The effect of systematic factors on milk yield in Simmental cows over complete lactations

Petrović, Milun; Skalicki, Z.; Petrović, M.M.; Bogdanović, Vladan

doi:10.2298/bah0902061p

Cited by 7 publications

(4 citation statements)

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“…1). These results are in agreement with those reported by Hatungumukana et al (2007); Petrović et al (2009), Sun et al (2009Bormann and Wilson (2010) and Hayhurst et al (2010). The majority of the cows in this study had calving intervals between 380 and 400 days.…”

Section: Effect Of Calving Intervalsupporting

confidence: 93%

“…The variation in milk, fat and protein yields can be attributed to several environmental factors. These include herd, parity, age at calving, season (month) of calving, calving interval, dry period, days open, cow class, region (area), milking frequency and length of the lactation period (Petrović et al 2009). Amimo et al (2007) partitioned herd, year and season variance in an analysis of milk production for Ayrshire cattle and reported that herd effect accounted for 35% of the total variance in milk and fat yields.…”

Section: Introductionmentioning

confidence: 99%

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Environmental factors affecting milk, fat and protein yields in Jersey cattle in Zimbabwe

Missanjo¹,

Imbayarwo-Chikosi

Halimani

2010

Trop Anim Health Prod

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A study was carried out to establish the factors affecting milk, butterfat and protein yields in Zimbabwean Jersey cattle. A total of 10,986 unedited 305-day lactation records were obtained from Zimbabwe Livestock Identification Trust containing 25 herds, with cows calving in the period 1996-2008. The general linear model procedure of the Statistical Analysis Systems version 9.1.3 was used to determine the environmental factors. Herd-year-season, calving interval, days dry and both the linear and quadratic effects of age at calving fitted as covariates significantly (P<0.0001) affected the milk, fat and protein yields. Herd-year-season accounted for 36%, 36% and 35% to the total variation in milk, fat and protein yields, respectively. Milk, fat and protein yields increased with an increase in calving interval. The optimum dry period for milk, fat and protein yields obtained was 60-75 days dry. The relationship between the production traits and age at calving was both linear and quadratic, implying that milk, fat and protein yields increase with the age of the animal. It is thus necessary to preadjust data for these environmental factors when carrying out genetic evaluations of production traits in dairy cattle.

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Section: Effect Of Calving Intervalsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Environmental factors affecting milk, fat and protein yields in Jersey cattle in Zimbabwe

Missanjo¹,

Imbayarwo-Chikosi

Halimani

2010

Trop Anim Health Prod

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“…For example, Doğan and Özdamar ( 2003 ) and Berry et al ( 2007 ) investigated the factors that impacted milk yield in Holstein Frisian cows using classical linear and nonlinear regression models. Other research carried out by previous authors (Akçay et al 2007 ; Koçak et al 2007 ; Tilki et al 2008 ; Aksakal and Bayram 2009 ; Petrovic et al 2009 ; Atashi et al 2021 ; Vrhel et al 2021 ) reported the effects of calving season, gender, type of birth, and number of births on birth weight of Holstein dairy cattle using analysis of variance procedures and the ordinary multiple regression models. Additionally, in recent studies by Valchev et al ( 2020 ), Van Eetvelde et al ( 2020 ), and Temesgen et al ( 2022 ), the factors affecting milk yield were identified using regression-based models, but without handing the ordered nature of milk yield trait.…”

Section: Introductionmentioning

confidence: 98%

The estimation and interpretation of ordered logit models for assessing the factors connected with the productivity of Holstein–Friesian dairy cows in Egypt

Moawed

El-Aziz

2022

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The incorporation of novel technologies such as artificial intelligence, data mining, and advanced statistical methodologies have received wide responses from researchers. This study was designed to model the factors impacting the actual milk yield of Holstein–Friesian cows using the proportional odds ordered logit model (OLM). A total of 8300 lactation records were collected for cows calved between 2005 and 2019. The actual milk yield, the outcome variable, was categorized into three levels: low (< 4500 kg), medium (4500–7500 kg), and high (> 7500 kg). The studied predictor variables were age at first calving (AFC), lactation order (LO), days open (DO), lactation period (LP), peak milk yield (PMY), and dry period (DP). The proportionality assumption of odds using the logit link function was verified for the current datasets. The goodness-of-fit measures revealed the suitability of the ordered logit models to datasets structure. Results showed that cows with younger ages at first calving produce two times higher milk quantities. Also, longer days open were associated with higher milk yield. The highest amount of milk yield was denoted by higher lactation periods (> 250 days). The peak yield per kg was significantly related to the actual yield (P < 0.05). Moreover, shorter dry periods showed about 1.5 times higher milk yield. The greatest yield was observed in the 2nd and 4th parities, with an odds ratio (OR) equal to 1.75, on average. In conclusion, OLM can be used for analyzing dairy cows’ data, denoting fruitful information as compared to the other classical regression models. In addition, the current study showed the possibility and applicability of OLM in understanding and analyzing livestock datasets suited for planning effective breeding programs.

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“…Yield increases across generations as being facilitated by continuous breeding work and improving raising conditions, primarily nutrition and care, have been reported by international authors (Rycken, 1996(Rycken, , 1997(Rycken, , 1998, whereas Serbian authors observe declining trends in milk and milk fat yields across generations in imported breeding heifers as being primarily induced by poorer raising conditions and earlier exposure to breeding as compared to the situation in Western European developed countries (Germany, Switzerland, Austria) from which they were imported (Bogdanovic et al, 2008;Lazarevic et al, 1984;Nenadovic et al, 1986;Petrovic M.M.,1997Petrovic M.M., , 2008Petrovic D.M., 2008;Petrovic D.M. et al, 2009;Pantelic et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Regression analysis of milk production traits in simmental cows

Petrović¹,

Bogdanović²,

Petrović

et al. 2011

BIOTEC ANIM HUSB

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The relationship between milk production traits over whole lactations was evaluated across three generations of Simmental cows, i.e. between daughters, dams and grand dams, by a phenotypic regression analysis with whole lactation traits in the daughter generation being used as the dependent variables (x 1), and those in the dam and grand dam generations being used as the independent variables (x 2 and x 3). The results were obtained from a sample of 1170 daughters and as many dams and grand dams. The significance of the partial regression coefficients b 2 and b 3 was separately evaluated by a t-test. An analysis of variance was used to estimate the significance of the simultaneous effect of the production traits of dams and grand dams on the milk production achieved in the daughter generation. The calculated value of the partial regression coefficients for the whole lactation production traits across three generations (grand dams, dams and daughters) and their statistical significances determined by the t and F tests, as well as the regression equations used, suggested that the effect of the grand dam generation on the milk production traits in granddaughters was substantially lower than the effect of dams. The calculated partial regression coefficients (b 2 and b 3) were positive and statistically very significant (P<0.01), excepting the regression coefficients b 3 for lactation length and b 2 for milk fat content that were not statistically significant (P>0.05). A very significant change (P<0.01) was observed in all production traits in the daughter generation as simultaneously affected by the traits in the dam and grand dam generations

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The effect of systematic factors on milk yield in Simmental cows over complete lactations

Cited by 7 publications

References 2 publications

Environmental factors affecting milk, fat and protein yields in Jersey cattle in Zimbabwe

Environmental factors affecting milk, fat and protein yields in Jersey cattle in Zimbabwe

The estimation and interpretation of ordered logit models for assessing the factors connected with the productivity of Holstein–Friesian dairy cows in Egypt

Regression analysis of milk production traits in simmental cows

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