Genetic association between test-day milk fat to protein ratio and fertility traits in dairy cows: A random regression model analyses

In early lactating cows changes in energy balance (EB) and subsequent mobilisation of body reserves result changes in milk yield (MY) and milk composition. These variations could be used as indicators of changes or problems in feeding, health and fertility. Recently it is postulated that changes in milk fat to protein ratio (FPR) may be associated with a negative EB. A negative EB, typical of the early phase of lactation impairs cows fertility whereas a recovery in EB from its most negative state, signals the initiation of ovarian activity indicating a direct relationship. Therefore, since measuring EB in large populations is difficult and expensive, assessing the genetic association between ratios of milk components and fertility traits, especially at different stages of lactation may provide an inexpensive indicator of EB. Besides, in selection programs, such information could be used to identify sires and cow families that have chronic energy deficiency and poor fertility in early lactation. The objectives of this study were to estimate covariance components for test-day FPR, MY and fertility traits and to assess the genetic associations between these traits during lactation using random regression models (RRM). Genetic parameters of test-day FPR, MY and fertility were estimated using bivariate RRM that combine traits with different data structures employing a meta-model analyses. Fertility traits considered were days from calving to insemination (DFI), days open (DO), number of inseminations (NI), non-return rate to 56 days (NRR). Data was from a total of 22422 first lactation Finnish Ayrshire cows. The sire pedigree file had 638 males of which 509 sires had daughters with data. Heritability of test-day FPR during lactation ranged from 0.08 to 0.17 while the heritability of DFI, DO, NI and NRR were 0.06, 0.03, 0.01 and 0.02, respectively. Genetic correlations between test-day FPR and MY during early lactation ranged from 0.10-0.28. The positive genetic correlation between these traits indicates that genetically high producing cows tend to have high FPR during early lactation. Genetic correlations between test-day FPR and DFI, DO, NI, and NRR during early lactation were from 0.05-0.28, 0.03-0.24, 0.01-0.03, and -0.01-0.03, respectively. Of the fertility traits, the strongest genetic association was between test-day FPR and DFI or DO. The relatively low correlations between test-day FPR and the other fertility traits (NI and NRR) could be due to they are measures of fertility that are recorded after cows recovered from the most negative state of EB and started cycling. The positive and relatively higher genetic correlations between test-day FPR and DFI or DO indicate cows with high test-day FPR in early lactation tends to take longer from calving to first insemination and successful conception. The results from this study indicate that high FPR in early lactation could be used as an indicator of negative EB and cows of poor fertility, which take longer time from calving to first insemination and successful conception.

Download Full-text

Effect of milk fat to protein ratio on genetic variance for milk yield in Thai tropical Holstein cattle

Canadian Journal of Animal Science ◽

10.1139/cjas-2015-0125 ◽

2016 ◽

Vol 96 (3) ◽

pp. 410-415 ◽

Cited By ~ 1

Author(s):

S. Puangdee ◽

M. Duangjinda ◽

W. Boonkum ◽

S. Buaban ◽

S. Katawatin

Keyword(s):

Milk Fat ◽

Variance Components ◽

Legendre Polynomials ◽

Bayesian Method ◽

Genetic Variance ◽

Genetic Correlations ◽

Random Regression ◽

Third Order ◽

Protein Ratio ◽

Regression Test

The objective of this research was to investigate the optimum fat to protein ratio (FPR) in Thai tropical Holstein dairy cattle. First parity data consisting of 20 492 milk yields (MY) records for 24 891 cows for the period 2001 and 2011, were used in the analysis. The analysis used a random regression test-day animal model of third-order Legendre polynomials through the creation of a covariance function based on different FPRs. Variance components were estimated using the Bayesian method via the Gibbs sampling. The estimated heritability of MY in relation to FPR ranged from 0.19 to 0.27 with the pattern being similar to the genetic variances. Genetic correlations of MY at different FPRs were high at consecutive FPRs and then declined to negative in response to greater differences in FPR. Based on the results, it is concluded that the optimum FPR is in the range of 0.9 to 1.9, corresponding to the genetically controlled energy balance for MY in tropical Holsteins.

Download Full-text

Identification of Risk Factors for Lameness Detection with Help of Biosensors

Agriculture ◽

10.3390/agriculture11070610 ◽

2021 ◽

Vol 11 (7) ◽

pp. 610

Author(s):

Ramūnas Antanaitis ◽

Vida Juozaitienė ◽

Gediminas Urbonavičius ◽

Dovilė Malašauskienė ◽

Mindaugas Televičius ◽

...

Keyword(s):

Electrical Conductivity ◽

Milk Fat ◽

Milk Protein ◽

Standard Procedure ◽

Clinical Signs ◽

Experimental Period ◽

Early Lactation ◽

Protein Ratio ◽

Walking Activity ◽

Protein Milk

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.

Download Full-text

Relationship between Temperament and Stage of Lactation, Productivity and Milk Composition of Dairy Cows

Animals ◽

10.3390/ani11071840 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1840

Author(s):

Ramūnas Antanaitis ◽

Vida Juozaitienė ◽

Vesta Jonike ◽

Vytenis Čukauskas ◽

Danguolė Urbšienė ◽

...

Keyword(s):

Milk Fat ◽

Genetic Correlations ◽

Subclinical Mastitis ◽

Milk Composition ◽

Cow Milk ◽

Phenotypic Correlation ◽

Protein Ratio ◽

Stage Of Lactation ◽

Milk Urea ◽

Milk Performance

The aim of this study was to assess the relationship between temperament and milk performance in cows at different stages of lactation, describing their productivity, metabolic status and resistance to mastitis. This study showed that with increasing lactation, cows’ temperament indicators decreased (p < 0.001) and they became calmer. The highest temperament score on a five-point scale was found in cows between 45 and 100 days of lactation. In the group of pregnant cows, we found more cows (p = 0.005) with a temperament score of 1–2 compared with non-pregnant cows A normal temperament was usually detected in cows with lactose levels in milk of 4.60% or more and when the somatic cell count (SCC) values in cow milk were <100,000/mL and 100,000–200,000/mL, with a milk fat-to-protein ratio of 1.2. A larger number of more sensitive and highly aggressive cows was detected at a low milk urea level. In contrast to a positive phenotypic correlation (p < 0.05), this study showed a negative genetic correlation between the temperament of cows and milk yield (p < 0.001). Positive genetic correlations between temperament scores and milk somatic cells (p < 0.001) and milk fat-to-protein ratio (p < 0.05) were found to indicate a lower genetic predisposition in cows with a calmer temperament to subclinical mastitis and ketosis. On the other hand, the heritability of temperament (h2 = 0.044–0.100) showed that only a small part of the phenotypic changes in this indicator is associated with genetic factors.

Download Full-text

Revisiting the Relationships between Fat-to-Protein Ratio in Milk and Energy Balance in Dairy Cows of Different Parities, and at Different Stages of Lactation

Animals ◽

10.3390/ani11113256 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3256

Author(s):

Edward H. Cabezas-Garcia ◽

Alan W. Gordon ◽

Finbar J. Mulligan ◽

Conrad P. Ferris

Keyword(s):

Energy Balance ◽

Dairy Cows ◽

Milk Fat ◽

Early Lactation ◽

Protein Ratio ◽

Linear Relationships ◽

Holstein Friesian ◽

Partial Correlations ◽

Regression Slopes ◽

Beta Hydroxybutyrate

A statistical re-assessment of aggregated individual cow data was conducted to examine trends in fat-to-protein ratio in milk (FPR), and relationships between FPR and energy balance (EB, MJ of ME/day) in Holstein-Friesian dairy cows of different parities, and at different stages of lactation. The data were collected from 27 long-term production trials conducted between 1996 and 2016 at the Agri-Food and Biosciences Institute (AFBI) in Hillsborough, Northern Ireland. In total, 1321 lactations (1 to 20 weeks in milk; WIM), derived from 840 individual cows fed mainly grass silage-based diets, were included in the analysis. The energy balance was calculated daily and then averaged weekly for statistical analyses. Data were further split in 4 wk. intervals, namely, 1–4, 5–8, 9–12, 13–16, and 17–20 WIM, and both partial correlations and linear regressions (mixed models) established between the mean FPR and EB during these periods. Three FPR score categories (‘Low’ FPR, <1.0; ‘Normal’ FPR, 1.0–1.5; ‘High’ FPR, >1.5) were adopted and the performance and EB indicators within each category were compared. As expected, multiparous cows experienced a greater negative EB compared to primiparous cows, due to their higher milk production relative to DMI. Relatively minor differences in milk fat and protein content resulted in large differences in FPR curves. Second lactation cows displayed the lowest weekly FPR, and this trend was aligned with smaller BW losses and lower concentrations of non-esterified fatty acids (NEFA) until at least 8 WIM. Partial correlations between FPR and EB were negative, and ‘greatest’ in early lactation (1–4 WIM; r = −0.38 on average), and gradually decreased as lactation progressed across all parities (17–20 WIM; r = −0.14 on average). With increasing parity, daily EB values tended to become more negative per unit of FPR. In primiparous cows, regression slopes between FPR and EB differed between 1–4 and 5–8 WIM (−54.6 vs. −47.5 MJ of ME/day), while differences in second lactation cows tended towards significance (−57.2 vs. −64.4 MJ of ME/day). Irrespective of the lactation number, after 9–12 WIM, there was a consistent trend for the slope of the linear relationships between FPR and EB to decrease as lactation progressed, with this likely reflecting the decreasing milk nutrient demands of the growing calf. The incidence of ‘High’ FPR scores was greatest during 1–4 WIM, and decreased as lactation progressed. ‘High’ FPR scores were associated with increased energy-corrected milk (ECM) yields across all parities and stages of lactation, and with smaller BW gains and increasing concentrations (log transformed) of blood metabolites (non-esterified fatty acid, NEFA; beta-hydroxybutyrate, BHB) until 8 WIM. Results from the present study highlight the strong relationships between FPR in milk, physiological changes, and EB profiles during early lactation. However, while FPR can provide an indication of EB at a herd level, the large cow-to-cow variation indicates that FPR cannot be used as a robust indicator of EB at an individual cow level.

Download Full-text

Estimation of genetic parameters and comparison of random regression animal and sire models of production traits in the first three lactations of Iranian Holsteins

Biotechnology in Animal Husbandry ◽

10.2298/bah1402261m ◽

2014 ◽

Vol 30 (2) ◽

pp. 261-279 ◽

Cited By ~ 1

Author(s):

A. Mohammadi ◽

S. Alijani

Keyword(s):

Milk Fat ◽

Genetic Parameters ◽

Additive Genetic Variance ◽

Genetic Correlations ◽

Random Regression ◽

Lactation Period ◽

Production Traits ◽

Environmental Variance ◽

In The Beginning ◽

Residual Variances

This study was conducted to compare of random regression (RR) animal and sire models for estimation of the genetic parameters for production traits of Iranian Holstein dairy cows. For this purpose, the test day records were used belonged to first three lactations of cows and for, milk, fat and protein yields traits where, collected from 2003 to 2010, by the national breeding center of Iran. The genetic parameters were estimated using restricted maximum likelihood algorithm. To compare the model, different criterion -2logL value, AIC, BIC and RV were used for considered traits. Residual variances were considered homogeneous over the lactation period. Obtained results showed that additive genetic variance was highest in the beginning and end lactation and permanent environmental variance was highest in beginning of lactation than other lactation period. Heritabilities estimate for milk, fat and protein yields by RR animal and sire models were found to be lowest during early lactation (0.05, 0.04 and 0.07; 0.05, 0.19 and 0.13; 0.14, 0.19 and 0.15, for milk, fat and protein yields and in first, second and third lactation respectively). However, estimated heritabilities during lactation did not vary among different order Legendre polynomials, and also between RR animal and sire models. The variation in genetic correlations estimate in the RR animal and sire models was larger in the first lactation than in the second and third lactations. Thus, based on the results obtained, it can be inferred that the RR animal model is better for modeling yield traits in Iranian Holsteins.

Download Full-text

Random regression models to estimate genetic parameters for test-day milk yield and composition in Iranian buffaloes

Archives Animal Breeding ◽

10.7482/0003-9438-56-027 ◽

2013 ◽

Vol 56 (1) ◽

pp. 276-284 ◽

Cited By ~ 1

Author(s):

M. Madad ◽

N. Ghavi Hossein-Zadeh ◽

A. A. Shadparvar ◽

D. Kianzad

Keyword(s):

Milk Yield ◽

Milk Fat ◽

Milk Protein ◽

Genetic Parameters ◽

Genetic Correlations ◽

Random Regression ◽

Production Traits ◽

Environmental Correlations ◽

Protein Percentage ◽

Heritability Estimates

Abstract. The objective of this study was to estimate genetic parameters for milk yield and milk percentages of fat and protein in Iranian buffaloes. A total of 9,278 test-day production records obtained from 1,501 first lactation buffaloes on 414 herds in Iran between 1993 and 2009 were used for the analysis. Genetic parameters for productive traits were estimated using random regression test-day models. Regression curves were modeled using Legendre polynomials (LPs). Heritability estimates were low to moderate for milk production traits and ranged from 0.09 to 0.33 for milk yield, 0.01 to 0.27 for milk protein percentage and 0.03 to 0.24 for milk fat percentage, respectively. Genetic correlations ranged from −0.24 to 1 for milk yield between different days in milk over the lactation. Genetic correlations of milk yield at different days in milk were often higher than permanent environmental correlations. Genetic correlations for milk protein percentage ranged from −0.89 to 1 between different days in milk. Also, genetic correlations for milk percentage of fat ranged from −0.60 to 1 between different days in milk. The highest estimates of genetic and permanent environmental correlations for milk traits were observed at adjacent test-days. Ignoring heritability estimates for milk yield and milk protein percentage in the first and final days of lactation, these estimates were higher in the 120 days of lactation. Test-day milk yield heritability estimates were moderate in the course of the lactation, suggesting that this trait could be applied as selection criteria in Iranian milking buffaloes.

Download Full-text

Effects of dietary clinoptilolite supplementation on β-hydroxybutirate serum level and milk fat to protein ratio during early lactation in Holstein-Friesian cows

Microporous and Mesoporous Materials ◽

10.1016/j.micromeso.2019.109766 ◽

2020 ◽

Vol 292 ◽

pp. 109766 ◽

Cited By ~ 1

Author(s):

Dražen Đuričić ◽

Blanka Beer Ljubić ◽

Silvijo Vince ◽

Romana Turk ◽

Hrvoje Valpotić ◽

...

Keyword(s):

Serum Level ◽

Milk Fat ◽

Early Lactation ◽

Protein Ratio ◽

Holstein Friesian ◽

Friesian Cows

Download Full-text

Genetic relationship between milk dry matter and other milk traits in extended lactations of Polish Holstein cows

Czech Journal of Animal Science ◽

10.17221/49/2009-cjas ◽

2010 ◽

Vol 55 (No. 3) ◽

pp. 91-104 ◽

Cited By ~ 6

Author(s):

K. Yazgan ◽

J. Makulska ◽

A. Węglarz ◽

E. Ptak ◽

M. Gierdziewicz

Keyword(s):

Milk Yield ◽

Milk Fat ◽

Fixed Effects ◽

Dry Matter ◽

Genetic Correlations ◽

Random Regression ◽

Holstein Cows ◽

Milk Traits ◽

Data Set ◽

The Third

The objective of this research was to examine heritabilities and genetic, phenotypic and permanent environmental relationships between milk dry matter (DM) and milk traits such as milk, fat, protein and lactose yields, milk urea nitrogen (MUN) and somatic cell score (SCS) in extended (to 395 days) lactations of Holstein cows from a big farm in Poland. The data set consisted of 78 059 test day records from the first, second and third lactations of 3 792 cows, daughters of 210 sires and 1 677 dams. Single- or two-trait random regression models were used with fixed effects of calving year, calving month, dry period and calving interval and random additive genetic and permanent environmental effects. The last two fixed effects were not included in the analysis of first lactation data. The highest values of heritabilities for all traits, except DM, were observed in the second lactation. First lactation heritabilities for all traits – except milk yield and SCS – were smaller than those in the third lactation. Lactose yield was highly heritable, with average h<SUP>2</SUP> equal to 0.25, 0.29 and 0.28 in lactations 1, 2 and 3, respectively. Heritability for DM was slightly lower than that for lactose (0.22, 0.26 and 0.28 for lactations 1, 2 and 3, respectively). In all lactations heritabilities for SCS were below 0.1. Genetic correlations between DM and milk yield (0.64–0.74) were lower than those between MUN and milk yield (0.67–0.79) as well as between lactose and milk yield (0.72–0.82). In general, DM was much more closely correlated with fat or protein yield (0.55–0.79) than with MUN or lactose (0.38–0.76). Only in the third lactation the correlation between DM and protein (0.72) was lower than between lactose and protein (0.76). For all lactations there were very high genetic correlations between DM and lactose (0.96–0.98) and high correlations between DM and MUN (0.63–0.83) and between lactose and MUN (0.70–0.85). The results suggest that further research is needed, focused on DM and its relationship with other traits in larger populations.  

Download Full-text

0147 Evaluating milk fat to protein ratio and milk fat to lactose ratio as indicators for early lactation disease

Journal of Animal Science ◽

10.2527/jam2016-0147 ◽

2016 ◽

Vol 94 (suppl_5) ◽

pp. 69-70 ◽

Cited By ~ 1

Author(s):

S. Paudyal ◽

F. P. Maunsell ◽

C. A. Risco ◽

A. Donovan ◽

A. De Vries ◽

...

Keyword(s):

Milk Fat ◽

Early Lactation ◽

Protein Ratio

Download Full-text

Genetic parameters for milk production and persistency in the Iranian Holstein population by the multitrait random regression model

Archives Animal Breeding ◽

10.7482/0003-9438-57-012 ◽

2014 ◽

Vol 57 (1) ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Khabat Kheirabadi ◽

Sadegh Alijani

Keyword(s):

Milk Yield ◽

Milk Fat ◽

Genetic Correlations ◽

Random Regression ◽

Genetic Dissection ◽

Production Traits ◽

Data Set ◽

Random Regression Model ◽

Regression Test ◽

Fat Yield

Abstract. For genetic dissection of milk, fat, and protein production traits in the Iranian primiparous Holstein dairy cattle, records of these traits were analysed using a multitrait random regression test-day model. Data set included 763 505 test-day records from 88 204 cows calving since 1993. The (co)variance components were estimated by Bayesian method. The obtained results indicated that as in case of genetic correlations within traits, genetic correlations between traits decrease as days in milk (DIM) got further apart. The strength of the correlations decreased with increasing DIM, especially between milk and fat. Heritability estimates for 305-d milk, fat, and protein yields were 0.31, 0.29, and 0.29, respectively. Heritabilities of test-day milk, fat, and protein yields for selected DIM were higher in the end than at the beginning or the middle of lactation. Heritabilities for persistency ranged from 0.02 to 0.24 and were generally highest for protein yield (0.05 to 0.24) and lowest for fat yield (0.02 to 0.17), with milk yield having intermediate values (0.06 to 0.22). Genetic correlations between persistency measures and 305-d production were higher for protein and milk yield than for fat yield. The genetic correlation of the same persistency measures between milk and fat yields averaged 0.76, and between milk and protein yields averaged 0.82.

Download Full-text