Expression profiles of genes regulating dairy cow fertility: recent findings, ongoing activities and future possibilities

Subfertility has negative effects for dairy farm profitability, animal welfare and sustainability of animal production. Increasing herd sizes and economic pressures restrict the amount of time that farmers can spend on counteractive management Genetic improvement will become increasingly important to restore reproductive performance. Complementary to traditional breeding value estimation procedures, genomic selection based on genome-wide information will become more widely applied. Functional genomics, including transcriptomics (gene expression profiling), produces the information to understand the consequences of selection as it helps to unravel physiological mechanisms underlying female fertility traits. Insight into the latter is needed to develop new effective management strategies to combat subfertility. Here, the importance of functional genomics for dairy cow reproduction so far and in the near future is evaluated. Recent gene profiling studies in the field of dairy cow fertility are reviewed and new data are presented on genes that are expressed in the brains of dairy cows and that are involved in dairy cow oestrus (behaviour). Fast-developing new research areas in the field of functional genomics, such as epigenetics, RNA interference, variable copy numbers and nutrigenomics are discussed including their promising future value for dairy cow fertility

Investment Analysis of Alternative Dairy Systems under MILC

Three dairy systems, 120-cow grazing, 120-cow conventional, and 600-cow concentrated, were evaluated by internal rate of return (IRR) accounting for the Milk Income Loss Contract (MILC). With MILC, the grazing and conventional systems had higher IRRs. Without MILC, the 600-cow dairy had the highest IRR. Results were sensitive to assumptions.Concentrated feeding, conventional, grazing, internal rate of return, Livestock Production/Industries,

Nitrogen efficiency of dairy cattle : from protein evaluation to ammonia emission

Diet optimization contributes considerably to increased nitrogen efficiency of dairy cattle, resulting in reduced nitrogen losses. This thesis focuses on three themes: the potential advances in protein evaluation systems for ruminants, the relationship between dairy cow diet and ammonia emission and the opportunities to monitor ammonia emission from dairy cow barns by application of milk urea content as a practical indicator. Overall, the present work shows that farm management can be aimed at increased nitrogen efficiency of dairy cattle and reduced ammonia emission without compromising other sustainability objectives such as the integral ecological footprint, animal health and farm profitability. </p

Adding value to cull cow beef

End of project reportThis project addressed the prospects of increasing the value of cull cow beef and examined the potential of a number of different management and dietary strategies. In Ireland, the national cow herd contributes 350,000 animals to total beef production annually, which represents 22% of all cattle slaughtered (DAF, 2007). A dominant feature of beef production in Ireland is the disposal of cows from the dairy and beef industries, the time of year at which culling occurs influences the number of cows available for slaughter. Suitability of a cow for slaughter is generally not a consideration for dairy or beef farmers

Pregnancy Obstructs Involution Stage II of the Mammary Gland in Cows: General Biological Implications

*Background*&#xd;&#xa;Repeated research findings over the last 4 decades show that involution of mammary glands in dairy cows did not regress to same extend as that noticed in other mammalian species.&#xd;&#xa;&#xd;&#xa;*Methodology/Principal Findings*&#xd;&#xa;We took an advantage of a rare event in the normal modern dairy farming: A cow that was false-positively identified as being pregnant was &#x22;dried up&#x22; (i.e., induced into involution) conventionally about 60 before her expected parturition. This cow was culled, and samples of her mammary gland tissue were examined for gross histology. In this study we demonstrate for the first time that modern dairy cow may undergo extensive obliteration of the lobular-alveolar structure, as expected in involution stage II. &#xd;&#xa;&#xd;&#xa;*Conclusions/Significance*&#xd;&#xa;We conclude that lack of histological evidence for the appearance of involution stage II in the vast majority of modern cow&#x27;s population is related to the peculiar modern dairy husbandry, in which dairy cows are induced into involution still pregnant. Because retardation of involution stage II in pregnant mammals is most likely a general physiological phenomena, it might occurs in other mammals, particularly in lactating humans. Thus, based on basic comparative physiology considerations, we suggest that concurrent lactation and pregnancy should be considered as an independent risk factor for breast cancer

Milk production and survival of spring-calving carryover cows in New Zealand dairy herds : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Manawatu, New Zealand

Non-pregnant cows are generally culled from dairy herds and replaced with two-year-old heifers. Alternatively, non-pregnant cows can be dried-off at the end of lactation, retained for one year (carried over), before being mated and returned to a milking herd in the following year. In this study, calving interval was used as a tool to identify and define the carryover cow population in spring-calving dairy herds. Linear modelling methods were used to compare carryover cow milk production with that of heifers, lactation-matched and age-matched non-carryover cows. Lastly, the survival for second-lactation carryover cows was compared with that of two-year-old heifers and lactation-matched non-carryover cows. Results showed that annually, 2.5% of spring-calving cows had returned to a milking herd after a carryover period in the previous year. Of those carryover cows, 43% returned to a milking herd at four years old, after failing to conceive in their first lactation. Most (69%) dairy herds contained less than 5% carryover cows and 17% of dairy herds comprised of zero carryover cows. The difference between the proportion of Holstein-Friesian in the carryover cow and non-carryover cow group was minimal (2%) but statistically greater (P<0.01) for the carryover cow group. Estimated breeding values (EBVs) for milk traits (milk yield, fat yield, protein yield and somatic cell count) were greater (P<0.01), but fertility EBVs were lower (P<0.01) for the carryover cow group in the year when they failed to conceive, compared to those for the non-carryover cow group. These were reflected in greater (P<0.01) selection indices (Breeding Worth and Production Worth) for carryover cows. After the carryover period, EBVs for milk traits and fertility decreased, and Breeding Worth was lower (P<0.01) for the carryover cow group, compared to the non-carryover cow group. Carryover cow milk yield, fat yield, protein yield and somatic cell score was greater (P<0.01) than those for heifers, lactation-matched and age-matched non-carryover cows in their first carryover year. This milk production advantage was maintained for up to three carryover years, if the carryover cow maintained an annual calving pattern, but at a decreasing rate. The probability of survival (days) was lower (P<0.01) for second-lactation carryover cows when compared to heifers and lactation-matched non-carryover cows. These findings are important for the New Zealand dairy industry as they can aid on-farm culling (removal from the herd) decisions

Brief of requirements of the dairy cow

This report lists the brief of requirements of the dairy cow, based on her needs (also listed). The BoR indicates the actor’s needs with regards to the animal husbandry system. BoR of the main actors are incorporated in the redesign of a dairy husbandry system in the project Cow Powe

Swiss organic dairy farmer survey: Which path for the organic cow in the future?

The survey showed a high interest of the Swiss organic dairy farmers in breeding, suggesting that there is potential to breed an adapted organic dairy cow. However, it is clear that it would be difficult to breed an “organic dairy cow” that would be suitable for all farms. The differences between farms, particularly between mountain areas and valley regions, were notable. As a result, each farm manager has to specify criteria and breeding goals essential for his or her farm and try to pursue and reach these goals with the available services. Existing tools, like the EBI, are widely considered as helpful, but have to be improved with new knowledge, and further possibilities should be developed. The modern dairy cow for the organic sector must have a long productive lifespan, good milk yield and milk protein content, requiring little or no concentrate, and a low somatic cell count. In the future, FiBL will analyse anonymized herd book data of organic dairy farms. This should show whether the figures of the inquiry are confirmed or whether new perceptions become evident. FiBL also plan to discuss the results with representatives of breeding organizations and genetics associations as well as with interested organic dairy breeders, in order to evaluate the need of change and take action if necessary

Natural dairy cow health

guide to keeping your herd healthy with herbs and other natural product

Is automatic milking acceptable in organic dairy farming? Quantification of sustainability indicators

The objective of this research, was to quantify sustainability indicators of organic dairy farms using Automatic Milking Systems (AMS), and a comparative group of organic dairy farms using conventional milking systems (CMS). Milk yield per cow was higher for AMS farms but did not result in higher net return to management. Nitrogen surplus per ha of available land was higher for AMS farms, Animal health was unaffected by AMS use, as also most milk quality aspects; somatic cell count, clostridium spores and urea. Acid degree value (ADV), measured as free fatty acids (FFA) in the milk, was higher in milk from AMS users. Labour time was decreased by almost 50% for AMS users, to 2.3 min/cow/day. It could be concluded from quantification of selected indicators on economy, environment, cow health, milk quality, and labour time, that the organic dairy farms using AMS, in spite of the substantial decrease in grazing time, show potential for a sustainable development