose concentration of Israeli Holstein-Friesian cows peaked on day 66 of lactation. Total somatic cell count was constant during the experimental timeframe but tended to be higher at the end of the study.…”

Section: Milk Yield and Milk Compositionsupporting

confidence: 90%

Gene expression of six major milk proteins in primary bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation

Sigl¹,

Meyer²,

Wiedemann³

2012

CZECH J ANIM SCI

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ABSTRACT:The objective of the present study was to refine a previously developed method to isolate primary bovine mammary epithelial cells (pBMEC) from fresh milk. Using this method, it was tested whether the number of pBMEC and the relation of recovered pBMEC to total somatic cell count vary within the individual lactation stages. Furthermore, the expression levels of the milk protein genes during the first twenty weeks of lactation were determined by quantitative PCR method. A total number of 152 morning milk samples were obtained from twenty-four Holstein-Friesian cows during the first 20 weeks of lactation (day 8, 15, 26, 43, 57, 113, and 141 postpartum). Numbers of extracted pBMEC were consistent at all time-points (1.1 ± 0.06 to 1.4 ± 0.03 ×10 3 /ml) and an average value of RNA integrity number (RIN) was 6.3 ± 0.3. Percentage of pBMEC in relation to total milk cells (2.0 ± 0.2 to 6.7 ± 1.0%) correlated with milk yield. Expression patterns of the casein genes alpha (α) S1 , (α) S2 , beta (β), and kappa (κ) (CSN1S1, CSN1S2, CSN2, CSN3, respectively) and the whey protein genes α-lactalbumin (LALBA) and progestagen-associated endometrial protein (PAEP; known as β-lactoglobulin) were shown to be comparable, i.e. transcripts of all six milk protein genes were found to peak during the first two weeks of lactation and to decline continuously towards mid lactation. However, mRNA levels were different among genes with CSN3 showing the highest and LALBA the lowest abundance. We hypothesized that milk protein gene expression has a pivotal effect on milk protein composition with no influence on milk protein concentration. This paper is the first to describe milk protein gene expression during lactation in pBMEC collected in milk. Future studies will be needed to understand molecular mechanisms in pBMEC including regulation of expression and translation throughout lactation.

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Section: Milk Yield and Milk Compositionsupporting

confidence: 90%

Gene expression of six major milk proteins in primary bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation

Sigl¹,

Meyer²,

Wiedemann³

2012

CZECH J ANIM SCI

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“…2007), milk composition or contamination of milk samples (Friedrich et al. 2007), conceivably even dietary manipulations (Jenkins and McGuire 2006) or stage of lactation (Gaspardy et al. 2004), might contribute to variability.…”

Section: Discussionmentioning

confidence: 99%

“…Milk samples were handled in a standardized routine, yet apparently minute amounts of remaining fat may act as a source of interference. Factors, such as milk yield (Lopez-Gatius et al 2007), milk composition or contamination of milk samples (Friedrich et al 2007), conceivably even dietary manipulations (Jenkins and McGuire 2006) or stage of lactation (Gaspardy et al 2004), might contribute to variability. Consequently, at the present stage, under farming conditions, reliable pregnancy detection on the basis of a milk sample is not possible before day 150 of pregnancy.…”

Section: Discussionmentioning

confidence: 99%

Establishment of an ELISA for Measuring Bovine Pregnancy‐Associated Glycoprotein in Serum or Milk and Its Application for Early Pregnancy Detection

Friedrich

Holtz

2010

Reprod Domestic Animals

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It has been shown in several mammalian species that during pregnancy, trophoblast cells express a range of pregnancy-associated glycoproteins (PAG). The presence of PAG in the maternal serum of cows may serve as an indicator of pregnancy from day 28 after AI onward. The present study addresses (1) conversion of an existing PAG-RIA to a competitive double antibody ELISA using a polyclonal anti-bPAG-IgG and an anti-rabbit-IgG raised in sheep for coating and (2) application of newly established ELISA to test its suitability for pregnancy detection by measuring PAG in serum or milk. The intraassay coefficients of variation (CV) for the PAG-ELISA were 2-14% for serum and 10-12% for milk; the corresponding interassay CVs were 8-22% and 12-22%, respectively. Pregnancy-associated glycoprotein profiles established in milk and serum of 12 pregnant cows showed a characteristic pattern with measurable amounts from approximately day 20 onwards in serum and from day 60 onwards in milk. In a field trial, serum PAG was determined in 397 cows sampled between 20 and 50 days after insemination. The outcome was that, pregnancy could reliably be diagnosed from day 28 onwards in serum and from day 150 onwards in milk. In conclusion, it may be stated that the established ELISA provides an efficient and reliable means of pregnancy diagnosis that will, in our judgement, gain in popularity with cattle breeding. The ELISA proved to be an adequate and efficient way of measuring PAG in maternal serum or milk and will be a useful means of pregnancy detection in cows.

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“…The lactose synthesis pathway occurs in the Golgi vesicles during lactation (Mohammad et al, 2012) through the function of lactose synthase, which consists of the membrane-bound enzyme β-1,4-galactosyl transferase (B4GAlt) and the milk protein α-lactalbumin (α-lA; Farrell et al, 2004). Lactose is the major osmotic substance in milk and accounts for approximately 50% of the total osmotic pressure of milk; the other 50% is contributed by milk ions, proteins, citrate, and other substances (Gáspárdy et al, 2004).…”

mentioning

confidence: 99%

An insufficient glucose supply causes reduced lactose synthesis in lactating dairy cows fed rice straw instead of alfalfa hay1

Wang

Zhao

Zhang

et al. 2016

Journal of Animal Science

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The objective of the present study was to investigate the nutrient availability for milk production in the mammary gland of lactating cows fed different forage-based diets. The 3 diets contained 30% corn stover (CS), 30% rice straw (RS), or 23% alfalfa hay plus 7% Chinese wild rye hay (AH) as a forage source. All diets contained 15% of DM as corn silage and 55% of DM as concentrate. The percentage of milk lactose was always lower in the RS-fed cows than in the cows fed AH or CS during the 12-wk feeding trial ( < 0.01). Ruminal propionate concentrations were lower in the RS group than in the AH group ( = 0.03). The ratio of insulin to glucagon in the mammary venous plasma was greater in the AH group than in the CS or RS group ( = 0.04). The abundance of the pyruvate carboxylase mRNA in the liver was lower in the RS group than in the AH or CS group ( = 0.04), and the abundance of mitochondrial phosphoenolpyruvate carboxykinase, IGF-1 receptor, and phosphofructokinase-liver, phosphofructokinase-muscle, and phosphofructokinase-platelet mRNA in the liver were lower in the RS group than in the AH group ( < 0.05). The mammary glucose uptake was greater in the AH-fed cows than in the CS- or RS-fed cows ( = 0.02). The mRNA abundance of the glucose transporters in the mammary gland was similar among the 3 treatments. The mRNA abundance of α-lactalbumin in the mammary gland of the cows fed RS tended to be greater compared with that of the cows fed AH or CS. The milk potassium concentration was greater in the cows fed RS than those fed AH or CS ( < 0.01). In summary, the insufficient ruminal propionate concentrations in the cows fed RS were associated with lower gluconeogenesis in the liver, resulting in the shortage of glucose supply for mammary utilization.

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Changes in daily energy amounts of main milk components (lactose, protein and fat) during the lactation of high-yielding dairy cows

Cited by 11 publications

References 5 publications

Gene expression of six major milk proteins in primary bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation

Gene expression of six major milk proteins in primary bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation

Establishment of an ELISA for Measuring Bovine Pregnancy‐Associated Glycoprotein in Serum or Milk and Its Application for Early Pregnancy Detection

An insufficient glucose supply causes reduced lactose synthesis in lactating dairy cows fed rice straw instead of alfalfa hay1

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