J. P. Jacob

The feeding value of Kenyan sorghum, sunflower seed cake and sesame seed cake for broilers and layers

The feeding value of Kenyan sorghum, sunflower seed cake (SFC) and sesame seed cake (SSC) was studied in an 8 week broiler trial and a 24 week layer trial. In both trials the diets were either white maize (Hb25) or brown sorghum (Serena) based and contained either imported soybean meal (SBM), a combination of SFC and SBM, or SSC as the main protein source. In the broiler trial, mean weekly body weights were significantly higher for chicks fed the maize based diets, starting as early as the second week. At the end of the 8 week trial, however, the difference between the mean body weights for the two groups of broilers was not significantly different (2136 g vs. 2023 g for broilers on the maize and sorghum diets, respectively). Feed conversion ratio (FCR) was not significantly affected by grain type (2.72 vs. 2.76 for broilers on the maize and sorghum diets, respectively). In the last 4 weeks of the broiler trial, mean weekly body weights were significantly higher for chicks fed SSC diets than for those receiving SBM diets. By the end of the 8 week trial the mean body weight of the broilers receiving the SSC diets was 12.1% higher (2212 g vs. 1972 g for broilers receiving the SSC and SBM diets, respectively) than that of the broilers receiving the SBM diets. FCR was significantly lower for chicks receiving the SSC diets (2.52) as compared to those receiving either the SBM or SFC/SBM diet (2.86 and 2.88, respectively). In the layer trial, egg production and feed efficiency were significantly lower for the hens receiving the sorghum based diets (64.7%) as compared to those receiving the maize based diets (70.9%), but average egg weight was not significantly affected by grain type. Egg production, feed efficiency and egg weight were significantly lower for those hens receiving either the SFC/SBM or SSC diet than for those receiving the SBM diets. There was no effect of grain type or protein source on the incidence or severity of yolk mottling.

The effect of substituting Kenyan Serena sorghum for maize in broiler starter diets with different dietary crude protein and methionine levels

Abstract Currently there is interest in many parts of Africa in developing crops which can be grown in the semi-arid regions to help alleviate a feed and food shortage. Sorghum is well suited to cultivation in areas that are too dry or too hot for the production of other cereals. Although sorghum is similar in composition to maize, brown sorghum contains the anti-nutritive factor tannin. The possibility of overcoming any detrimental effects of sorghum tannin on the growth rate and feed efficiency of broiler chicks by supplementing the diet with intact crude protein (CP) or D,L-methionine (Met) was studied in two 4-week feeding trials of 280 chicks each. In each trial the effects of feeding maize or brown sorghum were compared under three dietary specifications (control, increased CP, increased Met). In both trials, the tannin content of the control brown sorghum diet was 1.3% catechin equivalents (dry matter basis). A seventh diet, with dietary specifications similar to the control diets, was included in each trial for comparison with the six main diets. In Trial 1 the seventh diet contained a combination of white and brown ( w b ) sorghum ( 50 50 , w w ) as the main energy source while in Trial 2 the main energy source of the seventh diet was white sorghum alone. In both trials there were no significant differences in final body weight among the three control diets (770.2, 759.0, and 753.0 g for the broilers on the maize, brown sorghum, and w b sorghum diets in Trial 1; and 822.7, 764.8, and 827.2 g for the broilers on the maize, brown sorghum, and white sorghum diets in Trial 2). In addition, there were no significant differences in feed conversion ratio (FCR) between the maize and brown sorghum fed broilers (2.01 vs. 2.03 in Trial 1; and 1.82 vs. 1.94 in Trial 2). In Trial 2, however, the FCR for the broilers receiving the white sorghum diet (1.73) was significantly lower than for those receiving the brown sorghum control diet (1.94), but not significantly different from those receiving the maize control diet (1.82). There was no effect of Met supplementation on final body weight or FCR in either trial. In Trial 1, increasing dietary CP content had no effect on final body weight or FCR for both the maize and brown sorghum fed broilers. In Trial 2, however, increasing the dietary CP content resulted in significantly lower final body weights (708.2 vs. 822.7 g) and higher FCR (2.06 vs. 1.82) for the maize fed broilers. The results of this study suggest that high tannin sorghum can be substituted for white maize in broiler starter diets with no significant adverse effects on growth or feed efficiency. The dietary treatments of increased CP or Met levels, which have been reported to be successful at overcoming the detrimental effects of sorghum tannins, were not required. A leg abnormality previously reported by other sorghum researchers was observed in both trials but the incidence and severity were low. Broilers receiving maize based diets with increased Met were most affected suggesting that the abnormality is related to increased Met and not to tannins.

Barley β-glucan in poultry diets.

There has been an increased interest in the use of immunomodulators as substitutes for antibiotics in food animal production. Beta-glucans from yeast and fungi may be ideal substitutes because of their positive effects on the avian immune system without adversely affecting poultry performance. Barley β-glucans, however, have not shown this potential due to the adverse effects dietary inclusion of barley has on poultry performance.

Investigating the effect of dietary calcium levels on ileal endogenous amino acid losses and standardized ileal amino acid digestibility in broilers and laying hens1

ABSTRACT Two studies were conducted to evaluate the effect of dietary Ca levels (low, 1% and high, 3%) on ileal endogenous amino acid losses (IEAAL) and standardized ileal amino acid digestibility (SIAAD) in broilers (BR) and laying hens (LH) fed nitrogen‐free diets (NFD) and distillers dried grain with solubles (DDGS)‐based diets. A total of 384 male Cobb 500 BR and 288 LH were used in a completely randomized design (CRD) with 16 (BR) or 12 (LH) replicate cages with 6 birds/replicate. IEAAL and apparent ileal digestibility (AID) of AA were analyzed using the GLM procedure of SAS appropriate for a CRD while SIAAD values were analyzed using the GLM procedure of SAS appropriate for a 2 × 2 factorial arrangement of treatments. For BR, IEAAL and N losses (mg/kg of dry matter intake, DMI) were higher (P < 0.05) when NFD with high Ca level was fed (total AA was 39%, N was 35% higher). For most of the AA, AID was higher (P < 0.05) in BR fed DDGS‐based diet with high Ca level. High dietary Ca resulted in higher (P < 0.05) SIAAD for all the AA except for Arg, Lys, Met, Cys, and Tyr. For LH, AID of AA was higher (P < 0.05) for the DDGS diet with high Ca level in 13 of the 18 AA evaluated. There was interaction (P < 0.05) between diet Ca level and correction method on LH SIAAD values for Thr, Asp, Gly, and Ser. The SIAAD values for 8 AA were higher (P < 0.05) in birds on high Ca DDGS diet. Correction with low Ca NFD resulted in higher (P < 0.05) SIAAD values for all the AA. Result from this study showed that high Ca increased total IEAAL in BR by 39% but decreased same by 27% in LH. Finally, SIAAD values were increased in BR fed high Ca DDGS‐based diet while SIAAD value in LH was lower when correction was done using values from high Ca‐NFD fed birds.

The effect of drying method temperature, collection method, and marker type on apparent ileal amino acid digestibility in 21-day-old broilers fed corn-soybean meal-barley based diet1

ABSTRACT For accurate estimation of nutrient digestibility, an ideal drying and sampling method is required to preserve the quality of the digesta. A standard corn‐soybean meal (corn‐SBM) broiler starter diet was fed from d 0 to 10 before birds were placed on the experimental diets until d 21. One hundred and sixty‐eight male Cobb 500 broiler chicks were used to evaluate the effect of two drying methods (freeze‐dryer vs. forced air‐oven) and two drying temperatures (40 vs. 55°C) (Exp 1), while ninety‐six chicks were used to evaluate the effect of flushing and squeezing as well as marker types (titanium vs. chromium) on apparent ileal DM, N, Ca, P, and AA digestibility (Exp 2). There were seven (Exp 1) or eight (Exp 2) replicate cages per treatment with 6 birds/cage. Digesta from the distal two thirds of the ileum was obtained from birds following euthanasia on d 21 by squeezing (Exp 1) and squeezing or flushing (Exp 2). Samples collected were stored in the freezer at −20°C until they were either freeze‐dried (FD) or oven‐dried (OD) at 40 or 55°C. There were no interactions between the drying methods and drying temperatures (Exp 1) on apparent ileal DM, N, and AA digestibility. Met had the highest (92.3%) while Cys had the lowest (73.8%) digestibility value. In Exp 2, no interaction between sampling methods and marker types was observed. The effect of sampling methods was not significant except for Arg and Met where squeezing resulted in higher (P < 0.05) digestibility values. Furthermore, apparent ileal His, Ile, Cys, Ser, and Tyr digestibility tended to be higher (P < 0.1) in squeezed digesta compared to the flushed digesta. Results from these studies showed that OD ileal digesta at 40 or 55°C had no negative effect on apparent ileal AA digestibility. Likewise, marker type did not influence apparent ileal AA digestibility values.

Examining the effect of dietary electrolyte balance, energy source, and length of feeding of nitrogen-free diets on ileal endogenous amino acid losses in broilers1

ABSTRACT The effect of dietary electrolyte balance (DEB), energy source (ES), and length of feeding of nitrogen‐free diet (NFD) on ileal endogenous amino acid (EAA) loss in mg/kg dry matter intake (DMI) was evaluated in broiler chickens. In Experiment 1, 720 chickens consisting of 15 replicate cages with 6 chickens/replicate were used. Treatments were arranged in a 2 × 2 × 2 factorial and consisted of 4 NFD with 2 levels (low or high) of DEB and 2 ES [corn starch (CS) or dextrose (DX)], and 2 sampling time‐points (diets were fed for either 72 h (d 16 to 19) or 120 h (d 16 to 21). Experiment 2 used 360 chickens in a 2 × 2 factorial arrangement of treatments with 2 levels (low or high) of DEB and 2 ES (CS or DX). Diets were fed for 72 h (d 18 to 21). All birds had access to feed and water on an ad libitum basis. Data were analyzed using the GLM procedure of SAS appropriate for a completely randomized design for a factorial arrangement of treatments. For Experiment 1, there were interactions (P < 0.05) between the 3 main factors for nitrogen and all the AA except Trp. Broilers that were fed DX‐based NFD with high DEB for 72 h had the highest (P < 0.05) EAA losses. In Experiment 2, there was no interaction between DEB and ES except for His and Lys. When ileal EAA losses from birds fed the low DEB, CS‐based NFD were used to standardize apparent ileal digestibility values from a previous study, there was no effect of length of feeding on standardized ileal AA digestibility values. In conclusion, DX‐based NFD with high DEB increased endogenous AA loses. Despite differences in ileal EAA losses from CS‐based NFD, standardized ileal AA digestibility values were not influenced by the length of feeding of NFD. Based on the results from these studies, NFD could be fed for 72 h without influencing SIAAD values.