Eight Jersey cows receiving a 50:50 ratio of forage to concentrate on a DM basis were used in a replicated 4 x 4 Latin square design to determine the effects of added fat (3.4% of dietary DM) and ruminally protected AA (8 g of Met and 24 g of Lys daily) on yield and composition of milk. Treatments were 1) basal control, 2) added fat, 3) added AA, and 4) fat plus AA. Compared with no added fat, fat supplementation increased 4% FCM yield (24.7 vs. 23.0 kg/d) and milk fat yield (1.05 vs. .97 kg), depressed milk protein content (3.58 vs. 3.74%), and altered fatty acid composition of milk. Blood triglyceride and NEFA were elevated (34.4 vs. 29.5 mg/dl and 175.1 vs. 143.7 microeq/L, respectively) by added fat. Supplementation with AA elevated blood Lys, Met, and urea N without increasing milk protein yield. Increase in blood NEFA was further augmented by fat plus AA supplementation, but no changes in concentrations of Lys or Met in blood were found. Addition of AA did not alleviate the depression of milk protein content when supplemental fat was added to the diet for Jersey cows.
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http://dx.doi.org/10.3168/jds.S0022-0302(94)77284-2 | DOI Listing |
J Dairy Sci
January 2025
Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova, Viale dell'Università 16, 35020 Legnaro (PD), Italy.
The quality of bovine colostrum, primarily determined by IgG concentration, is essential for the transfer of passive immunity and the development of the gastrointestinal tract in neonates. High IgG concentration in bovine colostrum (BC) is pivotal for the calf at first meal; however, while neonates often refuse to voluntarily drink the recommended amount of BC in the first hours of life, the dam frequently fails to produce a sufficient volume of colostrum at first milking. This study seeks to estimate the h of colostrum yield (CY) and its genetic correlations with total Ig, IgG, protein, and fat concentrations for the first time in the Italian Holstein population.
View Article and Find Full Text PDFGenes (Basel)
November 2024
Dipartimento di Agraria, Università degli Studi di Sassari, 07100 Sassari, Italy.
Objectives: The aim of this study was to investigate the genomic structure of the cattle breeds selected for meat and milk production and to identify selection signatures between them.
Methods: A total of 391 animals genotyped at 41,258 SNPs and belonging to nine breeds were considered: Angus (N = 62), Charolais (46), Hereford (31), Limousin (44), and Piedmontese (24), clustered in the Meat group, and Brown Swiss (42), Holstein (63), Jersey (49), and Montbéliarde (30), clustered in the Milk group. The population stratification was analyzed by principal component analysis (PCA), whereas selection signatures were identified by univariate (Wright fixation index, F) and multivariate (canonical discriminant analysis, CDA) approaches.
J Dairy Sci
December 2024
Food Chemistry and Technology Department, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland; VistaMilk SFI Research Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland. Electronic address:
This study compared the impact of 2 pasture-based feeding systems, namely a traditional perennial ryegrass (PRG) diet, and a recently introduced, more sustainable multispecies swards (MSS) diet, on the functional lipid profile of raw milk. In addition to the 2 pasture diets, the study uniquely examined the combined effects of breed, namely Holstein-Friesian (HF) or Jersey Holstein-Friesian (JFX), and lactation stage in Ireland, spanning from March to November. Bulk milk samples (n = 144 yearly) for the 4 groups examined were collected for 4 weeks per each of the 9 mo specified.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602; Council on Dairy Cattle Breeding, Bowie, MD 20716.
The US dairy cattle genetic evaluation is currently a multistep process, including multibreed traditional BLUP estimations followed by single-breed SNP effects estimation. Single-step GBLUP (ssGBLUP) combines pedigree and genomic data for all breeds in one analysis. Unknown parent groups (UPG) or metafounders (MF) can be used to address missing pedigree information.
View Article and Find Full Text PDFFood Chem
March 2025
School of Public Health, Lanzhou University, Lanzhou 730000, China; Institute of Animal Husbandry and Veterinary, Xizang Academy of Agricultural and Animal Husbandry Sciences, Lhasa 850000, China. Electronic address:
Ghee, a traditional fermented dairy product and dietary staple for inhabitants of the Tibet Plateau, has unclear lipid profiles and flavor formation mechanisms. This study aims to characterize superior ghee varieties and elucidate factors driving the production of beneficial lipids and flavor compounds. Through a comprehensive analysis of lipidomic profiles, volatile organic compound (VOC) release and microbial dynamics during ghee production from Holstein milk (HM) and Jersey milk (JM), A total of 126 differential lipids were identified, primarily associated with glycerophospholipid and sphingolipid metabolism.
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