A 100-Year Review: A century of dairy heifer research

Heinrichs, A.J.; Zanton, G.I.; Lascano, G.J.; Jones, Coleen

doi:10.3168/jds.2017-12998

Cited by 29 publications

(32 citation statements)

References 179 publications

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“…Rather than viewing an individual calf death as a demoralizing end-point, the narrative provides an understanding from which to elicit change across the population. Rearing dairy replacement heifers should focus on limiting environmental impact, protecting animal welfare, and minimizing required inputs while returning the most profitable outputs (Hoffman and Funk, 1992;Heinrichs et al, 2017). As such, reducing economic costs and impairment to animal welfare through improved understanding of dairy calf mortality provides a critical control point for accelerating whole-farm efficiency and sustainability.…”

Section: Discussionmentioning

confidence: 99%

Clarifying dairy calf mortality phenotypes through postmortem analysis

McConnel

Nelson

Burbick

et al. 2019

Journal of Dairy Science

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Health problems can be thought of as phenotypic expressions of the complex relationships between genes, environments, and phenomes as a whole. Detailed evaluations of phenotypic expressions of illness are required to characterize important biological outcomes. We hypothesized that classifying dairy calf mortality phenotypes via a systematic postmortem analysis would identify different cause-of-death diagnoses than those derived from treatments alone. This cross-sectional study was carried out on a dairy calf ranch in the northwestern United States from June to September 2017 and focused on calves ≤90 d of age. Comparisons were made between causes of death based on 3 levels of information: on-farm treatment records alone, necropsy-based postmortem analyses in addition to treatment records, and Washington Animal Disease Diagnostic Laboratory (WADDL) results in addition to all other information. A total of 210 dairy calves were necropsied during this study, of which 122 cases were submitted to WADDL. Necropsy-and WADDL-derived mortality phenotypes were in almost perfect agreement (Cohen's κ = 0.86) when broadly categorized as diarrhea, respiratory, diarrhea and respiratory combined, or other causes. The level of agreement between onfarm treatment records and postmortem-derived results was low and varied by the level of diagnostic detail provided. There was just fair agreement (κ = 0.22) between treatment-based and necropsy-based phenotypes without WADDL input and only slight agreement (κ = 0.13) between treatment-based and corresponding necropsy-based phenotypes with WADDL input. Even for those cases in which causes of death aligned along a comparable pathologic spectrum, the lack of detail inherent to standard treatment-based causes of death failed to identify meaningful target areas for intervention. This was especially apparent for numerous cases of necrotizing enteritis and typhlitis (cecal inflammation) that were variously categorized as diarrhea and pneumonia by treatment-based diagnoses. The specificity of these lesions stood in stark contrast to the otherwise generic cause of death diagnoses derived from treatments. The findings from this study supported the hypothesis and highlighted the value of on-farm necropsies and laboratory-based diagnostics to (1) detect antemortem disease misclassifications, (2) provide detail regarding disease processes and mortality phenotypes, and (3) direct disease mitigation strategies.

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Section: Discussionmentioning

confidence: 99%

Clarifying dairy calf mortality phenotypes through postmortem analysis

McConnel

Nelson

Burbick

et al. 2019

Journal of Dairy Science

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“…Heifer raising equals to 15% to 20% of the total cost of milk production, thereby representing the second largest share among the cost factors, following feed costs [1]. The aim of the dairy farm managers is to minimize the costs and maximize the future revenue of dairy heifers, however, modern objectives also include environmental impact and animal welfare considerations [2]. Therefore, those factors that are related to the performance of replacement heifers are relevant from an economic point of view.…”

Section: Introductionmentioning

confidence: 99%

Relationship of dairy heifer reproduction with survival to first calving, milk yield and culling risk in the first lactation

Fodor

Láng

Ózsvári³

2020

Asian-Australas J Anim Sci

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Objective: The aim of our study was to determine the associations of heifer reproductive performance with survival up to the first calving, first-lactation milk yield, and the probability of being culled within 50 days after first calving. Methods: Data from 33 large Holstein-Friesian commercial dairy herds were gathered from the official milk recording database in Hungary. The data of heifers first inseminated between January 1, 2011 and December 31, 2014 were analyzed retrospectively, using Cox proportional hazards models, competing risks models, multivariate linear and logistic mixed-effects models. Results: Heifers (n = 35,128) with younger age at conception were more likely to remain in the herd until calving, and each additional month in age at conception increased culling risk by 5.1%. Season of birth was related to first-lactation milk yield (MY1; n = 19,931), with cows born in autumn having the highest milk production (p<0.001). The highest MY1 was achieved by heifers that first calved between 22.00 and 25.99 months of age. Heifers that calved in autumn had the highest MY1, whereas calving in summer was related to the lowest milk production (p<0.001). The risk of culling within 50 days in milk in first lactation (n = 21,225) increased along with first calving age, e.g. heifers that first calved after 30 months of age were 5.52-times more likely to be culled compared to heifers that calved before 22 months of age (p<0.001). Calving difficulty was related to higher culling risk in early lactation (p<0.001). Heifers that required caesarean section were 24.01-times more likely to leave the herd within 50 days after first calving compared to heifers that needed no assistance (p<0.001). Conclusion: Reproductive performance of replacement heifers is closely linked to longevity and milk production in dairy herds.

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“…Moreover, earlier studies have shown that the AFC may substantially contribute to the total rearing costs [18,19]. We observed substantial differences in the AFC between visited farms and given the median AFC of 802 days; our findings suggest that some of the visited dairy farmers might be affected by some economic burden due to the elevated median AFC in relation with the general goal at 22 to 24 months (730 days) [20,21].…”

Section: Discussionmentioning

confidence: 45%

Reproductive Performance in a Selected Sample of Dairy Farms in Una-Sana Canton, Bosnia and Herzegovina

Softić

Martin

Skjerve

et al. 2020

Veterinary Medicine International

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Background. e production of milk and dairy products and their placement on the market represent a constant profit for the farmers/producers in Bosnia and Herzegovina (BH). e profitable operation of the dairy farms is influenced by the reproductive performance of the lactating animals. is study assessed individual animal reproductive characteristics in selected dairy farms and described their reproductive performance indicators. Results. e median age at first insemination was 493 days (5 th -95 th percentile range 429-840), while the age at first calving was 802 days (5 th -95 th percentile range 708-1168). e median pregnancy proportion at first insemination was 40% (5 th -95 th percentile range 17-62), while the cumulative pregnancy rate calculated at day-60, day-80, day-100, and day-120 showed that approximately 64% of all pregnancies happened before day-120. e calculated interservice intervals showed that approximately 69% of the repeat breeding animals came back to the oestrus in the period of 18 to 24 days. is is an indication of very good oestrus detection in selected dairy farms. e mean number of services per pregnancy was 2.61 (range 1-12). e median calving-to-first-insemination interval was 62.5 days (5 th -95 th percentile range 16-408). e calving-to-conception interval was 101 day (5 th -95 th percentile range 36-506). Finally, the calving interval was 385 days (5 th -95 th percentile range 329-773). Conclusions. ere is a need for an organised, regular, and more comprehensive recording system for the reproduction of dairy cattle among dairy farms in Una-Sana Canton. e calculated reproductive measures indicated an undulant trend in reproductive performance among selected dairy farms in Una-Sana Canton. Knowing the apparent reproductive indicators described in this study, the farmers and veterinary authorities may identify and correct areas in their management that contribute to the reproductive underperformance.

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A 100-Year Review: A century of dairy heifer research

Cited by 29 publications

References 179 publications

Clarifying dairy calf mortality phenotypes through postmortem analysis

Clarifying dairy calf mortality phenotypes through postmortem analysis

Relationship of dairy heifer reproduction with survival to first calving, milk yield and culling risk in the first lactation

Reproductive Performance in a Selected Sample of Dairy Farms in Una-Sana Canton, Bosnia and Herzegovina

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