scholarly journals Holsteins in Puerto Rico: II. Influence of Lactation Length, Days Dry, Days Open, and Calving Interval on Production Traits

1969 ◽  
Vol 60 (4) ◽  
pp. 540-550
Author(s):  
J. K. Camoens ◽  
R. E. McDowell ◽  
L. D. VanVleck ◽  
J. D. Rivera Anaya

Records of high grade or purebred Holsteins in 62 herds on DHIA recording in Puerto Rico were used to determine phenotypic correlations of lactation length, days dry prior to lactation, days open during lactation, and interval from previous parturition (calving interval) to lactation, milk and fat yields, and fat percent. Both milk and fat yields had a significant (P < .05) positive phenotypic correlation with lactation length, calving interval, and days open (0.178 to 0.658), hut fat percent had a low relation to these traits (-0.023 to +0.014). Lactation length, dry period, days open, and calving interval were regressed on milk yield, fat yield, and fat percent. The combined contribution of these variables to variation in milk yield was 44.4%. Days open, days dry, and calving interval accounted for only 13.4% of the variation in milk yield. Days dry and days open together accounted for 9.6% of the variation, and days dry, plus calving interval, made up 6.0%, of the variation. The values for fat yield were slightly lower but followed a similar pattern as for milk yield. The four variables combined contributed only 0.23% to the variance in fat percent. Total milk yield and fat yield were inf1uenced by lactation length, calving interval, and days dry in descending order of magnitude. Days open had comparatively little influence on either milk or fat yields. Length of dry period influenced fat percent more than any other variable but to little extent. Since the majority of the variation in milk and fat yields attributed to the four variables was due to lactation length, it appears that in Puerto Rico selection with emphasis on lactation yields is unlikely to decrease fertility.

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.


1969 ◽  
Vol 60 (4) ◽  
pp. 551-558
Author(s):  
J. K. Camoens ◽  
R. E. McDowell ◽  
L. D. VanVleck ◽  
J. D. Rivera Anaya

Variance components were estimated for herd, sire, and cow effects with a three-way nested model, using unadjusted and adjusted records for age and seasonal difference from 62 herds on DHIA recording in Puerto Rico. The cows calved from 1967 to 1973. They were high grade and purebred Holsteins imported from Canada or the United States or progeny of bulls and semen from the two countries. The percentages of the total variance for milk yield were 18.7, 4.9, and 40.8% for herd, sire, and cow, respectively. The percentages for fat yield were similar. These, plus the component for lactation length and days open, were in the range reported from temperate regions. The variance components of fat percent were similar to that of temperate regions for herd ( 14.9%) and cow (54.1%), but the sire component was negative, indicating factors yet unidentified that influenced this trait. Total variances for milk and fat yields indicated sufficient variability to permit selection. Estimates of heritability and repeatability for milk yield, fat yield, fat percent, lactation length, and days open computed from the sire and cow variance components were consistent with those reported from the temperate regions. The estimates indicate there was no loss of genotypic variance in the tropical environment. It appears that genotype exerts as much influence on production in Puerto Rico as elsewhere.


2007 ◽  
Vol 50 (2) ◽  
pp. 155-164 ◽  
Author(s):  
A. z. Abdel Gader ◽  
M.-K. A. Ahmed ◽  
L. M.-A. Musa ◽  
K. J. Peters

Abstract. The data obtained from the dairy herd of the Arab Company for Agricultural Production and Processing (ACAPP) in a semi arid area 40 km south of Khartoum involved 337 cows with a total of 1049 records from 16 years between 1986 and 2002. The least squares means for age at first calving, calving interval, days open, lactation milk yield, daily milk yield, lactation length and dry period were 29.76±0.40 months, 433.12 ± 6.70 days, 167.79±7.08 days, 3475.53±78.89 kg, 12.29±0.28 kg, 294.10±3.62 days and 164.08 ± 6.70 days, respectively. The analysis of variance showed that the parity number had significant (p<0.05) influences on all studied traits, while year-season of calving influenced (p<0.05) age at first calving, milk yield per lactation and daily milk yield. The sire of cow influenced (p<0.05) lactation yield, daily yield, lactation length and days open. The effects of linear and quadratic regressions of both lactation yield and daily yield on length of lactation were also highly significant (p<0.01). Heritability estimates of age at first calving, calving interval, milk yield per lactation, daily milk yield, lactation length and dry period were generally low (0.098±0.104, 0.047±0.046, 0.130±0.042, 0.123±0.041, 0.172±0.062 and 0.044±0.031, respectively) except the heritability of days open which was 0.51±0.37. The productivity of the herd in this study which averaged 12.3 kg/cow/day was much lower than the expected productivity of Holstein Friesian cows, which reflects the negative impact of the prevalent environment in the Sudan. More records and economic data are required to examine the economic feasibility of raising pure Friesians under Sudan conditions.


Author(s):  
Rajeev . ◽  
Ravinder Kumar

Background: The Frieswal cattle a crossbred cattle breed having 62.50 per cent of exotic (inheritance) having total lactation milk yield of 4000 Kg with average lactation length 300 days (PDC Annual Report, 2015-16). Presently, the Frieswal Animal is mainly maintained at 36 Military Farms located in various agro-climatic regions in the country. Methods: The present study was undertaken on first Part lactation production, reproduction and part lactation records of 1470 Frieswal cows maintained over a period of 10 years (2003-2012) two military farms viz Meerut and Ambala at CIRC, Meerut. Result: The estimate the heritability of production and reproduction traits were 0.29 ±0 .098,0.142±.081, 0.130±0.079, 0.087 ±.074, 0.631 ± 0.255, 0.345 ± 0.247 and 0.100 ± 0.153 for standard 305 days milk yield, age of first calving (AFC), First lactation total milk yield (FLMY), First lactation 305-day or less milk yield (FL305DMY), First lactation length (FLL), Inter calving interval (ICI), First dry period (FDP), First Service Period (FSP), respectively. All the genetic and phenotypic correlation among different production and reproduction traits were high and positive. The estimates of heritability of first lactation individual part monthly yields in Frieswal cattle were found to be 0.100 ± 0.069, 0.105 ± .070, 0.100 ± 0.069, 0.112 ± 0.071, 0.204 ± 0.086, 0.160±0.079, 0.176 ± 0.081, 0.221 ± 0.088, 0.213 ± 0.087 and 0.192 ± 0.09, respectively. 


Author(s):  
P. Panduranga Reddy ◽  
Siddalingswamy Hiremath ◽  
Krovvidi Sudhakar ◽  
Muralidhar Metta ◽  
R. Vinoo ◽  
...  

Background: The knowledge and estimation of genetic and non-genetic factors on the production and reproduction traits of Ongole cattle are important to enable the breeders to design efficient conservation strategies and adopt better selection methods, management practices and culling operations. Methods: Data available on 220 Ongole cows mated to 22 sires- at the Livestock Research Station, Mahanadi, Kurnool (District), Andhra Pradesh over a period of eight years was used for the present analysis. Result: Results in the present study revealed that performance of animals was improved in lactation milk yield (LMY, 1063.33±31.13), 305 lactation milk yield (LMY, 1019.83±29.22), lactation length (LL, 266.26±5.6), less calving interval (CI, 497.95±8.58), service period (SP, 188.19±5.17) and dry period (DP, 214.79±19.6) compared to earlier reports. Parity and period have shown significant effect on all production traits and calving interval. Effect of season was non-significant on all productive and reproductive traits. Most of the heritability estimates for milk production traits were medium in range but low for reproductive traits. The correlations between productive traits and calving interval were negative.


Author(s):  
M.S. Khan ◽  
K. Z. Gondal ◽  
S. H. Raza ◽  
A. A. Asghar

There are many computational algorithms available for estimating (co) variance components under multiple trait models. Paternal half-sib correlation is the most commonly used method for estimating genetic parameters of economic traits of buffaloes. The models used are Single trait, ignoring covariances with other traits. The relationship matrices are also ignored. This study was undertaken to estimate genetic parameters of first lactation traits of Nili Ravi buffaloes under a multiple trait animal model. First lactation milk yield was l7% heritable when traits such as age of calving interval were considered. Age at first calving was 18% heritable with very low genetic correlations with other traits. Lactation length, dry period and calving interval were lowly heritable traits. Estimates differed by inclusion or exclusion of traits due to the covariances present among all these traits. A high genetic correlation between mills yield and lactation length (0.74) does not warrant the selection of milk yield as the only trait.


Author(s):  
Nawal Kishor Pareek ◽  
K. J. Ankuya ◽  
M. P. Patel ◽  
B. S. Rathod ◽  
K. B. Prajapati

The present investigation was undertaken to study the effect of non-genetic factors, viz., service period (SP), dry period (DP) and gestation period (GP) on various milk production traits in Kankrej cattle. 1235 lactation records (2nd-7th) of 475 Kankrej cows, progeny of 75 bulls that were maintained at University Livestock Research Station, Sardarkrushinagar (Gujarat), calved during 1980-2014, were studied. The effects of service period (111.64 ± 52.55 days) and dry period (143.17±28.78 days) on total lactation milk yield (2089.45±582.38 kg),305 days milk yield (2045.66±531.92 kg) and lactation length (282.90±49.46 days) were highly significant (pis less than 0.01), while the effect of gestation period (288.86±7.14 days) was non-significant on all these production traits. Cows which took more time to conceive after parturition produced more milk with longer lactation length


1962 ◽  
Vol 4 (3) ◽  
pp. 329-336 ◽  
Author(s):  
E. B. Galukande ◽  
P. Mahadevan ◽  
J. G. Black

An analysis has been made of milk production data from indigenous East African zebu cattle at the Baraton, Maseno and Sangalo Livestock Improvement Centres in Kenya, covering a period of twenty-five to thirty years.The relationships between milk production and length of lactation, dry period, calving interval, month of calving and age were examined. Lactation length accounted for from 53% to 66% of the total variance in milk yield. Variations in length of dry period caused significant differences in milk yield between, but not within cows. Increasing length of previous calving interval improved current lactation milk yield but month of calving had no significant effect. Yield increased from first to second lactation by 8% after which it remained relatively constant up to the fifth lactation. Age at first calving was positively correlated with first lactation milk yield.Intra-herd repeatabilities were 0·55 for milk yield, 0·38 for lactation length, 0·17 for calving interval and 0·12 for dry period. The highest estimates of heritability were those obtained for lactation yield and length (0·5); the lowest, for calving interval, was close to zero. All heritability estimates had high standard errors. The probable genetic improvement in milk production achieved by the selection practised in the herds was estimated as ranging from zero to 0·15% of the average yield per year.


2005 ◽  
Vol 48 (5) ◽  
pp. 445-459 ◽  
Author(s):  
L. M.-A. Musa ◽  
M.-K. A. Ahmed ◽  
K. J. Peters ◽  
B. Zumbach ◽  
K. E. A. Gubartalla

Abstract. Data from the Butana herd of Atbara Livestock Research Station were analyzed for the period 1949–1999. The least squares means for age at first calving, calving interval, milk yield per lactation, daily milk yield, lactation length and dry period were 45.05 ± 3.56 months, 382.38 ± 8.30 days, 1662.57 ± 108.96 kg, 6.10 ± 0.40 kg, 268.17 ± 5.56 days and 119.10 ± 8.30 days, respectively. The analysis of variance revealed that the sire and parity number influenced the studied traits, while year-season of calving influenced the milk yield per lactation, daily milk yield and lactation length. Linear and quadratic regressions on lactation length significantly influenced milk yield per lactation and daily milk yield. Heritability estimates for age at first calving, calving interval, milk yield per lactation, daily milk yield, lactation length and dry period were 0.19 ± 0.07, 0.09 ± 0.03, 0.26 ± 0.06, 0.27 ± 0.07, 0.04 ± 0.02, and 0.09 ± 0.03, respectively. This study highlighted the importance of conserving the indigenous dairy cattle breeds for future generations. The presence of significant variation and the corresponding heritability estimates give promise of reasonable genetic improvement under selective breeding with respect to milk yield characters.


1970 ◽  
Vol 27 (1) ◽  
pp. 18-25 ◽  
Author(s):  
MA Habib ◽  
MA Afroz ◽  
AKFH Bhuiyan

The present study was undertaken to estimate effects of environmental factors onmilk production traits in Red Chittagong Cattle (RCC). A total of 103 milk yield recordsof 45 RCC cows obtained between 2005 and 2009 were analysed. Actual lactation yield,lactation length, daily milk yield and dry period were estimated as 500.7 ± 19.3 kg, 259.6 ±6.2 days, 1.9 ± 0.1 kg and 162.4 ± 7.7 days, respectively. Age and season correctedlactation yield, 305 day milk yield and daily milk yield were estimated as 605.4 ± 22.9,677.1 ± 19.4 and 2.2 ± 0.1 kg, respectively. Sex of calf and season of birth did notsignificantly (P>0.05) affect production, but lactation order significantly (P<0.05) affectedproduction except lactation length. Year of birth had no effect (P>0.05) on the traitsanalysed except daily milk yield (P<0.05). Calving age significantly (P<0.05) affectedlactation yield but did not other traits. Cows in 5th lactation produced highest total (604.3± 69.3 kg) and daily milk yield (2.17 ± 1.8 kg). Cows aged 6 – 7 years had best lactationyield (576.8 ± 60.5 kg).(Bangl. vet. 2010. Vol. 27, No. 1, 18 – 25)DOI: 10.3329/bvet.v27i1.5911


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