44,723 research outputs found
Slow-release somatotropin reduces plasma leptin in lactating dairy cows
No full textSomatotropin has dramatic effects on adipose tissue and lipid metabolism. Leptin, produced and released primarily by adipose cells, exerts a regulatory control on energy homeostasis. The aims of this study were to determine the effects of bST administration on milk production, plasma leptin and selected plasma metabolites in lactating dairy cows. Forty Holstein cows(90±33 DIM)were randomly divided into 2 groups: Control and bST. The bST group received 640mg/4wk of slow release bST(Posilac) for two cycles. Milk yield and composition were measured at 7 days post-injection of each cycle. Blood samples were collected on the same day before feeding, and analyzed for leptin, NEFA, total protein, α-amino nitrogen, and urea nitrogen. Both milk yield and milk fat percentage were increased(29.9 vs. 35.3 kg/d; P≤.01; 3.59 vs. 3.92%; P≤.05) by bST administration, while milk protein content was unaffected by treatment (3.19 vs. 3.13%. At 7 days post-injection, bST decreased (P<.01) plasma leptin by 33% (4.26 vs. 2.86 μg/l) whereas plasma NEFA was drastically increased (225 vs. 875 μmol/l; P≤.01). Plasma total protein was increased by bST (78.9 vs. 81.4 g/l; P≤.05), while both α-amino nitrogen and urea in plasma of treated cows were reduced (P≤.01) by 20% (2.54 vs. 2.03 mmol/l; 6.55 vs. 5.27 mmol/l, respectively). These data confirmed a galactopoetic effect of bST, which imposed, on peak of response, a higher demand of nutrients sustained by an enhanced lipolysis in adipose tissue. Lower plasma leptin observed in present study could be due to reduced body fat mass as consequence of lipolysis induced by bST. This is in line with higher plasma NEFA concentration observed in bST group. Plasma nitrogen metabolites indicate a higher efficiency in protein metabolism in treated cows. This study show that plasma leptin is linked with the nutritional status of cows, even though other hormones and metabolites are also involved in the signaling and control of body energy store
Leptin in bovine colostrum and milk
No full textWe studied leptin content in bovine colostrum, milk and plasma during the first month of lactation, and investigated relationships between selected milk components and milk leptin in five multiparous dairy cows. Colostrum/milk yield and composition were measured on days 0, 10, 20, and 30 of lactation. Leptin was assayed using a multi-species leptin RIA kit. Leptin concentration was 56 % lower in mature milk (day 10) than colostrum (13.90 vs. 6.14 μg/l; p < 0.001), but remained steady over the twenty days afterwards. Daily secretion of leptin into mature milk was 28 % lower than into colostrum (173.2 μg/d vs. 220.0 μg/d; p = 0.09) notwithstanding an 80 % increase in production. Colostrum and milk leptin levels correlated with fat (0.90; p < 0.001) and choline phospholipid (0.76; p < 0.05). Plasma and milk leptin decreased during the first month, but remained higher in milk, and highest in colostrum. Thus, leptin is present in large quantities in colostrum, less so and more variably in untreated milk, and is likely to be decreased in skimmed milk. These findings have implications for the use of untreated milk and colostrum-based (functional) food products
Growth performance and nutrient balance of pigs fed low protein diets without mineral phosphate supplementation
No full textThe 48 pigs were blocked by gender, body weight (BW), and litter, assigned to 1 of the 4 treatments (C=control, N-=low crude protein (CP) with amino acid (AA) addition, P-=no MP, and N-P-=combination of N- and P-), fed ad libitum, and all housed in one pen. Grower and finisher diets with C contained respectively 15.5% and 13.5% CP, 0.47% and 0.41% P, and 0.29% and 0.26% digestible P (dP), diets with N- contained 10% and 15% less CP, and diets with P- contained 20% and 22% less P, leading to 24% and 21% less dP than C. Diets with N- were optimized to use minimal amounts of imported soybean meal, replaced by Swiss-origin protein beans and rapeseed meal, and synthetic AAs to reach minimal CP but equal digestible AA contents as in C. In P-, phosphate was removed and calcium:dP ratios were fixed as in C by adjusting calcium carbonate.
Individual feed intake and weekly BW were recorded. Average daily feed intake and gain, and feed conversion ratio (FCR) were calculated. Over grower and finisher phases (47±4.0d and 40±8.2d, respectively), nutrient balance data were derived by differences between nutrient intake and body nutrient accretion which was derived from body composition assessment by dual X-ray absorptiometry at the start (22.3±3.35kg BW), middle (≈60kg BW at diet change from grower to finisher), and end (BW≥100kg) of the experiment. Urinary and daily fecal samples were obtained during two 4-d collection periods (40-50kg BW grower and 75-85kg BW finisher).
There were no interactions (P>0.05) between N- and P- effects on any measured parameter. No differences (P>0.10) were observed in growth performance due to N- or P- effects, except finisher pigs with P- had a higher FCR (P<0.05, 2.66 vs 2.60). In grower, finisher, and overall periods, the intake and excretion of N and P were reduced (P<0.01) in pigs fed respectively diets N- and P-, and female pigs had better nutrient utilization rates (P≤0.001) regardless of treatments.
The findings suggest replacing imported soybean meal with local protein sources and AA supplementation while simultaneously reducing CP contents and the MP removal in growing-finishing pig’s diet can maintain animal growth and reduce N and P excretion into the environment
Leptin in bovine plasma, colostrum and milk during the first month of lactation
No full textThe objective of this study was to determine leptin content in bovine colostrum and mature milk during the first month of lactation, and their possible relation with plasma leptin. Five multiparous Holstein dairy cows homogenous for parity and mean production in the previous lactation were used. Colostrum and milk yield and composition were measured on day 0, 10, 20, and 30 of lactation. Blood samples were collected on day 0, 10, and 20 post-calving. Plasma, skim colostrum and skim milk were analysed for leptin content using a commercial multi-species leptin RIA kit. Leptin concentration was 56% lower in mature milk than in colostrum (13.90 vs. 6.14 microg/l; P<.01), while no significant differences were observed during the first month of lactation (5.88, 6.16, 6.38 microg/l on day 10, 20 and 30, respectively). Leptin daily secretion in mature milk was 21% lower than in colostrum (220.0 microg/d vs. 173.2 microg/d; P<.01). Plasma leptin at calving was 2.64 microg/l, decreasing by 18% during post-partum (2.17 microg/l; P<.05). Although, both plasma and milk leptin concentrations showed a similar decreasing time trend during the first month of lactation, colostrum and milk showed a higher leptin level than plasma, suggesting that transfer of leptin from the blood account only partially for its milk content
Intracellular evaluation of ER targeting elucidates a mild form of inherited coagulation deficiency
No full textMissense mutations reduce protein levels through several molecular mechanisms. Among them, altered targeting to endoplasmic reticulum (ER) and its relationship with clinical phenotypes in patients have been poorly investigated. To address this point, we studied the prepeptide mutations (L-48P, L-42P) associated with mild deficiency of factor VII (FVII), the serine-protease triggering blood coagulation. Mutations were introduced into the native FVII to evaluate secreted and intracellular protein levels, and into a chimeric FVII-GFP to study ER targeting in living cells. In conditioned medium from stably or transiently transfected cells, expression levels of the -48PFVII (9% and 55%, respectively) and particularly those of the -42PFVII (2% and 12%) were decreased compared with those of WtFVII, indicating the causative nature of mutations. Markedly reduced protein levels were observed in cell organelles for -48PFVII (10.5 +/- 4.9 ng/mL; Wt-FVII, 130 +/- 43.4 ng/mL) and -42PFVII (approximately 5 ng/mL), thus suggesting impaired ER targeting. Fluorescence of the -48PFVII-GFP and -42PFVII-GFP was diffuse, covered the nucleus, and declined upon plasma membrane permeabilization with digitonin, which demonstrated mislocalization of variants in the cytosol. Noticeably, the residual fluorescence of -48PFVII-GFP (10%) and -42PFVII-GFP (20%) in organelles was fairly compatible with FVII levels in patients' plasma. The studies with the native and chimeric proteins indicated that both prepeptide mutations were associated with residual expression of normal FVII, which explained the mild form of FVII deficiency in patients. This approach, extendable to other coagulation serine proteases, clearly contributed to elucidate the relationship of genotype with plasma and clinical phenotype
Somatotropin and fat administration to lactating dairy buffalo: effects on milk production and plasma leptin
No full textThe aims of this study were to determine the effects of somatotropin (bST) and dietary Fat administration on milk production, plasma leptin, and selected plasma lipid parameters in dairy buffalo. Forty lactating Italian river dairy buffalo in mid to late lactation were randomly divided into 4 groups: Control, Fat (0.3 kg/d of rumen-protected fat), bST (320 mg/3wk of slow release bST for 4 cycles) and bST+Fat. Milk production was measured weekly. Blood samples were collected weekly at 14.00h and plasma analyzed for leptin, NEFA and triglyceride. Somatotropin administration increased (P<.01) milk yield (6.76, 7.55, 9.03, and 8.99 kg/d in control, Fat, bST and bST+Fat respectively), whereas milk composition was unaffected by treatments. Although plasma NEFA was unaffected by treatments, mean plasma leptin (2.33, 2.81, 2.28, 3.32 microg/l; P<.01) and triglyceride (309, 370, 321, 351mmol/l; P<.05) were increased by Fat supplementation. Results herein presented confirmed a galactopoetic effect of bST in lactating dairy buffalo. On the other hand increased plasma leptin level observed in fat supplemented buffalo pcould confirm that, like in other mammals, plasma leptin is related to dietary fat composition and to the nutritional status of the animal
Systematic analysis of choline supplementation in dairy cows
No full textAlthough, the choline requirement of dairy cows is still unknown, higher choline availability (by feeding rumen-protected choline, RPC) can improve milk production, suggesting that this substance may be a limiting nutrient in transition dairy cows. Based on these assumptions, we investigated the effects of rumen protected choline (RPC) administration on milk production and selected plasma metabolites (non-esterified fatty acids and beta-hydroxybutyrate) in 11 and 9 different studies, respectively, carried out between 1991 and 2008. Accordingly, 42 and 28 experimental groups for milk and plasma metabolites respectively, have been considered in the dataset. Mean and standard error data have been used in a regression model in which milk production response to RPC supplementation has been investigated. Dataset analysis indicated that although most of variability among experiments was related to treatments schedule, dry matter intake and dietary composition, these factors were also highly correlated. For this reason, and in order to avoid any redundancy in the model, our regression analysis included only RPC supplementation (control/treated) as fixed effect, while all the other variables have been considered as experimental effects and treated as random components in the mixed model, according to the idea that results of different experiments are affected by different experimental conditions. The data reviewed in this analysis are consistent with the fact that choline supplementation (5<20g/d) significantly (P<.05) increased milk yield in dairy cows. By contrast, effect of choline supplementation on plasma metabolites are inconclusive
Evaluation of phenolic profile and antioxidant activity of cocoa (Theobroma Cacao L.) by-products to explore their potential as animal feed additives
No full textThe research focused on the evaluation of phenolic profile and antioxidant activity of cocoa (Theobroma Cacao L.) by-products to explore their potential as animal feed additive
Effect of seaweed or selenium enriched substrates on live and reproductive performance in BSF
No full textAnalisi economica del comportamento illegale
No full textIl lavoro svolge un ruolo fondamentale nella vita dell’uomo. Non solo ha effetti sul benessere delle persone e influisce sulle loro decisioni di istruzione, utilizzo del tempo libero e pensionamento, ma costituisce anche una risorsa centrale per il successo degli investimenti effettuati dalle imprese. Proprio per questo si configura come un mercato alquanto diverso da quelli in cui vengono scambiati beni e servizi: occorre considerare le disparità di potere contrattuale, la presenza di asimmetrie informative, l’esigenza di intervento pubblico e il ruolo delle istituzioni. Il manuale illustra questa realtà complessa rapportandosi costantemente ai «fatti», da cui l’economia del lavoro non può prescindere, e facendo ricorso a tecniche statistiche per descriverli e per illustrare le relazioni che li caratterizzano.
INDICE DEL VOLUME: Premessa. - Prefazione. - Parte prima: Fondamenti. - I. Offerta di lavoro, di G. Zanella. - II. Domanda di lavoro, di F. Origo e L. Pagani. - III. Equilibrio del mercato del lavoro in concorrenza perfetta, di F. Drago e G. Pica. – IV. Imperfezioni del mercato del lavoro e disoccupazione, di L. Cappellari e A. Rosolia. V. La regolamentazione del mercato del lavoro, di M. Leonardi e G. Pica. – VI. Istruzione e capitale umano, di M. Bratti e D. Checchi. – VII. Selezione e formazione dei lavoratori, di V. Scoppa. – VIII. Sistemi retributivi incentivanti, di M. De Paola e G. Brunello. - Parte seconda: Approfondimenti. - IX. Causalità, di M. Pellizzari. - X. L’uso degli esperimenti randomizzati in economia del lavoro, di M. De Paola e V. Scoppa. – XI. La discriminazione, di L. Flabbi e D. Vuri. – XII. Diseguaglianza e mobilità dei redditi, di L. Cappellari e M. Leonardi. - XIII. Analisi economica del comportamento illegale, di F. Drago, R. Galbiati e P. Pinotti. – XIV. Immigrazione e mercato del lavoro, di T. Frattini. - Indice analitico
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