Effect of somatic cell count on milk and protein yields and female fertility in Tunisian Holstein dairy cows

Rekik, B.; Ajili, N.; Belhani, H.; Gara, A. Ben; Rouissi, H.

doi:10.1016/j.livsci.2007.11.001

Cited by 25 publications

(29 citation statements)

References 25 publications

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“…There are several studies regarding the detrimental impact of the health status and increased production levels on fertility. Rekik et al (2008) documented that both intervals DFI and FIC increased by 1.3 to 2 days for each unit increase in somatic cell score in Tunisian Holsteins. Melendez and Pinedo (2007) reported that for each 100 kg increase in a 305-day milk yield, the DO increased by 0.6 and the conception rate at first insemination decreased by 0.9 %.…”

Section: Discussionmentioning

confidence: 95%

“…In Tunisia, milk yield has traditionally been the most important breeding objective, with little or no focus on functional traits (Rekik and Ben Gara, 2004). Plans for the improvement of the national milk production have been developed in Tunisia since 1960 through the use of semen from highmerit sires and the importation of pregnant heifers from the United States and European countries such as Germany and the Netherlands (Djemali and Berger, 1992;Rekik and Ben Gara, 2004;Rekik et al, 2008). Reproductive data were included in the recording scheme in the late 1990s .…”

Section: Introductionmentioning

confidence: 99%

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Genetic parameters of reproductive traits in Tunisian Holsteins

et al. 2016

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Abstract. Multi-trait Bayesian procedure was used to estimate genetic parameters for reproductive traits in Tunisian Holstein cows. A total of 31 348 lactations of the calving years 2005 to 2012 were analyzed. Fertility traits were the calving interval (CI), days open (DO), days to first insemination (DFI), days from first insemination to conception (FIC), and number of inseminations per conception (NI). Posterior means of heritabilities of CI, DO, DFI, FIC, and NI were 0.047, 0.03, 0.025, 0.024, and 0.069, respectively. Posterior means of repeatabilities of the same respective traits were 0.106, 0.094, 0.051, 0.036, and 0.17. Genetic correlations among female fertility traits were also computed. Calving interval and DO had the highest genetic correlation estimate (0.85) because they have overlapping genetic meanings. The lowest genetic correlation estimate ( − 0.25) was found between DFI and NI. Genetic parameter estimates are low and are even lower than those reported in most literature, implying that more focus should be put upon improving the management of reproduction in dairy cattle herds in Tunisia.

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Section: Discussionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Genetic parameters of reproductive traits in Tunisian Holsteins

et al. 2016

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“…SCC also has an economic value in their own right in industries where there are milk price penalties for milk supplied for processing with very high counts. High SCC is not only associated with udder health and milk losses, but also negatively affects the longevity [9] and fertility [10] of dairy cows. Thus, incorporation of SCC in selection decisions seems desirable.…”

Section: Introductionmentioning

confidence: 99%

Genetic parameters for daily milk somatic cell score and relationships with yield traits of primiparous Holstein cattle in Iran

Kheirabadi

Razmkabir

2016

J Anim Sci Technol

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BackgroundDespite the importance of relationships between somatic cell score (SCS) and currently selected traits (milk, fat and protein yield) of Holstein cows, there was a lack of comprehensive literature for it in Iran. Therefore we tried to examine heritabilities and relationships between these traits using a fixed-regression animal model and Bayesian inference. The data set consisted of 1,078,966 test-day observations from 146,765 primiparous daughters of 1930 sires, with calvings from 2002 to 2013.ResultsMarginal posterior means of heritability estimates for SCS (0.03 ± 0.002) were distinctly lower than those for milk (0.204 ± 0.006), fat (0.096 ± 0.004) and protein (0.147 ± 0.005) yields. In the case of phenotypic correlations, the relationships between production and SCS were near zero at the beginning of lactation but become increasingly negative as days in milk increased. Although all environmental correlations between production and SCS were negative (−0.177 ± 0.007, −0.165 ± 0.008 and −0.152 ± 0.007 between SCS and milk, fat, and protein yield, respectively), slightly antagonistic genetic correlations were found; with posterior mean of relationships ranging from 0.01 ± 0.039 to 0.11 ± 0.036. This genetic opposition was distinctly higher for protein than for fat.ConclusionAlthough small, the positive genetic correlations suggest some genetic antagonism between desired increased milk production and reduced SCS (i.e., single-trait selection for increased milk production will also increase SCS).

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“…Across studies primiparous cows with 200 000 SCC showed, in kilograms per day, a milk loss of 0.13 (Boland et al, 2013), 0.23 to 1.76 (Rekik et al, 2008), 0.28 (Halasa et al, 2009), 0.61 (Hortet et al, 1999), 0.46 to 0.72 (Dürr et al, 2008), 0.35 to 0.80 (Hand et al, 2012). The results of the present study for thresholds of 200 000 and 400 000 SCC predicted higher milk yield losses in the range of 0.8 to 1.4 and 1.0 to 2.7 kg day −1 , respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Dürr et al (2008) set the limit for subclinical mastitis at more than 7400 SCC, Hand et al (2012) at 200 000, and in our study more than 100 000 SCC with additional specific limitations. Various lower limits of SCC over a broad range have been proposed in previous studies: 51 000 to more than 1 000 000 in PAR of one to four (Boland et al, 2013), 31 000 to more than 400 000 (Green et al, 2006), less than 200 000 (Rekik et al, 2008), 100 000 to 600 000 (Hortet et al, 1999), and 500 000 for primiparous and multiparous cows (Hagnestam-Nielsen et al, 2009). In some higher classes, the ranges were from less than 200 000 to 1 000 000 SCC with milk yield loss of 0.387 to 2.351 kg day −1 (Guo et al, 2010), 403 000 to 1 900 000 SCC with 0.6 to 3.8 kg estimated milk yield loss (Yalçin et al, 2000), and 200 000 to 2 000 000 SCC with a reduction of milk production of 0.35-1.09 kg day −1 to 1.49-4.70 kg day −1 (Hand et al, 2012).…”

Section: Resultsmentioning

confidence: 99%

A new somatic cell count index to more accurately predict milk yield losses

2017

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Abstract. Intramammary infection and clinical mastitis in dairy cows leads to considerable economic losses for farmers. The somatic cell concentration in cow's milk has been shown to be an excellent indicator for the prevalence of subclinical mastitis. In this study, a new somatic cell count index (SCCI) was proposed for the accurate prediction of milk yield losses caused by elevated somatic cell count (SCC). In all, 97 238 lactations (55 207 Holstein cows) from 2328 herds were recorded between 2010 and 2014 under different scenarios (high and low levels of SCC, four lactation stages, different milk yield intensities, and parities (1, 2, and ≥ 3). The standard shape of the curve for SCC was determined using completed standard lactations of healthy cows. The SCCI was defined as the sum of the differences between the measured interpolated values of the natural logarithm of SCC (ln(SCC)) and the values for the standard shape of the curve for SCC for a particular period, divided by the total area enclosed by the standard curve and upper limit of ln(SCC) = 10 for SCC. The phenotypic potential of milk yield (305-day milk yield -MY305) was calculated using regression coefficients estimated from the linear regression model for parity and breeding values of cows for milk yield. The extent of daily milk yield loss caused by increased SCC was found to be mainly related to the early stage of lactation. Depending on the possible scenarios, the estimated milk yield loss from MY305 for primiparous cows was at least 0.8 to 0.9 kg day −1 and for multiparous cows it ranged from 1.3 to 4.3 kg day −1 . Thus, the SCCI was a suitable indicator for estimating daily milk yield losses associated with increased SCC and might provide farmers reliable information to take appropriate measures for ensuring good health of cows and reducing milk yield losses at the herd level.

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Effect of somatic cell count on milk and protein yields and female fertility in Tunisian Holstein dairy cows

Cited by 25 publications

References 25 publications

Genetic parameters of reproductive traits in Tunisian Holsteins

Genetic parameters of reproductive traits in Tunisian Holsteins

Genetic parameters for daily milk somatic cell score and relationships with yield traits of primiparous Holstein cattle in Iran

A new somatic cell count index to more accurately predict milk yield losses

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