scholarly journals Effect of β-lactoglobulin gene polymorphism, lactation stage and breed on milk traits in Chios and Karagouniko sheep breeds

2017 ◽  
Vol 17 (2) ◽  
pp. 371-384 ◽  
Author(s):  
Kostas A. Triantaphyllopoulos ◽  
Panagiota Koutsouli ◽  
Athanassios Kandris ◽  
Dimitris Papachristou ◽  
Kalliopi E. Markopoulou ◽  
...  
Keyword(s):  
Milk Yield ◽  
Milk Traits ◽  
Weinberg Equilibrium ◽  
Sheep Breeds ◽  
Lactation Stage ◽  
Pcr Rflp ◽  
Hardy Weinberg Equilibrium ◽  
Daily Milk Yield ◽  
Β Lactoglobulin ◽  
Daily Milk

Abstract The animal selection with favourable phenotypes of the past has been, currently, replaced by the genotype selection on quantitative traits, assisted by the expanding molecular techniques in the context of livestock improvement. In this study, the c.112T>C polymorphism in exon II of β-lactoglobulin (β-LG) gene was investigated in Karagouniko and Chios sheep breeds by using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP), and possible associations with milk traits were examined. In total, 125 blood DNA samples were isolated for PCR-RFLP analysis and the respective 217 milk samples′ composition profile was obtained. The goodness of fit test to Hardy-Weinberg equilibrium (HWE) for β-LG genotypes was estimated and associations found between β-LG genotypes and raw milk composition. Two alleles and three genotypes were observed (AA, AB and BB) in both breeds, and Chios breed significantly deviated (P≤0.05) from Hardy-Weinberg equilibrium (HWE). Conclusively, linear mixed model analysis on samples, from both breeds collectively, showed significant effects of β-LG genotype on lactose percentage and somatic cell count (SCC), lactation stage on daily milk yield and protein, while the breed effect was significant only on daily milk yield.

scholarly journals Genetic association of variations in the kappa-casein and β-lactoglobulin genes with milk traits in girolando cattle

2019 ◽  
Vol 20 ◽  
Author(s):  
Severino Benone Paes Barbosa ◽  
Ítala Iara Medeiros de Araújo ◽  
Marta Fonseca Martins ◽  
Elizabete Cristina da Silva ◽  
Laís Aberrachid Jacopini ◽  
...  
Keyword(s):  
Milk Yield ◽  
Dairy Farm ◽  
Transmission Capacity ◽  
Farm Animals ◽  
Substitution Effects ◽  
Milk Traits ◽  
Pcr Rflp ◽  
Dairy Animals ◽  
Hardy Weinberg Equilibrium ◽  
Β Lactoglobulin

SUMMARY In dairy farm animals, one the most important goal of the selection is the improvement of milk yield and composition. Several studies have demonstrated that the candidate genes of the kappa-casein (CSN3) and β - lactoglobulin (β-LG) are associated with milk yield, milk quality and health traits in dairy animals. Therefore the aim of this study was to detect polymorphisms in CSN3 and β-LG genes and its association with milk yield in up to 305 days (305MY) and predicted transmission capacity (PTA) for 305MY in Girolando cattle. Totally, 138 bulls and 729 cows (n=867) were sampled. The genotypes of both genes were obtained by the PCR-RFLP method using HinfI and HaeIII enzymes for CSN3 and β-LG genes, respectively. Statistical results revealed two alleles A and B for both genes. The genotypes and alleles more frequents for CSN3 and β-LG genes were respectively: AA (0.7324) and A (0.8558), and AB (0.4827) and A (0.5017). The x2 test revealed that the two loci were at Hardy-Weinberg equilibrium (p<0.001). The allele substitution effects for the variants were not significant on 305MY and PTA for 305MY (p>0.05). The allele variants of β-LG and CSN3 might be more investigated before include them into future breeding schemes designed for Girolando dairy cattle with objective of improving milk traits as milk yield in up to 305 days (305MY) and predicted transmission capacity (PTA) for 305MY..

scholarly journals 11. Effect of Heat Stress on Metabolic Disorders Prevalence Risk and Milk Production in Holstein Cows in Croatia

2016 ◽  
Vol 16 (2) ◽  
pp. 451-461 ◽  
Author(s):  
Vesna Gantner ◽  
Krešimir Kuterovac ◽  
Klemen Potočnik
Keyword(s):  
Heat Stress ◽  
Milk Yield ◽  
Environmental Conditions ◽  
Milk Fat ◽  
Metabolic Disorders ◽  
Disease Risk ◽  
Milk Traits ◽  
Lactation Stage ◽  
Daily Milk Yield ◽  
Daily Milk

Abstract The objectives were to evaluate the effect of heat stress on daily milk traits (yield, fat and protein content, F/P ratio) as well as to determine the differences in metabolic disorders (acidosis, ketosis) prevalence risk regarding the heat stress conditions. For statistical analysis 1,187,781 test-day records of milk, fat, and protein from 89,030 Holsteins reared on 6,388 farms provided by the Croatian Agricultural Agency, were used. Based on the results it could be concluded that heat stress condition causes decline of daily milk yield and components as well as increase of acidosis risk regardless of the lactation stage and increase of ketosis risk during mid-lactation. The research results point out that the test-day records and environmental measurements collected in regular milk recording could be used as a tool for dairy herd monitoring enabling the early detection of unfavourable environmental conditions and the subclinical disorders. Since environmental conditions significantly affect daily milk yield and components, and consequently F/P ratio, further research with the purpose of detailed formulation of metabolic disease risk in relation to the environmental conditions is needed.

scholarly journals Covariance components by a repeatability model in Slovenian dairy sheep using test-day records

2009 ◽  
Vol 54 (No. 9) ◽  
pp. 426-434 ◽  
Author(s):  
A. Komprej ◽  
G. Gorjanc ◽  
D. Kon ◽  
M. Kovač
Keyword(s):  
Protein Content ◽  
Litter Size ◽  
Milk Yield ◽  
Genetic Correlations ◽  
Dairy Sheep ◽  
Milk Traits ◽  
Environment Effect ◽  
Covariance Components ◽  
Daily Milk Yield ◽  
Daily Milk

The estimation of covariance components for daily milk yield, fat and protein content was performed in three Slovenian dairy sheep breeds (Bovec, Improved Bovec, and Istrian Pramenka). In the period 1994–2002, 38 983 test-day records of 3 068 ewes were collected according to ICAR regulations (method A4). All the available relationships between animals were considered. For that reason, information on 3 534 animals was included. Test-day records were analysed by a multiple-trait repeatability animal model. In its fixed part, the model contained breed and season of lambing as classes. Days after lambing, parity, and litter size were treated as covariates. Days after lambing were modelled with modified Ali-Schaeffer’s lactation curve, parity with quadratic, and litter size with linear regression. The random part of the model consisted of flock-test month effect, additive genetic effect, permanent environment effect over lactations, and permanent environment effect within lactation. Covariance components were estimated using the restricted maximum likelihood method (REML). The estimated heritabilities were 0.11 for daily milk yield, 0.08 for fat content, and 0.10 for protein content. A relatively high variance ratio for all milk traits was explained by the flock-test month effect (from 0.27 for daily milk yield to 0.57 for protein content), while ratios explained by both permanent environment effects were lower (up to 0.13). Additive genetic correlations between daily milk yield and fat content, and daily milk yield and protein content were negative and similar (–0.36 and –0.37). A high and positive (0.67) additive genetic correlation between fat and protein content was found. Correlations for environmental effects showed a pattern similar to additive genetic correlations. Genetic parameters estimated in Slovenian dairy sheep showed that genetic progress in milk traits could be achieved using test-day milk records.

Significance of Environmental Influences on Average Daily Milk Traits of Sirohi Goats in Their Native Tract

2019 ◽  
Author(s):  
L. Gautam H.A. Waiz ◽  
R. K. Nagda
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Environmental Conditions ◽  
Genetic Factors ◽  
Genetic Correlations ◽  
Goat Milk ◽  
Least Square ◽  
Milk Traits ◽  
Daily Milk Yield ◽  
Daily Milk

Data on 3244 Sirohi kidding during 2004 to 2016 in farmer’s flocks under All India Co-ordinated Research Project on Goat Improvement (AICRP) project, Vallabhnagar, Udaipur were utilized to estimate the average daily milk (ADM) at different lactation months and subjected to least square analysis to study the effect of various non-genetic factors like cluster, periods of kidding, season of kidding, parity, type of birth and regression of dam’s weight. The overall least-squares means for ADM1, ADM2, ADM3, ADM4, ADM5 and overall ADM were 564.07±18.34, 671.92±15.17, 633.41±10.75, 508.93±8.01, 329.72±7.93 and 540.79±10.78 ml, respectively. Cluster and period wise variation were highly significant on all stages of average daily milk yields. The parity had statistically highly significant effect on average daily milk yields, in which seemed that milk yields increase as parity increase, thereafter declined slowly. The effect of type of kidding was non-significant on all stages of average daily milk yield under this study. The regression of dam’s weight at kidding was positive and highly significant (P£ 0.01) on all average daily milk yield. The heritability estimates for these traits ranged from 0.03 ± 0.01 (ADM4) to 0.19 ± 0.02 0.06 ± 002 (ADM1). The high estimates of genetic correlations of average milk yield of different periods with overall average daily milk yield. The phenotypic correlations were positive and low between ADM1 and ADM4­, ADM5 and medium between ADM1 and ADM4, ADM5. In order to augment goat milk production, goat keepers need to be focused on nutritional and others environmental conditions as it affect their flock.

scholarly journals Genetic and environmental parameters estimation for milk traits in Slovenian dairy sheep using random regression model

2013 ◽  
Vol 58 (No. 3) ◽  
pp. 125-135 ◽  
Author(s):  
A. Komprej ◽  
Š. Malovrh ◽  
G. Gorjanc ◽  
D. Kon ◽  
M. Kovač
Keyword(s):  
Regression Model ◽  
Protein Content ◽  
Milk Yield ◽  
Random Regression ◽  
Dairy Sheep ◽  
Milk Traits ◽  
Random Regression Model ◽  
Lactation Curve ◽  
Daily Milk Yield ◽  
Daily Milk

(Co)variance components for daily milk yield, fat, and protein content in Slovenian dairy sheep were estimated with random regression model. Test-day records were collected by the ICAR A4 method. Analysis was done for 38 983 test-day records of 3068 ewes in 36 flocks. Common flock environment, additive genetic effect, permanent environment effect over lactations, and permanent environment effect within lactation were included into the random part of the model and modelled with Legendre polynomials on the standardized time scale of days in lactation. Estimation of (co)variance components was done with REML. The eigenvalues of covariance functions for random regression coefficients were calculated to quantify the sufficient order of Legendre polynomial for the (co)variance component estimation of milk traits. The existing 13 to 24% of additive genetic variability for the individual lactation curve indicated that the use of random regression model is justified for selection on the level and shape of lactation curve in dairy sheep. Four eigenvalues sufficiently explained variability during lactation in all three milk traits. Heritability estimate for daily milk yield was the highest in mid lactation (0.17) and lower in the early (0.11) and late (0.08) lactation. In fat content, the heritability was increasing throughout lactation (0.08&ndash;0.13). Values in protein content varied from the beginning toward mid lactation (0.15&ndash;0.19), while they rapidly increased at the end of lactation (0.28). Common flock environment explained the highest percentage of phenotypic variability: 27&ndash;41% in daily milk yield, 31&ndash;41% in fat content, and 41&ndash;49% in protein content. Variance ratios for the two permanent environment effects were the highest in daily milk yield (0.10&ndash;0.27), and lower in fat (0.04&ndash;0.08) and protein (0.01&ndash;0.10) contents. Additive genetic correlations during the selected test-days were high between the adjacent ones and they tended to decrease at the extremes of the lactation trajectory.

scholarly journals Effect of crossbreeding on linear udder scores and their phenotypic relationships in Iranian fat-tailed ewe’s

2014 ◽  
Vol 30 (1) ◽  
pp. 61-77 ◽  
Author(s):  
S. Sadeghi ◽  
A. Rafat ◽  
M. Bohlouli
Keyword(s):  
Milk Yield ◽  
Morphological Characteristics ◽  
Milk Traits ◽  
Breeding Programs ◽  
Genetic Groups ◽  
Three Stages ◽  
Left And Right ◽  
Daily Milk Yield ◽  
Daily Milk

Now, image processing is a better technique than the subjectively assessments for linear scoring of morphologic traits, especially in fattailed ewe?s. The objective of this study was to assess this application in animal characterization on a case study in order to comparing of, udder morphological characteristics in two Iranian crossbred sheep populations including Ghezel-Arkhamerino (GH-MR; 25 ewes), Moghani-Arkharmerino (MG-MR; 25 ewes) and a pure one that was Ghezel ewes (20 ewes). Ten udder factors and five milk traits were measured on seventy ewes during three stages of lactation. Digital pictures were analyzed by Digimizer 3.6 software. Statistical analysis of udder liner scores was performed by using the MIXED procedure of SAS 9.1 software. Results showed that long udders were more frequent in the Ghezel ewes than in crossbred?s ewes. Least variation was observed for teat placement score in Ghezel purebred ewes. The means of udder depth in the Ghezel ewes were larger than in the crossbreds (P<0.01). A positive correlation between left and right teat length scores were found in the all genetic groups (rp=0.47-0.65). Milking rate (rp= 0.81) and milking time (rp= 0.37) showed significant correlations with milk yield (P <0.001). The most useful udder scores for predicting daily milk yield appears to be the left teat length, teat placement and attachment width in Ghezel ewes. Phenotypic correlations variations within linear scores and their relationships with daily milk showed the potential of improvement of these traits in breeding programs of dairy sheep.

scholarly journals Effects of herd, season and days in milk on milk urea nitrogen of crossbred dairy cows in Sylhet

2015 ◽  
Vol 2 (2) ◽  
pp. 287-292
Author(s):  
Nusrat Zahan Shoshe ◽  
Md Abdul Baset ◽  
Md Tariqul Islam ◽  
Shiekh MA Matin ◽  
Md Abdullah Al Mahmud
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Milk Fat ◽  
Wet Season ◽  
Urea Nitrogen ◽  
Lactation Stage ◽  
Milk Urea ◽  
Daily Milk Yield ◽  
Daily Milk ◽  
Milk Urea Nitrogen

The study included 724 crossbred cows (Local × Holstein Friesian) from 9 dairy farms of Sylhet district from July 2013 to June 2014 to determine the effect of herd, season, and days in milk in milk urea nitrogen and the effect of milk production and composition on milk urea nitrogen. According to the season, milk samples were divided into two groups: wet season (June - October) and dry season (November - February). Days in milk (DIM) were grouped into two lactation stages: Lactation 1 (?100 days in milk) and Lactation 2 (?100 days in milk). Milk urea nitrogen was grouped into five categories by increments of 5 mg/dl, started with those less than 10 mg/dl and finishing with concentration greater than 25 mg/dl. The daily milk yield was 6.78 kg ranged from 2.00 to 18.00 kg. The mean of milk urea nitrogen (MUN) concentration was 14.58 mg/dl. Mean values for milk fat and protein contents were 3.74 % and 3.72 %. Among the 9 herds, the highest content of milk urea (MU) was 16.37 mg/dl which was found in herd 2 and the second highest estimation of MU content were in herd 1, 3, 6 and 9 (15.58, 15.51, 15.12 and 14.45 mg/dl, respectively). In the district of Sylhet, the lowest MU content was estimated in herd 4, 5, 7 and 8 (13.59, 13.48, 13.16 and 13.60 mg/dl, respectively). Difference of MUN concentration was not significant between the dry and wet season. The MUN concentrations were 14.82 mg/dl and 14.90 mg/dl in dry and wet season respectively. The concentration of MUN in Lactation 1 was 13.61 mg/dl and in Lactation 2 was 16.26 mg/dl. Milk fat (%) were 3.56, 3.77, 3.64, 4.15 and 3.66 when MUN concentration were ?10.00, 10.01- 15.00, 15.01-20.00, 20.01-25.00 and ?24.01 mg/dl respectively. Daily milk yield did not increase with the increase of MUN concentration. Milk yield were 6.37, 7.21, 6.23, 7.31 and 7.00 Kg/d while MUN concentration were ?10.00, 10.01-15.00, 15.01-20.00, 20.01-25.00 and ?25.01 mg/dl. It may be concluded that herd category and lactation stage influence the milk urea nitrogen concentration of crossbred dairy cows in the Sylhet district.Res. Agric., Livest. Fish.2(2): 287-292, August 2015

scholarly journals Prevalence of metabolic disorders and effect on subsequent daily milk quantity and quality in Holstein cows

2016 ◽  
Vol 59 (3) ◽  
pp. 381-386 ◽  
Author(s):  
Vesna Gantner ◽  
Tina Bobić ◽  
Klemen Potočnik
Keyword(s):  
Milk Yield ◽  
Metabolic Disorder ◽  
Cost Effective ◽  
Herd Health ◽  
Milk Traits ◽  
Daily Production ◽  
Subclinical Ketosis ◽  
Negative Effect ◽  
Daily Milk Yield ◽  
Daily Milk

Abstract. Aiming at the determination of the metabolic disorder prevalence as well as the effect of subclinical disorders on daily milk traits of Holsteins, over 1 million (1 962 831) test day records were analysed. The metabolic disorder (ketosis or acidosis) prevalence was indicated by the fat-to-protein (F ∕ P) ratio, while subclinical disorder was indicated by the F ∕ P ratio and cows' daily production. The effect of subclinical disorders on daily milk traits was tested by Scheffe's method (SAS/STAT). The highest ketosis prevalence occurred in early lactation. In first-parity cows ketosis prevalence was highest in the first 15 days of lactation, while in cows in higher lactations, the prevalence peak occurred on the 25th day. A higher ketosis prevalence during the entire lactation was observed in multiparous cows compared to first-parity cows. Regarding the acidosis prevalence, high values were determined at the beginning of the lactation with a decreasing trend until mid-lactation, when the prevalence increased up to 22 %. The highest decrease in daily milk yield as a consequence of subclinical ketosis was determined as 4.21 and 3.72 kg day−1 in first-parity cows and those with more than four lactations, respectively. A significant negative effect of subclinical acidosis on daily milk yield (2.79 kg day−1) was highest in cows in the third lactation. A production decline in subsequent milk controls due to subclinical ketosis or acidosis in all cows was also determined. Subclinical disorders also significantly alter daily milk quality. This indicates that the test day records could be used as a cost-effective and non-invasive method for monitoring herd health.

Analysis of milk traits in relation to feeding level and organization in a herd of high-yielding cows

2016 ◽  
Vol 12 (4) ◽  
pp. 59-70
Author(s):  
Stanisław Winnicki ◽  
Jerzy Lech Jugowar ◽  
Zbigniew Sobek ◽  
Anna Nienartowicz-Zdrojewska ◽  
Jolanta Różańska-Zawieja
Keyword(s):  
Milk Yield ◽  
Milk Traits ◽  
Lactating Cows ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Daily Milk Yield ◽  
Recommended Level ◽  
Group 1 ◽  
Daily Milk

The aim of the study was to determine factors influencing the balance of energy and protein in high-yielding cows. Daily milk yield, lactation number and month of lactation were analysed. The study was carried out in a herd with yield of 11,000 kg milk/year, on 517 lactating cows. The cows were divided into four feeding groups. They were fed TMR calculated for levels of milk production, as follows: group 1 – for 45 kg, group 2 – for 35 kg, group 3 – for 26 kg and group 4 – for 20 kg. The actual mean milk yield for these groups was 49.1 kg, 38.1 kg, 26.3 kg and 17.5 kg per day. Each group consisted of cows in their first to sixth lactation and in their first to tenth month of lactation. No significant differences were noted in daily milk yield between lactation numbers or months of lactation. As milk yield increased in the groups, the content of fat and protein decreased. The estimated balance of energy, based on the protein percentage in the milk, was negative for nearly the entire lactation in group 1, for the first four months of lactation in group 2, for the first two months in group 3, and in the second month of lactation for group 4. Group 1 was divided into three subgroups according to yield: up to 45 kg, 45-50 kg and 50 kg or more. Energy was estimated to be wellbalanced only in the first subgroup. The balance of energy in the cows was strongly determined by daily milk yield, and to a lesser degree by the month of lactation. Protein, based on the concentration of urea in the milk, was well-balanced in groups 1 and 2. In groups 3 and 4, the recommended level of protein in the rations was exceeded by 10-20%.

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