A Further Study of Effects of Vacuum Level and Milking Duration on Udder Health and Milk Production

Abstract Background Over the last years, genome-wide association studies (GWAS) based on imputed whole-genome sequences (WGS) have been used to detect quantitative trait loci (QTL) and highlight candidate genes for important traits. However, in general this approach does not allow to validate the effects of candidate mutations or determine if they are truly causative for the trait(s) in question. To address these questions, we applied a two-step, within-breed GWAS approach on 15 traits (5 linked with milk production, 2 with udder health, and 8 with udder morphology) in Montbéliarde (MON), Normande (NOR), and Holstein (HOL) cattle. We detected the most-promising candidate variants (CV) using imputed WGS of 2515 MON, 2203 NOR, and 6321 HOL bulls, and validated their effects in three younger populations of 23,926 MON, 9400 NOR, and 51,977 HOL cows. Results Bull sequence-based GWAS detected 84 QTL: 13, 10, and 30 for milk production traits; 3, 0, and 2 for somatic cell score (SCS); and 8, 2 and 16 for udder morphology traits, in MON, NOR, and HOL respectively. Five genomic regions with effects on milk production traits were shared among the three breeds whereas six (2 for production and 4 for udder morphology and health traits) had effects in two breeds. In 80 of these QTL, 855 CV were highlighted based on the significance of their effects and functional annotation. The subsequent GWAS on MON, NOR, and HOL cows validated 8, 9, and 23 QTL for production traits; 0, 0, and 1 for SCS; and 4, 1, and 8 for udder morphology traits, respectively. In 47 of the 54 confirmed QTL, the CV identified in bulls had more significant effects than single nucleotide polymorphisms (SNPs) from the standard 50K chip. The best CV for each validated QTL was located in a gene that was functionally related to production (36 QTL) or udder (9 QTL) traits. Conclusions Using this two-step GWAS approach, we identified and validated 54 QTL that included CV mostly located within functional candidate genes and explained up to 6.3% (udder traits) and 37% (production traits) of the genetic variance of economically important dairy traits. These CV are now included in the chip used to evaluate French dairy cattle and can be integrated into routine genomic evaluation.

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Influence of Vacuum Level and Overmilking on Udder Health and Teat Thickness Changes in Dairy Ewes

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(03)73997-6 ◽

2003 ◽

Vol 86 (12) ◽

pp. 3891-3898 ◽

Cited By ~ 16

Author(s):

C. Peris ◽

J.R. Díaz ◽

S. Balasch ◽

M.C. Beltrán ◽

M.P. Molina ◽

...

Keyword(s):

Vacuum Level ◽

Udder Health ◽

Dairy Ewes

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Effects of Vacuum Level and Milking Duration on Guernseys and Holsteins Differing with Respect to Lactation Number and Status of Udder Health. II. Milk Yield, Milking Time, and Rate of Milk Flow

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(55)95107-9 ◽

1955 ◽

Vol 38 (11) ◽

pp. 1283-1292 ◽

Cited By ~ 7

Author(s):

E.V. Caruolo ◽

Cecilia M. Dembiczak ◽

R.D. Mochrie ◽

R.E. Johnson ◽

H.D. Eaton ◽

...

Keyword(s):

Milk Yield ◽

Vacuum Level ◽

Udder Health ◽

Milk Flow

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Genetic and environmental parameters for milk production, udder health, and fertility traits in Mexican Holstein cows

Journal of Dairy Science ◽

10.3168/jds.2009-2050 ◽

2010 ◽

Vol 93 (5) ◽

pp. 2168-2175 ◽

Cited By ~ 15

Author(s):

H.H. Montaldo ◽

H. Castillo-Juárez ◽

M. Valencia-Posadas ◽

E.G. Cienfuegos-Rivas ◽

F.J. Ruiz-López

Keyword(s):

Milk Production ◽

Environmental Parameters ◽

Holstein Cows ◽

Udder Health ◽

Fertility Traits

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Udder health in organic dairy cattle in Northern Spain

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2015133-6610 ◽

2015 ◽

Vol 13 (3) ◽

pp. e0503 ◽

Cited By ~ 4

Author(s):

Ana Villar ◽

Marta López-Alonso

Keyword(s):

Milk Production ◽

Individual Variability ◽

Northern Spain ◽

Organic Farms ◽

Udder Health ◽

Lactating Cows ◽

Sanitary Condition ◽

Cell Counts ◽

Organic Dairy ◽

Conventional Farms

This paper presents first data on the udder health status of organic dairy farms in Northern Spain and analyses some management and productive characteristics related to milk production comparing with the conventional sector. Five certified organic farms from the Cantabrian Region were monitored monthly from February 2006 to January 2008 and individual samples of all lactating cows were taken from parturition to the end of lactation. Although organic farms in our study showed a great individual variability, overall these were small (<50 lactating cows) traditional farms, with a high degree of pasture (66-82% dry matter intake) and a milk production (average milk yield: 5950 L) 23% lower compared with the reference conventional sector (<50 cow farms). The organic farms had higher (p<0.05) average number of calves per cow (3.93) and a lower number of first-lactation cows (16.9%) than the comparable conventional farms (2.47 calves per cow and 33.1% first-lactation cows). Organic farms showed higher (p<0.05) somatic cell counts (SCC) than the reference conventional farms (mean log10±SD for all cows: 5.25±0.49 and 5.06±0.59, respectively). Detailed analysis of the SCC depending on the number of lactation and % of monthly SCC tests with linear scores indicative of udder infection suggest that while the heifers’ sanitary condition at the beginning of their productive cycle was similar in both types of farms, this seems to become worse along the productive cycle in the organics. This could be related to a low use of antibiotics for prophylaxis and treatment of udder infections and merits further investigation.

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Overmilking causes deterioration in teat-end condition of dairy cows in late lactation

Journal of Dairy Research ◽

10.1017/s0022029913000307 ◽

2013 ◽

Vol 80 (3) ◽

pp. 344-348 ◽

Cited By ~ 12

Author(s):

J Paul Edwards ◽

Bernadette O'Brien ◽

Nicolas Lopez-Villalobos ◽

Jenny G Jago

Keyword(s):

Milk Production ◽

Flow Rate ◽

Cow Milk ◽

Udder Health ◽

Milk Samples ◽

Bulk Milk ◽

Milk Flow ◽

Holstein Friesian ◽

Mixed Age ◽

Friesian Cows

The objective of the study was to determine the effect of varying degrees of overmilking on teat-end hyperkeratosis, milk production variables and indicators of udder health during late lactation. This was examined by assessing the effect of four end-of-milking criteria on 181 spring-calving, mixed-age Holstein-Friesian cows, at an average 217±24 d in milk, over a six-week period. The four treatments were: remove cluster once milk flow rate fell to 0·2 kg/min plus 5 s (Ovr0), plus 120 s (Ovr2), plus 300 s (Ovr5), and plus 540 s (Ovr9). Daily measurements included individual cow milk yield, milking duration, overmilking duration, maximum milk flow rate, milk flow rate at cluster removal and the number of cluster re-attachments. Individual cow bulk milk samples were collected weekly at AM and PM milkings to determine composition (fat, protein and lactose) and somatic cell count (SCC; AM only). Teat-end hyperkeratosis score was assessed at weeks 0, 3, 5 and 6. At week 6 mean teat-end hyperkeratosis score of the Ovr2 treatment was not greater than Ovr0, whilst Ovr5 was greater than Ovr2 and Ovr9 was greater than Ovr5 and Ovr2. Milk production, milking characteristics and SCC were not different between treatments, except milking duration and milk flow rate at cluster removal. However, higher teat-end hyperkeratosis scores may have a longer-term impact on indicators of udder health if teat-end condition reaches severe levels. Results indicate that to minimise changes in teat-end condition overmilking should be limited to 2 min, which has implications for milking management in large parlours not fitted with automatic cluster removers.

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Local cooling of the mammary gland and milk production in the cow

Journal of Dairy Research ◽

10.1017/s0022029900013625 ◽

1971 ◽

Vol 38 (1) ◽

pp. 3-7 ◽

Cited By ~ 5

Author(s):

C. W. Holmes

Keyword(s):

Mammary Gland ◽

Milk Production ◽

Air Temperature ◽

Milk Fat ◽

The Other ◽

Local Cooling ◽

Udder Health ◽

Air Movement ◽

Cooling Conditions ◽

Jersey Cows

SummaryAn experiment has been performed with 2 Jersey cows to determine the effect of a reduction in udder temperature on milk production. One half of the udder was covered while the other half was cooled by an increase in air movement at an air temperature of 6−10°C; for closely clipped udders it was estimated that the cooling conditions might be equivalent to an air temperature of −10°C with low air movement. Yields of milk, fat, protein and lactose were reduced significantly at the morning milking after 22 h cooling; the decreases which occurred at the afternoon milking after 9 h cooling, in all components except fat, were not significant. Wisconsin Mastitis Tests on the milk indicated that changes in udder health did not contribute to these effects.

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