41 research outputs found

    The effects of cow genetic group on the density of raw whole milk

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    peer reviewedThe density of milk is dependent upon various factors including temperature, processing conditions, and animal breed. This study evaluated the effect of different cow genetic groups, Jersey, elite Holstein Friesians (EHF), and national average Holstein Friesians (NAHF) on the compositional and physicochemical properties of milk. Approximately 1,040 representative (morning and evening) milk samples (~115 per month during 9 mo) were collected once every 2 wk. Milk composition was determined with a Bentley Dairyspec instrument. Data were analysed with a mixed linear model that included the fixed effects of sampling month, genetic group, interaction between month and genetic group and the random effects of cow to account for repeated measures on the same animal. Milk density was determined using three different analytical approaches – a portable and a standard desktop density meter and 100 cm3 calibrated glass pycnometers. Milk density was analysed with the same mixed model as for milk composition but including the analytical method as a fixed effect. Jersey cows had the greatest mean for fat content (5.69 ± 0.13%), followed by EHF (4.81 ± 0.16%) and NAHF (4.30 ± 0.15%). Milk density was significantly higher (1.0313 g/cm³ ± 0.00026, P < 0.05) for the milk of Jersey breed when compared to the EHF (1.0304 ± 0.00026 g/cm³) and NAHF (1.0303 ± 0.00024 g/cm³) genetic groups. The results from this study can be used by farmers and dairy processors alike to enhance accuracy when calculating the quantity and value of milk solids depending upon the genetic merit of the animal/herd, and may also improve milk payment systems through relating milk solids content and density

    Fatty Acid Composition and Thermal Properties of Lipid From Milk and Butter From Lactating Holstein Cows Fed a Supplemental Lipid Either High or Low In Palmitic Acid

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    Abstract of paper presented at the 2006 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science

    Feeding High Amounts of Almond Hulls to Lactating Cows

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    The objective of this study was to determine the feasibility of feeding varying amounts of almond hulls to replace mainly corn and soyhulls in diets fed to lactating dairy cows. Four total mixed- rations with increasing percentages of almond hulls were fed to high producing dairy cows to measure the effect on dry matter intake, milk production and composition, rumination time, and digestibility. Overall, this work demonstrated that almond hulls can be fed to lactating dairy cows at up to 20% of their diet to support high levels of production performance

    Supplemental Tables

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    Supplemental Tables for "Feeding high amounts of almond hulls to lactating cows" by K. L. Swanson, H. M. Bill, J. Asmus, J. M. Heguy, and E. J. DePeter

    Carbon and blue water footprints of California sheep production

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    While the environmental impacts of livestock production have been studied for a variety of livestock production systems, information is still lacking for US sheep production. A cradle-to-farm gate life cycle assessment was conducted according to international standards (ISO 14040/44), analyzing the impacts of five different meat sheep production systems in California, and focusing on carbon footprint (carbon dioxide equivalents, CO2sub&gt;22e) and irrigated water usage (MT). This study is the first to look at the carbon footprint of the California sheep industry and to consider both wool and meat production across the diverse sheep production systems within California. This study also explicitly examined the carbon foot-print of hair sheep as compared with wooled sheep production. Data were derived from producer interviews and literature values, and California-specific emission factors were used wherever possible. The carbon footprint of market lamb production ranged from 13.9 to 30.6 kg CO2e/kg market lamb production on a mass basis, 10.4 to 18.1 on an economic basis, and 6.59 to 10.1 on a protein mass basis. Whole-ranch water usage ranged from 2.06 to 44.8 MT/kg market lamb, almost entirely from feed production, and four of five case studies used irrigated pasture for at least part of the year. Enteric methane (CH4) production was the largest single source of emissions for all case studies, averaging 72% of total emissions. Emissions from manure credited to feed or from feed production averaged 22% in total. Sensitivity analysis showed that carbon footprint per kg market lamb increased as ewe replacement rate increased and decreased as lambs born/ewe bred increased. These results provide a proactive benchmark for the previously-unknown environmental impacts of current sheep production systems in California, which could be used to spur research into other US sheep production systems
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