Using compositional mixed-effects models to evaluate responses to amino acid supplementation in milk replacers for calves

The consequences of supplementing Lys, Met, and Thr in milk replacers (MR) for calves have been widely studied, but scarce information exists about potential roles of other AA (whether essential or not). The effects on growth performance of supplementation of 4 different AA combinations in a mixed ration (25.4% crude protein and 20.3% fat) based on skim milk powder and whey protein concentrate were evaluated in 76 Holstein male calves (3 ± 1.7 d old). The 4 MR were as follows: CTRL with no AA supplementation; PG, supplying additional 0.3% Pro and 0.1% Gly; FY, supplying additional 0.2% Phe and 0.2% Tyr; and KMT, providing additional 0.62% Lys, 0.22% Met, and 0.61% Thr. All calves were fed the same milk allowance program and were weaned at 56 d of study. Concentrate intake was limited to minimize interference of potential differences in solid feed intake among treatments. Animals were weighed weekly, intakes recorded daily, and blood samples obtained at 2, 5, and 7 wk of study to determine serum urea and plasma AA concentrations. Plasma AA concentrations were explored using compositional data analysis, and their isometric log-ratio transformations were used to analyze their potential influence on ADG and serum urea concentration using a linear mixed-effects model. We detected no differences in calf performance and feed intake. Plasma relative concentration of the AA supplemented in the KMT and PG treatments increased in their respective treatments, and, in PG calves, a slight increase in the proportion of plasma Gly, Glu, and branched-chain AA was also observed. The proportions of plasma branched-chain AA, His, and Gln increased, and those of Thr, Arg, Lys, and Glu decreased with calves' age. A specific log-contrast balance formed by Arg, Thr, and Lys was found to be the main driver for lowering serum urea concentrations and increasing calf growth. The use of compositional mixed-effects models identified a cluster formed by the combination of Arg, Thr, and Lys, as a potential AA to optimize calf growth.info:eu-repo/semantics/publishedVersio

Surveying selected European feed and livestock production chains for features enabling the case-specific post-market monitoring of livestock for intake and potential health impacts of animal feeds derived from genetically modified crops

This review, which has been prepared within the frame of the European Union (EU)-funded project MARLON, surveys the organisation and characteristics of specific livestock and feed production chains (conventional, organic, GM-free) within the EU, with an emphasis on controls, regulations, traceability, and common production practices. Furthermore, an overview of the origin of animal feed used in the EU as well as an examination of the use of genetically modified organisms (GMOs) in feed is provided. From the data, it shows that livestock is traceable at the herd or individual level, depending on the species. Husbandry practices can vary widely according to geography and animal species, whilst controls and checks are in place for notifiable diseases and general health symptoms (such as mortality, disease, productive performance). For feeds, it would be possible only to make coarse estimates, at best, for the amount of GM feed ingredients that an animal is exposed to. Labeling requirements are apparently correctly followed. Provided that confounding factors are taken into account, practices such as organic agriculture that explicitly involve the use of non-GM feeds could be used for comparison to those involving the use of GM feed.info:eu-repo/semantics/acceptedVersio

Methods in cattle physiology and behaviour research : Recommendations from the SmartCow consortium

This book provides an inventory of guidelines for different recordings in an experimental unit. The chapters of this book will encompass methods that deal with measuring different metabolic, digestive, anatomic and behavioural traits in cattle. The experimental methods have been divided into two main categories:a) routine measurements, conducted in different research infrastructures, e.g. daily feed or water intake of cattle, heat detection, body condition scoring and back-fat thickness measurement;b) specific recordings, using particular methods, such as: estimating passage rate of digesta, respiratory chamber and/or nitrogen balance experiment.Wherever possible, the authors sought to include the most recently established, innovative and non-intrusive tools/systems for each of the enlisted methods

Air pollution and green spaces in relation to breast cancer risk among pre and postmenopausal women : A mega cohort from Catalonia

Background The association between air pollution and green spaces with breast cancer risk stratified by menopausal status has not been frequently investigated despite its importance given the different impact of risk factors on breast cancer risk depending on menopausal status. Objectives To study the association between air pollution, green spaces and pre and postmenopausal breast cancer risk. Methods We conducted a population-based cohort study using electronic primary care records in Catalonia. We included women aged 17–85 years free of cancer at study entry between 2009 and 2017. Our exposures were particulate matter <2.5 μm (PM2.5) & <10 μm (PM10), nitrogen dioxide (NO2), normalized difference vegetation index (NDVI), and percentage of green spaces estimated at the census tract level. Breast cancer was identified with ICD-10 code C50. We estimated cause-specific hazard ratios (HR) for the relationship between each individual exposure and pre and postmenopausal breast cancer risk, using linear and non-linear models. Results Of the 1,054,180 pre and 744,658 postmenopausal women followed for a median of 10 years, 6,126 and 17,858 developed breast cancer, respectively. Among premenopausal women, only very high levels of PM10 (≥46 μg/m3) were associated with increased cancer risk (compared to lower levels) in non-linear models. Among postmenopausal women, an interquartile range increase in PM2.5 (HR:1.03; 95%CI:1.01–1.04), PM10 (1.03; 1.01–1.05), and NO2 (1.05; 1.02–1.08) were associated with higher cancer risk. NDVI was negatively associated with decreased cancer risk only among postmenopausal women who did not change residence during follow-up (0.84; 0.71–0.99) or who were followed for at least three years (0.82; 0.69–0.98). Discussion Living in areas with high concentrations of PM2.5, PM10, and NO2 increases breast cancer risk in postmenopausal women while long-term exposure to green spaces may decrease this risk. Only very high concentrations of PM10 increase breast cancer risk in premenopausal women