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Níveis de energia metabolizável mantendo a relação lisina digestível: caloria em rações para suínos machos castrados em terminação

Forty barrows from commercial hybrids averaging initial weight of 60.1 ± 1.3 kg were used in a trial to evaluate different ME levels, maintaining the digestible lysine:calorie ratio, on the performance and carcass characteristics. A randomized block experimental design with four treatments, five replicate and two animals per experimental unit was used. The treatments consisted of four ME levels (3,100, 3,230, 3,370, and 3,500 kcal/kg) with 2.41 g of digestible lysine/Mcal of EM ratio. Animals were fed until the end of the experimental period, when the animals reached 95.46 ± 2.89 kg. It was observed linear effect of treatments on feed intake. Feed:gain ratio increased linearly as the ME levels increased. There was no treatment effect on energy efficiency, weight gain, carcass yield, backfat thickness and lean meat yield. It was concluded that increasing ME levels (3,100 to 3,500 kcal/kg, maintaining the dietary digestible lysine:calorie ratio of barrows, increase feed:gain ratio and decrease feed intake with no effect on weight gain and carcass characteristics.

Níveis de lisina digestível em rações, utilizando-se o conceito de proteína ideal, para suínos machos castrados de alto potencial genético dos 15 aos 30 kg

Fourty barrows with high genetic potential for lean gain averaging initial and final body weights of 15.76 + 0.93 kg and 30.23 + 1.56 kg, respectively, were used to evaluate the effect of digestible lysine levels, using the ideal protein concept, on the performance and carcass composition. The treatments were composed of a basal diet containing 19.46% crude protein and 3,280 kcal of ME/kg, that were supplemented with different levels of HCl-L-Lysine, resulting in diets with 0.90, 1.00, 1,10, and 1.20% of digestible lysine. The diets were supplemented with increasing levels of synthetic amino acids, resulting in diets with ratios of methionine + cystine, threonine, tryptophan and valine:lysine constant in 60, 60, 19 e 69%, respectively, based on the true digestibility. No treatment effects on feed intake, concentration of plasma urea and percentages of water, protein and fat in the carcass were observed in this trial. However, significant quadratic effects on weight gain and feed:gain ratio with quadractic maximum and minimum of 1.10 and 1.12% of lysine, respectively, were detected. Intake of digestible lysine increased linearly among treatments. The depositions of protein and fat in the carcass answered quadractily with quadratic maxima at 1.12 and 1.08%, respectively. The level of digestible lysine that provided the best results of performance and carcass characteristics of barrows with high genetic potential from 15 to 30 kg was of 1.12% of true digestible lysine, corresponding to a digestible lysine intake of 12.03 g/day (3.42 g of Lys/Mcal of ME).

Níveis de energia metabolizável em rações para frangos de corte mantidos em ambiente de alta temperatura

Four hundred birds Hubbard linage with average weight of 675g were distributed to completely randomized block design, based in birds he weight, with five treatments and four replications. The experimental diets were constituted of five metabolizable energy levels (2,800, 2,900, 3,000, 3,100 and 3,200 kcal of ME/kg ration) formulated to attend the nutritional requirements, except for metabolizable energy. The increase of energy was obtained by the addition of soybean oil. The variance and regression analysis was made, associating the energy levels with the values of the studied characteristics. The birds were evaluated by performance (feed intake, weight gain and feed: gain ratio) and carcass characteristics in the periods from 22 to 35 days, 36 to 42 days, 43 to 49 days and 22 to 49 days of age, respectively. Weight gain and feed:gain ratio of broilers maintained in high temperature environment were not influenced by metabolizable energy levels of diets. Metabolizable energylevels of the diet did not affect: carcass, thigh, over thigh, wing, tulip, gizzard, heart, liver and proventricle and intestine. However, the abdominal fat increases and breast yield proportionally decrease with the increase of the metabolizable energy levels of the diet in high temperature environment conditions.

Digestible lysine for barrows of genetic lines selected for meat deposition from 60 to 100 days of age

In order to evaluate the effects of dietary digestible lysine levels on performance and carcass traits of two genetic lines of pigs selected for meat deposition, from 60 to 100 days of age, a total of 120 crossbred barrows, with initial average body weight of 25.42 ± 2.08 kg were used. Pigs were allotted in a complete randomized block design, within a 4 × 2 factorial arrangement (four digestible lysine levels: 0.90, 1.00, 1.10, and 1.20%, and two genetic lines: A and B), with five replicates and three pigs per pen, which was the experimental unit. There was no interaction between genetic and digestible lysine levels for any variable of performance and carcass traits assessed. There was also no effect of digestible lysine levels in feed intake, body weight gain, and feed conversion. Digestible lysine intake of pigs increased linearly with increasing digestible lysine levels in the diets. Except for carcass yield that increased quadratically up to 1.04% estimate level of digestible lysine, there was no effect of lysine levels on the other carcass traits assessed (loin and ham yield, and amount of meat in the carcass). The digestible lysine level of 0.90%, corresponding to an estimated daily intake of 19.10 g, meets the requirements of castrated male pigs selected for meat deposition from both genetic lines, from 60 to 100 days of age.

Raspa integral da raiz de mandioca para frangas de um a 42 dias de idade

This research was developed to evaluate the effect of inclusion the levels of integral scraping of cassava roots on performance and carcass characteristic of pullets of Ross strain, in the period from 1 to 42 days. The experimental design was a randomized block with five treatments and four replications, being the experimental unit represented by twenty birds, housed in each box. The treatments consisted of diets containing different levels of inclusion of integral scraping of cassava root (0; 5; 10; 15 and 20%), formulated to attend the nutritional requirements according to each phase of the birds, using four feeding programs. The inclusion of scrapings of cassava root in diets did not affect the weight gain and feasibility of housing of pullets in the period from 1 to 42 days. However, feed intake and feed conversion were affected with inclusion levels scraping cassava root. The scrapings of cassava root can be used in diets of pullets, in the period from 1 to 42 days in levels up to 6.77%, without compromising carcass characteristics and main cuts and edible organs.

Níveis de treonina digestível para suínos machos castrados, de alto potencial genético para deposição de carne, na fase de terminação

An experiment was carried out to determine the effects of digestible threonine levels in ration on the performance and carcass traits of hogs genetically selected for lean deposition at finishing. Seventy barrows averaging an initial weight of 59.00+1.25kg were distributed in a randomized experimental block design with five treatments and seven replicates, being two animals per experimental unit. Initial weight was adopted as a criterion for animal distribution in the treatments, which were the levels of digestible treonine in the diet (0.480; 0.504; 0.528; 0.554; and 0.572%). No effect (P>0.05) was observed among the treatments on daily weight gain, daily feed intake, and feed conversion. Digestible threonine levels did not influence (P>0.05) lean and backfat thickness percentage. It can be concluded that the level of 0.480% of digestible treonine, corresponding to the rate digestible treonine:lysine 60%, supplied the requirments of high potential lean deposition barows from 60 to 95kg.An experiment was carried out to determine the effects of digestible threonine levels in ration on the performance and carcass traits of hogs genetically selected for lean deposition at finishing. Seventy barrows averaging an initial weight of 59.00+1.25kg were distributed in a randomized experimental block design with five treatments and seven replicates, being two animals per experimental unit. Initial weight was adopted as a criterion for animal distribution in the treatments, which were the levels of digestible treonine in the diet (0.480; 0.504; 0.528; 0.554; and 0.572%). No effect (P>0.05) was observed among the treatments on daily weight gain, daily feed intake, and feed conversion. Digestible threonine levels did not influence (P>0.05) lean and backfat thickness percentage. It can be concluded that the level of 0.480% of digestible treonine, corresponding to the rate digestible treonine:lysine 60%, supplied the requirments of high potential lean deposition barows from 60 to 95kg.

Ichthyometry and electrical bioimpedance analysis to estimate the body composition of tambatinga

Body composition analysis is relevant to characterize the nutritional requirements and finishing phase of fish. The aim of this study was to investigate the relationship between ichthyometric (weight, total and standard length, density and yields), bromatological (fat, protein, ash and water content) and bioelectrical-impedance-analysis (BIA) (resistance, reactance, phase angle and composition indexes) variables in the hybrid tambatinga (Colossoma macropomum × Piaractus brachypomus). In a non-fertilized vivarium, 520 juveniles were housed and fed commercial rations. Then, 136 days after hatching (DAH), 15 fish with an average weight of 37.69 g and average total length of 12.96 cm were randomly chosen, anesthetized (eugenol) and subjected to the first of fourteen fortnightly assessments (BIA and biometry). After euthanasia, the following parts were weighed: whole carcass with the head, fillet, and skin (WC); fillet with skin (FS); and the remainder of the carcass with the head (CH). Together, FS and CH were ground and homogenized for the bromatological analyses. Estimates of the body composition and yields of tambatinga, with models including ichthyometric and BIA variables, showed correlation coefficients ranging from 0.81 (for the FS yield) to 1,00 (for the total ash). Similarly, models that included only BIA variables had correlation coefficients ranging from 0.81 (FS and CH yields) to 0.98 (for the total ash). Therefore, in tambatinga, the BIA technique allows the estimation of the yield of the fillet with skin and the body composition (water content, fat, ash, and protein). The best models combine ichthyometric and BIA variables.

Heat negatively affects lactating swine: a meta-analysis

A meta-analysis was carried out to evaluate the effect of heat on the performance of lactating sows and their litters. The database containing information on the effects heat stress has on the productive and reproductive performance of lactating sows was composed by 20 articles published in international journals from 2000 to 2016, totalizing 2222 lactating sows. The duration of lactation was corrected to 21d. In the studies analyzed, the most representative variables were piglet weight at 21 days (kg) and litter weight at 21 days (kg). Daily ambient temperature (T°C) ranged from 15.0° to 32.0 °C. Rectal temperature and respiratory rate were higher in lactating sows maintained in hot conditions compared to those maintained in the thermal comfort range. The nutrient intake by the lactating sows was inversely proportional to the ambient temperature. The piglets weaned of lactating sows were kept in thermal comfort 90.84 heavier percentage point after 21 days of the piglets of lactating sows kept in heat stress environment. Piglet weight gain exhibited a high and negative correlation with ambient temperature. At 1 °C above the thermal comfort range (from 15° to 25°C) leads to a decrease in food intake (kg/d) and milk yield (kg/d), which represents a high and negative correlation with at room temperature, that is, as the ambient temperature increases, there is less consumption of nutrients, resulting in reduced milk production (less mobilization of nutrients to the mammary gland). Increased respiratory rate is an efficient parameter for evaluating the intensity of heat stress in lactating sows.

Desconstruindo um artigo científico

“Pedimos somente um pouco de ordem para proteger do caos.Nada e mais doloroso, mais angustiante do que umpensamento que escapa a si mesmo, ideias que fogem, que desaparecem apenas esbocadas, ja corroidas peloesquecimento ou precipitadas em outras, que tambem nao dominamos [....] Perdemos sem cessar nossas ideias. E porisso que queremos tanto agarrarmo-nos a opinioes prontas.” (Deleuze e Guattari)

Relative bioavailability of l-lysine sulfate is equivalent to that of l-lysine HCl for nursery piglets

Supplementary l-lysine sources include l-lysine HCl and l-lysine sulfate. l-Lysine sulfate contains at least 50% l-Lys and other components as residues from the fermentation process, other amino acids, and other organic and inorganic substances, being an alternative to l-Lys HCl. The aim of this study was to evaluate the relative bioavailability (RBV) of l-Lys sulfate in comparison with l-Lys HCl and its effects on performance, blood parameters, intestinal functionality, and the apparent total tract digestibility in nursery piglets. A total of 168 female piglets (DB90 × PIC337), weaned at 22 d (BW = 6.29 ± 0.41 kg), were distributed in seven dietary treatments and eight replicates, with three pigs per pen. The experimental period of 42 d was divided into two phases (phase 1, days 0-21; phase 2, days 21 to 42). The basal diet (CON) was lysine-deficient formulated to meet 73% of standardized ileal digestible Lys requirements. For the other diets, the CON was supplemented with three levels (80%, 90%, and 100% of standardized ileal digestible Lys requirements) of l-Lys sulfate (70% l-Lys) or l-Lys HCl (79% l-Lys). There were no significant differences (P > 0.05) in the performance and concentrations of plasma urea and creatinine between the l-Lys sources. The RBV of l-Lys sulfate relative to l-Lys HCl was 106%, 119%, and 117% for effects on ADG, G:F, and plasma urea, respectively. Lys deficiency resulted in a greater (P < 0.05) incidence of diarrhea, while pigs supplemented with Lys sulfate or Lys HCl showed greater (P < 0.05) villus height in the jejunum when compared to those receiving the CON. Diets supplemented with l-Lys sulfate had greater (P < 0.05) apparent total tract digestibility of dry matter, gross energy, and crude protein. In conclusion, the RBV of l-Lys sulfate for effects on ADG, G:F, and plasma urea is equivalent to that of l-Lys HCl for nursery piglets.