scholarly journals  Estimation of genetic parameters and evaluation of test-day milk production in sheep

2012 ◽  
Vol 57 (No. 11) ◽  
pp. 522-528 ◽  
Author(s):  
J. Bauer ◽  
M. Milerski ◽  
J. Přibyl ◽  
L. Vostrý
Keyword(s):  
Milk Production ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Least Squares Method ◽  
Coefficient Of Determination ◽  
Suitable Model ◽  
Breeding Values ◽  
Parity Number ◽  
Daily Milk Production ◽  
Daily Milk

 Genetic parameters and breeding values were estimated based on 11 708 daily milk yields from 2255 lactations (1351 sheep, 19 different flocks) between the years 2004 and 2010. The pedigree covered 2334 individuals, including both the recorded animals and their known ancestors. The fixed effects were estimated by the least-squares method, while the genetic parameters were estimated by the REML method. The data were tested by 49 models, but on the basis of the coefficient-of-determination value and the significance of the effects, only 10 models were used for REML analysis. The most suitable model was chosen on the basis of the breeding values distribution and the heritability of daily milk production, which was estimated at 0.28. The fixed effects of the flock parity number, the flock test day, and the linear and quadratic coefficients of flock’s days-in-milk in the chosen model were all highly significant (P < 0.0001) for the test-day milk yield. The breeding values had a normal distribution and a standard deviation of 0.46 kg.  

scholarly journals Estimation of genetic parameters and breeding values for daily milk production of dairy Simmentals in terms of heat stress

Genetika ◽  
2020 ◽  
Vol 52 (2) ◽  
pp. 641-650
Author(s):  
Goran Vuckovic ◽  
Tina Bobic ◽  
Pero Mijic ◽  
Mirna Gavran ◽  
Maja Gregic ◽  
...  
Keyword(s):  
Heat Stress ◽  
Milk Production ◽  
Genetic Parameters ◽  
Breeding Values ◽  
Daily Milk Production ◽  
Estimation Of Genetic Parameters ◽  
Daily Milk

scholarly journals Biochemical processes in cows and the biological value of milk under influence of cobalt citrate

2017 ◽  
Vol 19 (74) ◽  
Author(s):  
M. Khomyn ◽  
I. Kovalchuk ◽  
S. Kropyvka ◽  
M. Tsap
Keyword(s):  
Milk Production ◽  
Total Protein ◽  
Dry Matter ◽  
Inorganic Phosphorus ◽  
Animal Blood ◽  
Biological Value ◽  
Biochemical Processes ◽  
Mineral Supplements ◽  
Daily Milk Production ◽  
Daily Milk

The aim of research was to study the effect of different amounts of cobalt citrate produced by nanotechnology on biochemical processes in cows, their productivity and biological value of milk in the first two months of lactation. To achieve this goal the subsequent problems have been solved. We investigated the effect of different amounts of cobalt citrate on biochemical parameters of blood and milk of cows and controlled their average daily yield. The experiment has been conducted in 3 groups of cows (5 cows each) of Ukrainian black and white dairy cattle, analogue by body weight (590–620 kg), performance (6,5–6,8 thousand kg of milk per past lactation) and lactation (3–4 lactation). Unlike the control cows, animals experimental (ІІ) group for two months were fed by mineral supplements in the form of cobalt citrate in an amount of 19 mg Co/kg of dry matter of diet and research (ІІІ) – cobalt citrate in an amount of 34 mg Co/kg of dry matter of diet. Duration of cobalt citrate feeding of cows of research groups was 2 months. In all groups of cows the samples of venous blood were taken in preparation for feeding additives period and during 60 day of additives feeding period in order to determine the concentration of total protein, ceruloplasmin, sialic acids, hexoses bound to proteins and activity of amino transferases. The milk production has been controlled in days of sampling with the definition of daily milk yield per cow and taking an average sample for the determination of milk fat, protein, lactose, inorganic phosphorus and calcium. It has been established that the inclusion in the diet of cows of experimental (ІІ) group of mineral supplements contributed to an increase in animal blood total protein content by 11.9% (P < 0.05), inorganic phosphorus by 15.3% (P < 0.05) and hexoses bound protein by 8.8% (P < 0.05). Under these conditions milk content of inorganic phosphorus increased by 5.6% (P < 0.05) and average daily milk production increased by 4.5%. The use of mineral additives in third experimental group of animals within two months contributed to an increase in blood ceruloplasmin content by 5.1% (P < 0.05) and hexoses bound protein by 11.5% (P < 0.01). Mineral supplements promote 5.4% raise of average daily milk production and increase it to the lactose content by 0.10% (in absolute).

scholarly journals Selection of a suitable data set and model for the genetic evaluation of the linear description of conformation and type description in Old Kladruber horses

2012 ◽  
Vol 55 (2) ◽  
pp. 105-112
Author(s):  
L. Vostrý ◽  
K. Mach ◽  
J. Přibyl
Keyword(s):  
Random Effects ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Suitable Model ◽  
Residual Variance ◽  
Linear Type ◽  
Colour Variant ◽  
Repeated Evaluation ◽  
Estimation Of Genetic Parameters ◽  
Selection Of

Abstract. The objective of this paper was to select a suitable data subset and statistical model for the estimation of genetic parameters for 36 traits of the linear type in 977 Old Kladruber horses. Two subsets were tested to identify a suitable subset for analysis. One subset included repeated evaluation of certain individuals, whereas the other did not. The most suitable subset included repeated evaluation (n=1 390). The selection of a suitable model was made from 4 candidate models. These models comprised a number of random effects (direct individual effect and animal permanent environmental effect of the animal) and a number of fixed effects (colour variant, stud, colour variant × stud interaction, sex, age at description, year of birth, year of description). The model was selected based on the Akaike information criterion (AIC, Akaike 1974), residual variance and heritability coefficient. The model that included colour variant, stud, colour variant × stud interaction, sex, age at description, and year of description as fixed effects and direct individual and animal permanent environment as random effects was the most suitable model for the estimation of genetic parameters and for the subsequent estimation of breeding values.

scholarly journals Yield and chemical composition of milk of grazing and supplemented Tropical Milking criollo cows

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Adalberto Rosendo Ponce ◽  
Adrián Sánchez Gómez ◽  
Ángel Ríos Ortíz ◽  
Glafiro Torres Hernández ◽  
Carlos Miguel Becerril Pérez
Keyword(s):  
Chemical Composition ◽  
Milk Production ◽  
Dry Matter ◽  
Daily Production ◽  
Commercial Feed ◽  
Multiplicative Effect ◽  
Increase Milk Production ◽  
Daily Milk Production ◽  
Brachiaria Mutica ◽  
Daily Milk

Milk production under grazing conditions is carried out in the intertropical region of hot climates due to its low production cost. The Tropical Milking criollo breed (LT) is characterized by its hardiness in this region, and its high milk quality and cheese yield. Grazing supplementation can increase milk production; however, it can also change its chemical composition. The effect of supplementation with commercial feed in LT cows was evaluated concerning the quantity and physicochemical traits of their milk by lactation. The treatments used were feeding based only on grazing para grass (Brachiaria mutica) and grazing plus 1 kg supplementation with 20 % protein commercial feed for every 5 kg of milk produced daily. The daily milk production per cow increased from 5.82 ± 0.18 to 7.10 ± 0.18 kg due to supplementation. Dry matter intake was similar in both treatments. The concentration of fat, protein, lactose, non-fat, and total solids did not suffer modifications (p > 0.05), but the daily production of each component per cow increased in animals supplemented due to the multiplicative effect of the amount of milk. The number of calvings affected milk production, fat, and ureic nitrogen in milk, and somatic cell count (p ≤ 0.05). It can be concluded that the supplementation used in this study was enough to increase milk production by 22 %, without modifying its chemical composition.

scholarly journals Random regression models using different functions to estimate genetic parameters for milk production in Holstein Friesians

2016 ◽  
Vol 46 (9) ◽  
pp. 1649-1655
Author(s):  
Mariana de Almeida Dornelles ◽  
Paulo Roberto Nogara Rorato ◽  
Luis Telo Lavadinho da Gama ◽  
Fernanda Cristina Breda ◽  
Carlos Bondan ◽  
...  
Keyword(s):  
Milk Production ◽  
Legendre Polynomials ◽  
Fixed Effects ◽  
Regression Models ◽  
Genetic Parameters ◽  
Random Regression ◽  
Residual Variance ◽  
Lower Estimation ◽  
The One ◽  
Residual Variances

ABSTRACT: The objective of this study was to compare the functions of Wilmink and Ali and Schaeffer with Legendre polynomials in random regression models using heterogeneous residual variances for modeling genetic parameters during the first lactation in the Holstein Friesian breed. Five thousand eight hundred and eighty biweekly records of test-day milk production were used. The models included the fixed effects of group of contemporaries and cow age at calving as covariable. Statistical criteria indicated that the WF.33_HE2, LEG.33_HE2, and LEG.55_HE4 functions best described the changes in the variances that occur throughout lactation. Heritability estimates using WF.33_HE2 and LEG.33_HE2 models were similar, ranging from 0.31 to 0.50. The LEG.55_HE4 model diverged from these models, with higher estimates at the beginning of lactation and lower estimates after the 16th fortnight. The LEG55_HE4, among the three better models indicated by the index, is the one with highest number of parameters (14 vs 34) and resulted in lower estimation of residual variance at the beginning and at the end of lactation, but overestimated heritability in the first fortnight and presented a greater difficulty to model genetic and permanent environment correlations among controls. Random regression models that used the Wilmink and Legendre polynomials functions with two residual variance classes appropriately described the genetic variation during lactation of Holstein Friesians reared in Rio Grande do Sul.

scholarly journals Hycole Doe Milk Properties and Kit Growth

Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 214
Author(s):  
Agnieszka Ludwiczak ◽  
Joanna Składanowska-Baryza ◽  
Beata Kuczyńska ◽  
Marek Stanisz
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Milk Production ◽  
Litter Size ◽  
Somatic Cell Count ◽  
Quality Traits ◽  
Litter Weight ◽  
Daily Milk Production ◽  
Rabbit Milk ◽  
Daily Milk

The level of production and the physiochemical traits of rabbit milk affect the growth and the mortality of bunnies during lactation. The goal of the study was to analyze the effect of litter size and day of lactation on the quality traits of rabbit milk, milk production, and associative traits. The study was conducted on 32 Hycole does and their litters. The rabbit milk pH ranged from 6.61 to 7.46. The colostrum was characterized by the highest content of total solids (31.54 and 31.80 g kg−1) and fat content (15.73 and 15.9 g kg−1). The milk from the beginning of the lactation was characterized by the highest level of somatic cell count (SCC) (523.67 and 536.57 103 mL−1), which gradually decreased to reach the lowest level on days 17 and 21 of lactation. The daily milk production was greater for does nursing 10 kits per litter compared to those nursing eight kits per litter (p < 0.001). The peak of milk production occurred on day 17 postpartum. To conclude, the litter size has a clear effect on milk production as well as litter weight and litter weight gains. It is also important to note that the day of lactation affected the physiochemical traits of rabbit milk.

scholarly journals Effects of Calliandra and Sesbania on Daily Milk Production in Dairy Cows on Commercial Smallholder Farms in Kenya

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
D. N. Makau ◽  
J. A. VanLeeuwen ◽  
G. K. Gitau ◽  
S. L. McKenna ◽  
C. Walton ◽  
...  
Keyword(s):  
Milk Production ◽  
Dairy Farms ◽  
Protein Supplementation ◽  
Smallholder Farms ◽  
Study Objective ◽  
Final Model ◽  
Smallholder Dairy ◽  
Daily Milk Production ◽  
Daily Milk ◽  
Smallholder Dairy Farms

There is a growing interest in protein supplementation of dairy-cow diets using leguminous shrubs. The study objective was to ascertain the association between diet supplementation with Calliandra calothyrsus and Sesbania sesban and milk production in dairy cattle on commercial smallholder farms. This trial involved 235 cows from 80 smallholder dairy farms in Kenya randomly allocated to 4 intervention groups: (1) receiving Calliandra and Sesbania and nutritional advice; (2) receiving reproductive medicines and advice; (3) receiving both group 1 and 2 interventions; and (4) receiving neither intervention. Farm nutritional practices and management data were collected in a questionnaire, and subsequent physical examinations, mastitis tests, and milk production of cows on the farm were monitored approximately monthly for 16 months. Descriptive and univariable statistical analyses were conducted, and multivariable mixed-model regression was used for identification of factors associated (P<0.05) with daily milk production. The mean milk production was 6.39 liters/cow/day (SD = 3.5). Feeding Calliandra/Sesbania to cows was associated (P<0.0005) with an increase in milk produced by at least 1 liter/cow/day with each kg fed. Other variables positively associated with ln daily milk production in the final model included feeding of Napier grass, amount of silage and dairy meal fed, body condition score, and appetite of the cow. Other variables negatively associated with ln daily milk production in the final model included amount of maize germ fed, days in milk, sudden feed changes, pregnancy, and subclinical mastitis. In conclusion, our field trial data suggest that use of Calliandra/Sesbania through agroforestry can improve milk production in commercial smallholder dairy farms in Kenya. Agroforestry land use systems can be adopted as a way for dairy farmers to cope with feed shortages and low crude protein in farm-available feeds for their cows.

scholarly journals Short-term rate of milk synthesis and expression interval of preterm mothers

2019 ◽  
Vol 105 (3) ◽  
pp. 266-269 ◽  
Author(s):  
Ching Tat Lai ◽  
Alethea Rea ◽  
Leon R Mitoulas ◽  
Jacqueline C Kent ◽  
Karen Simmer ◽  
...  
Keyword(s):  
Preterm Infants ◽  
Milk Production ◽  
P Value ◽  
Inverse Association ◽  
Short Term ◽  
Start Time ◽  
Daily Milk Production ◽  
The Impact ◽  
Maximum Interval ◽  
Daily Milk

AimTo determine the impact of the pumping regimes of women with preterm infants on the daily milk production, and on the short-term rate of milk synthesis during early lactation to support evidence-based recommendations for optimising milk production.MethodsMothers of preterm infants (n=25) recorded start time, finish time and expression volumes from every breast expression on days 10, 15–20 postpartum.ResultsExpressing more often than five times per day did not result in a significant increase in daily milk production. Milk volume per expression per breast increased for intervals between expressions of between 2and6 hours then reached a plateau when the interval between expression was 7 hours or longer. The short-term rate of milk synthesis decreased as the interval between expressions increased until about 7.5 hours at which point it begun to increase (p value associated with interval between expressions^2<0.001).ConclusionThe strong inverse association between the short-term rate of milk synthesis and the interval between expressions for intervals up to 7 hours suggest that the maximum interval between expressions should be 7 hours. Data suggest that, on average, the mothers should express at least five times a day to maximise daily milk production. Considering inter-individual variation, determination of an individual mother’s maximum interval between expressions that does not compromise the short-term rate of milk synthesis will help to optimise daily milk production while minimising the demands on the mother’s time.

Statistical research on the fate of dietary mineral elements in dry and lactating cows IV. Chloride

1969 ◽  
Vol 73 (2) ◽  
pp. 223-229 ◽  
Author(s):  
R. Paquay ◽  
F. Lomba ◽  
A. Lousse ◽  
V. Bienfet
Keyword(s):  
Milk Production ◽  
Dry Matter ◽  
Mineral Elements ◽  
Statistical Research ◽  
Lactating Cows ◽  
Chloride Excretion ◽  
Daily Milk Production ◽  
Very High ◽  
Matter Energy ◽  
Daily Milk

SUMMARYStatistical analyses were carried out on the data obtained under very strict conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows, and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.The authors have calculated and studied the correlations between faecal and urinary losses of chloride, chloride excretion with the milk, digestible chloride and chloride balance and many other nutritive factors which were analysed for each of the 55 above mentioned experimental diets.The results show that the digestion and utilization of chloride is not influenced by the amount of ingested chloride at the time of the trial. The digestion is generally very high, negatively correlated with dry matter, energy, and pentosans intakes, and positively with nitrogen and potassium intakes. But the most important factor in the fate of dietary chloride seems to be the necessity for the cow to eliminate most of the time high amounts of potassium in the urines.

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