scholarly journals Factors affecting lactation length and effect of current lactation length on the subsequent production and reproduction in Iranian Holsteins

2013 ◽  
Vol 56 (1) ◽  
pp. 873-881 ◽  
Author(s):  
N. G. Hossein-Zadeh

Abstract. Calving records of Holstein cows from January 1983 to December 2006 comprising 1,190 herds with 385,102 calving events were used to evaluate factors affecting the length of lactation and effect of current lactation length on the next productive and reproductive performances of Iranian Holsteins. Statistical analyses of productive and reproductive traits in this study were performed as linear mixed models. Lactation length (LL) of cows was grouped into 10 classes from <100 days through 500 days. Average LL was 314 days in Iranian Holsteins. Primiparous cows had the greatest LL and the mean of LL increased over the years from 1983 to 2006 and spring calvers had the longest LL (P<0.05). Cows within the LL class of 500 had the greatest unadjusted milk yield, adjusted milk yield, adjusted protein yield and adjusted fat yield and also had the longest calving intervals (P<0.05). Cows within the LL classes of 150–199 and 200–249 had the greatest values of adjusted protein percentage. Also, age at calving was the lowest for the LL class of 250–299 (P<0.05). There were linear and increasing trends for unadjusted milk yield, adjusted milk yield, adjusted protein yield and adjusted fat yield over the LL classes in this study, but a linear but decreasing trend was observed for adjusted protein percentage over LL classes. On the other hand, there were non-linear relationships between adjusted fat percentage, calving interval and age at calving with LL classes in the current study.

2014 ◽  
pp. 4033-4040 ◽  
Author(s):  
Pelmus RS ◽  
Pistol GC ◽  
Lazar C ◽  
Gras MA ◽  
Ghita E

ABSTRACTObjective. Estimate the genetic parameters for milk traits in a Romanian local sheep population Teleorman Black Head. Material and methods. Records of 262 sheep belonging to 17 rams and 139 ewes were used in the study. The following traits were investigated: milk yield, fat yield, protein yield, fat percentage and protein percentage. The genetic parameters were estimated using the Restricted Maximum Likelihood method, with a model including maternal effects. Results. The results from our study revealed that direct heritability estimates were moderate for milk yield (0.449), fat yield (0.442), protein yield (0.386) while for protein percentage (0.708) and fat percentage (0.924) were high. The high direct and maternal genetic correlation was between milk yield and protein yield (0.979, 0.973) and between protein yield and fat yield (0.952, 0.913) while the phenotypic correlation between the milk yield and fat yield (0.968), the milk yield and protein yield (0.967), fat yield and protein yield (0.936) was high and positive. Conclusions. The genetic parameters are important in selection program on this breed for genetic improvement.


2014 ◽  
Vol 59 (No. 12) ◽  
pp. 539-547 ◽  
Author(s):  
V. Zink ◽  
L. Zavadilová ◽  
J. Lassen ◽  
M. Štípková ◽  
M. Vacek ◽  
...  

Genetic and phenotypic correlations between production traits, selected linear type traits, and somatic cell score were estimated. The results could be useful for breeding programs involving Czech Holstein dairy cows or other populations. A series of bivariate analyses was applied whereby (co)variance components were estimated using average information (AI-REML) implemented via the DMU statistical package. Chosen phenotypic data included average somatic cell score per a 305-day standard first lactation as well as the production traits milk yield, fat yield, protein yield, fat percentage, and protein percentage per the standard first lactation. Fifteen classified linear type traits were added, as they were measured at first lactation in the Czech Holstein population. All phenotypic data were collected within the progeny testing program of the Czech-Moravian Breeders Corporation from 2005 to 2009. The number of animals for each linear type trait was 59&nbsp;454, except for locomotion, for which 53 424 animals were recorded. The numbers of animals with records of&nbsp;milk production data were 43 992 for milk yield, fat percentage, protein percentage, and fat-to-protein percentage ratio and 43 978 for fat yield and protein yield. In total, 27 098 somatic cell score records were available. The strongest positive genetic correlation between production traits and linear type traits was estimated between udder width and fat yield (0.51 &plusmn; 0.04), while the strongest negative correlation estimated was between body condition score and fat yield (&minus;0.45 &plusmn; 0.03). Other estimated correlations were between those two extremes but generally they were close to zero or positive. The strongest negative phenotypic correlations were estimated between udder depth and milk yield and protein yield (both &minus;0.17), while the strongest positive phenotypic correlations were estimated between milk yield, protein yield, and udder width (both 0.32). &nbsp;


2011 ◽  
Vol 54 (4) ◽  
pp. 338-347
Author(s):  
N. G. Hossein-Zadeh

Abstract. Calving records from the Animal Breeding Center of Iran collected from January 1990 to December 2007 and comprising 207 106 first calving events of Holsteins from 2 506 herds were analysed using linear sire models to estimate genetic trends for age at first calving (AFC) and milk traits. Genetic trends were obtained by regressing yearly mean estimates of breeding values on year of birth. In general, there were decreasing genetic trends for AFC, fat percentage and protein percentage over the years but there were increasing genetic trends for milk yield, mature-equivalent milk yield, fat yield, mature-equivalent fat yield, protein yield and mature-equivalent protein yield over the years. On the other hand, there was a decreasing phenotypic trend for AFC but estimates of phenotypic trends were positive for milk yield and compositions over the years. It seems that the decline in calving age in this study over time resulted primarily from increased turnover rate and increased culling of heifers that failed to get pregnant. On the other hand, increasing trend for yield traits over time in this study indicated that Iranian dairy producers were successful in choosing progressively better semen and sires from imported and local sources over the years.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ruike Jia ◽  
Yihan Fu ◽  
Lingna Xu ◽  
Houcheng Li ◽  
Yanhua Li ◽  
...  

Abstract Background Our preliminary work confirmed that, SLC22A7 (solute carrier family 22 member 7), NGFR (nerve growth factor receptor), ARNTL (aryl hydrocarbon receptor nuclear translocator like) and PPP2R2B (protein phosphatase 2 regulatory subunit Bβ) genes were differentially expressed in dairy cows during different stages of lactation, and involved in the lipid metabolism through insulin, PI3K-Akt, MAPK, AMPK, mTOR, and PPAR signaling pathways, so we considered these four genes as the candidates affecting milk production traits. In this study, we detected polymorphisms of the four genes and verified their genetic effects on milk yield and composition traits in a Chinese Holstein cow population. Results By resequencing the whole coding region and part of the flanking region of SLC22A7, NGFR, ARNTL and PPP2R2B, we totally found 20 SNPs, of which five were located in SLC22A7, eight in NGFR, three in ARNTL, and four in PPP2R2B. Using Haploview4.2, we found three haplotype blocks including five SNPs in SLC22A7, eight in NGFR and three in ARNTL. Single-SNP association analysis showed that 19 out of 20 SNPs were significantly associated with at least one of milk yield, fat yield, fat percentage, protein yield or protein percentage in the first and second lactations (P < 0.05). Haplotype-based association analysis showed that the three haplotypes were significantly associated with at least one of milk yield, fat yield, fat percentage, protein yield or protein percentage (P < 0.05). Further, we used SOPMA software to predict a SNP, 19:g.37095131C > T in NGFR, changed the structure of NGFR protein. In addition, we used Jaspar software to found that four SNPs, 19:g.37113872C > G,19:g.37113157C > T, and 19:g.37112276C > T in NGFR and 15:g.39320936A > G in ARNTL, could change the transcription factor binding sites and might affect the expression of the corresponding genes. These five SNPs might be the potential functional mutations for milk production traits in dairy cattle. Conclusions In summary, we proved that SLC22A7, NGFR, ARNTL and PPP2R2B have significant genetic effects on milk production traits. The valuable SNPs can be used as candidate genetic markers for genomic selection of dairy cattle, and the effects of these SNPs on other traits need to be further verified.


Author(s):  
Sukanta Basak ◽  
D. N. Das ◽  
U. T. Mundhe

The present study was carried out in Deoni, the dual purpose cattle breed of Southern India, maintained at NDRI herd, SRS, Bengaluru. Mean phenotypic performances for the traits of age at first calving (AFC), first service period (FSP), first lactation milk yield (FLMY) and first lactation length (FLL) were estimated as 42.90 ± 0.49 months, 179.00 ± 6.3 days, 643.08 ± 25.16 kg and 178.24 ± 4.41 days respectively. Significant effect of parity was found on AFC and FSP. Effect of period of birth, period of calving and season of calving was found to be significant on FSP. Significant effect of period of birth, period of calving, classes of AFC and FLL were found on FLMY. The heritability of first lactation milk yield was estimated as 0.38 ± 0.29. Phenotypic correlation of FLMY with FLL (0.88 ± 0.02) was found to be highly significant (p Lass Than 0.01).


2007 ◽  
Vol 50 (2) ◽  
pp. 136-146
Author(s):  
J. Citek ◽  
V. Rehout ◽  
E. Hradecka ◽  
L. Vecerek ◽  
L. Panicke

Abstract. The effect of the genotypes and alleles at nucleotide positions 10433 and 10434 of the DGAT1 gene on the breeding values for milk performance of German Holstein sires born in 1993 (n=66), and in 1998-2001 (n=200) was analyzed. The differences in breeding values had in both years the same trend. In the younger sires, the breeding value for fat percentage was higher by 0.42 % in the Lysine homozygotes compared to the Alanine homozygotes (P<0.001). A higher milk breeding value in the Alanine homozygotes (811 kg) was found compared to the Lysine homozygotes (256 kg) (P<0.001), and the fat yield breeding value was higher in the Lysine sires (DGAT1K/DGAT1K 29.6, DGAT1A/DGAT1A 15.9). The breeding value for the protein percentage was higher in the sires carrying the Lysine variant (0.02) than in the Alanine homozygotes (- 0.03, P<0.05), and the protein yield was higher in the Alanine homozygotes (DGAT1K/DGAT1K 10.9, DGAT1A/DGAT1A 25.0, P<0.001). Because of the high emphasis of the index on the protein yield, the relative breeding value for milk was 110 among Alanine homozygotes, and 104 among Lysine. Comparing old and young sires, the genetic background against which the effect of DGAT1 is evaluated has changed. The selection on breeding value for protein yield increased the prevalence of DGAT1A/DGAT1A genotypes in protein and milk yield, and in relative breeding value for milk. In the old group, there was the highest protein yield in the heterozygous sires DGAT1KA, it could be explained by another genetic background of the tested female population. Because the breeding value for fat percentage of heterozygous sires has lain within the values of homozygotes in both old and young sires, we assume the intermediary heredity on the locus. The differences of genotypic and allelic frequencies among old and young sires were not significant, however, there was certain tendency of increase of allele A (0.60 old sires, 0.64 young). On the results of this paper, the locus of DGAT1 offers information for evaluation of breed animals.


1969 ◽  
Vol 60 (4) ◽  
pp. 526-539
Author(s):  
J. K. Camoens ◽  
R. E. McDowell ◽  
L. D. Van Vleck ◽  
J. D. Rivera Anaya

The effects of herd, year, age, season, and their interactions on milk and fat yield, fat percent, days in milk, days dry, and days open for purebred and high grade Holsteins in a tropical environment were determined by analysis of variance using DHIA records from Puerto Rico. There were 33,950 records for calvings from 1967 to 1973 in 62 herds. Herd effects were significant (P < .05) for all traits, but seasonal effects were significant only for milk yield, fat yield, and days open. Variation among herds significantly influenced all traits except milk yield. Age of calving affected all traits except lactation length and days open. A number of the interactions were also significant. The statistical model explained 39, 40, 24, 17, 13 and 12% of the total variation in milk yield, fat yield, fat percent, lactation length, days dry, and days open, respectively. Total variances were 12,900,000 lb2 for milk yield and 15,000 lb2 for fat yield, which are comparable to those for temperate areas. It is concluded that the factors affecting the performance of Holsteins in Puerto Rico do not differ markedly from those in temperate countries. The total variation appears large enough to permit selection for higher milk and fat yields. As in temperate regions, length of lactation, length of dry period, and time of rebreeding (days open) are largely influenced by decisions made on the part of herd owners.


1935 ◽  
Vol 6 (3) ◽  
pp. 320-339 ◽  
Author(s):  
Elizabeth O. Whetham ◽  
John Hammond

1. The ratio of the weight of fat in the milk required to make 1 lb. of butter has been taken to indicate the size of the fat globule in the milk, and so the type of “ cream line ” produced.2. The Dairy Show records have been analysed from this standpoint, and variations in the above ratio studied together with variations in milk yield, fat yield and fat percentage. The effects considered are those between breeds and within breeds, the latter including milk yield, period of lactation and ageof cow.3. With a constant milk yield the fat percentage does vary between breeds, but not to the same extent as it does when no account is taken of the differences in average yield of the different breeds; the same applies tothe fat: butter ratio, i.e. size of fat globule. The effect of equal increases of milk yield on the butter:fat ratio is much greater between breeds than it is within any one breed.4. It is suggested that the size of the fat globule is determined by two factors: (a) the rate of butterfat formation by the cell, which varies with breed and stage of lactation, and (b) the rate of milk secretion which affects the size of the globules by the rate at which they are washed out from the cell.


Author(s):  
Himanshu Mehta ◽  
Neeraj Kashyap ◽  
Simarjeet Kaur ◽  
Puneet Malhotra ◽  
Chandra Sekhar Mukhopadhyay

Background: The study was conducted to unravel the consequences of abnormal lactation lengths (Extremely short, short, prolong and extremely prolong lactation length) on production and reproduction traits of crossbred cattle (Red Dane x Sahiwal x Holstein Friesian), which otherwise remains unutilized in routine breeding data analysis owing to normalization and standardization of lactation lengths. Methods: The performance data of 2541 lactations of 1001 crossbred cattle, sired by 146 bulls over a period of 30 years maintained at the Livestock Farms of Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Ludhiana were used for this study. The data on production and reproduction traits were analysed using general linear model procedures based on extremely short ( less than 102 days), short (102-179 days), prolong (483 - 560 days) and extremely prolong (≥ 560 days) lactation lengths on the basis of mean lactation length and its standard deviation. Result: Result indicated that the alteration of lactation lengths affected all important performance traits of crossbred cattle in contemporary as well as in next lactation. The values of 305 days milk yield, lactation milk yield, average fat (%), 305 days fat yield and lactation fat yield of contemporary lactation cycle were higher (P≤0.05) for the extremely prolong lactation length and reduced for shorter lactations. Similar trend was seen for next lactation cycle of the animal having abnormal lactation length in previous lactation cycle for all traits except calf birth weight, whereas days to reach peak yield and fat yield traits were not significantly affected by lactation length classes. The preferred lactation length for crossbred cattle for optimum performance was concluded as 180 to 483 days ranging one standard deviation from mean lactation length, covering more than 72% of population; however, it needs further studies to break it into groups in terms of productive life and economical merits. Farmers should avoid breeding of animal having extremely short and short lactation lengths, as their production and reproductive traits are lower in successive production cycle.


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