1,721,006 research outputs found
Genetic parameters among Body Condition Score, fertility, type and production traits in Italian Brown Swiss dairy cows
No full textWageningen Academic, Publisher
Effect of crossbreeding on market value of calves from dairy cows
No full textMarket values (/kg) of calves obtained from six paternal breeds, Brown Swiss (BS), Holstein Friesian (HF), Simmental (SI), Alpine Grey (AG), Limousin (LI) and Belgian Blue (BB), and four maternal breeds (BS, HF, SI, AG), were studied in order to estimate the crossbreeding effects. A total of 58,877 calves sold during 143 weekly auctions from 2003 to 2005 in Bolzano in Italy near the Austrian border, were analyzed using ANOVA procedure according to a linear model that included the effects of cross, sex and age of the calf, year and month of the auction. Coefficient of determination (R-2) was 0.84; cross and sex effects resulted the most important. The BBxSI calves showed the highest commercial value (7.01 /kg), while the BS purebreds the lowest one (2.74 /kg). The LI and BB breeds used as sire breeds showed the greater commercial prices when crossbred with SI and AG respect to BS and HF. However, BB resulted the best sire breed. On average male calves showed greater commercial values than female ones (5.16 vs. 4.44 /kg), but in HF and BS purebreds the commercial value of males and females was similar
Milk coagulation ability of five dairy cattle breeds
Full text linkSamples of herd milk (506) were analyzed to assess
sources of variation for milk coagulation properties
(MCP) for 5 different dairy cattle breeds. Data were
recorded in 55 single-breed dairy herds in the Trento
province, a mountain area in northeast Italy. The 5
cattle breeds were Holstein-Friesian (8 herds), Brown
Swiss (16 herds), Simmental (10 herds), Rendena (13
herds), and Alpine Gray (8 herds). Herd milk samples
were analyzed for the MCP traits, milk rennet coagulation
time (RCT), curd-firming time, and curd firmness
(a30), as well as protein and fat percentages, somatic
cell count, Soxhlet-Henkel acidity, and bacterial count.
An ANOVA was performed to study the effect of breed,
herd within breed, DIM, month of lactation, protein
and fat percentages, somatic cell score, titratable acidity,
and log bacterial count within breed on MCP. Breed
was the most important source of variation. In particular,
the Rendena breed showed the best MCP traits at
13.5 min and 27.0 mm for RCT and a30, respectively.
The Holstein-Friesian breed had the worst coagulation
properties at 18.0 min and 17.5 mm for RCT and a30,
respectively. The other 3 breeds showed intermediate
coagulation properties. The RCT values were better at
the beginning of lactation, whereas RCT and a30 values
were better in September and October (14.3 min and
25.7 mm, respectively). Among the composition traits,
only the titratable acidity affected MCP traits of herd
milk positively
Sources of variation of milk rennet-coagulation ability of five dairy cattle breeds reared in Trento province
No full textA total of 506 samples of bulk tank milk from morning and evening milkings were analyzed to assess the milk rennet-coagulation ability. Data from the following dairy breeds reared in 55 herds of Trento province, were available: Holstein Friesian (8 herds), Brown (16 herds), Simmental (10 herds), Rendena (13 herds) and Alpine Grey (8 herds). Minimum and maximum number of samples per herd was 4 and 12, respectively. Traits analyzed were: coagulation time in minutes (R), curd-firming time in minutes (K20) and curd firmness in millimeters (A30). Mean and standard deviation for R, K20 and A30 was: 15.90 ± 3.26, 6.13 ± 2.52 and 24.03 ± 6.95, respectively. Analysis of variance was performed using a GLM procedure (SAS package) in order to study the effect of the following sources of variation: breed, herd, recording season, class of milk yield, fat and protein percentage, acidity, urea, bacterial count, clostridia contamination, somatic cell count, herd average days in milk and herd average age at calving. Breed resulted one of the most important sources of variation analysed; other results will be discussed
Evaluation of mid-infrared spectroscopy as a technique for predicting coagulation properties of milk
No full textThis study aimed to investigate the application of mid-infrared spectroscopy (MIRS) as a tool for predicting milk coagulation properties (MCP). Experimental data were from 79 Holstein Friesian cows; 6 milk samples were collected from each cow, and half of them were added with Azidiol preservative. Samples were analyzed at 3 different times: at collection (T0), after 4 (T4) or 8 d (T8) of storage. Milk coagulation time (RCT,min) and curd firmness (a30,mm) were measured using Computerized Renneting Meter (CRM) on T0 samples with or without preservative. MIRS analyses on T0, T4 and T8 samples with or without preservative were performed using MilkoScan FT120. Prediction equations were estimated by PLSR (WINISI II version 1.02). The reference average RCT and a30 values were 15.2 min and 36.1 mm, respectively, with a variation coefficient of 0.26 and 0.23 respectively. Correlation coefficients between CRM and MIRS analysis were 0.78 and 0.67 for RCT and a30, respectively. MCP at different times predicted by MIRS were comparable, while the coefficients of determination in calibration and in cross validation were better in the milk sample added with preservative. In conclusion, MIRS allowed for a rapid and rather accurate analysis of the MCP of cow milk and could be proposed as a tool for recording milk coagulation properties on a large scale, such as within milk recording schemes
Heterosis effects in a black and white dairy cattle population under different production environments
No full textThe aim of the study was to quantify the effects of
composite β- and κ-casein (CN) genotypes on genetic
variation of milk coagulation properties (MCP); milk
yield; fat, protein, and CN contents; somatic cell score;
pH; and titratable acidity (TA) in 1,042 Italian Holstein-
Friesian cows. Milk coagulation properties were defined
as rennet coagulation time (RCT) and curd firmness
(a30). Variance components were estimated using 2 animal
models: model 1 included herd, days in milk, and
parity as fixed effects and animal and residual as random
effects, and model 2 was model 1 with the addition
of composite β- and κ-CN genotype as a fixed effect.
Genetic correlations between RCT and a30 and between
these traits and milk production traits were obtained
with bivariate analyses, based on the same models. The
inclusion of casein genotypes led to a decrease of 47, 68,
18, and 23% in the genetic variance for RCT, a30, pH,
and TA, respectively, and less than 6% for other traits.
Heritability of RCT and a30 decreased from 0.248 to
0.143 and from 0.123 to 0.043, respectively. A moderate
reduction was found for pH and TA, whereas negligible
changes were detected for other milk traits. Estimates
of genetic correlations were comparable between the
2 models. Results show that composite β- and κ-CN
genotypes are important for RCT and a30 but cannot
replace the recording of MCP themselves
Heritabilities and genetic correlations of body condition score and calving interval with yield, somatic cell score, and linear type traits in Brown Swiss cattle
Full text linkThis study aimed to estimate genetic parameters for body condition score (BCS), calving interval (CI), somatic cell score (SCS), yield, and linear type traits for the Italian Brown Swiss cattle population. A total of 32,359 records of first-parity lactating cows were collected from 2002 to 2004 in 4,885 dairy herds. The pedigree file included 96,661 animals. Multiple-trait animal models were analyzed using REML to estimate (co)variance components without repeated observations on traits. The estimated heritability was 0.15 for BCS, 0.05 for CI, and 0.06 for SCS, and ranged from 0.09 to 0.14 for test-day yield traits and from 0.07 to 0.32 for linear type traits. The genetic correlations of CI with yield and most linear type traits were positive, whereas the correlation between CI and BCS was negative (-0.35). For type traits, BCS showed, in general, a moderately negative genetic correlation except for strength, pastern, and heel height. The genetic correlation of CI or BCS with SCS was moderately low but favorable (0.19 and -0.26, respectively). The estimated correlations indicated that selection for greater yield and type traits can exert unfavorable effects on the reproductive ability of cows. To counterbalance these effects and to carry out early prediction of breeding values of bulls for fertility, inclusion of BCS in the breeding program is advisable
Breed assignment test in four Italian beef cattle breeds
No full textThe assessment of a method able to assign individuals to the breed of origin is needed to certify origin and quality of livestock products.
A set of 21 microsatellites was tested for breed identification in four native Italian beef breeds: Chianina, Marchigiana, Romagnola,
and Piemontese. Two statistical approaches, based on maximum likelihood and on a Bayesian method, were evaluated. Different marker
sets, chosen in order of the highest gene diversity and FST estimates were also tested. The Bayesian method performed better, achieving a
correct assignment rate of about 90% even with six microsatellites. The marker sets with the highest gene diversity were shown to perform
best. Considering a threshold probability of 90%, only 52.5% of the genotypes were correctly allocated. Such results are mainly due to the
low genetic differentiation estimates among breeds (FST = 0.049). These findings suggest that markers with high gene diversity and the
presence of private alleles should be investigated and the Bayesian method used
Genetic characterization of the Burlina cattle breed using microsatellites markers
No full textThe present study was a contribution on the genetic characterization of
the Burlina local cattle breed, and an approach to understanding the
relationships between Burlina, Holstein Friesian and Brown Swiss which
represent the majority of the dairy cattle reared nowadays in North-East
Italy. The obtained results helped to clarify the genetic diversity and distinctiveness
of Burlina population. In particular, the low genetic distance
between Burlina and Holstein Friesian and the assignment of a
moderate percentage of Burlina animals to Holstein Friesian suggested
that crosses between them took place in the past, while crosses with
Brown Swiss seemed to be less frequent. However, analyses of marker
genotypes, showed a cluster with only Burlina individuals, which demonstrates
the genetic distinctness of this breed. The Burlina breed
showed the highest variability among the analysed breeds and its
inbreeding coefficient was low. The data contribute to the feasibility of a
conservation and selection programme for this breed and the results are
useful for the implementation of a conservation strategy that should
aim to conserve animals where the contribution from foreign breeds is
as small as possible
A Field Study on Fertility and Purity of Sex-Sorted Cattle Sperm
Full text linkThe study assessed the fertility and purity of sexed semen used for inseminating Holstein-Friesian heifers in commercial dairy herds. Sex-sorted semen from 4 proven Holstein-Friesian bulls and available under commercial conditions was used on nulliparous Hol- stein heifers reared on 61 dairy farms of northern Italy. Data from 536 artificial inseminations with pregnancy diagnosis and 258 calvings were analyzed using the logistic regression procedure. The effects of year and season of insemination or calving, age at insemination or calving, heifer inbreeding, and the sperm dose used for insemination on the probability of a positive preg- nancy diagnosis or of the birth of a female calf, respec- tively, were studied. The overall pregnancy rate for sexed semen was 51% and was affected by year of in- semination and bull. Heifers inseminated with sexed semen from 2 bulls had lower pregnancy rates than heifers inseminated with sexed semen from other bulls. Purity of the sexed sperm, based on the proportion of female calves, was 87% and this percentage was not affected by explanatory variables included in the logis- tic regression. The results demonstrate that bulls differ in terms of fertility of their sexed semen. Careful selec- tion of the insemination sires used for sorted semen is advisable for avoiding low fertility inseminations
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