scholarly journals The relation of type and conformation to production in dairy cattle

1916 ◽  
Author(s):  
◽  
Robert Wylie
Keyword(s):  

Text from introduction: "The object of this investigation is to determine so far as possible how much importance should be attached to form and type in the selection of dairy cows and to what extent type may be expressed by definite measurements."

2016 ◽  
Vol 52 ◽  
pp. 6-12 ◽  
Author(s):  
M. V. Gladiy ◽  
G. S. Kovalenko ◽  
S. V. Priyma ◽  
G. A. Holyosa ◽  
A. V. Tuchyk ◽  
...  

The main goal of dairy breeds selection should be improving breeding and productive qualities of animals under modern conditions. The majority of farms, using native breeds to produce milk, has created optimal conditions for keeping and feeding, selection and matching, growing of replacements etc. Further improvement of created native dairy breeds for economically useful traits occurs at total use of purebred Holstein bulls (semen) of foreign selection. In order to realistically assess milk productivity (milk yield, fat content in milk and fat yield) of Ukrainian Black-and-White and Red-and-White Dairy cows should be conducted a comparative analysis of Holstein cows under the same conditions of feeding and keeping. It was established that Ukrainian Red-and-White Dairy cows were characterized by the highest milk yields for 305 days of all lactations, taken into account, the among three investigated breeds. Their milk yield during the first lactation was 5933 kg of milk, during the second – 6393 kg, the third – 6391 kg and during higher lactation – 6650 kg. Ukrainian Black-and-White Dairy cows were second by milk yield (except for the second lactation), during the first lactation – 5932 kg of milk, the third – 6462 kg and higher – 6541 kg, and Holstein cows were third, during the first lactation – 5794 kg of milk, the second – 6381 kg, the third – 6335 kg and higher – 6469 kg. The fat content was almost the same and varied within 3.49-3.58% in milk of Ukrainian Red-and-White Dairy cattle, 3.50-3.60% in milk of Ukrainian Black-and-White Dairy cattle and 3.50-3.56% in Holsteins’ milk. The difference between the breeds was within 0.01-0.04%. All the investigated breeds had predominance in fat yield for three lactations over standards of these breeds: Ukrainian Red-and-White Dairy cows from 75.1 to 93.4 kg, Ukrainian Black-and-White Dairy cows – 75.1-89.0 kg respectively and Holstein cows – 41.9-60.2 kg. It was found different level of positive correlation between milk yield and fat yield in all the cases and high correlation (r = 0.604-0.921, P < 0.001) in five cases (41.7%) Negative correlation coefficients indicate that selection of animals to higher milk yield in the herd will decrease the second trait – fat content in milk. Positive and highly significant correlation between milk yield and fat yield indicates that selection of cows in the herd to higher milk yields will increase fat yield. It was revealed that bulls were among the factors impacted the milk productivity (milk yield, fat content, fat yield) of three investigated breeds. So, the force (η²x) of father’s impact on milk yield was15.4-47.9%, fat content – 22.0-43.4% and fat yield – 14.9-47.7% taking into account a lactation and a breed. The force of lines impact (η²x) was second; it was on milk yield 6.1-24.5%, fat content – 4.1-17.1 and fat yield – 5.8-23.5%. The force of breeds impact (η²x) was last; it was on milk yield 0.3-2.9%, fat content – 0.2-0.3% and fat yield – 0.6-2.7%. So, the comparative studies of milk productivity of Ukrainian Red-and-White and Black-and-White Dairy cattle with Holsteins indicate that under similar conditions of feeding and keeping, these native breeds can compete with Holstein cattle. The milk yield for 305 days of higher lactation was 6650 kg of milk in Ukrainian Red-and-White Dairy cows, 6541 kg in Ukrainian Black-and-White Dairy cows and 6469 kg in Holsteins. It was found the inverse correlation r = -0.025-0.316 between milk yield and fat content in milk in most cases. Selection and matching of animals in the herd should be carried out simultaneously on these traits. It was found positive repeatability of milk yields between the first and second, the third and higher lactations (rs = 0.036-0.741), indicating the reliability of forecasting increase in milk productivity during the next lactations in all herd. Bulls have the greatest impact (η²x) on milk productivity among the factors taken into account: milk yield – 15.4-47.9%, fat content in milk – 22.0-43.4% and fat yield – 14.9-47.7%.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Belete Abebe ◽  
Mulugeta Alemayehu

In this paper, the potentials and constraints on estrus synchronization (ES) and artificial insemination (AI) practice for dairy cattle producers were overviewed. Compared to other African countries, Ethiopia has large numbers of dairy cattle population. However, the self-sufficiency in milk production is not yet attained due to the presence of a lot of limitations that hamper the success of ES and mass AI practice in many parts of the country such as improper selection of cows/heifers, inseminating a large number of cows/heifers in one day at a specific place (which creates stress for both AI technicians and female animals), absence of a data recording system, lack of clearly defined share of responsibilities among stakeholders, poor communication and collaboration among stakeholders, lack of motivations and skills of AI technicians, lack of support and readily available inputs, feed shortages, improper heat detection by smallholders and time of insemination, and lower reproductive performances of both indigenous and crossbred cows which consequently contributed to the unsuccessfulness of the technology.


2016 ◽  
Vol 52 ◽  
pp. 41-48 ◽  
Author(s):  
А. P. Krugliak

The scientific research analysis of crossbreeding using in dairy cattle of guiding countries has been implemented. There has been proved, that positive results of crossbreeding can be only for observing methodical basis of its using. They are: successful selection of initial-breeds, types and plans of theirs crossing, definition of feeding conditions and management of crossbred animals, application of methods of traits valuing, directed selection of bulls. Methodical bases of crossbreeding using in dairy cattle are following: - clear determination of main aim of crossbreeding program; - selection of improve breed may realize not for the most positive but for the less number of traits. A complementary breed shouldn’t have lower milk productivity but higher level of traits, for the sake of which it is selected to crossbreeding. It should be suitable to concrete system of milk production, have satisfactory population, the ramified genealogy and sufficient number of bulls-improvers. Plan of crossing significantly influences on the results of crossbreeding. The complex rotational crossing using 3-4 selected unrelated breeds is effective. The bulls, which are selected to crossbreeding, should have the highest estimation for traits, by which the selection is being carried out. They should be free from of exterior and genetic defects. The selection level should correspond to pure breeding. The innerbreed crossbreeding of Ukrainian Red-and-White dairy cows with top bulls of Montbeliarde, Holstein Red-and-White and Fleckvieh breeds has been suggested.


1965 ◽  
Vol 7 (3) ◽  
pp. 397-399 ◽  
Author(s):  
K. J. Robertson

One of the causes of culling dairy cows is low milk yield and to the extent that this has any genetic basis one might expect the daughters of old cows to outyield their contemporaries from younger and hence less selected mothers. This is quite apart from any confounding effects resulting from the non-genetic influences of dams' parity. The rate of genetic improvement derived from the culling process will be modified within a population by the extent to which farmers choose to retain the progeny of older rather than younger cows. Milk yields for recorded cows in Scotland, available to the Livestock Records Bureau, have been used to obtain some information on these points.


2000 ◽  
Vol 70 (3) ◽  
pp. 92-101 ◽  
Author(s):  
Burim Ametaj ◽  
Brian Nonnecke ◽  
Ronald Horst ◽  
Donald Beitz

Individual and combined effects of several isomers of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on interferon-gamma (IFN-gamma) secretion by blood mononuclear leukocytes (MNL) from nulliparous and postparturient Holstein cattle were evaluated in vitro. In the first experiment, effects on incubation period (24 to 72 hours) and time of supplementation (0 to 32 hours) with all-trans, 9-cis, 13-cis-, and 9,13-dicis-RAs (0 to 100 nM) on IFN-gamma secretion by pokeweed mitogen (PWM)-stimulated (0 and 10 mug/ml) MNL from nulliparous cattle were evaluated. In the second experiment, MNL from postparturient cows (bled at 0, 2, 4, and 16 days postpartum) were stimulated with PWM (0 and 10 mug/ml) in the presence of RA isomers (9-cis- or 9,13-dicis-RA; 0 to 100 nM), 1,25-(OH)2D3 (0 to 100 nM), or with combinations of these metabolites. The results show that individual isomers of RA had no effect on IFN-gamma secretion by PWM-stimulated MNL from nulliparous or postparturient cows. Furthermore 1,25-dihydroxyvitamin D3 inhibited IFN-gamma secretion by MNL from nulliparous and postparturient dairy cows; however, the degree of inhibition was greater when 9-cis- and 9,13-dicis-RA were also present in the cultures. Finally mononuclear leukocytes from postparturient dairy cows produced substantially less IFN-gamma than did MNL from nulliparous cattle. It is concluded that retinoic acids individually did not affect the capacity of leukocytes from dairy cattle to secrete IFN-gamma. This result is in marked contrast to studies in monogastric species indicating that RAs inhibit IFN-gamma secretion by peripheral blood T cells. Inhibition of IFN-gamma secretion by 1,25-(OH)2D3 was potentiated by 9-cis- and 9,13-di-cis-retinoics acids, suggesting that an excess of dietary vitamins A and D may compromise further the naturally immunosuppressed postparturient dairy cow. Additional research is necessary to determine if the combined effects of these metabolites on IFN-gamma secretion represent an increased susceptibility of the dairy cow to infectious diseases during the periparturient period. Lower secretion of IFN-gamma by MNL from postpartutient dairy cows, relative to nulliparous cattle, suggests that recently-calved cows are naturally immunosuppressed.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 599
Author(s):  
Miguel A. Gutierrez-Reinoso ◽  
Pedro M. Aponte ◽  
Manuel Garcia-Herreros

Genomics comprises a set of current and valuable technologies implemented as selection tools in dairy cattle commercial breeding programs. The intensive progeny testing for production and reproductive traits based on genomic breeding values (GEBVs) has been crucial to increasing dairy cattle productivity. The knowledge of key genes and haplotypes, including their regulation mechanisms, as markers for productivity traits, may improve the strategies on the present and future for dairy cattle selection. Genome-wide association studies (GWAS) such as quantitative trait loci (QTL), single nucleotide polymorphisms (SNPs), or single-step genomic best linear unbiased prediction (ssGBLUP) methods have already been included in global dairy programs for the estimation of marker-assisted selection-derived effects. The increase in genetic progress based on genomic predicting accuracy has also contributed to the understanding of genetic effects in dairy cattle offspring. However, the crossing within inbred-lines critically increased homozygosis with accumulated negative effects of inbreeding like a decline in reproductive performance. Thus, inaccurate-biased estimations based on empirical-conventional models of dairy production systems face an increased risk of providing suboptimal results derived from errors in the selection of candidates of high genetic merit-based just on low-heritability phenotypic traits. This extends the generation intervals and increases costs due to the significant reduction of genetic gains. The remarkable progress of genomic prediction increases the accurate selection of superior candidates. The scope of the present review is to summarize and discuss the advances and challenges of genomic tools for dairy cattle selection for optimizing breeding programs and controlling negative inbreeding depression effects on productivity and consequently, achieving economic-effective advances in food production efficiency. Particular attention is given to the potential genomic selection-derived results to facilitate precision management on modern dairy farms, including an overview of novel genome editing methodologies as perspectives toward the future.


1953 ◽  
Vol 20 (1) ◽  
pp. 1-12 ◽  
Author(s):  
C. P. Cox

1. Some questions concerning the interpretation of observations on milking dairy cattle are considered.2. A formula is presented for analysing the contributions of changes in the numerator and denominator to the changes in a percentage or fraction, and the formula is applied to changes in the composition of milk.3. The depressions of the butterfat and solids-not-fat percentages consequent on diets reduced in hay in a dairy-cattle feeding experiment are examined with this constituent analysis.The contributions of changes in the magnitudes of the aqueous, butterfat and solids-not-fat constituents to the difference between the butterfat percentages of cows on two treatments, 18 lb. hay/day (control) and 6 lb. hay /day, are about equal. There is an apparent qualitative difference between the effects of the two non-control treatments, and a reduced yield of butterfat would alone largely account for the lower butterfat percentage of cows on the 2 lb. hay /day treatment.


2017 ◽  
Vol 26 (3) ◽  
pp. 292-298 ◽  
Author(s):  
Cesar Augusto Barbosa de Macedo ◽  
Madlaine Frigo Silveira Barbosa de Macedo ◽  
Ana Carolina Miura ◽  
Alessandra Taroda ◽  
Sergio Tosi Cardim ◽  
...  

Abstract The aim of the present study was to investigate the occurrence of N. caninum associated with abortions of dairy cattle from Santa Catarina state, southern Brazil by using enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and polymerase chain reaction (PCR). Blood from dairy cows that aborted along with intrathoracic fluid and tissue samples (brain, heart, liver, and lung) from their fetuses were collected and used for serology; PCR, histopathological, and immunohistochemistry (IHC) evaluations were also conducted. Twenty-one cows (51.2%) out of 41, and eight fetuses (26.7%) out of 30 were ELISA (HerdCheck, IDEXX) positive for N. caninum. Dams > 36 months of age had a higher risk of being serum positive than younger animals. PCR and IHC revealed that 38.8% (14/36) and 25.0% (9/36) of the fetuses were positive for N. caninum, respectively for each of the tests. Seropositive cows had a higher frequency of fetuses that were also positive by either intrathoracic fluid, PCR, or IHC. In summary, the present study observed a high frequency of N. caninum in abortions from dairy cows from southern Brazil, with a higher N. caninum prevalence found in cows that were older than 36 months. In addition, serology, PCR, and IHC should be used all together for better diagnosis of neosporosis in cattle.


2012 ◽  
Vol 21 (2) ◽  
pp. 92-96 ◽  
Author(s):  
Jenevaldo Barbosa da Silva ◽  
Charles Passos Rangel ◽  
Bruna de Azevedo Baêta ◽  
Adivaldo Henrique da Fonseca

The aim of this study was to investigate whether season, lactation number, breed standard and milk production were risk factors relating to occurrences of gastrointestinal nematodes in dairy cows during the peripartum period. Eighty-four cows were randomly selected through proportional stratified sampling. In order to analyze the fecal egg per gram (EPG) count, the data were subjected to the Spearman test, Kruskal-Wallis test at 5% significance and linear regression. At the time of calving, the cows showed high EPG counts in relation to all variables analyzed. Among the animals studied, we observed that purebred Holstein cows at their first lactation and with high milk production showed high EPG counts (600) and comprised the group most at risk within the herd studied. In this group, the animals showed moderate EPG during the prepartum period (300) and a significant increase (p < 0.01) in EPG count from the time of calving (900), i.e. an increase of the order of 300%. Selection of animals for milk production in tropical countries should be based not only on productive potential, but also on adaptive features.


1970 ◽  
Vol 6 ◽  
pp. 91-96
Author(s):  
M Saiful Islam ◽  
Susanta Kumar Kundu

Impact of genotypes and parity on some vital reproductive and productive attributes in the local (L×L, n = 100) and four crossbred cows (L×F, L×SL, L×JR and L×S; n = 318) raised in randomly selected smallholder dairy farms scattered all over Natore District and adjacent areas have been assessed during a period from September 2007 to June 2010. With regard to reproductive attributes, significant differences existed among the cattle genotypes (P<0.05) except for gestation length (GL) and age at weaning (AW). The lowest age at puberty (AP) was found for L×F (21.42±0.37 months), while the highest for L×L (31.67±0.74 months). In terms of productivity, L×F cows produced the highest daily milk yield (DMY; 6.22±0.13 L), coupled with the highest total lactation yield (TLY; 2163.43±47.77 L), while L×L produced the lowest values (1.49±0.04 L and 416.40±12.3 L, respectively) for the traits. The effect of parity on both reproductive and productive attributes showed that the middle-aged dairy cows of the 3rd and 4th parities performed better than the younger (1st and 2nd parities) or the older (5th and beyond) ones. Considering the overall performance, the L×F cows could be ranked as the best genotype followed by their L×SL, L×JR, L×S and L×L counterparts in the study area. DOI: http://dx.doi.org/10.3329/jles.v6i0.9727 JLES 2011 6: 91-96


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