The effect of dietary crude protein as protected soybean mean on mammary metabolism in the lactating dairy cow

Metabolism in the mammary gland was related to changes in milk output in response to changes in dietary protein intake. Three diets of grass silage and concentrate were fed to four lactating dairy cows equipped with intravascular catheters across the mammary gland. Concentrates differed in the inclusion of protected soybean meal and provided 11.3, 15.4, and 20.1% CP, respectively. Blood samples were taken to assess the effect of protein percentage on the nutrient fluxes across the gland and their relationship to milk production. Milk production, milk protein yield, and milk protein concentration were all increased as CP intake increased, although these responses were not linear. Concentrations of urea in milk reflected those in plasma and increased as dietary protein intake increased. Uptake of glucose and BHBA by the mammary gland tended to increase as milk production increased. Arterial supply of essential AA increased as the dietary protein increased. Supply and uptake of nonessential AA were unchanged by dietary treatment, and uptake was insufficient to account for output of nonessential AA residues in milk protein. The supply of essential AA was not limiting for milk protein synthesis, and some alternative mechanism must have existed for the control of milk protein yield

Towards progressive regulatory approaches for agricultural applications of animal biotechnology.

Traditional breeding techniques, applied incrementally over thousands of years, have yielded huge benefits in the characteristics of agricultural animals. This is a result of significant, measurable changes to the genomes of those animal species and breeds. Genome editing techniques may now be applied to achieve targeted DNA sequence alterations, with the potential to affect traits of interest to production of agricultural animals in just one generation. New opportunities arise to improve characteristics difficult to achieve or not amenable to traditional breeding, including disease resistance, and traits that can improve animal welfare, reduce environmental impact, or mitigate impacts of climate change. Countries and supranational institutions are in the process of defining regulatory approaches for genome edited animals and can benefit from sharing approaches and experiences to institute progressive policies in which regulatory oversight is scaled to the particular level of risk involved. To facilitate information sharing and discussion on animal biotechnology, an international community of researchers, developers, breeders, regulators, and communicators recently held a series of seven virtual workshop sessions on applications of biotechnology for animal agriculture, food and environmental safety assessment, regulatory approaches, and market and consumer acceptance. In this report, we summarize the topics presented in the workshop sessions, as well as discussions coming out of the breakout sessions. This is framed within the context of past and recent scientific and regulatory developments. This is a pivotal moment for determination of regulatory approaches and establishment of trust across the innovation through-chain, from researchers, developers, regulators, breeders, farmers through to consumers

Peptide Utilisation by the Mammary Gland of Lactating Goats

Most considerations of protein digestion assume that amino acids are made available to the body tissues as the free form but recent reports suggest that a substantial portion may be absorbed from the stomach region of ruminants as small peptides (1). However, the quantitative relevance of this absorption to amino acid supply to tissues remains unclear. We have previously indicated that in early lactation at least part of the amino acid supply to the lactating mammary gland may be met from blood derived peptides or small proteins (2) but at present there is no direct evidence to suggest that peptides can contribute amino acids to the gland for milk protein synthesis. However, it has been demonstrated in dairy animals that the uptake of certain amino acids across the mammary gland is insufficient to account for their output in milk protein (J.A. Metcalf, unpublished observation) and the possible utilisation of amino acids in ‘non-free’ form must be considered. The present study involves the use of a dual-labelled tracer approach to evaluate the ability of the mammary gland to utilise amino acids in peptide-bound form for milk protein synthesis. The technique involves infusion into the external pudic artery (EPA) supplying one half of die gland of a dipeptide XY where Y is a [13C]-labelled amino acid, coupled with a simultaneous (jugular) infusion of the amino acid Y but with a deuterium label. The jugular infusion allows a correction for recycled amino acid generated by whole animal (i.e. non-mammary) hydrolysis of the infused peptide. In theory if the half of the gland receiving direct infusion of the dipeptide utilises peptide-bound Y for milk protein synthesis then the ratio of [13C] : deuterium should be greater in casein secreted from that half of the gland compared with the other (control) side of the gland.</jats:p

Reviews in Aquaculture

Foreign Agricultural Service of the U.S. Department of Agriculture; U.S. Department of AgriculturePublished versionThe work of author Eric M. Hallerman in this area is supported by a grant from the Foreign Agricultural Service of the U.S. Department of Agriculture. The work of author Diane Wray-Cahe is supported by the U.S. Department of Agriculture.Public domain – authored by a U.S. government employe