Determining the temperature-humidity index (THI) threshold for the onset of heat stress (HS) can serve as a decision-making tool in HS mitigation management in dairy cows. Although classic thresholds are based on production losses, other physiological and behavioral changes may appear at lower THI. The objective of this observational study was to model the changes of daily rumination time (RT) and milk yield (MY) of lactating dairy cows to identify potential HS thresholds of different indicators. Daily RT and MY were collected from Chinese Holstein cows of 1,007 cow-lactations (532 ± 72.8 min/d RT; 38.0 ± 8.92 kg/d MY [mean ± SD]). Daily mean THI in the barn ranged from 25.6 to 84.8, and HS duration (i.e., h/d when THI was above 68) ranged from 0.0 to 24.0 h/d. Four datasets were used to evaluate differences in parity (primiparous or multiparous), lactation stage for each parity (early, peak, mid, or late lactation at 1 to 40, 41 to 60, 61 to 160, or 161 to 305 DIM, respectively), and production level of multiparous cows (low or high, MY averaging 37.1 or 52.1 kg/d, respectively). The marginal effect of mean, minimum, and maximum THI and HS duration on RT or MY were analyzed using a generalized additive mixed model framework. Pointwise slopes of the fitted means were calculated and used to determine the HS threshold (based on mean THI or HS duration) and, subsequently, the average rate of decrease in RT or MY upon reaching the threshold. The study demonstrates that for most of the cow groups, a significant decrease in RT was detected at a lower mean THI (∼57.2-62.2) than losses in MY (mean THI 64.9 or higher). The same trend was observed when the effect of HS duration was evaluated, wherein it generally took a shorter HS duration to detect the onset of the decrease in RT than in MY. Upon reaching the threshold, cows decreased their RT by 1.98 to 4.67 min/d per unit of mean THI or 0.64 to 3.64 min/d per hour more of HS duration, and their MY by 0.041 to 0.171 kg/d per unit of mean THI or 0.036 to 0.112 kg/d per hour more of HS duration. The onset and the severity of HS responses differed according to cow parity, lactation stage, and production level, with high-producing, multiparous cows in mid lactation being the most susceptible to HS. Therefore, our results suggest that management strategies to mitigate HS should be applied based on the animal's heat tolerance, which should be before the mean THI exceeds 57. More studies may be needed to incorporate intensity, duration, and possibly timing of heat exposure to better understand the daily heat load that the different cow types can tolerate.

Dairy polar lipids have demonstrated anti-inflammatory properties and protective effects on intestinal integrity, potentially mitigating the adverse impacts of weaning in piglets by modulating microbiota composition and intermediary metabolism. This study evaluated a dairy by-product rich in polar lipids on the microbiome and plasma lipid mediators of weaned piglets. A total of 240 male piglets (21 days old; 6.3 ± 0.5 kg) received either a soybean lipid-based diet (SD) or a polar lipid-based diet (PD) from weaning to day 21, followed by a common diet until day 42. Within each diet, animals were provided with one of the three milk replacers (MRs) for the first 7 days: (1) Commercial MR (CO); (2) Polar lipid-based MR (PO); and (3) Soybean lipid-based MR (SO). Fecal and plasma samples were analyzed to assess microbial composition and lipid mediator profiles. Taxonomical distance between diets increased over time, whereas MR type had no effect. The PD diet significantly altered microbiota composition, increasing, for instance, the relative abundance of Firmicutes-belonging genera of the Lachnospiraceae family (Coprococcus, Roseburia), and increasing levels of ethanolamides (e.g., AEA, PEA, SEA, and DPEA). In contrast, the SD diet increased pro-inflammatory lipid mediators (e.g., 13-HODE, 13-KODE) derived from linoleic acid. Polar lipid supplementation in diet, but not in MRs, influenced microbiota diversity and lipid mediator profiles, suggesting a potential long-term impact on immune regulation and metabolism, highlighting their potential to enhance resilience during early-life stress. Future studies should explore these effects under traditional weaning conditions or other stress models.

Background: Polar lipids from dairy are novel sources of energy that may replace other dietary lipids and impact plasma lipidomic profiles in piglets. This study evaluated the impact of feeding diets rich in polar lipids on the plasma lipidome of piglets during the weaning period. Material and Methods: Weaned male piglets (n = 240; 21 days of age; 6.3 ± 0.5 kg of BW) were blocked by initial weight and distributed into 48 pens of five animals each in a complete randomized block design with a 2 × 3 factorial arrangement of treatments as follows: a plant-based diet rich in neutral lipids from soybeans (24 pens; SD) or a polar lipid-rich diet by-product of cheese making (24 pens; PD) from weaning until the 21st day of the nursery phase. Within each diet group, animals received one of three milk replacers (MR; 0.5 L/d/animal) for the first 7 days after weaning: (1) commercial MR containing animal and coconut lipids (CO); (2) polar lipid-based MR (PO); or (3) soybean lipids-based MR (SO). Results: The PD diet group increased the plasma concentrations of sphingolipids, phospholipids, and cholesterol esters, but did not impact the concentrations of glycerolipids (GLs). Both the PO and CO milk replacers increased the plasma concentrations of ceramide, acyl-chain phosphatidyl choline, and cholesterol esters. The plasma concentrations of GLs containing 18-carbon fatty acids such as 18:0, 18:1, 18:2, and 18:3, were higher in SD, whereas GLs containing 16:0 and 20:3 were higher in PD. Conclusions: In summary, the diet lipid type significantly modulated the plasma lipid composition in piglets 7 days after weaning. The dietary inclusion of polar lipids in diets for growing pigs can modulate the plasma lipidomic profile, relative to plant-based diets rich in soybean lipids. Cost may be a major consideration when using these lipids in pig diets. Their health benefits need to be further characterized in other models of stress and inflammation.

Increasing dietary Met, Lys, and His supply without increasing the dietary protein content was reported to partially alleviate the productive and physiological impact of heat stress. Nevertheless, the metabolic pathways involved are yet to be identified. Thus, we aimed to explore the metabolic pathways associated with these positive effects and develop new metabolomics-based hypotheses. Twelve lactating Holstein cows (primiparous, n = 6; multiparous, n = 6; 42.2 ± 10.6 kg/d milk yield; 83 ± 28 days in milk) were enrolled in two 3×3 replicated Latin squares consisting of 14-day treatment periods: heat stress [HS; max. Temperature Humidity Index (THI) 84, 16.8% crude protein (CP), 1,741 g/d metabolizable protein (MP), 108 Lys, 33 Met, and 37 His (g/d)], pair feeding in thermo-neutrality (TN; max. THI 64, same diet as HS), and HS with increased Lys, Met and His supply [HS+AA; max. THI 84; 17.0% CP, 1,730 g/d MP, 179 Lys, 58 Met, and 45 His (g/d)]. Blood plasma and milk were sampled on day 14 for metabolomics profiling. Several amino acids (AA) and derivatives differed between the treatments. Plasma and milk Met, Val, Trp and α-amino adipic acid concentrations were highest in HS+AA (false discovery rate-P (FDR) < 0.05). Moreover, only plasma Lys and milk His were highest in HS+AA (FDR < 0.05). Some phosphatidylcholines (PC) and diglycerides had lower concentrations in HS than TN (FDR < 0.05), while HS+AA had similar concentrations as TN. The pathway enrichment analysis revealed that the AA-related pathways were more significantly affected in multiparous than in primiparous cows. Our results suggest that increased supply of Met stimulated PC synthesis in HS+AA to similar concentrations as in TN. Increased Lys supply likely elevated the oxidation rate of Lys and downregulated the catabolism of other essential AA (EAA) such as Val and Trp, stimulating milk protein synthesis. No clear associations were found related to His availability. In conclusion, partial amelioration of productive and physiological effects of heat stress associated with increased dietary Met and Lys supply were likely explained by stimulated PC synthesis and increased plasma and milk concentrations of other EEA.

International Journal of Dairy TechnologyEarly View Editorial Understanding the causes and consequences of variability in the compositional quality of milk Daniel E. Rico, Corresponding Author Daniel E. Rico [email protected] Search for more papers by this author Daniel E. Rico, Corresponding Author Daniel E. Rico [email protected] Search for more papers by this author First published: 01 April 2024 https://doi.org/10.1111/1471-0307.13087Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Early ViewOnline Version of Record before inclusion in an issue RelatedInformation

The aim of this study was to determine plasma biotin (B8), folate (B9), and vitamin B 12 (B12) concentrations of multiparous dairy cows under heat stress (HS) fed with adequate or high concentrations of vitamin D 3 (VITD) and E (VITE), Ca, and Se. Twelve multiparous Holstein cows were used in a split-plot design. The main plot was: (1) Adequate VITE and Se; (2) High VITE and Se. Within each main plot, cows were assigned to treatments: (1) HS with adequate concentrations of VITD and Ca; (2) HS with high concentrations of VITD and Ca; (3) pair-feeding (PF) with HS in thermoneutrality with adequate concentrations of VITD and Ca in a duplicated 3 × 3 Latin square. There were no treatment effects on plasma B8 and B12. Plasma B9 was lower by 21% for HS with adequate VITD and Ca than PF cows. Results suggested that HS might modify folate status in dairy cows, regardless of treatments.

AbstractTriacylglycerols (TAG) are the primary sources of preformed fatty acids (FA) for lipid synthesis in the mammary gland. However, polyunsaturated FA escaping ruminal biohydrogenation are selectively incorporated into cholesterol esters (CE) and phospholipids (PL). The aim of the current experiment was to study the effects of abomasal infusion of increasing amount of linseed oil (L-oil) on plasma distribution of α-linolenic acid (α-LA) and its transfer efficiency into milk fat. Five rumen-fistulated Holstein cows were randomly distributed in a 5 × 5 Latin square design. Abomasal infusion of L-oil (55.9% α-LA) was performed at the rate of 0, 75, 150, 300, and 600 ml/d. Concentrations of α-LA increased quadratically in TAG, PL, and CE; a less steep slope was observed with an inflexion at an infusion rate of 300 ml L-oil per day. The increase in plasma concentration of α-LA was of a lower magnitude in CE as compared with the other two fractions, resulting in a quadratic decrease in relative proportion of this FA circulating as CE. The transfer efficiency into milk fat increased from 0 to 150 ml L-oil infused, and a plateau was maintained thereafter with greater levels of infusion (quadratic response). This pattern resembles the quadratic response of the relative proportion of α-LA circulating as TAG, and the relative concentration of this FA in TAG. Increasing the postruminal supply of α-LA partly overcame the segregation mechanism of absorbed polyunsaturated FA in different plasma lipid classes. Proportionately more α-LA was then esterified as TAG, at the expense of CE, increasing its efficiency of transfer into milk fat. This mechanism appears to be surpassed in its turn when L-oil infusion was increased over 150 ml/d. Nevertheless, the yield of α-LA in milk fat continued to increase, but at a slower rate at the highest levels of infusion.

Our objective was to study the effect of increasing postruminal supply of linseed oil (L-oil), as a source of cis-9, cis-12, cis-15 18:3, on milk fatty acid profile and to assess the resulting impact on the development of volatile degradation products during the storage of homogenized milk. Five Holstein dairy cows fitted with a rumen cannula were randomly distributed in a 5 × 5 Latin square design. Abomasal infusion of L-oil was performed at the rate of 0, 75, 150, 300, and 600 ml/d during periods of 14 d. The concentration of cis-9, cis-12, cis-15 18:3 in milk fat increased linearly with L-oil dose. Concentrations of primary (conjugated diene and triene hydroperoxides) and secondary oxidation products (1-octen-3-one, propanal, hexanal, trans-2 + cis-3-hexenals, cis-4-heptenal, trans-2, cis-6-nonadienal trans-2, trans-4-nonadienal) increased during 11 d of storage at 4°C of homogenized milk under fluorescent light. The magnitude of the increase (difference between final and initial measurements) was linearly greater for all nine lipid oxidation products evaluated in response to increasing level of infusion. Results of the current experiment have shown that milk enriched in cis-9, cis-12, cis-15 18:3 via postruminal supply of L-oil is highly prone to oxidative degradation. This low oxidative stability, exposed under controlled experimental conditions, would represent a major obstacle to those who aim to market milk enriched in polyunsaturated fatty acids.

A wide range of nutritional and non-nutritional factors influence milk fat synthesis and explain the large variation observed in dairy herds. The capacity of the animal to synthesize milk fat will largely depend on the availability of substrates for lipid synthesis, some of which originate directly from the diet, ruminal fermentation or from adipose tissue stores. The mobilization of non-esterified fatty acids from adipose tissues is important to support the energy demands of milk synthesis and will therefore have an impact on the composition of milk lipids, especially during the early lactation period. Such mobilization is tightly controlled by insulin and catecholamines, and in turn, can be affected indirectly by factors that influence these signals, namely diet composition, lactation stage, genetics, endotoxemia, and inflammation. Environmental factors, such as heat stress, also impact adipose tissue mobilization and milk fat synthesis, mainly through endotoxemia and an immune response-related increase in concentrations of plasma insulin. Indeed, as proposed in the present review, the central role of insulin in the control of lipolysis is key to improving our understanding of how nutritional and non-nutritional factors impact milk fat synthesis. This is particularly the case during early lactation, as well as in situations where mammary lipid synthesis is more dependent on adipose-derived fatty acids.

We compared the potential of dietary lipid supplements of different fatty acid compositions to affect milk performance when early lactation dairy goats were fed a high-concentrate diet. Thirty Alpine goats at 23 ± 5 d in milk were allocated to 1 of 10 blocks according to parity and milk fat concentration. Within each block, goats were randomly assigned to receive, during a period of 41 d, either CONT) a basal diet with a forage to concentrate ratio of 45:55, used as control, or PALM) the basal diet + 2% of a palmitic acid-enriched fat supplement, or FLAX) the basal diet + 7% of extruded flaxseed. Body weight, dry matter intake and milk yield were not different between treatments. As compared with CONT, goats fed PALM and FLAX had a greater milk fat concentration. Moreover, milk fat yield was numerically (but non-significantly) greater with PALM than with CONT. Milk fat from goats receiving PALM had a greater concentration of 16:0 as compared with CONT and FLAX, whereas a greater concentration of cis-9, cis-12, cis-15 18:3 was observed when goats were fed FLAX as compared with CONT and PALM. Under the conditions of the current experiment, dietary fat supplementation had only minor impacts on the yield of major milk constituents, with the exception of a modest increase in fat yield when goats were fed PALM. The impact of a greater concentration of 16:0 in milk fat of goats receiving this feed ingredient on the nutritive value of dairy products remains to be determined.

Context Dairy cows with autumn-calving season in low-input pastoral systems are subjected to challenging conditions as their early lactation falls in autumn and winter when shortages in pasture availability and harsh weather conditions often occur. Aims We aimed to assess the associations between breed (Holstein Friesian (HF) vs Normande (NR)) and stage of lactation on productive and metabolic responses over lactation in a low-input pastoral dairy system. Methods Twenty-seven HF (n = 14) and NR (n = 13) cows were studied. Milk yield was measured fortnightly, and milk composition, milk solid yield, liveweight (LW), body condition score (BCS) and blood plasma energy metabolites were assessed monthly. Key results The greater milk for HF versus NR cows (e.g. 17.4 vs 12.1 ± 1.0 kg/day of milk; P < 0.001) were associated with a lower LW (510 vs 540 ± 10 kg; P = 0.021) and BCS (1.84 vs 2.37 ± 0.10; P = 0.001) at nadir for HF than NR cows. Blood plasma concentrations of non-esterified fatty acids (NEFA) were high for longer in HF versus NR cows (18 vs 8 WRC). Plasma glucose was greater (P = 0.002) and insulin was lower (P = 0.021) for HF versus NR cows at 3 WRC. During mid-lactation, glucose (22 WRC, P = 0.021) and insulin (26 to 34 WRC, P ≤ 0.041) were lower for HF vs. NR cows. Conclusions Because of their lower milk yields, NR cows had a shorter period of body reserves mobilisation, which was associated with an earlier decrease of plasma concentrations of NEFA and greater insulin concentrations at 3 WRC, and then again during mid-lactation when LW and BCS were also greater for NR cows. Implications In constraining pastoral environments, NR cows would redirect fewer nutrients for milk synthesis, leading to lower depletion of body reserves, which could be associated with a better ability to cope with winter challenging conditions. Although HF cows had a greater depletion of body reserves, there was no increase in the incidence of health problems for these cows.

Bovine milk is a significant source of sphingolipids, dietary compounds that can exert anti-inflammatory actions, and which can modulate the host's microbiome. Because sphingolipid synthesis can be modified by diet, we hypothesized that dietary conditions which reduced FFA availability may result in reduced sphingolipid synthesis. Twelve ruminally cannulated cows (120 ± 52 DIM; 35.5 ± 8.9 kg of milk/d; mean ± SD) were randomly assigned to treatment in a crossover design with 21-d periods. Treatments were (1) High starch (HS), (2) Control. The HS diet contained 29% starch, 24% NDF, and 2.8% fatty acids (FA), whereas the Control diet contained 20% starch, 31% NDF, and 2.3% FA. Plasma and milk samples were obtained on d 21 of each period and sphingolipids were quantified using targeted metabolomics. Univariate and multivariate analyses of generalized log-transformed and Pareto-scaled data included ANOVA (fixed effects of treatment) and discriminant analysis. The lipidomics analysis detected 71 sphingolipids across plasma and milk fat, including sphinganines (n = 3), dihydro-ceramides (n = 8), ceramides (Cer; n = 15), sphingomyelins (SM; n = 17), and glycosylated ceramides (n = 28). Followed by Cer, SM were the most abundant sphingolipids detected in milk and plasma, with a preponderance of 16:0-, 23:0-, and 24:0-carbon sidechains. Although no effects of HS diets were observed on plasma sphingolipids, we detected consistent reductions in the concentrations of several milk Cer (e.g., 22:0- and 24:0-Cer) and SM (17:0- and 23:0-SM) in response to HS. Discriminant analysis revealed distinct metabolite separation of HS and Control groups, with several Cer and SM being distinctively predictive of dietary treatment. We conclude that HS diets can reduce the secretion of milk Cer and SM, even in the absence of changes in circulating sphingolipids.

Vitamin B-12 is synthesized by prokaryotes in the rumens of dairy cows-and this has implications in human nutrition since humans rely on consumption of dairy products for vitamin B-12 acquisition. However, the concentration of vitamin B-12 in milk is highly variable, and there is interest in determining what causes vitamin B-12 variability. We collected 92 temporally linked rumen, fecal, blood, and milk sample sets from Holstein cows at various stages of lactation fitted with rumen cannula and attempted to define which bacterial genera correlated well with vitamin B-12 abundance. The level of vitamin B-12 present in each sample was measured, and the bacterial population of each rumen, fecal, and milk sample (n = 263) was analyzed by 16S rRNA-targeted amplicon sequencing of the V4 region. The bacterial populations present in the rumen, small intestine, and milk were highly dissimilar. Combined diet and lactation status had significant effects on the composition of the microbiota in the rumen and in the feces. A high ruminal concentration of vitamin B-12 was correlated with the increased abundance of Prevotella, while a low ruminal concentration of vitamin B-12 was correlated with increased abundance of Bacteroidetes, Ruminiclostridium, and Butyrivibrio. The ultimate concentration of vitamin B-12 is controlled by the complex interaction of several factors, including the composition of the microbiota. Bacterial consumption of vitamin B-12 in the rumen may be more important in determining overall levels than bacterial production. IMPORTANCE In this paper, we examined the microbiome of the bovine rumen, feces, and milk and attempted to understand how the bacterial communities at each site affected the production and movement of vitamin B-12 around the animal's body. It was determined that the composition of the bovine rumen microbiome correlates well with vitamin B-12 concentration, indicating that the rumen microbiota may be a good target for manipulation to improve production of this important vitamin.

Fifty-five Holstein Friesian cows were assigned according to previous milk performance and days-in-milk into control (n = 27) or experimental group (n = 28) on a commercial farm in Czech Republic. Animals were housed in groups including one milking robot in each building. Experimental cows received a partly mixed ration (PMR) with a phytogenic feed additive (PFA) including herbs, spices, essential oils and plant extracts [Digestarom Dairy (3 g/head/day), Biomin Phytogenics GmbH, Germany]. Control cows received PMR without any supplementation during the trial period of 90 d. Both groups received additional concentrates based on wheat, barley, corn and soybean extraction meal according to their milk performance in the milking robots. Feed intake was recorded per group. Feed refusals were evaluated once daily. Milk performance was recorded each time visiting the milking robot, while milk solids were determined 3 times during the trial period. Health status and medical treatments were recorded throughout the trial. Data of daily milk performance were statistically analyzed using the independent t-test (IBM SPSS 21.0). PFA addition in the PMR of dairy cows resulted in a slightly higher dry matter intake (44.23 vs. 43.88 kg/d). The PFA supplemented group produced higher quantities of milk fat (1.27 vs. 1.19 kg/d; P > 0.05), milk protein (1.20 vs. 1.18 kg/d; P > 0.05) and lactose (1.75 vs. 1.67 kg/d; P > 0.05). Animals receiving the PFA showed a significantly higher milk production (35.37 vs. 33.67 kg/d; P < 0.001). Increased daily milk yield and enhanced quantity of milk solids resulted in a superior amount of energy-corrected milk (33.01 vs. 31.89 kg/d; P > 0.05). In conclusion, the tested PFA was able to improve feed intake and milk performance, hence resulting in an increased farm benefit.

Para determinar la actividad de las enzimas tripsina y lipasa pancreatica de cerdos alimentados con harina de pijiguao (Bactris gasipaes H.B.K., HP) y lisina sintetica (LS), se diseno un experimento con 48 cerdos castrados, con peso vivo promedio de 30 ± 0,5 kg, distribuidos al azar en seis diferentes dietas experimentales, con un arreglo factorial 3 x 2, con tres niveles de HP (0, 16 y 32 %), con o sin adicion de 0,27% de LS; con cuatro repeticiones por dieta y dos cerdos por unidad experimental. Se sacrificaron cuatro cerdos por dieta en la tercera y sexta semana, para obtener muestras de pancreas. No se observo efecto de dieta (HPxLS) sobre la actividad de las enzimas, pero si hubo efecto (P<0,05)de la interaccion dieta x semana sobre la actividad de la tripsina y lipasa. No hubo diferencias significativas en la actividad de la tripsina en la tercera semana despues del consumo de las dietas. En la sexta semana todas las dietas, excepto la que contenia 0,27% LS y 16% HP, mostraron menor (P<0,05) actividad de la tripsina que la dieta basal. La actividad de la lipasa pancreatica fue mayor (P<0,05) en los cerdos que consumieron la dieta con 32% HP sin LS en la tercera semana; y en la sexta semana, la actividad fue menor (P<0,05) en los cerdos cuyas dietas contenian 16% HP con y sin la adicion de AbstrAct

Milk fat depression (MFD) caused by intermediates of ruminal biohydrogenation commonly occurs in dairy cattle. The time course of recovery from MFD is important to mechanistic investigation and management of the condition. Nine cows were used in a repeated design, allowing analysis of recovery from diet-induced MFD. A high-fiber, low-oil diet was fed during the control and recovery periods, and a low-fiber, high-oil (LFHO) diet was fed during the induction period. Milk yield was not affected by treatment. Milk fat percentage and yield decreased progressively during induction and were lower by d 3 and 5, respectively. Milk fat concentration and yield increased progressively when cows were fed the recovery diet and were not different from control on d 19 and 15, respectively. Yield of de novo synthesized fatty acids (FA) decreased progressively during the induction period and was lower than that of controls by d 5. A biphasic response was seen for milk fat trans isomers, where trans-11 C18:1 and cis-9,trans-11 conjugated linoleic acid (CLA) were elevated initially and trans-10 C18:1 and trans-10,cis-12 CLA increased progressively during the induction period. A similar biphasic response was seen during recovery from MFD, with trans-10 C18:1 and trans-10,cis-12 rapidly decreasing initially and trans-11 C18:1 and cis-9,trans-11 CLA increasing slightly above control levels during the second phase. Recovery from diet-induced MFD occurs gradually with a short lag when dietary fiber and oil concentrations are corrected. This time course provides a framework to identify factors causing MFD and set expectations during recovery from MFD.

It was designed and implemented an electromechanical system controlled by keyboard for controlling the growth parameters of semiconductor films such as ZnO and ZnSe on glass substrates. The parameters that can be controlled by keyboard are time and sequence of the immersion in the solutions, and the number of cycles. The SILAR system is autonomous, versatile, with control measures such as temperature. Microcontrollers have been used to fit the electromechanical system and stepper motors place the sample holder in the respective solutions, the information of the control parameters is displayed on a display.The results obtained in the growth of semiconductor films indicate that the automated system SILAR has a high performance for obtaining a homogeneous sample with thicknesses controlled by the number of cycles. This system reduces costs, time and gets better control over the parameters used in different applications.

Se diseñó e implementó un sistema electromecánico controlado por teclado que permite controlar los pará-metros de crecimiento de películas semiconductoras tales como ZnO y ZnSe sobre substratos de vidrio. Los parámetros que se pueden controlar vía teclado son tiempo y secuencia de inmersión en las soluciones, ade-más del número de ciclos. El Sistema SILAR es autónomo, versátil y cuenta con medidas de control como la temperatura. Se han empleado microcontroladores que se adaptan al sistema electromecánico y motores paso a paso que ubican los portamuestras en las soluciones respectivas, la información de los parámetros de control es visualizada en un display. Los resultados obtenidos en los crecimientos de las películas semiconductoras indican que el sistema SILAR automatizado posee un alto desempeño que permite obtener muestras homogéneas con espesores que son controlados por medio del número de ciclos. Este sistema permite reducir los costos, el tiempo y obtener un mejor control sobre los parámetros empleados en diferentes aplicaciones.

Para evaluar la hematologia, los metabolitos sanguineos y el peso de organos de cerdos en crecimiento alimentados con harina de pijiguao (HP) y lisina sintetica (LS), se utilizaron 72 cerdos machos castrados, del cruce de las razas Yorkshire x Landrace de 30 ± 0,5 kg. Los cerdos fueron distribuidos en seis tratamientos en un diseno al azar con arreglo factorial 2x3: dos niveles de LS (0 y 0,27%) y tres de HP (0, 25, y 50%), con cuatro replicas por tratamiento y tres cerdos por unidad experimental. El estudio se condujo durante seis semanas y se tomaron muestras sanguineas al inicio, en la tercera y sexta semana. Se evaluaron variables hematologicas: hemoglobina, recuento de eritrocitos y leucocitos, formula leucocitaria, hematocrito, volumen corpuscular medio (VCM) y concentracion de hemoglobina corpuscular media (CHCM). Los metabolitos evaluados fueron, proteinas plasmaticas totales, enzimas alanina aminotransferasa (ALT) y aspartato aminotransferasa (AST), urea, glucosa y fructosamina. Al final del experimento, se sacrificaron 24 cerdos (cuatro por tratamiento) y se pesaron los pulmones, corazon, estomago, pancreas, intestino delgado, intestino grueso, higado, bazo y rinones. La interaccion HPxLS no afecto ninguna de las variables estudiadas. La LS no afecto la hematologia, mientras que la HP (25 y 50%) redujo el recuento de eritrocito (P<0,05), el hematocrito (P<0,05) y la hemoglobina (P=0,09), sin variaciones significativas sobre la VCM, CHCM y el recuento de leucocitos con respecto al grupo sin HP. Las proteinas totales fueron menores en los cerdos alimentados con HP (P<0,01) y la urea disminuyo por efecto de la LS (P<0,05). La AST fue menor (P=0,01) en los cerdos con LS con respecto al grupo sin LS. Los cerdos que consumieron dietas con 25% HP tendieron a presentar (P=0,10) estomagos mas pesados que el grupo de la dieta basal y el que recibio 50% HP (P= 0,06). El bazo resulto menos pesado (P<0,01) en los cerdos alimentados con 25 y 50% HP, que el grupo sin HP. La HP conjuntamente con LS en las dietas de cerdos en crecimiento no ocasionaron efectos negativos sobre la hematologia, los metabolitos sanguineos y el peso de los organos. ( Palabras clave : Cerdo; Bactris gasipaes; lisina; hematologia; metabolitos; peso; organos ) Abstract To evaluate the hematology, blood metabolites, and organ weights in growing pigs fed peach-palm meal (PPM) and synthetic lysine (SL), 72 crossbred (Yorkshire x Landrace) barrows (30±0.5 kg) were used. Pigs were allotted into six treatments in a completely randomized design with a 2 x 3 factorial arrangement, with two levels of SL (0 and 0.27%) and three levels of PPM (0, 25 and 50%), with four replications per treatment and three pigs per experimental unit. The study lasted six weeks and blood samples were collected at the onsent of the assay and at third and sixth weeks. The hematological variables evaluated were hemoglobin, erythrocytes and leukocyte count, total leukocyte count, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC). Blood metabolites evaluated were: total plasma proteins, urea, glucose, fructosamine, alanine aminotransferase (ALT), aspartate aminotransferase (AST). At the end of the trial, 24 pigs were slaughtered (four/treatment) and the lungs, heart, stomach, pancreas, small intestine, liver, spleen, and kidneys were weighed. The PPM x SL interaction did not significantly influence the variables studied. The SL did not affect hematology, while PPM (25 and 50%) significantly decreased erythrocyte count (P<0,05), hematocrit (P<0,05) and hemoglobin (P=0.09), without significant variations in MCV, MCHC, and leukocyte count, when compared to pigs that were fed no PPM. Pigs fed PPM had lower total proteins(P<0.01) and the SL reduced urea (P<0.05). The AST was lower (P=0.01) in pigs fed SL than in pigs without SL. Pigs that consumed 25% PPM tended to have (P=0.10) heavier stomachs than those fed basal diet or 50% PPM (P=0.06). Pigs fed 25 and 50% PPM exhibited the lightest spleens (P<0.01), compared to those without PPM. The PPM together with SL in the diet of growing pigs had no detrimental effects on hematological variables, blood metabolites, and organ weights. ( Key words : Pigs; Bactris gasipaes; lysine; hematology; metabolites; weight; organ)