Feed Protein Level Research Articles

Functional Characteristics of Extruded Blends of Potato Flakes and Whey Protein Isolate

The purpose of the present study was to explore the effects of feed moisture and the addition of whey protein isolate on some physicochemical properties of the obtained extrudates from potato flakes. Extrudates were produced using a laboratory single-screw extruder. Conditions during extrusion were: screw speed - 200 rpm; compression ratio - 3:1; extruders temperature zones - 120, 150, 160 °C; diameter of the nozzle - 5 mm. With increasing of feed moisture content and protein level, there was a significant rise of density as well as lowering of expansion of extrudates. As the feed moisture content increased from 13 to 20 percent w.w. the water absorption index (WAI) increased and the water solubility index (WSI) decreased. The feed protein level increased the protein content and decreased WAI. A maximum of WSI was observed at feed moisture content 20 percent w.w. and protein level 18 percent w.w. The extrusion and the protein addition do not affect the equilibrium moisture of the potato flakes extrudates.

Microscopic identification and PCR based assay in feed analysis

which 20% is manufactured compound feed (Brookes, 2001). This production level imposes an adequate high quality standards especially with regard to the EU Commission’s ban on the use of processed animal proteins. From this point of view a complete separation of plants dedicated to feed production from plants processing raw material, stretcher rules for traceability of animal by-products, as well as feed analysis and feed inspection of raw material or compound feed, are all critical points in food safety. In a previous study (Pinotti et al., 2002) it was suggested that higher protein level in compound feed could be a risk factor for low level cross contamination with meat and bone meal. This could be associated with the same route followed by protein sources, in the feed processing/manufacturing (collection, transport, milling, etc)

Effects of dietary protein level in the early fattening period on free amino acids and dipeptides in the blood and Longissimus thoracis muscle in Japanese Black steers

The effects of crude protein (CP) concentration in feed using soybean meal as its source in the early fattening period on the levels of free amino acids (FAAs) and dipeptides in the blood, and the levels in the M. longissimus thoracis after slaughter were studied in Japanese Black steers. Sixteen steers were divided into four groups and given feed with a CP content of 12, 14, 16, or 18% of dry matter (DM) from 10 to 20 months old, and they were fed with the same level of CP (13.5-13.9% of DM) until slaughter at 30 months of age. There was no significant difference in the weight gain, carcass weight or marbling score between the groups. Concerning the serum FAA and dipeptide contents at 20 months of age, the alanine, tyrosine and tryptophan levels decreased, while the carnosine (Car) level increased, with increases in the CP level in the feed. Although there were no significant differences in the FAA contents of the Longissimus thoracis muscle between the groups, the Car content decreased with increases in the feed protein level.

Effects of dietary protein content and feeding level on carcass characteristics and organ weights of Iberian pigs growing between 50 and 100 kg live weight

AbstractThe effects of dietary protein content and level of feeding on carcass characteristics and organ weights were studied in castrated male Iberian pigs growing from 50 to 100 kg live weight (LW). Animals were offered four diets providing 145, 120, 95 and 70 g ideal crude protein (CP) per kg dry matter (DM) and 13·94, 14·29, 14·56 and 14·83 MJ metabolizable energy (ME) per kg DM, respectively. Three levels of feeding were assayed: 0·60, 0·80 and 0·95 of ad libitum intake. The pigs were slaughtered at 100 kg LW. Daily gain in carcass (carcass gain, g/day) and protein deposition (PD, g/day) in this component attained 76·2% and 78·8% of whole-body average daily gain and PD, respectively. Carcass gain improved with each decrease in dietary CP from 145 up to 120 g/kg DM and then levelled off. A small but significant effect of dietary CP on carcass composition was observed, due to an enhanced fat deposition in pigs fed the lowest protein content diet. Mean values of protein, fat, ash and water contents in the carcass were 101·8, 522·7, 27·6 and 353·7 g/kg respectively. PD in the eviscerated carcass was not affected significantly by dietary protein level but tended to reach a maximum value with the diet that provided 95 g CP per kg DM: 55·7 g/day at the highest feeding level assayed. Carcass energy retention (MJ/day) increased significantly (P<0·001) with decreasing dietary protein supply and on increasing level of feeding. Raising feed intake resulted in a significant decrease for carcass and a concomitant increase for viscera, as proportions of empty body weight (P<0·05 andP<0·001, respectively). Proportional weights of shoulder and ham were not affected either by dietary CP content or feeding level. Proportionate weights of dissectable fat in the shoulder and intermuscular and subcutaneous fat in the ham were not affected by CP content of the diet. In contrast, intermuscular fat content of ham was increased by feeding level (P<0·05), likely with implications for the quality of the cured meat product.

Short communication. Lactation performance of Duroc gilts under the single farrowing production system

Twelve Duroc gilts were used in order to study production and composition of milk during the lactation period and the litter performance under the single farrowing production system. Estrus was induced using PG-600 (400 IU of pregnant mare serum gonadotrophin + 200 IU of human corionic gonadotrophin) and the females were artificially inseminated at 171 +/- 6 d and 95.1 +/- 5.6 kg live weight. Daily milk production was determined according to the weigh-suckle-weigh technique at 1, 7, 14 and 21 d of lactation and colostrum and mature milk samples were collected at farrowing and on 8, 15 and 22 d of lactation. The sows net gain during pregnancy was of 49.1 +/- 7.1 kg and during lactation their feed intake was of 3.4 +/- 0.3 kg dE–1 and their weight loss was 5.83 +/- 2.5 kg. The production of milk increased in a linear way through the lactation period and the average daily production was very low (4.29 +/- 0.7 kg). The contents of colostrum dry matter, gross energy and proteinwere higher than the mature milk but lower regarding fat and lactose. Dry matter, gross energy, protein and lactose contents in milk did not significantly vary during lactation. Nevertheless, an increase in fat content was found in the eighth day of lactation. The average daily gain in piglets was 130.4 +/- 31.5 g and the milk conversion ratio was 3.47 +/- 0.39 kg kgE–1. The protein level in lactation feed did not have a significant influence on sows and piglets performances.

The Transfer of Zinc in Two Linked Trophic Levels in Fresh Water and Its Effect on the Reproduction of Daphnia magna

ABSTRACT The green algae, Pseudokirchneriella subcapitata, was cultured in five different Zn concentrations (0, 50, 100, 500, and 1000 nM) for 4 d. Accumulation and toxicity of Zn in the algae increased with increasing Zn concentration, and highest and lowest algal growth rates occurred in medium containing 50 nM and 1000 nM Zn, respectively. There was a negative relationship (r = −0.89, P<0.05) between Zn accumulation and algal growth. Diets prepared from these cultures were fed to Daphnia magma up to 7 d to investigate the Zn transfer between the two trophic levels. Feeding rate, growth, protein levels, and offspring production of the clad- were investigated. Adult D. magma accumulated Zn from algae, and there was a significant positive relationship (r = 0.64, P = 0.01) between Zn in algae and Zn in D. magna. Accumulated Zn was depurated rapidly from D. magna during a 7 d elimination period. Carapace lengths of animals were not significantly altered by dietary Zn exposures (P>0.05). Likewise, the amount of algae consumed by the animals was not significantly affected by dietary Zn exposures. However, numbers of offspring produced were significantly (P<0.01) affected by different feeding regimes. Dietary Zn had a stimulating effect on the juvenile production. Dietary Zn also had a significant (P<0.01) influence on total protein levels of individual animals. Zn and protein levels showed a positive relationship (r = 0.78, P<0.01).

Evaluation of the effect of dietary crude protein reduction, with or without fishmeal, on post weaning performance

The post-weaning phase is a critical period in pig growth. The transition from sow milk to solid plant or animal proteins together with the physiological development of the intestinal tract can sometimes lead to digestive disorders depressing growth and impacting upon the lifetime performance of the pig herd. Lowering feed protein level or changing the type of protein offered appears as a practical solution to decrease the incidence and severity of digestive disorders leading to diarrhoea. It is crucial that in reducing crude protein levels that the balance of amino acids are maintained to meet the pigs requirement for growth. Fishmeal is often used in diets as a source of protein and amino acids. It also is said to be an aid to palatability. The objective of this experiment was to evaluate the performance of post-weaned piglets offered diets that differed in crude protein content and in protein source from weaning until 43 days post-weaning.

Influence of Creep Feeding and Protein Level on Growth and Maternal Performance of Replacement Beef Heifers

Crossbred Simmental cows (n = 102) nursing heifer calves at two farms (36 pairs grazed mixed cool-season grasses; 66 pairs grazed endophyte infected tall fescue pasture) were randomly assigned to three treatments to determine the effects of creep feed and creep feed protein level on growth, reproduction, and first lactation performance of replacement heifers. Treatments were no creep, 14% CP creep, and 18% CP creep. Creep feeds were offered ad libitum for 84 d prior to weaning. Pasture replicate served as the experimental unit for pre-weaning performance, and postweaning growth, reproduction, and maternal performance utilized individual animal as the experimental unit. Creep feeding and additional dietary protein in creep feed improved (P≤0.05) ADG of nursing calves on pasture. Creep feeding resulted in heavier weight, fatter (P≤0.05) heifers at breeding, but creep CP level did not affect (P>0.05) breeding composition. Body weight at pregnancy determination and postcalving were not different (P≥0.05) because of treatments. Pre-weaning treatment did not influence (P≥0.05) pregnancy, weaning, and calving rates. Noncreep-fed heifers produced more (P≤0.01) milk during the first lactation than creep-fed replacements. High protein creep tended (P≤0.10) to improve milk production during the first 2 mo of lactation. Nonetheless, total milk production was not different (P≥0.05) because of creep CP level. Creep feeding improves pre-weaning growth and depresses first lactation milk production; however, providing additional dietary CP in creep feeds may improve lactation performance during the first 2 mo.

Effects of dietary protein content and food intake on carcass characteristics and organ weights of growing Iberian pigs

AbstractThe effects of dietary protein content and level of feeding on carcass characteristics and organs weight were evaluated in 72 male castrated Iberian pigs growing from 15 to 50 kg live weight. Animals were offered six diets providing 223, 192, 175, 156, 129 and 101 g crude ideal protein (CP) (N × 6·25) per kg dry matter (DM) and 14·64, 14·14, 14·37, 14·80, 15·36 and 15·53 MJ metabolizable energy (ME) per kg DM, respectively. Each diet was offered at three levels of feeding : 0·60, 0·80 and 0·95 × ad libitum intake. Mean values of protein, fat, ash and water contents in the carcass determined at 50 kg live weight were 130, 378, 28·2 and 458 g/kg, respectively, with a small but significant effect of CP content of the diet on carcass composition (P &lt;0·001 to P &lt;0·01) favouring both protein and fat content on decreasing dietary protein level. Protein deposition (PD) in the eviscerated carcass reached a maximum value when the diet containing 129 g CP per kg DM was offered (54·6 g/day at the highest feeding level). Nitrogen (N) retention in the carcass represented 70·9% of whole-body N retention and the efficiency of this process (carcass N retention : N intake) increased with declining dietary protein content (P &lt;0·001). Carcass energy retention increased significantly with decreasing dietary CP content (P &lt;0·001) and with feeding level (P &lt;0·001). Raising energy intake resulted in a significant increase on total weight of viscera as proportion of empty body weight (P &lt;0·001). Decreasing the CP content in the diet resulted in a lower proportional shoulder weight (P &lt;0·01) meanwhile the proportion of ham decreased significantly (P &lt;0·05) with increase in feeding level. The proportionate weights of dissectable fat in the shoulder and of intermuscular and subcutaneous fat in the ham increased significantly (P &lt;0·05 and P &lt;0·001) in response to decreasing dietary CP content meanwhile only ham intermuscular fat content increased with feeding level (P &lt;0·001). Thus, decreasing dietary protein concentration from well in excess of requirements and increasing energy intake enhance N and fat retention in the carcass but also increases intermuscular fat content in the ham of the Iberian pig with possible implications for meat quality.

Ways to reduce nitrogen pollution from Swedish pork production

The aim of this paper is to examine measures in Swedish pork production to improve N-use efficiency and to reduce N-pollution of water and air. The entire chain of feed production, animal feed conversion and the use of animal manure is included, as well as the spatial allocation of pork production. A calculation model is developed using experimental data. It is simple and possible to use in practical environmental control. Using catch crops and halving N-input in feed grain production reduces N-leaching up to 25% per hectare. These measures have considerably less effect on leaching per kilo of produced animal growth and NH3-losses than on leaching per hectare. Reduced protein level in feed and Specific Pathogen Free pig production reduce both leaching and volatilisation, especially per kilo of animal growth. These animal-centred measures can also be profitable for many producers. Spreading all manure in spring and rapid incorporation is an effective way to reduce N-losses. However, as with catch crops and reduced fertilization, it is associated with considerable costs for the producers. A combination of best manure handling, catch crops and low protein feeding can reduce N-leaching and volatilisation up to 50%. Leaching from pig production on clay soil in Central Sweden is only one third of that on sandy soil in southwest Sweden. Spatial allocation of pork production also influences the environmental effects of N losses. These effects can be more negative in coastal zones with high N-deposition and low N-retention before the water reaches the sea, than in interior regions of Sweden with low original deposition. The results indicate that improved animal protein conversion, and especially suitable spatial allocation of pig production, are more cost-effective than additional measures in feed production and manure handling.

The effects of variation in feed protein level on the culture of white shrimp, Litopenaeus vannamei (Boone) in low-water exchange experimental ponds

The present study was conducted to evaluate the effect of varying dietary protein level on pond water quality and production parameters of white shrimp Litopenaeus vannamei (Boone). Experimental units consisted of nine 400-m2 earthen ponds with a low water exchange. Two treatments were tested: treatment HP consisted of shrimp fed a high-protein diet (40%) during the whole grow-out, and treatment LP consisted of the use of a low-protein diet for the complete farming period. No differences on any of the water quality parameters were observed among treatments. Excellent survival (over 85%) and feed conversion ratios (around 1.6), and acceptable growth (over 12 g) and biomass (from 1721 to 1793 kg ha−1) were recorded in all experimental ponds. No significant differences in any of the production parameters were found among treatment groups.

Simulation of inorganic nitrogen dynamics and shrimp survival in an intensive shrimp culture system

Nitrogenous wastes are major concerns in shrimp production and as a component of total farm wastes that impact the aquatic environment. This study describes a simulation model of the role of heterotrophic and nitrifying bacteria on nitrogen dynamics in intensive Litopenaeus vannamei (Boone) culture systems using different feeds and feeding strategies. The model represents: (i) use and remineralization by heterotrophic bacteria of nitrogen wastes and ammonia excreted by shrimp; and (ii) nitrification. The model was quantified using published and unpublished information. The model is multivariate, deterministic and uses a compartment model structure based on difference equations. Evaluation of the model consisted of simulating two indoor and one outdoor experiment that examined the effects of different feeds and feeding levels on nitrogen dynamics. In summary, the model is capable of qualitatively following inorganic nitrogen dynamics. Simulations investigating the effect of heterotrophic remineralization on total inorganic nitrogen suggested that this process may contribute up to 97% of the inorganic nitrogen in the system. This indicates that strategies to increase production, such as increases in feed protein levels or feeding rates, should be carefully evaluated before they are implemented. Future studies need to address bacterial community role in these systems and inorganic nitrogen toxicity mechanisms.

Growth and body composition of juvenile largemouth bassMicropterus salmoidesin response to dietary protein and energy levels

To determine the dietary protein and energy requirements of juvenile largemouth bass, 1350 feed-conditioned fishes (average weight 14.46 ± 0.81 g) were stocked in ninety 60-L cages, set up in 1000-L tanks at three cages/tank, and fed for 64 days with a dry, extruded feed containing six levels of crude protein (CP) (340–540 g kg–1, with increases of 40 g kg–1) and five levels of energy (150.7–171.7 kJ g–1 feed, with increases of 5.2 kJ). The trial was set up in a 6 × 5 factorial, completely randomized design (n=3). Weight gain (WG), daily feed consumption (DFC), feed conversion rate (FCR), protein efficiency ratio (PER), specific growth rate (SGR), protein and energy retention were recorded and evaluated. There was no interaction between feed energy and protein levels with all parameters evaluated. Data analysis by the broken line method showed that the minimum dietary requirement for maximum daily weight gain of 8.0 g kg–1 is 435.9 g kg–1 CP; the best feed conversion ratio (1.04:1) was attained with a minimum of 448.2 g kg–1 CP; a minimum of 162.1 kJ g–1; DFC was reduced as dietary protein and energy levels increased; dietary levels of 460–500 g kg–1 CP led to best PER (1.665); best values for protein (33.14 g 100 g–1) and energy (26.87 g 100 g–1) retention were observed for fish feeding on the 420 g kg–1 CP ration. Limits of energy to protein ratio to feed largemouth bass are 25.01 and 26.89 mg protein kJ–1, enabling feed conversion ratios of 0.96–1.10.

Uso de Saccharomyces cerevisiae y monensina sódica en raciones con distinto nivel de proteína para vaquillas holstein

Zaragoza HC, Ayala OJ, Mendoza MGD. Tec Pecu Mex 2001,39(3)207-214. It has been reported that ionophores and yeast culture can modify duodenal amino acid flow, therefore those additives were included in heifers rations with three levels of protein. Twenty seven Holstein heifers were individually fed (189 kg body weight), 10 months of age according to a completely randomized design with a 3 x 3 factorial arrangement, protein levels (12, 14 and 16 % CP), and additives (none, 10 g/ d of Saccharomyces cerevisiae, and 30 ppm monensin). There was no interaction among protein level and feed additive. Feed additives did not affect dry matter intake, daily gain, feed conversion or body condition. Dry matter intake was reduced with the medium protein level, however, no differences were observed in the rest of the variables. Estimation of metabolizable lysine and methionine indicated that requirements were met. Lack of interaction between feed additives and protein level indicates that amino acid flow was not altered. Heifers can be fed with rations with 12 % CP if requirements of metabolizable amino acids are met.

Retenção de proteína e energia em juvenis de "black bass" Micropterus salmoides

O objetivo deste trabalho foi avaliar alterações nas formas de reserva de energia na carcaça de juvenis de "black bass" (14,46 ± 0,81 g de peso vivo). Peixes condicionados a aceitar alimento artificial foram estocados em 90 gaiolas de volume 60 L alojadas em caixas de 1.000 L em laboratório com condições ambientais controladas, e alimentados por 64 dias com rações extrusadas com níveis de proteína variando entre 34 e 54% (incrementos de 4%) e teores de energia digestível variando de 3.600 a 4.100 kcal kg-1 de alimento (incrementos de 125 kcal kg-1). Foram analisados as variáveis de ganho de peso, consumo alimentar diário, relação hepato-somática, relação víscero-somática, deposição protéica e energética, glicogênio tecidual hepático e lipídio visceral. Não houve interação (P &gt; 0,05) entre níveis de proteína e energia para os parâmetros avaliados. Os níveis de proteína e energia digestível dietética que garantiram melhor desempenho foram 42% e 3.850 kcal kg-1, respectivamente. Dietas com teores médios de 42% de proteína bruta, induziram um alto acúmulo de glicogênio hepático (P &lt; 0,0442), assim como aumento da relação hepato-somática (P &lt; 0,0001), mostrando alta eficiência no acúmulo de energia prontamente utilizável bem como melhor capacidade de retenção dos nutrientes, quando os níveis de carboidratos foram inferiores a 30% na ração. O aumento dos níveis de energia das dietas, através da inclusão de óleo nas rações, induziu aumentos significativos no acúmulo total de lipídios na carcaça quando as médias eram agrupadas por níveis de energia, e induziu acúmulo de lipídios nas vísceras para os agrupamentos de médias tanto por teor de proteína (P &lt; 0,0001) como de energia dietética (P &lt; 0,0021).

Effect of stocking density, protein level and frequency of feeding on survival, growth and production of Tilapia monosex in ponds

Effect of stocking density, protein level and frequency of feeding on survival, growth and production of Tilapia monosex in ponds

Effect of Dietary Protein Content, Litter and Drinker Type on Ammonia Emission from Broiler Houses

Using a dynamic chamber technique and passive diffusion samplers, NHr3 emissions were measured individually from 24 pens in an experimental broiler house with a total of about 3600 broiler chickens on litter. Two multi-factorial experiments were conducted in which the influence of litter, drinker type and diets was investigated. There was no difference in NHr3 emission related to litter type or amount used. Litter dry matter content was higher and N losses lower in pens with nipple drinkers than in pens with bell drinkers. An increase in feed protein level significantly increased litter N content, NHr3 emission rate, and total N loss.

The effect of dietary protein level on growth, protein utilization and body composition ofColossoma macropomum(Cuvier)

Three size groups of Colossoma macropomum were submitted to a 4-week growth trial. Five nearly isocaloric (18.8-21.0 kJ g−1) diets with protein concentrations ranging between 17 and 64% were administrated at a fixed, near satiation level. Maximum growth was 6.6, 3.6 and 1.9 g protein kg−0.8 day−1 for 5, 50 and 125 g fish, respectively. The protein requirement to achieve maximum growth decreased from 28.9 g protein kg−0.8 day−1 for 5 g fish to 11.7 g kg−0.8 day−1 for 125 g fish. Possibly because of its high growth rate. C. macropomum needs a slightly higher dietary P/E ration (25.4-27.9 mg protein kJ−1) to obtain maximal growth than most other fishes. The relation between protein ration and protein gain was studied by a quadratic regression model. In fish receiving protein rations equal or below rations resulting in maximal growth, protein ration and protein gain were almost linearly related. The model showed that the portion of the dietary protein which is digested decreases with increasing protein ration. Body protein content increased and body lipid content decreased with feed protein level. Fish fed a 17% protein diet deposited as much as 18% lipid.

Parameterization and calibration of a model to simulate effects of feeding level and feed composition on growth of Oreochromis niloticus (L.) and Oncorhynchus mykiss (Walbaum)

A dynamic model to simulate growth of the African catfish. Clarias gariepinus (Burchell), was parameterized and calibrated for Nile tilapia. Oreochromis niloticus (L.), and rainbow trout, Oncorhynchus mykiss (Walbaum). The model predicts fish weight and fat percentage from the amount and composition of the feed and water temperature. The major factor determining the efficiency of feed conversion is the proportion of energy provided by protein oxidation, which is positively related to the protein feeding level and the protein/energy ratio of the feed. The model predicted fresh weight of the herbivorous Oreochromis niloticus in independent experimental data with a mean deviation of -2.1% (range -23% to +37%) of observed values (fish weights 10-40 g), For the carnivorous Oncorhynchus mykiss, this value was 4.8% (range -21% to +24%, 50-800 g), Options for further improvement of the model are discussed. We conclude that the structure of the model applies to a broad range of fish species and feeding schedules, provided that both feed and fish are characterized by a set of specific parameters.

Biological and nutritional approach to the environmental impact of trout culture in Portugal

In order to address the problems of pollution from commercial farms, the bioavailability of nutrients in commercial feeds available in Portugal was evaluated in three size (40 g, 100 g and 180 g) groups of rainbow trout (Oncorhynchus mykiss) over a one year period and under natural production conditions. The principal factors influencing apparent digestibility values were diet quality, temperature and dissolved oxygen. Most probably suspended solids also affected digestibility especially during the summer months. The apparent digestibilities of crude protein, organic matter and dry matter were strongly inversely correlated with dietary fibre level in the 3 size groups of farmed trout. In addition, significant positive correlations were obtained between lipid level in commercial feeds and the organic matter digestibility coefficients. A significant correlation was also obtained between all apparent digestibility coefficients and the feed protein level for all size groups of fish studied in the field. The need for, and importance of, digestibility studies is demonstrated through estimates of nutrient flow and waste production in two different situations illustrating the effect of dietary quality.