Effect of seaweed-containing diets on visceral organ sizes, carcass characteristics, and meat quality and stability of Boschveld indigenous hens.

Seaweeds are functional feed ingredients that have antioxidant, antimicrobial, and growth-boosting properties that can improve poultry product quality. This study, therefore, investigated the effect of graded levels of green seaweed meal (Ulva spp.) (SWM) on visceral organ sizes, carcass characteristics, and meat quality and stability of Boschveld indigenous hens. A total of 275, four-week-old female chicks (202.4 ± 6.65 g of live weight) were reared on 5 isocaloric and isonitrogenous diets formulated by adding SWM at a concentration of 0 (SW0), 2 (SW20), 2.5 (SW25), 3 (SW30), and 3.5% (SW35). Birds were humanely slaughtered at 14 wk of age. Cecum weight linearly increased (R2 = 0.366, P = 0.002), whereas proventriculus (R2 = 0.205, P = 0.025) and duodenum (R2 = 0.242, P = 0.010) weights linearly decreased with SWM levels. Neither linear nor quadratic trends (P > 0.05) were observed for carcass traits, meat quality parameters, and shelf life indicators in response to dietary SWM levels. Repeated-measures analysis showed a significant time × diet interaction effect on meat redness (a∗). After 24 h of storage, meat from hens fed with SW35 (2.47) diet had a higher a∗ value than meat from hens fed with SW30 diet (0.48). However, the inclusion of SWM promoted similar (P > 0.05) shelf life indicators as the control diet for the rest of the 7-d storage period at room temperature. In conclusion, dietary inclusion of SWM had no adverse effect on visceral organ size, carcass and meat quality traits, and meat stability of Boschveld indigenous hens.

Partial replacement of soybean products with canola meal in indigenous chicken diets: size of internal organs, carcass characteristics and breast meat quality.

While the use of canola meal (CM) as an alternative to soybean meal in broiler diets is well-documented, there is no information on the utility of this valuable by-product for slow-growing indigenous chickens. This study was, therefore, conducted to evaluate the effects of partially replacing soybean products in a chicken grower diet with graded levels of CM on carcass characteristics, relative organ sizes and meat quality in Potchefstroom Koekoek (PK) cockerels. A total of 175 PK cockerels (342.6 ± 15.2 g body weight, 5 wk old) were randomly allocated to 25 pens. Five isonitrogenous and isoenergetic grower diets containing 0, 3.75, 6.25, 8.75, and 17.5% of CM were then randomly allocated to the pens (experimental units). After 12 wk of feeding, chickens were slaughtered to measure carcass traits, size of internal organs and meat quality traits. There were no effects of graded levels of CM on carcass weights. Wing weight increased quadratically [y = 6.27(±0.23) + 0.23 (±0.063) x-0.009 (±0.0003) x2; R2 = 0.28] in response to incremental levels of dietary CM. Drumstick, vertebrae, liver, and small intestine weights linearly increased (P < 0.05) in response to incremental levels of dietary CM. Redness (a*), initial meat pH (pHo), and shear force linearly increased (P < 0.05) but lightness (L*) and water holding capacity decreased with an increase in CM inclusion levels. However, there were no significant linear and quadratic trends for yellowness (b*), ultimate pH (pHu), drip loss, and cooking loss in response to incremental levels of CM. There were also significant quadratic trends for mineral contents of the meat with the exception of iron (Fe). It can be concluded that inclusion of CM in place of soybean products had no negative impact on carcass traits, organ size and meat quality traits of indigenous PK chickens.

Polyethylene glycol inactivates red grape pomace condensed tannins for broiler chickens.

1. This study was conducted to investigate the effect of inactivating GP condensed tannins using graded levels of polyethylene glycol (PEG) on feed intake, physiological, carcase, and meat quality traits of male Cobb 500 broilers. 2. Three hundred, two-week old, male Cobb 500 broilers (334.6 ± 21.43 g live weight) were allocated to 30 pens carrying 10 birds each. Five isonitrogenous and isoenergetic diets were formulated for grower (14-35 d) and finisher (36-42 d) phases by diluting a commercial broiler diet with untreated GP (PEG0) at 6.5% (w/w) or with the same amount of GP but pre-treated with PEG at 2.5% (PEG1), 5% (PEG2), 10% (PEG3) or 15% (w/w) (PEG4) and randomly allocated to pens in a four-week feeding period. 3. Feed intake, weight gain, feed conversion efficiency (FCE), and blood, carcase and meat quality parameters were determined. Weekly weight gain and FCE linearly (P < 0.05) increased in week 4 and linearly (P < 0.05) decreased in week 6 in response to PEG treatment levels. 4. Mean corpuscular volume linearly (P < 0.05) decreased in response to PEG levels, whereas blood urea nitrogen/creatinine ratio, urea, total protein, globulin and cholesterol showed quadratic trends in response to PEG levels. Spleen and ileum weights tended (P < 0.1) to linearly decrease with PEG levels. Heart weight and meat redness tended (P < 0.1) to quadratically respond to increasing levels of PEG. 5. It was concluded that PEG treatment partially inactivated GP condensed tannins without compromising the health status of broiler chickens. An optimum PEG inclusion level could not be determined for feed intake, weight gain and FCE. However, the presence of other antinutrients such as fibre and low molecular weight phenolics in GP may be responsible for the linear decreases observed in this study.

Humic acid and enzymes inclusion in canola-based diets generate different responses in growth performance, protein utilization dynamics, and hemato-biochemical parameters in broiler chickens.

The current study was conducted to investigate the effect of a humic acid and enzymes on growth performance, protein utilization, and blood parameters in broilers fed canola-based diets. Canola meal (CM) is characterized as low protein compared to soybean meal. Two-hundred-twenty broiler chickens were randomly allotted to the following 5 dietary treatments: 1. Control (commercial broiler diet); 2. CM (17.5% canola meal inclusion); 3. CMEnz (CM + 0.3 g/kg enzymes [Axtra XAP]); 4. CMPh (CM + 1.5% potassium humate, PH) and 5. CMEnzPh (CM + 1.5% PH + 0.3 g/kg Axtra XAP). Each treatment was replicated 4 times with each pen holding 11 birds as the experimental unit. The feeding trial was conducted over a grower (15 to 28 d) and a finisher phase (29 to 42 d). Diet did not affect (P > 0.05) feed intake across either grower or finisher phase but affected average daily gain (ADG) in the grower phase. In the grower phase, broilers fed CM had the highest ADG (71± 1.08 g/d), while the control (63.75 ± 1.08 g/d) had the lowest. However, control chickens had the highest feed conversion ratio (FCR) (1.65), while those fed CM (1.47) had the lowest. Diet significantly affected total white blood cell and white blood cell differential, which were consistently high in broilers fed CMEnzPh. With regard to serum metabolites, CM had the highest levels (P < 0.05) of aspartate aminotransferase (AST) (406.86 ± 38.07 IU/L), while CMEnzPh (254.17 ± 41.11 IU/L) had the lowest levels. Additionally, broilers fed CMPh had the highest (P < 0.05) serum sodium content (150.57 ± 0.69 mmol/l). Overall, canola meal, in the presence of enzymes and humic acid, was shown to have great potential as an alternative replacement of soybean meal in broiler diets. The findings from the study can, therefore, contribute to the design of low-cost canola-based feed formulations that will improve growth performance and health status in poultry farming systems in the future.

Growth performance, blood parameters, carcass characteristics and meat quality traits in Potchefstroom Koekoek chickens fed Lippia javanica leaf meal.

Lippia javanica leaves may have nutraceutical bioactivity and thus could be a viable alternative to antibiotic growth promoters in poultry diets. To test this hypothesis, a feeding trial was carried out to determine the effects of dietary inclusion of Lippia javanica leaf meal (LJ) on growth performance, blood parameters, carcass characteristics and meat quality of indigenous Potchefstroom Koekoek (PK) chickens. The leaf meal was used to dilute a commercial chicken grower diet at a rate of 25 or 50 g/kg diet. Two additional experimental diets, a positive control (commercial chicken grower diet with antibiotics, CON+) and a negative control (commercial chicken grower diet without antibiotics, CON-), were also formulated. Feed intake and growth performance were measured over a period of 13 weeks before slaughtering for carcass and meat quality measurements. Blood was collected in week 11 to determine haematological and serum biochemical parameters. Diet had no effect on overall FCE but significantly (P < 0.05) affected bilirubin, alanine aminotransferase (ALT), aspartate transaminase (AST), sodium, potassium, cholesterol and magnesium levels in blood. When included at 50 g/kg, LJ increased carcass weight (P < 0.05). Meat from CON- (6.07) and LJ50 (6.08) chickens had a higher pH than from CON+ (5.9) and LJ25 (5.8) chickens. Breast muscle in CON- chickens had higher (P < 0.05) lightness (L*) value (53.2) compared to chickens fed on other diets. It was observed that meat from LJ25 chickens had the highest for redness value (2.3). It was concluded that L. javanica leaf meal can be included up to 50 g/kg in Potchefstroom koekoek chicken diets without causing negative effects on the birds' feed intake, utilisation and weight gain. Diet-induced changes observed in blood parameters and meat quality fell within the expected normal ranges for indigenous chickens.

Influence of harvesting site on chemical composition and potential protein value of Acacia erioloba, A. nilotica and Ziziphus mucronata leaves for ruminants.

This study was designed to evaluate the chemical composition, buffer N solubility, in vitro ruminal N degradation and in vitro ruminal biological activity of condensed tannins in Acacia erioloba, Acacia nilotica and Ziziphus mucronata leaves harvested from two sites (Masuthle communal grazing land and Molelwane private farm). Leaves were harvested, dried at 60 °C and milled. The highest crude protein (CP) content was found in leaves of Z. mucronata (177.7 g/kg DM). Leaves harvested from Masuthle had higher (p < 0.05) soluble phenolics (SPh) (44.6 g TAE/kg DM) compared to those harvested from Molelwane (29.8 g TAE/kg DM). In both Molelwane and Masuthle, leaves of A. nilotica had higher levels of condensed tannins (CT) (0.76 AU550/200 mg and 0.52 AU550/200 mg respectively) followed by A. erioloba and Z. mucronata, which did not differ (p > 0.05). Nitrogen degradability at 24 h was the same (p > 0.05) for all tree species but not at 12 and 36 h. No linear association (p > 0.05) was found between buffer-soluble N and in vitro ruminal N degradability in leaves with high SPh content. The largest polyethylene glycol (PEG) effect was in leaves of A. nilotica (448%) harvested from Masuthle after 36 h of incubation. Ziziphus mucronata leaves harvested from Molelwane had the least PEG effect at 48 h. There was no linear association (p > 0.05) between PEG effect and SPh for all incubation periods, but a positive relationship was observed between PEG effect and condensed tannins content. There was no linear association between solubility index (SI) and in vitro ruminal N degradability for tannin-rich leaves. It was concluded that higher browsing pressure in Masuthle communal rangeland resulted in leaves with higher levels of condensed tannins, which had higher in vitro ruminal biological activity, compared to those harvested from Molelwane.

Effects of Lactobacillus formosensis S215T and Lactobacillus buchneri on quality and in vitro ruminal biological activity of condensed tannins in sweet potato vines silage.

AIMS: This study investigated the influence of two microbial inoculants; Lactobacillus formosensis and Lactobacillus buchneri on fermentation quality, chemical composition, aerobic stability and in vitro ruminal biological activity of condensed tannins in sweet potato vines silage. METHODS AND RESULTS: Sweet potato vines were ensiled for 28 and 60 days; without inoculant (CON), with Lact. buchneri (LB) or with Lact. formosensis (LF), both inoculants applied to achieve 1 × 106  CFU g-1 fresh forage. Lactobacillus formosensis silage had lower pH and higher lactic acid than all treatments. Yeasts and moulds were not detected in LB silage after ensiling. Lactobacillus buchneri silage was more aerobically stable than all treatments, whereas LF was more stable than CON silage. In vitro ruminal biological activity of condensed tannins was lower in microbial-inoculated silages than CON after ensiling. CONCLUSION: Lactobacillus formosensis improved fermentability by reducing silage pH and improved aerobic stability by producing more propionate, which inhibited yeast activity. Lactobacillus buchneri improved aerobic stability of the silage by producing more acetate. Both strains effectively reduced the antinutritional effect of condensed tannins after ensiling. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus formosensis has the potential to be used as a silage inoculant because of its ability to improve fermentability and aerobic stability in sweet potato vines silage.

Growth performance, hematology, and meat quality characteristics of Mutton Merino lambs fed canola-based diets.

A 56-day feeding trial was carried out to evaluate the effect of feeding canola meal (CM) on growth performance, hematology, and meat quality parameters of lambs. Twenty lambs with an average body weight of 23 ± 2.64 kg were randomly assigned to five dietary treatments and fed in individual cages for 56 days. The soya bean meal (SBM) in the control ration was replaced with canola meal at 0 (CM0), 25 (CM25), 50 (CM50), 75 (CM75), and 100 % (CM100) inclusion levels. Average daily weight gain (ADWG) and average daily feed intake (ADFI) were significantly higher in the CM25 and CM50, respectively. Feed conversion ratio (FCR) (3.09-3.41) and slaughter weight (SLW) (33.2-34.7 kg) were, however, similar among the treatment groups. Diet had no effect on carcass length (78.7-83.7 cm) and ultimate meat pH (pHu) (5.70-5.81). Nevertheless, hot carcass weight (HCW) (16.5-18.7 kg) and cold carcass weight (CCW) (16.2-18.2 kg) were higher (P < 0.05) in the CM0 and CM50 treatment groups. The shear force measurements (1.67-2.17 kg) differed (P < 0.05) across treatments. There was no dietary effect on the lightness (L*) (33.5-35.8), redness (a*) (11.35-12.7), and yellowness (b*) (13.4-14.8) of meat. In conclusion, CM can completely replace SBM in lamb diets without any negative effects on growth performance, general health, and meat quality of Mutton Merino lambs.

Chemical composition, nitrogen degradability and in vitro ruminal biological activity of tannins in vines harvested from four tropical sweet potato (Ipomoea batatas L.) varieties.

This study investigated the potential of vines from four sweet potato varieties (Tia Nong 57, Tia Nong 66, Ligwalagwala and Kenya) as alternative feed resources for ruminant livestock. The chemical composition [neutral detergent fibre (NDF), acid detergent fibre (ADF), crude protein (CP) and acid detergent insoluble nitrogen (ADIN)], in vitro ruminal nitrogen (N) degradability and in vitro ruminal biological activity of tannins in the vines, harvested at 70 and 110 days after planting (DAP), were determined. Variety and harvesting stage did not (p > 0.05) influence CP and NDF content of the vines. Concentration of CP ranged from 104.9 to 212.2 g/kg DM, while NDF ranged from 439.4 to 529.2 g/kg DM across harvesting stages and varieties. Nitrogen degradability (ND) at 70 and 110 DAP was highest (p < 0.05) in Ligwalagwala (743.1 and 985.0 g/kg DM, respectively). Treatment of vines with tannin-binding polyethylene glycol (PEG) increased (p < 0.05) in vitro ruminal cumulative gas production parameters (a, b and c). The in vitro ruminal biological activity of tannins, as measured by increment in gas production parameters upon PEG inclusion, had a maximum value of 18.2%, suggesting low to moderate antinutritional tannin activity. Ligwalagwala vines, with highly degradable N, would be the best protein supplement to use during the dry season when ruminant animals consume low N basal diets and maintenance is an acceptable production objective. Tia Nong 66 and Kenya varieties, with less degradable N, may be more suitable for use as supplements for high-producing animals such as dairy goats.

Buffer nitrogen solubility, in vitro ruminal partitioning of nitrogen and in vitro ruminal biological activity of tannins in leaves of four fodder tree species.

This study explores the chemical composition, buffer N solubility, in vitro ruminal N degradability and in vitro ruminal biological activity of tannins in leaves from Gliricidia sepium, Leucaena leucocephala, Morus alba and Trichanthera gigantea trees. These tree leaves are a potential protein source for ruminants, but their site-influenced nutritive value is largely unknown. Leucaena leucocephala leaves had the highest N content (42.1 g/kg DM), while T. gigantea leaves had the least (26.1 g/kg DM). Leucaena leucocephala had the highest buffer solubility index (20%), while 10% of the total N in leaves of the other three species was soluble. The rapidly fermentable N fraction 'a' was highest in M. alba leaves (734.9 g/kg DM) and least in T. gigantea leaves (139.5 g/kg DM). The rate of fermentation (c) was highest for M. alba (7%/hours) leaves. No significant correlations were recorded between buffer solubility index of N and in vitro ruminal N degradability parameters: a, b, and c. The highest response to tannin inactivation using polyethylene glycol, in terms of percentage increase in 36-hours cumulative gas production, was recorded in M. alba (39%) and T. gigantea (38%) leaves. It was concluded that buffer solubility of N is not a good indicator of ruminal N degradation in the leaves of these tree species. Leaves of M. alba could be more valuable as a source of rapidly fermentable N when animals are offered low-protein, high-fibre diets compared with other tree species evaluated in the current study. However, when feeding M. alba leaves, the role of tannins must be considered because these secondary plant compounds showed significant in vitro ruminal biological activity.