Heritabilities of Teat Traits and their Relationships with Milk Yield, Somatic Cell Count, and Percent Two-Minute Milk

Seykora, Anthony J; McDaniel, B.T.

doi:10.3168/jds.s0022-0302(85)81152-8

Cited by 50 publications

(34 citation statements)

References 15 publications

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“…These authors used data from 200 animals belonging to three different herds, which might have contributed to the lower estimates found. However, the range of h 2 observed in this study was close to the estimates reported in the literature, which range from 0.15 to 0.28 for data measured objectively (Seykora and Mcdaniel, 1985;Povinelli et al, 2003;Rensing & Ruten, 2005;Zwald et al, 2005;Vicario et al, 2006).…”

Section: Resultssupporting

confidence: 90%

“…Estimates of genetic parameters for milk flow depend on the type of model and measurement used. Thus, heritability estimates reported in the literature vary widely, with values of 0.42 for flow measured during the first 2 min of milking, 0.19 for total milk flow and 0.15 for flow -E-mail: monyka.laureano@gmail.com data obtained subjectively (Seykora and Mcdaniel, 1985;Boettcher et al, 1998;Vicario et al, 2006). Some models used for the evaluation of milk yield might be candidates for the study of milk flow.…”

Section: Introductionmentioning

confidence: 99%

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Genetic parameters for first lactation test-day milk flow in Holstein cows

Laureano

Bignardi

Faro

et al. 2012

Animal

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Genetic parameters for test-day milk flow (TDMF) of 2175 first lactations of Holstein cows were estimated using multiple-trait and repeatability models. The models included the direct additive genetic effect as a random effect and contemporary group (defined as the year and month of test) and age of cow at calving (linear and quadratic effect) as fixed effects. For the repeatability model, in addition to the effects cited, the permanent environmental effect of the animal was also included as a random effect. Variance components were estimated using the restricted maximum likelihood method in single-and multiple-trait and repeatability analyses. The heritability estimates for TDMF ranged from 0.23 (TDMF 6) to 0.32 (TDMF 2 and TDMF 4) in single-trait analysis and from 0.28 (TDMF 7 and TDMF 10) to 0.37 (TDMF 4) in multiple-trait analysis. In general, higher heritabilities were observed at the beginning of lactation until the fourth month. Heritability estimated with the repeatability model was 0.27 and the coefficient of repeatability for first lactation TDMF was 0.66. The genetic correlations were positive and ranged from 0.72 (TDMF 1 and 10) to 0.97 (TDMF 4 and 5). The results indicate that milk flow should respond satisfactorily to selection, promoting rapid genetic gains because the estimated heritabilities were moderate to high. Higher genetic gains might be obtained if selection was performed in the TDMF 4. Both the repeatability model and the multiple-trait model are adequate for the genetic evaluation of animals in terms of milk flow, but the latter provides more accurate estimates of breeding values.Keywords: functional trait, genetic correlation, heritability, milkability ImplicationsThe milk flow trait can be considered as functional, of great importance in dairy cattle, both related to udder health on the efficiency of labor. A increased milk flow is associated with a decrease in occupancy time of labor and thus a decrease in spending on it. In addition, a faster milking implies a reduction in electricity costs and maintenance of machines. Studies investigating milk flow are still limited and the best approach for analyzing this trait has not been well defined.

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Genetic parameters for first lactation test-day milk flow in Holstein cows

Laureano

Bignardi

Faro

et al. 2012

Animal

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“…Longer teats were associated with higher SCC, which agree with the results from Seykora and McDaniel (1985). Perhaps longer teats are more prone to injury due to housing, handling, and milking machine incompatibility (Rogers et al, 1991).…”

Section: Estimate Of Variance Componentsupporting

confidence: 82%

Relationship of Somatic Cell Score and Udder Type Traits of Holstein Cattle

2008

Journal of Animal Science and Technology

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“…7,8 However, Seykora and McDaniel, found a negative correlation between milk yield and hyperkeratosis in a study based on milk flow rates for milk yield. 21 In this study, a significant increase was observed in the degree of hyperkeratosis and a decrease in milk yield. It was concluded that the reason for this might be connected to the fact that milking finishes earlier in quarters with less or no milk compared with those that have high milk yield and therefore the teats are subjected to the vacuum for longer.…”

Section: Figurementioning

confidence: 88%

The Occurrence of Teat Hyperkeratosis in Cows and Its Effect on Milk Somatic Cell Counts

Emre¹,

Alaçam²

2015

Turkiye Klinikleri J Vet Sci

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A AB BS ST TR RA AC CT T O Ob bj je ec ct ti iv ve e: : In this study, the frequency of hyperkeratosis and its effect on milk somatic cell counts were researched. M Ma at te er ri ia al l a an nd d M Me et th ho od ds s: : A total of 2332 teats in 583 Holstein cows in different stage of lactation were evaluated on the base of the criteria of morphological structure of the teat end and teat length, milk yield and number of lactations. Macroscopic appearances of lesions on the teat orifice were classified and also were photographed. Somatic cell counts (SCC) were evaluated using the fossomatic method. R Re es su ul lt ts s: : The SCC was determined to be less than 200.000 cells/mL in 72.8% of the quarters and greater than this in 27.2%. Forty-nine percent of the teat ends were normal while hyperkeratosis was identified in 51%. Hyperkeratosis degrees of 1, 2, 3, 4 and 5 was determined in 17%, 13.8%, 9.2%, 5% and 6% respectively. The study findings demonstrated that there was a significant rise in SCC parallel to increasing severity of hyperkeratosis (p<0.001) and that even mild hyperkeratosis could result in an increase in SCC (p<0.05). A significant correlation was determined between severe hyperkeratosis and pointed teat ends (p<0.001). The relationship between hyperkeratosis and milk yield was determined to be significant (p<0.001). However the connection between number of lactations and teat length with hyperkeratosis was not identified as statistically significant. C Co on nc cl lu us si io on n: : It was concluded that pointed teat ends have a greater tendency to develop hyperkeratosis, the development of hyperkeratosis increased as milk yield dropped and hyperkeratosis could result in a significant increase in SCC and consequently pose a risk to udder health. K Ke ey y W Wo or rd ds s: : Cattle; hyperkeratosis, epidermolytic Ö ÖZ ZE ET T A Am ma aç ç: : Bu çalışmada; hiperkeratozun rastlantısı ve süt somatik hücre sayısına etkisi araştırıldı. G Ge er re eç ç v ve e Y Yö ön nt te em ml le er r: : Çalışma, laktasyonun farklı dönemlerinde bulunan 583 baş Holstein ineğe ait 2332 adet meme başında değerlendirildi. Çalışmada laktasyon sayısı, süt verimi, meme başı ucunun morfolojik yapısı ve meme başı uzunluğu kaydedildi. Meme başı deliğinde yer alan lezyonların makroskopik görünümleri sınıflandırıldı ve fotoğrafları kaydedildi. Somatik hücre sayımları (SHS) fossomatik yöntemiyle değerlendirildi. B Bu ul lg gu ul la ar r: : Somatik hücre sayısı meme loblarının %72,8'inde 200 000 hücre/mL'den düşük, %27,2'sinde ise yüksek olarak tespit edildi. Meme başlarının %49'u normal olup, %51'inde ise hiperkeratoz belirlendi. Bir, 2, 3, 4 ve 5. derece hiperkeratoz oranları sırasıyla %17; %13,8; %9,2; %5 ve %6 olarak tespit edildi. Çalışma bulguları, hiperkeratoz şiddetindeki artışa paralel olarak SHS'ında önemli bir yükselme olduğunu (p<0,001) ve orta derece hiperkeratozların da SHS'nda yükselmeye neden olabileceğini gösterdi (p<0,05). Şiddetli hiperkeratoz ile sivri tip meme başı uçları arasında önemli düzeyde bir ilişki tes...

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Heritabilities of Teat Traits and their Relationships with Milk Yield, Somatic Cell Count, and Percent Two-Minute Milk

Cited by 50 publications

References 15 publications

Genetic parameters for first lactation test-day milk flow in Holstein cows

Genetic parameters for first lactation test-day milk flow in Holstein cows

Relationship of Somatic Cell Score and Udder Type Traits of Holstein Cattle

The Occurrence of Teat Hyperkeratosis in Cows and Its Effect on Milk Somatic Cell Counts

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