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The objective of the present study was to evaluate the overall adaptations of liver and mammary tissue to a corn stover (CS) compared to a mixed forage (MF) diet in mid-lactation primiparous dairy cows. Twenty-four primiparous lactating Holstein cows were randomly allocated to 2 groups receiving either an alfalfa forage diet (MF, F:C = 60:40) with Chinese wildrye, alfalfa hay and corn silage as forage source or a corn stover forage diet (CS, F:C = 40:60). A subgroup of cows (n = 5/diet) was used for analysis of liver and mammary transcriptome using a 4 × 44K Bovine Agilent microarray chip. The results of functional annotation analysis showed that in liver CS vs. MF inhibited pathways related to lipid metabolism while induced the activity of the potassium channel. In mammary tissue, fatty acid metabolism was activated in CS vs. MF. In conclusion, the analysis of genes affected by CS vs. MF indicated mammary gland responding to lower level of linoleate from the diet (lower in CS vs. MF) by activating the associated biosynthesis metabolic pathway while the liver adaptively activated potassium transport to compensate for a lower K ingestion.

Arginine, a semi-essential functional amino acid, has been found to promote the synthesis of casein in mammary epithelial cells to some extent. Data from mouse indicated that microRNA (miRNA) are important in regulating the development of mammary gland and milk protein synthesis. Whether there are potential links among arginine, miRNA and casein synthesis in bovine mammary gland is uncertain. The objective of the present work was to detect the effects of arginine supplementation on the expression of miRNA associated with casein synthesis in mammary tissue and mammary epithelial cells (BMEC). The first study with bovine mammary epithelial cells (BMEC) focused on screening for miRNA candidates associated with the regulation of casein production by arginine. The BMEC were cultured with three different media, containing 0, 1.6 and 3.2 mM arginine, for 24 h. The expression of candidate miRNA was evaluated. Subsequently, in an in vivo study, 6 Chinese Holstein dairy cows with similar BW (mean ± SE) (512.0 ± 19.6 kg), parity (3), BCS (4.0) and DIM (190 ± 10.3 d) were randomly assigned to three experimental groups. The experimental cows received an infusion of casein, arginine (casein plus double the concentration of arginine in casein), and alanine (casein plus alanine, i.e., iso-nitrogenous to the arginine group) in a replicated 3 × 3 Latin square design with 22 d for each period (7 d for infusion and 15 d for washout). Mammary gland biopsies were obtained from each cow at the end of each infusion period. Results of the in vitro study showed differences between experimental groups and the control group for the expression of nine miRNA: miR-743a, miR-543, miR-101a, miR-760-3p, miR-1954, miR-712, miR-574-5p, miR-468 and miR-875-3p. The in vivo study showed that arginine infusion promoted milk protein content, casein yield and the expression of CSN1S1 and CSN1S2. Furthermore, the expression of miR-743a, miR-543, miR-101a, miR-760-3p, miR-1954, and miR-712 was also greater in response to arginine injection compared with the control or alanine group. Overall, results both in vivo and in vitro revealed that arginine might partly influence casein yield by altering the expression of 6 miRNAs (miR-743a, miR-543, miR-101a, miR-760-3p, miR-1954, and miR-712).

Objetivo: Evaluar la aplicación de las guías de manejo de diabetes mellitus tipo 2 que han demostrado una reducción de la mortalidad en los pacientes con esta enfermedad en pacientes atendidos en un establecimiento rural en el Carmen, Manabí (Ecuador) durante el periodo mayo a agosto de 2016. Metodología: Se diseñó y aplicó una entrevista estructurada a los pacientes que acudieron a la consulta externa del Hospital Básico El Carmen en el periodo mayo a agosto de 2016. Los elementos destacados de la encuesta estuvieron relacionados con variables sociodemográficas pero sobre todo vinculados con el cumplimiento de las guías de tratamiento de la enfermedad que han demostrado reducción de la mortalidad de la diabetes: abandonar el hábito de fumar, reducción de la tensión arterial, uso de metformina, empleo de estatinas y control glicémico. Resultados: Se observó un cumplimiento promedio de 47% del total de las recomendaciones requeridas para reducir mortalidad en los pacientes con diabetes mellitus. Las recomendaciones que mayor cumplimiento tuvieron fueron no fumar (97,3), el empleo de metformina además de algún otro medicamento antidiabético (82%) y el uso de antihipertensivos (43,3%). Las recomendaciones que obtuvieron la aplicación más baja fueron dieta y actividad física (15,3%) y uso de estatinas (28%). Conclusiones: Se requiere desarrollar esfuerzos para fomentar la aplicación de las recomendaciones que benefician a los pacientes con diabetes mellitus. La aplicación de las recomendaciones observada en esta comunidad rural es similar a la observada en otros estudios. Existen recomendaciones cuya utilidad es muy clara en países anglosajones, pero su relevancia debe analizarse para contextos rurales latinoamericanos. Se necesitan estudios más amplios para poder identificar los factores relacionados con la aplicación de estas recomendaciones.

This review summarises the effects of nutritional factors on fat content, different isomers of trans18:1 and conjugated linoleic acids (CLA) in milk fat from dairy cows and goats. Main dietary factors taken into account are the nature of for- ages and pasture, and supplementation with oil seeds, vegetable or marine oils. The effects of interactions between the nature of forages and lipid supplements in cows or goats are reviewed with particular attention. Lipid supplements could highly increase mean trans-vaccenic acid (TVA) and cis-9, trans-11 CLA content in ruminant milk fat, and interact with the quantity of concentrate in the diet or the type of preserved forage. Vegetable or fish oil supplementation increased milk cis-9, trans-11 CLA up to 4% (in total milk fatty acids (FA)). The content of copper or vitamin E in the diet could modify the milk percentage of TVA and cis-9, trans-11 CLA. Other isomers of trans-18:1 (e.g. trans-10) and CLA (e. g. cis-11, trans-13 or trans-11, trans-13 or trans-7, cis-9 or cis-9, cis-11 CLA) may be manipulated by diet composition. However, further studies are needed to establish their responses to different feeding strategies. The trans-10, cis-12 CLA in percentage in milk fat was always lower than 0.15% of total FA. The proportions of different trans-18:1 isomers in milk fat are similar in caprine and bovine species. Recent studies showed that the CLA content of goat milk fat was sim- ilar to values (0.4 - 0.9% and up to 4% for winter and lipid-supplemented diets, respectively) observed in the cow.

Lipoprotein lipase (LPL) serves as a central factor in hydrolysis of triacylglycerol and uptake of free fatty acids from the plasma. However, there are limited data concerning the action of LPL on the regulation of milk fat synthesis in goat mammary gland. In this investigation, we describe the cloning and sequencing of the LPL gene from Xinong Saanen dairy goat mammary gland, along with a study of its phylogenetic relationships. Sequence analysis showed that goat LPL shares similarities with other species including sheep, bovine, human and mouse. LPL mRNA expression in various tissues determined by RT-qPCR revealed the highest expression in white adipose tissue, with lower expression in heart, lung, spleen, rumen, small intestine, mammary gland, and kidney. Expression was almost undetectable in liver and muscle. The expression profiles of LPL gene in mammary gland at early, peak, mid, late lactation, and the dry period were also measured. Compared with the dry period, LPL mRNA expression was markedly greater at early lactation. However, compared with early lactation, the expression was lower at peak lactation and mid lactation. Despite those differences, LPL mRNA expression was still greater at peak, mid, and late lactation compared with the dry period. Using goat mammary epithelial cells (GMEC), the in vitro knockdown of LPL via shRNA or with Orlistat resulted in a similar degree of down-regulation of LPL (respectively). Furthermore, knockdown of LPL was associated with reduced mRNA expression of SREBF1, FASN, LIPE and PPARG but greater expression of FFAR3. There was no effect on ACACA expression. Orlistat decreased expression of LIPE, FASN, ACACA, and PPARG, and increased FFAR3 and SREBF1 expression. The pattern of LPL expression was similar to the changes in milk fat percentage in lactating goats. Taken together, results suggest that LPL may play a crucial role in fatty acid synthesis. [ABSTRACT FROM AUTHOR]