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Lindley G, Willshire J, Van Winden S. Reproductive Performance and Partial Budget Analysis of a Prostaglandin or a Modified Ovsynch Protocol in Autumn Calving Dairy Herds. Animals (Basel) 2021; 11:ani11041031. [PMID: 33917310 PMCID: PMC8067381 DOI: 10.3390/ani11041031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/14/2021] [Accepted: 03/31/2021] [Indexed: 12/02/2022] Open
Abstract
Simple Summary In autumn calving dairy herds cattle must conceive within a restricted timeframe to maintain the seasonality of calving. Cattle not observed in estrus prior to the mating start date are frequently treated with a single prostaglandin injection even though its relative effectiveness is unknown. The perceived cost of other treatments, such as a modified Ovsynch protocol, may be a reason why they are less favored. This study compares the reproductive and economic outcomes associated with treating cows not observed in estrus prior to breeding with a modified Ovsynch protocol, in comparison to a single prostaglandin injection. The main inputs influencing profitability are identified, and differences in dry-off strategy are considered. From the analyses, cows treated with a modified Ovsynch protocol had a greater likelihood of conception at the beginning of, and throughout, the breeding season. Differences in barren rate and the amount of milk produced were the main variables affecting profitability, the latter strongly influenced by drying-off policy. Farmers and advisors should consider the relative performance of their breeding strategies as well as their own management policies to optimize reproductive and economic performance. Abstract In autumn calving dairy herds, treatment of cattle not observed in estrus prior to the breeding season is common. Routinely, a single prostaglandin or a modified Ovsynch (MOFT) protocol are used—without evidence of their relative effectiveness. This study compares the effects on conception, associated timing, and profitability of administering cows with prostaglandin or MOFT treatment. A hundred and ninety-two Holstein-Friesian cows from three herds without an observed estrus within 28-days before mating start date were randomly treated with d-cloprostenol (PGOD) or an 8-day MOFT protocol. The association of treatment and calving-breeding start-date interval (CBSI) on the risk of conception were investigated. Partial budget, sensitivity analysis, and Monte Carlo simulation was used to assess economic performance, identify critical input variables, and explore the effects of input uncertainties on model output. There was a significant association between MOFT treatment and conception during 21 and 84 days after mating start date, compared to PGOD. MOFT treatment was associated with a mean net benefit of £58.21 (sd £19.42) and £27.29 (sd £17.75) per cow for herds with a fixed or variable dry-off date, respectively. The relative profitability of an MOFT protocol is dependent on its effects on barren rate and herd dry-off strategy.
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Affiliation(s)
- George Lindley
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK;
- Correspondence:
| | - Jim Willshire
- Endell Farm Vets, 49 Endless Street, Salisbury SP1 3UH, UK;
| | - Steven Van Winden
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK;
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Hills JL, Wales WJ, Dunshea FR, Garcia SC, Roche JR. Invited review: An evaluation of the likely effects of individualized feeding of concentrate supplements to pasture-based dairy cows. J Dairy Sci 2015; 98:1363-401. [PMID: 25582585 DOI: 10.3168/jds.2014-8475] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 11/13/2014] [Indexed: 12/21/2022]
Abstract
In pasture-based dairy systems, supplementary feeds are used to increase dry matter intake and milk production. Historically, supplementation involved the provision of the same amount of feed (usually a grain-based concentrate feed) to each cow in the herd during milking (i.e., flat-rate feeding). The increasing availability of computerized feeding and milk monitoring technology in milking parlors, however, has led to increased interest in the potential benefits of feeding individual cows (i.e., individualized or differential feeding) different amounts and types of supplements according to one or more parameters (e.g., breeding value for milk yield, current milk yield, days in milk, body condition score, reproduction status, parity). In this review, we consider the likely benefits of individualized supplementary feeding strategies for pasture-based dairy cows fed supplements in the bail during milking. A unique feature of our review compared with earlier publications is the focus on individualized feeding strategies under practical grazing management. Previous reviews focused primarily on research undertaken in situations where cows were offered ad libitum forage, whereas we consider the likely benefits of individualized supplementary feeding strategies under rotational grazing management, wherein pasture is often restricted to all or part of a herd. The review provides compelling evidence that between-cow differences in response to concentrate supplements support the concept of individualized supplementary feeding.
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Affiliation(s)
- J L Hills
- Tasmanian Institute of Agriculture, Dairy Center, The University of Tasmania, Burnie, Tasmania 7320, Australia
| | - W J Wales
- Agriculture Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria 3821, Australia
| | - F R Dunshea
- Melbourne School of Land and Environment, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - S C Garcia
- MC Franklin Laboratory, Faculty of Veterinary Science, University of Sydney, Camden, New South Wales 2570, Australia
| | - J R Roche
- DairyNZ, Private Bag 3221, Hamilton 3240, New Zealand.
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Applications and cost benefits of sexed semen in pasture-based dairy production systems. Animal 2014; 8 Suppl 1:165-72. [PMID: 24679704 DOI: 10.1017/s1751731114000664] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Sexed semen technology is now commercially available in many countries around the world, and is primarily used in dairy cattle breeding. Sperm are sorted by flow cytometry on the basis of a 4% difference in DNA content between sperm containing X and Y chromosomes. Despite reliably producing a 90% gender bias, the fertility of the sexed semen product is compromised compared with conventional semen. The negative implications of the reduced fertility of sexed semen are amplified in seasonal systems of dairy production, as the importance of fertility is greater in these systems compared with year-round calving systems. A review of the literature indicates that conception rates (CR) to 1st service with frozen-thawed sexed semen are ~75% to 80% of those achieved with conventional frozen-thawed semen. Preliminary results from a large-scale field trial carried out in Ireland in 2013 suggest that significant improvements in the performance of sexed semen have been made, with CR of 87% of those achieved with conventional semen. The improved fertility of a sexed semen product that delivers a 90% gender bias has considerable implications for the future of breeding management in pasture-based dairy production systems. Sexed semen may facilitate faster, more profitable dairy herd expansion by increasing the number of dairy heifer replacements born. Biosecurity can be improved by maintaining a closed herd during the period of herd expansion. In a non-expansion scenario, sexed semen may be used to increase the value of beef output from the dairy herd. The replacement heifer requirements for a herd could be met by using sexed semen in the 1st 3 weeks of the breeding season, with the remaining animals bred to beef sires, increasing the sale value over that of a dairy bull calf. Alternatively, very short gestation sires could be used to shorten the calving interval. Market prices have a considerable effect on the economics of sexed semen use, and widespread use of sexed semen should be restricted to well managed herds that already achieve acceptable herd fertility performance.
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Use of herd management programmes to improve the reproductive performance of dairy cattle. Animal 2014; 8 Suppl 1:199-210. [DOI: 10.1017/s1751731114000457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Brownlie TS, Morton JM, Heuer C, Hunnam J, McDougall S. Reproductive performance of seasonal-calving, pasture-based dairy herds in four regions of New Zealand. N Z Vet J 2013; 62:77-86. [PMID: 24256438 DOI: 10.1080/00480169.2013.848499] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
AIMS The primary objective of this study was to describe the reproductive performance of a selection of New Zealand dairy herds in 2009/10 and 2010/11. A secondary objective was to explore associations between a number of biophysical and socio-demographic herd-level variables and herd-level reproductive outcomes. METHODS Seasonal-calving, pasture-based herds from the Waikato (n=16), Taranaki (n=16), North Canterbury (n=17) and South Canterbury (n=14) regions of New Zealand were enrolled as part of a larger study. Submission, conception and pregnancy risks ("in-calf risks") were calculated for 2009/10 and 2010/11 based on cow-level records and from the results of strategically timed pregnancy diagnoses. Additional herd-level information was collected during interviews with the herd key decision maker (KDM). Associations between independent variables and reproductive performance were examined using univariable and multivariable generalised linear models. RESULTS Mean 6-week in-calf risk of the herds over both study years was 67 (min 46, max 86)%, mean 3-week submission risk was 81 (min 44, max 95)% and mean probability of pregnancy at first insemination was 48 (min 25, max 71)%. On univariable analyses, the herd's 6-week in-calf risk in the year before enrollment (2008/09) was the strongest identified predictor of each of submission risk, probability of pregnancy at first insemination and 6-week in-calf risk (all p<0.01), while other predictor variables considered were non-significant. From multivariable modelling, herds using extensive production systems had better reproductive performance than more intensively managed systems. Higher 3-week submission risks were achieved in herds where the KDM were farm managers rather than owner operators, and where the predominant breed was Jersey rather than Friesian. CONCLUSIONS The New Zealand dairy industry has set a target for a mean 6-week in-calf risk of 78%, with minimal hormonal intervention, by 2016. Achieving this target appears unlikely unless there are substantial increases in both submission risks and pregnancy at first inseminations. The mean 6-week in-calf risk of New Zealand dairy herd does not appear to have changed in the last decade. However the large differences between herds indicate that better reproductive performance is currently possible in many herds. The herd's 6-week in-calf risk in the year before enrollment (2008/09) was the strongest identified predictor of current 6-week in-calf risk, suggesting that rate of improvement in reproductive performance would be slow within current management systems unless substantial changes are introduced.
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Affiliation(s)
- T S Brownlie
- a Cognosco, Anexa Animal Health , Morrinsville , New Zealand
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Hutchinson I, Shalloo L, Butler S. Expanding the dairy herd in pasture-based systems: The role of sexed semen use in virgin heifers and lactating cows. J Dairy Sci 2013; 96:6742-52. [DOI: 10.3168/jds.2012-6476] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 06/16/2013] [Indexed: 11/19/2022]
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Doole GJ, Romera AJ, Adler AA. An optimization model of a New Zealand dairy farm. J Dairy Sci 2013; 96:2147-2160. [PMID: 23415534 DOI: 10.3168/jds.2012-5488] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 11/22/2012] [Indexed: 11/19/2022]
Abstract
Optimization models are a key tool for the analysis of emerging policies, prices, and technologies within grazing systems. A detailed, nonlinear optimization model of a New Zealand dairy farming system is described. This framework is notable for its inclusion of pasture residual mass, pasture utilization, and intake regulation as key management decisions. Validation of the model shows that the detailed representation of key biophysical relationships in the model provides an enhanced capacity to provide reasonable predictions outside of calibrated scenarios. Moreover, the flexibility of management plans in the model enhances its stability when faced with significant perturbations. In contrast, the inherent rigidity present in a less-detailed linear programming model is shown to limit its capacity to provide reasonable predictions away from the calibrated baseline. A sample application also demonstrates how the model can be used to identify pragmatic strategies to reduce greenhouse gas emissions.
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Affiliation(s)
- Graeme J Doole
- Centre for Environmental Economics and Policy, School of Agricultural and Resource Economics, Faculty of Natural and Agricultural Sciences, University of Western Australia, Crawley, Western Australia 6009, Australia; Department of Economics, Waikato Management School, University of Waikato, Private Bag 3105, Hamilton, New Zealand.
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Hutchinson I, Shalloo L, Butler S. Expanding the dairy herd in pasture-based systems: The role for sexed semen use on virgin heifers. J Dairy Sci 2013. [DOI: 10.3168/jds.2012-6126] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Beukes P, Gregorini P, Romera A. Estimating greenhouse gas emissions from New Zealand dairy systems using a mechanistic whole farm model and inventory methodology. Anim Feed Sci Technol 2011. [DOI: 10.1016/j.anifeedsci.2011.04.050] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Roche JR, Burke CR, Meier S, Walker CG. Nutrition × reproduction interaction in pasture-based systems: is nutrition a factor in reproductive failure? ANIMAL PRODUCTION SCIENCE 2011. [DOI: 10.1071/an10162] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dairy cow fertility has declined in recent decades, coincidental with large increases in milk production. Cows take longer to return to oestrus, display poorer signs of oestrus, have greater early embryo loss, and may have poorer conception rates. The problem is often considered to be nutritional, at least in part, and, therefore, can be corrected through dietary adjustment. Although acknowledged as highly digestible, high quality pastured forages tend to be low in non-structural carbohydrates (NSC), high in rumen degradable protein and the temporal supply may not be adequate for cow demand at key times; diet adjustment is often recommended to overcome these limitations. The interaction between nutrition and reproduction is poorly defined, however, and study results are often contradictory. Hypothesised limitations to pastured forages within a grazing system will be discussed, and the likely impact of nutritional adjustment on pre- and post-ovulatory reproductive processes examined. The effect of energy balance, carbohydrate type, protein and fat on reproductive outcomes will be considered. Nutrition is an important component of successful reproduction, but dietary adjustment to improve pregnancy rates is complicated, and merely offering pastured cows a supplement is unlikely to result in large effects. Conclusions indicate that care must be taken in interpreting associative analyses and in applying results from different farming systems.
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