Effects of feeding strategy, fiber source of the diet, and crude protein content on productive performance of broiler breeder hens

A 12-wk experiment was conducted to investigate the effect of feeding program, dietary fiber, and CP content of the diet on productive performance of Ross broiler breeder hens (41 wk of age). There were 12 treatments arranged factorially with 2 levels of CP (14.5 vs. 17.4%), 3 fiber sources (0 vs. 3% inulin vs. 3% cellulose), and 2 levels of feed intake (160 vs. 208 g/d) that corresponded to restricted (R) or ad libitum (AL) feeding systems. The experimental diets contained 2,800 kcal ME with either 0.65 (14.5% CP) or 0.78% Lys (17.4% CP).

Effect of crude protein and fat content of diets with similar indispensable amino acid profile on productive performance and egg quality of brown egg laying hens differing in initial body weight

In total of 504 Lohmann Brown hens were used to study the influence of the initial BW of the birds and the crude protein (CP) and fat content of the diet on performance and egg quality traits from 22 to 49 weeks of age. The experiment was completely randomized with 8 treatments arranged factorially with 2 initial BW (1,726 vs. 1,987g) and 4 diets with similar AMEn (2,750 kcal AMEn/ kg) and indispensable (lys, Met+Cys, Thr, and Trp) amino acid contents.

Influence of crude protein content, ingredient complexity, feed form, and duration of feeding of the phase I diets on productive performance and nutrient digestibility of Iberian pigs.

The influence of CP content and ingredient complexity, feed form, and duration of feeding of the Phase I diets on growth performance and total tract apparent digestibility -TTAD- of energy and nutrients was studied in Iberian pigs weaned at 28 d of age. There were 12 dietary treatments with 2 type of feeds -high-quality, HQ; and low-quality, LQ-, 2 feed forms -pellets vs. mash-, and 3 durations -7, 14, and 21 d- of supply of the Phase I diets.

Increasing crude protein content of forage with atrazine on shortgrass range /

"In cooperation with Colorado State University Experiment Station."

The effect of different levels of dietary crude protein on urea metabolism of rusa deer (Cervus timorensis)

Two experiments were conducted to measure urea recycling and rumen flow dynamics in young rusa deer fed low (LP) or high (HP) protein diets. Pool size and flux rate of labelled urea. into and out of the blood pool were measured using single intravenous (i.v.) injection solutions containing [C-14] - and [N-15]-urea. A curve peeling technique was used to fit the enrichment of N-15 or specific radioactivity (SRA) of C-14 to exponential equations. Body urea-N pool size was significantly greater (P < 0.05) when a HP, compared to a LP diet, was fed. Urea space, expressed as a percent of live weight, total flux rate of urea through the blood pool and the irreversible loss of urea was similar for both diets. The mean (+/- S.E.M.) concentration of plasma urea-N was greater when animals were fed the HP diet compared to the LP diet (2 1.1 +/- 0.3 versus 14.4 +/- 1.4 mg/100 ml, respectively). Voluntary feed intake and digestibility of dietary components were also measured. Daily dry matter intakes were not affected by the crude protein (CP) content of the diet, although apparent DM digestibility was significantly greater for HP diet fed in both experiments. An intraruminal infusion of CrEDTA was used to determine rumen flow dynamics. Ruminal mean retention time, relative net outflow rate of water and passage rate constant (k(w)) were significantly greater (P < 0.05) when the HP diet was fed compared to the LP diet. The extent of urea metabolism and flux rates of urea between the blood and secondary pools appear similar to those previously reported for other ruminants fed diets contrasting in CP content. (c) 2005 Elsevier B.V. All rights reserved.

Apparent digestibility of dry matter, crude protein, and amino acids of six rendered by-products in juvenile Litopenaeus vannamei

Apparent digestibility coefficients (ADC) of dry matter, crude protein (CP), and amino acids (AA) were evaluated in diets with six rendered by-products used to feed juvenile Pacific white shrimp: two poultry meals (poultry meal 1, 69% CP; poultry meal 2, 72% CP), two feather meals (89% CP), one blood meal (96% CP), and one pork meal (57% CP). Experimental diets were formulated with 30% of the test ingredient and 70% of a commercial diet supplemented with 1% of chromium oxide as inert marker. AA contents in ingredients, diets, leached diets, and feces were determined by high performance liquid chromatography. Preprandial AA losses attributed to leaching were higher in the blood meal diet (15%) and pork meal diet (10%). Poultry meal diets 1 and 2 showed mean AA losses of 3% and 5%, respectively, while the reference diet had a mean AA leaching of 6%. The AA that had the highest leaching rates were lysine (21%), methionine (15%), and histidine (12%). The ADC of dry matter was higher for poultry meals 1 (70%) and 2 (73%), followed by pork meal (69%), feather meals (61%), and blood meal (57%). The digestibility of CP was higher for poultry meals (78–80%), followed by pork meal (76%), and blood meal and feather meals (65–67%). The digestibility of CP in the reference diet (83%) was higher than that observed for all the animal by-product meals except the poultry meals. The ADC of the sum of AA adjusted for nutrient leaching fluctuated from 65% for blood meal to 80% for poultry meals.

Productive performance and milk protein fraction composition of dairy cows supplemented with sodium monensin

The objective of this work was to evaluate the levels of sodium monensin on lactating cows and their effects on productive performance and milk protein fraction composition. It was used 12 Holstein cows, distributed in four balanced 3 × 3 Latin squares, and fed three diets: one control without monensin, and two diets with monensin at the levels of 24 or 48 mg/kg DM added to the concentrate. Milk production was daily measured throughout the entire experimental period. The samples used for analysis of milk composition were collected on two alternated days from the two daily milking. Non-protein nitrogen, total nitrogen and non-casein nitrogen contents were directly evaluated in the milk, and casein, whey protein and true protein contents were indirectly determined. The use of monensin in the rations reduced dry matter and nutrient intake, especially when diet with 48 mg/kg of dry matter was given. The ration with 24 mg/kg of DM increased milk production, with or without correction, and also fat and lactose yield, and it improved productive efficiency. The levels of monensin in the ratios did not influence contents of milk crude protein, non-protein nitrogen, non-casein nitrogen, true protein, casein, casein/true protein ratio, whey protein, and of all those fractions expressed as percentage of crude protein. The utilization of monensin in the ratio at the dose of 24 mg/kg of DM influences positively the productive performance of lactating cows, and it does not influence the composition of milk protein fractions.

Productive performance and composition of milk protein fraction in dairy cows supplemented with fat sources

The objective of this study was to evaluate the use of fat sources in rations for lactating cows on the productive performance and composition of milk protein fraction. Twelve Holstein cows were used, grouped in three balanced 4 × 4 Latin squares, fed with the following rations: control; refined soybean oil; whole raw soybean; and calcium salts of unsaturated fatty acid (Megalac-E). Dry matter and nutrient intake, and daily milk production were evaluated. The samples used to analyze milk composition were collected in two alternate days and were obtained from two daily milking. Milk composition and total nitrogen, non-protein nitrogen and non-casein nitrogen ratios were analyzed. The casein, serum protein and true protein ratios were obtained by difference. Dry matter and nutrient intakes were lower when cows received the diet containing calcium salts of fatty acids, in relation to the control diet. Among the diets with fat sources, the one with whole raw soybean and calcium salts decreased milk production. There was no effect of fat sources added to the diet on crude protein, non-protein nitrogen, non-casein nitrogen, true protein, casein, casein/milk true protein ratio and serum protein. Similarly, the experimental diets did not influence the protein fractions when expressed in percentage of milk crude protein. The utilization of fat sources in diets changes milk production and composition of lactating cows, but does not influence the composition of milk protein fractions.

Growth performance and body composition of pacu Piaractus mesopotamicus (Holmberg 1887) in response to dietary protein and energy levels

Improper dietary protein and energy levels and their ratio will lead to increased fish production cost. This work evaluated effects of dietary protein : energy ratio on growth and body composition of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 +/- 0.4 g) were fed twice a day for 10 weeks until apparent satiation with diets containing 220, 260, 300, 340 or 380 g kg-1 crude protein (CP) and 10.9, 11.7, 12.6, 13.4 or 14.2 MJ kg-1 digestible energy (DE) in a totally randomized experimental design, 5 x 5 factorial scheme (n = 3). Weight gain, specific growth rate increased and feed conversion ratio (FCR) decreased significantly (P < 0.05) when CP increased from 220 to 271, 268 and 281 g kg-1 respectively. Pacu was able to adjust feed consumption in a wide range of dietary DE concentration. Fish fed 260 CP diets showed best (P < 0.05) protein efficiency ratio and FCR with 11.7-12.6 MJ kg-1; but for the 380 CP-diets group, significant differences were observed only at 14.2 MJ kg-1 dietary energy level, suggesting that pacu favours protein as energy source. DE was the chief influence on whole body chemical composition. Minimum dietary protein requirement of pacu is 270 g kg-1, with an optimum CP : DE of 22.2 g MJ-1.

Growth and haematology of pacu, Piaractus mesopotamicus, fed diets with varying protein to energy ratio

Haematopoiesis and blood cells` functions can be influenced by dietary concentration of nutrients. This paper studied the effects of dietary protein:energy ratio on the growth and haematology of pacu, Piaractus mesopotamicus. Fingerling pacu (15.5 +/- 0.4 g) were fed twice a day for 10 weeks until apparent saciety with diets containing 220, 260, 300, 340 or 380 g kg(-1) crude protein (CP) and 10.88, 11.72, 12.55, 13.39, 14.22 MJ kg(-1) digestible energy (DE) in a totally randomized experimental design, 5 x 5 factorial scheme (n=3). Weight gain and specific growth rate were affected (P < 0.05) by protein level only. Protein efficiency ratio decreased (P < 0.05) with increasing dietary protein at all levels of dietary energy. Daily feed intake decreased (P < 0.05) with increasing dietary energy. Mean corpuscular haemoglobin concentration was affected (P < 0.05) by DE and interaction between dietary CP and DE. Total plasma protein increased (P < 0.05) with dietary protein and energy levels. Plasma glucose decreased (P < 0.05) with increasing dietary protein. The CP requirement and optimum protein:energy ratio for weight gain of pacu fingerlings, determined using broken-line model, were 271 g kg(-1) and 22.18 g CP MJ(-1) DE respectively. All dietary CP and DE levels studied did not pose damages to fish health.

Apparent digestibility coefficient of protein and amino acids of acid, biological and enzymatic silage for Nile tilapia (Oreochromis niloticus)

Using the fish silage to partially replace proteic feedstuff in aquafeeds is an alternative to mitigate sanitary and environmental problems caused by the lack of adequate destination for fisheries residues. It would also lower feed costs, consequently improving fish culture profitability. However, using fish silages in aquafeeds depends on determination of its apparent digestibility coefficients (ADC). This work aimed to determining the ADC of crude protein and amino acids of acid silage (AS), biological silage (BS) and enzymatic silage (ES) for juvenile Nile tilapia (94.5 +/- 12.7 g). The ADC(CP) was: 92.0%, 89.1% and 93.7% for AS, BS and SE respectively. The average ADC of amino acids was: 91.8%, 90.8% and 94.6% for AS, BS and ES respectively. Results encourage the use of AS, BS and ES to partially replace protein sources in balanced diets for neotropical fish.