Genetic factors affecting milk production in a selected Holstein-Friesian herd

"September, 1950."Analyses were made of all normal lactation records (up to the ninth record of each cow) in the Missouri Station Holstein-Friesian herd from its foundation in 1902 to January 1, 1950. There were 314 cows with a total of 933 lactation records. The progeny of 34 herd sires were represented. Within the 34 sire progeny groups are 299 daughters with records and 270 daughter-dam pairs. All lactation records were standardized to a herd test, 305 day, 2x, mature equivalent basis by means of factors derived from the data. A significant upward time trend in production was found. Differences between 5 year periods accounted for 5.5 per cent of the total variance in milk production, 20.4 per cent of the total variance in butterfat production and 38 .8 per cent of the total variance in butterfat percentage. Estimates of the repeatability of contemporary production records were 0.41 for milk production, 0.36 for butterfat production and 0.61 for butterfat percentage. Heritability estimates derived from the intra-sire regression of daughter on dam were found to be: 0.36 for milk production, 0.29 for butterfat production and 0.54 for butterfat percentage. Lifetime average es were used a s the measure of each cow's producing ability but the heritability estimates were expressed on a single record basis. Variation of daughters and dams records was found to be essentially equal. When each cow's lifetime average was expressed as her "most probable producing ability" no increase was observed in the correlation between the records of daughter and dam. The correlation between lifetime average milk and butterfat yield was found to be + 0.89, between milk and butterfat per cent - 0.10 and between butterfat yield and butterfat per cent + 0.35. The corresponding genetic correlations were estimated by two methods: ( a ) by the ratios of appropriate regression coefficients and ( b) by the ratios of genetic covariance to the geometric mean of genetic variance estimates. The estimated genetic correlations by method ( a ) were: + 0.87 between milk and butterfat yield. - 0.52 between milk yield and butterfat per cent, and -0.03 between butterfat yield and butterfat per cent. The three estimates by method ( b) were : + 0.99, - 0.20 and -0.13 respectively. Both the gross and genetic correlations indicate that a slight but real relative decline in butterfat percentage may be expected to accompany increased milk production. The effect of mild inbreeding was analyze d by the intra-sire regression of production on inbreeding. A significant decline of 66 pounds of milk and 2 pounds of butterfat p e r one percent in crease in inbreeding was observed. Th er e was no significant effect on butterfat percentage. The performance of herd sires a s indicated by daughter-dam comparison s is presented for 20 sires having at least 5 daughter-dam pairs. Ten of these sires increased milk production, 15 increased butterfat production, and 13 increased butterfat percentage of their daughters over their corresponding dams. No evidence of nicking was found in a tabulation of sires' daughters according to their maternal grandsires

Synthetic aperture radar and optical remote sensing image fusion for flood monitoring in the Vietnam lower Mekong basin: a prototype application for the Vietnam Open Data Cube

Flood monitoring systems are crucial for flood management and consequence mitigation in flood prone regions. Different remote sensing techniques are increasingly used for this purpose. However, the different approaches suffer various limitations, including cloud and weather effects (optical data), and low spatial resolution and poor colour presentation (synthetic aperture radar data). This study fuses two data types (Landsat and Sentinel-1) to overcome these limitations and produce better quality images for a prototype flood application in the Vietnam Open Data Cube (VODC). Visual and quantitative evaluation of fused image quality revealed improvement in the images compared with the original scenes. Ground-truth data was used to develop the study flood extraction algorithm and we found a good agreement between our results and SERVIR Mekong (a joint initiative by the US agency for International Development (USAID), National Aeronautics and Space Administration (NASA), Myanmar, Thailand, Cambodia, Laos and Vietnam) maps. While the algorithm is run on a personal computer (PC), it has a clear potential to be developed for application on a big data system

The need for country specific composition data on milk

Milk is a food with high nutritional benefits and is therefore considered an important source of food for all age groups. Laben (1963) reported that whole milk provides energy from carbohydrates, essential amino acids, fatty acids, vitamins and minerals in varying amounts, brought about by both environmental and genetic differences. Not only has the economic impact of variation in fat and protein content led to much research on manipulation and alteration of these constituents, but the different amino acid, fatty acid and micronutrient profiles, and their consequent impact on health, have become current topics of debate. Increased knowledge of the impact of feeding on the quality and quantity of milk production has led to more sophisticated diet formulations for cattle (Jenkins & McGuire, 2006). In the 1980s, diets were modified to induce changes in fat percentage, protein and lactose content. Apart from diet, breed and other environmental factors influence the composition of milk. Nutritional composition forms the basis of consumer education, and it is evident that international data for milk cannot be used in all contexts. During this study country specific composition data for milk is compared and the differences discussed. Key words: Milk composition, feeding, breed, milk volume 1