Evaluation of dietary crude protein concentrations, fishmeal, and sorghum inclusions in broiler chickens offered wheat-based diet via Box-Behnken response surface design

The objective of this study was to investigate the impacts of dietary crude protein (CP), fishmeal and sorghum on nutrient utilisation, digestibility coefficients and disappearance rates of starch and protein, amino acid concentrations in systemic plasma and their relevance to growth performance of broiler chickens using the Box-Behnken response surface design. The design consisted of three factors at three levels including dietary CP (190, 210, 230 g/kg), fishmeal (0, 50, 100 g/kg), and sorghum (0, 150, 300 g/kg). A total of 390 male, off-sex Ross 308 chicks were offered experimental diets from 14 to 35 days post-hatch. Growth performance, nutrient utilisation, starch and protein digestibilities and plasma free amino acids were determined. Dietary CP had a negative linear impact on weight gain where the transition from 230 to 190 g/kg CP increased weight gain by 9.43% (1835 versus 2008 g/bird, P = 0.006). Moreover, dietary CP linearly depressed feed intake (r = -0.486. P < 0.001). Fishmeal inclusions had negative linear impacts on weight gain (r = -0.751, P < 0.001) and feed intake (r = -0.495, P < 0.001). There was an interaction between dietary CP and fishmeal for FCR. However, growth performance was not influenced by dietary inclusions of sorghum. Total plasma amino acid concentrations were negatively related to weight gain (r = -0.519, P < 0.0001). The dietary transition from 0 to 100 g/kg fishmeal increased total amino acid concentrations in systemic plasma by 35% (771 versus 1037 μg/mL, P < 0.001). It may be deduced that optimal weight gain (2157 g/bird), optimal feed intake (3330 g/bird) and minimal FCR (1.544) were found in birds offered 190 g/kg CP diets without fishmeal inclusion, irrespective of sorghum inclusions. Both fishmeal and sorghum inclusions did not alter protein and starch digestion rate in broiler chickens; however, moderate reductions in dietary CP could advantage broiler growth performance.

Effects of Crude Protein Degradability on Some Blood Parameters of Ruminants

The experiment was investigated the effects of degradability crude protein on some blood parameters of ruminants, two experiments were conducted for three sources dietary crude protein: Soya, whey protein and urea. First experiment, soya was replaced with whey protein, while second experiment, soya was replaced with urea. Fifteen male lambs were used for each experiment and randomly distributed to five treatments T1, T2, T3, T4 and T5. Concentrated was fed at 3% of body weight as DM basis, while alfalfa was fed ad-libitum. Jugular blood was sampled from lambs after 90 days of experiment before feeding morning. Results of replacing soya with whey protein showed decreased blood protein and cholesterol, while, blood urea was increased and blood glucose had a linear increase with increasing whey protein intake, 45.75, 48.5, 52.5, 66.0 and 89.75 mg/dl for T1, T2, T3, T4 and T5. In second experiment, the results of replacing soya with urea showed decreased blood glucose and cholesterol for 2% urea in contrast with control, while blood urea was increased for 2% urea 36.11 mg/dl in contrast with 22.73mg/dl for control. In concluded, feeding high soluble crude proteins, decreased cholesterol and increased blood urea nitrogen.

293 Effect of Supplementing Rumen-protected Methionine on Blood Parameters and Ruminal Metabolites in Lactating Holstein Dairy Cows

The aim of the present study was to evaluate the effects of reducing dietary crude protein (CP) levels and supplementing rumen-protected methionine (RPM) on blood parameters and ruminal metabolites in lactating Holstein dairy cows. A total of 30 lactating Holstein dairy cows (60 ± 7 d in milk; mean ± SD) were randomly assigned to 1 of 2 treatments: diet containing 17.3% CP without RPM (control group; CON); diet containing 16.4% CP with supplementing 15.0 g/d of RPM (treatment group; RPM). All repeated, continuous data were subjected to PROC MIXED procedure of SAS (SAS version 9.2, SAS Institute Inc., Cary, NC.). The results related to blood showed that cows in RPM group exhibited lower concentration of blood urea nitrogen than that in CON group (P &lt; 0.001). Moreover, there were no differences among treatments on concentrations of aspartate transaminase, alanine transaminase, alkaline phosphatase, globulin and albumin (P &gt; 0.05). In ruminal metabolites, microbial CP (MCP) of dairy cows in RPM group was higher compared with CON group (P = 0.006). The concentrations of butyrate, valerate and isovalerate of RPM group were higher than that of CON group at 2h after feeding (P &lt; 0.05). In conclusion, lower dietary CP with RPM supplementation could improve nitrogen utilization of dairy cows and synthesis of MCP in rumen, as well as change volatile fatty acids production at 2h after feeding.

The effects of pharmacological levels of zinc, diet acidification and dietary crude protein on growth performance on nursery pigs

This experiment was conducted to evaluate potential replacements for pharmacological levels of Zn (provided by Zn oxide), such as diet acidification (sodium diformate), and low dietary crude protein (CP: 21 vs 18%) on nursery pig performance and fecal dry matter (DM). A total of 360 weaned pigs (Line 200 × 400, DNA, Columbus, NE; initially 5.90 ± 0.014 kg) were used in a 42-d growth study. Pigs were weaned at approximately 21-d of age and randomly assigned to pens (5 pigs per pen). Pens were then allotted to 1 of 8 dietary treatments with 9 pens per treatment. Experimental diets were fed in two phases: Phase 1 from weaning to d 7 and phase 2 from d 7 to 21; with all pigs fed the same common diet from d 21 to 42. The eight treatment diets were arranged as a 2 × 2 × 2 factorial with main effects of Zn (110 mg/kg from d 0 to 21 or 3,000 mg/kg from d 0 to 7, and 2,000 mg/kg from d 7 to 21), diet acidification, (without or with 1.2% sodium diformate), and dietary CP (21 or 18%, 1.40 and 1.35% in Phase 1 and 2 vs 1.20% standardized ileal digestible Lys, respectively). Fecal samples were collected weekly from the same 3 pigs per pen to determine DM content. No 2- or 3-way interactions (P &gt; 0.05) were observed throughout the 42-d study for growth performance; however, there was a Zn × acidifier × CP interaction (P &lt; 0.05) for fecal DM on d 7 and for the overall average of the 6 collection periods. Reducing CP without acidification or pharmacological levels of Zn increased fecal DM, but CP had little effect when ZnO was present in the diet. From d 0 to 21, significant (P &lt; 0.05) main effects were observed where average daily gain (ADG) and gain:feed (G:F) increased for pigs fed pharmacological levels of Zn, sodium diformate, or 21% CP (P &lt; 0.065). In the subsequent period (d 21 to 42) after the experimental diets were fed, there was no evidence of difference in growth performance among treatments. Overall (d 0 to 42), main effect tendencies were observed (P &lt; 0.066) for pigs fed added Zn or sodium diformate from d 0 to 21 whereas pigs fed 21% CP had greater G:F than those fed 18% CP. Pig weight on d 42 was increased by adding Zn (P &lt; 0.05) or acidifier (P &lt; 0.06) but not CP. In summary, none of the feed additives had a major influence on fecal DM, but dietary addition of pharmacological levels of Zn or sodium diformate independently improved nursery pig performance.

Impact of Microbial Protease Enzyme and Dietary Crude Protein Levels on Growth and Nutrients Digestibility in Broilers over 15–28 Days

In this trial, a 3 × 2 factorial design with different dietary crude protein levels (CP, 17, 19 and 21%) and two levels of exogenous protease (0 and 30,000 IU/kg) was used. A total of 540 two-week old broilers (Ross-308) was randomly allocated to experimental diets over 15–28 days of age. The interaction between dietary protein levels and enzyme supplementation showed that body weight gain was significantly (p < 0.05) higher in birds fed CP-19 (1114.7 g) and CP-21 (1108.8 g) with enzymes supplementation. Feed intake was higher (p < 0.05) in broilers fed with CP-17 than CP-19 with supplementation of the protease enzyme. Results also revealed that the feed conversion ratio (FCR) was significantly (p < 0.05) improved in birds fed with CP-19 and CP-21 and protease supplementation. Total tract N retention was lower (p < 0.05) in birds fed CP-17 with no enzyme than the other dietary groups. Similarly, the gross energy (GE) was significantly (p < 0.05) lower in birds fed CP-17 with or without the protease enzyme. Abdominal fat was higher (p < 0.05) in CP-17 (0.96%) without the protease enzyme. It was concluded that a diet at 19% CP with the protease enzyme improved the performance and nutrient digestibility in broilers over 15–28 days.