Dietary protein and energy requirements of Venda village chickens

The objective of this study was to determine the dietary protein and apparent metabolisable energy (AME) requirements of local chickens. Freshly laid eggs of scavenging chickens collected in rural villages were hatched and randomly distributed to 27 floor pens, 10 chicks per pen. Chicks were fed 9 experimental diets that were combinations of three CP levels (140, 170 and 190 g kg−1 DM) and three AME levels (11.0, 11.7 and 12 MJ kg−1) during the starter phase (0–6 weeks) and combinations of three CP levels (120, 150 and 180 g kg−1 DM) and three ME levels (11.3, 12.0 and 12.4 MJ kg−1) during the grower phase (7–17) weeks. Significant differences within means on CP × AME interaction effect were observed in all parameters measured, except feed intake during starter period and dressing percentage (%) and breast yield of 17 weeks old chickens. The results of the present study indicated that during the starter and grower phases, unsexed chickens would require dietary combinations of 170 g CP kg−1 and 11.0 AME MJ kg−1 and 150 g CP kg−1 and 12 AME MJ kg−1 in their diets to optimise weight gain and FCR, and 150 g CP kg−1 and 11.3 MJ kg−1 to optimise ash content of muscles, protein content of the breast and fat content of the leg muscle. Supplementation of 27 g CP kg−1 feed to grower scavenging chickens would be enough to improve chicken production in the rural villages

Growth performance and digestive tract development of indigenous scavenging chickens under village management

The study was conducted on indigenous scavenging chickens under village management firstly, to evaluate the early development of the digestive tract to 28 days of age and secondly, to determine the growth performance of these chickens up to 20 weeks of age. One hundred and seventeen chicks, 13 chicks per age class (day 1, 4, 7, 10, 14, 17, 21, 24, 28) were randomly purchased from six rural villages in the Vhembe District, Venda, South Africa. The chickens were weighed and sacrificed for measurement of the different parts of its gastrointestinal tract. The liver and pancreas were also weighed. The relative weight of the storage organs and liver peaked at day 4 while that of the small intestine and duodenum peaked at day 10. The relative lengths of the small intestine and jejunum peaked at day 7, duodenum at day 10 and ileum at day 4. Four hundred and forty four (444) chicks from 13 households were recorded at two weekly intervals starting from day old until 20 weeks of age. The mean body weight obtained for males and females were 201.7 and 171.5 g at six weeks of age and 1048.1 and 658.6 g at 20 weeks of age, respectively. The indigenous chickens under village management were characterised by slow digestive tract development, poor growth performance and high mortalities. Further research needs to be conducted to determine the effect of early feed supplementation on the development of the digestive tract and the performance of indigenous chickens under village management

Litter characteristics of pine shavings, bio-secure pine shavings and sunflower hulls and its impact on broiler performance

The aim of this study was to investigate the physical characteristics of three litter materials, namely pine shavings (PS), bio-secure, fumigated pine shavings (BS) and sunflower hulls (SH) and its influence on broiler performance over a 33-day production cycle. The experiment was conducted in commercial poultry houses holding 42,500 chicks each, utilising a randomised block design with six house replicates per treatment. Litter samples were collected weekly for analyses of moisture, water-holding capacity, bulk density, pH and litter caking. Broiler footpad dermatitis was monitored at 21 and 31 days, together with acid detergent fibre (ADF) concentration of gizzard content, gizzard weight and small intestinal weight and length of 120 birds per treatment. Broilers across treatments consumed litter material which was evident in increased ADF levels of gizzard contents relative to feed. The SH contained more nutrients based on proximate analysis as compared to other treatments. Rearing on SH led to lower 7-day cumulative mortality, higher kilograms of broilers produced per square meter, average daily gain and slaughter weight. Improvements seen with SH did not alter commercial indicators, namely, production efficiency factor and feed conversion ratio. Litter converged toward similar physical characteristics at the end of production cycles when few differences were observed between treatments due to addition of feed, feathers and excreta

The ameliorating effect of oxihumate on aflatoxicosis in broilers

Mycotoxins have become an important issue for the grain industry and animal producers with a growing interest in the decontamination and remediation of highly contaminated feedstuffs. Practical methods to detoxify mycotoxin-contaminated grain on a large scale and in a cost-effective manner are essential but not currently available. The most recent and promising approach to detoxify mycotoxin-contaminated grain is the use of non-nutritive adsorbents, which bind the aflatoxin and thereby reduce their absorption from the gastrointestinal tract. Humic acids are products of chemical and biological transformations of animal and plant residues and are widely distributed in nature. Humic acids have some therapeutic characteristics and a strong binding affinity for several compounds. A South African company developed an effective large-scale regeneration process for humic acids from coal, called oxihumate. This study evaluated the effectiveness of oxihumate to adsorb mycotoxins, for the purpose of developing it as a commercial mycotoxin binder to be used in the preventative management of contaminated poultry feedstuffs. The in vitro affinity and adsorption capacity of oxihumate to aflatoxin was evaluated and the efficacy of oxihumate as an aflatoxin binder in broiler feeds in vivo was determined. The data showed adsorptions of about 10.3, 7.4 and 11.9 mg aflatoxin B1/g oxihumate at pH 3, 5 and 7, respectively. Oxihumate adsorbed 1.2, 2.6 and 8.5 mg aflatoxin G2/g at pH 3, 5 and 7, respectively. Oxihumate supplementation at a concentration of 3.5 g/kg feed was effective in diminishing the growth inhibitory effects of aflatoxin and apparent protection was noted for some of the organ, haematological and serum biochemical changes associated with aflatoxicosis. These results suggest that oxihumate could alleviate some of the toxic effects of aflatoxin in growing broilers, and when used with other sound mycotoxin management practices, might prove beneficial in the preventative management of aflatoxin-contaminated feedstuffs for poultry. The improvement observed during this specific study was, however, not satisfactory enough to recommend oxihumate as a commercially available product.Thesis (PhD (Animal and Wildlife Sciences))--University of Pretoria, 2007.Animal and Wildlife Sciencesunrestricte

The response of weaned piglets to dietary valine and leucine

Valine (Val) is considered to be the fifth-limiting amino acid in a maize–soyabean meal diet for pigs. Excess leucine (Leu) levels often occur in commercial diets, which may attenuate the effect of Val deficiency because of an increased oxidation of Val. The objective of the present experiment was to determine the effect of increasing concentrations of Leu on the response of young piglets to dietary Val. In all, 75 Large White×Landrace entire male pigs, 44 days of age and with a mean starting weight of 13.5 kg, were used. Three of these were sacrificed at the start to determine their mean initial chemical composition. A summit feed first limiting in Val was serially diluted with a non-protein diluent to produce a series of five digestible Val concentrations of 11.9, 10.1, 8.3, 6.6 and 4.8 g/kg, with a sixth treatment being added to test that the feeds were limiting in Val. Three identical Val series, each with six levels of Val, were supplemented with increasing amounts of Leu (23, 45 and 67 g/kg), thus 18 treatments in total. All pigs were killed at the end of the trial after 18 days for analysis of water, protein, lipid and ash in the carcass. The levels of Val and Leu and their interaction significantly influenced all the measurements taken in the trial. Daily gain in liveweight, water and protein, and feed conversion efficiency all increased with dietary Val content, whereas feed intake decreased as both Val and Leu contents increased. The deleterious effect of increased Leu on feed intake and growth was more marked at lower levels of Val. Supplementing the feed with the lowest Val content with additional Val largely overcame the effect of excess Leu. The efficiency of utilisation of Val for protein growth was unaffected by the level of Leu in the feed, the primary response to excess Leu being a reduction in feed intake. An intake of around 9 g Val/day yielded maximal protein growth during the period from 44 to 62 days of age in pigs of the genotype used in this trial.The South African Pork Producers Organisationhttp://journals.cambridge.org/action/displayJournal?jid=ANM2018-02-27hb2017Animal and Wildlife Science

Embryonic thermal manipulation and dietary fat source during acute heat stress : 1. Effect on hatchability and broiler performance

Modern broilers have been selected for rapid growth but demonstrate reduced heat tolerance toward market age. As the poultry industry expands globally, strategies must be developed to support broiler performance in challenging climates. The objective of this study was to evaluate the effect of embryonic thermal manipulation (TM) and dietary fat source during the finisher period on broiler performance during acute heat stress (AHS) close to market age. The cyclic exposure to high temperatures during mid-incubation used in TM has been demonstrated to improve broiler tolerance to heat stress. However, high incubation temperatures can be detrimental to embryonic development and impair posthatch broiler performance. Embryos were exposed to 39.5°C for 12 h daily from incubation day 7 to 16 to assess the impact of TM on hatching and broiler performance. Dietary fat is commonly added to poultry diets during heat stress and it was theorized that differences in fat source may further impact bird performance. Finisher diets were supplemented with soya oil, poultry fat, or olive oil at 4.5% each. Broilers were exposed to a period of AHS at 43 d. Embryo mortality was increased, and hatchability was reduced by TM. Broiler performance was also decreased for the TM birds, but mortality during AHS was markedly reduced. Dietary fat source did not influence bird performance but was shown to interact with incubation treatment. Overall, the present data suggest optimal performance in modern broiler strains may be at odds with improved heat tolerance.The North Carolina Department of Agriculture and Consumer Services Piedmont Research Station, as well as the North Carolina State University Prestage Department of Poultry Science and Feed Mill.https://www.sciencedirect.com/journal/journal-of-applied-poultry-researchhj2022Animal and Wildlife Science

Effects of different penning conditions, feeding regimens and season on growth and carcass attributes of boars of a selected genetic line

The study tested the performance of intact male pigs from a selected genetic line subjected to differing feeding regimens and penning conditions. The trial was a 2 x 3 x 2 x 3 factorial design, consisting of winter and summer periods, three sire lines, two diets and three feeding regimens. The pigs were intact males grown over three phases, starter (25 to 50 kg); grower (51 to 80 kg) and finisher (81 to 105 kg).The pigs were randomly allocated to three feeding regimens, a controlled single feeding, ad libitum single feeding and ad libitum group feeding, with six animals per ad libitum group. This resulted in 96 pigs in six treatments with six replicates. The diets were high (HF) and low (LF) nutrient dense feeds, where the LF was 95% of the HF. Season affected growth; the winter animals had a significantly greater growth response, end-mass and average daily gain (ADG). The HF diet resulted in significant improved ADG, feed conversion ratio and protein deposition rate, especially during summer. However, end-mass, ADG and average protein deposition rates of controlled-fed pigs were significantly lower compared to the ad libitum group and single-fed animals. The hypothesis was affirmed that high-performing intact male pigs are sensitive to and affected by feeding regimens and penning conditions that will affect their production.http://www.sasas.co.za/nf201

A novel Bacillus based multi-strain probiotic improves growth performance and intestinal properties of Clostridium perfringens challenged broilers

There is a necessity for the implementation of in-feed probiotics in the poultry production industry, following strict regulations around the use of antibiotic growth promoters (AGP). Bacillus spp. are becoming an attractive alternative because of their functionality and stability. This study aims to evaluate the effect of a novel multi-strain Bacillus based probiotic on growth performance and gut health in male Ross 308 broiler chickens challenged with Clostridium perfringens Type A. Broilers on a 4 phase feeding program were fed diets containing either a standard metabolizable energy (ME) (100%) or a reduced ME (98%) level. The test probiotic was compared to an un-supplemented negative control and a commercial benchmark product as positive control over a 35 D feeding trial, using a 2 × 3 factorial experimental design. Chicks were inoculated with a once-off dose of C. perfringens on day 14. Growth performance was measured weekly to calculate body weight (BW), feed intake (FI) and feed conversion ratio (FCR). Villi histomorphology, gut lesions, and liver weight were assessed at day 35. Broilers fed the reduced ME diet with the test probiotic achieved higher final BWs (P = 0.037) and FCR (P = 0.014) than the negative control. Broilers fed the standard ME diet with the test probiotic showed improved (P = 0.001) FCR than the negative control from day 21 onwards. Increased duodenal villi height (P = 0.012) and villi height to crypt depth ratio in the duodenum (P < 0.0001) and jejunum (P = 0.0004) were observed in broilers fed the reduced ME diet containing the test probiotic. Additionally, the test probiotic resulted in significantly reduced relative liver weights in both ME groups. Consequently, the results suggest that the novel multi-strain Bacillus based probiotic enhanced broiler performance and improved gut health and is thus attractive as an alternative to AGP’s in broiler production.The Department of Science and Technology, the CSIR (Pretoria, South Africa) and Ceva Animal Health (Pty) Ltd (Johannesburg, South Africa).http://ps.oxfordjournals.orgam2020Animal and Wildlife SciencesBiochemistryGeneticsMicrobiology and Plant Patholog

Influence of incubation, diet, and sex on avian uncoupling protein expression and oxidative stress in market age broilers following exposure to acute heat stress

Genetic selection for rapid growth in broilers has inadvertently resulted in increased susceptibility to heat stress, particularly in male birds. Increased oxidative stress associated with hyperthermia may be reduced by avian uncoupling protein (avUCP), which has been proposed to modulate free radical production. However, the relationship between avUCP expression and current heat stress management strategies is unclear. Embryonic acclimation or thermal manipulation (TM) and dietary fat source are 2 heat stress interventions that may alter avUCP expression and oxidative stress, but the literature is inconclusive. The objective of this trial was to investigate the effect of TM and dietary fat source on avUCP gene expression and oxidative damage in the breast meat of market age broilers before and after acute heat challenge. The influence of bird sex was also evaluated as broilers exhibit a high degree of sexual dimorphism in growth and stress susceptibility. Concentration of thiobarbituric acid reactive substances (TBARS) was measured as a marker of oxidative damage. Embryonic TM occurred from incubation d 7 to 16 for 12 h daily at 39.5°C. Dietary treatments were applied during the finisher period using either poultry fat, soya oil, or olive oil supplemented at 4.5% in the diet. Acute heat stress (AHS) occurred on d 43 at 32°C for 4 h. Bird performance was decreased by TM, but no significant differences were noted between dietary fat source treatments. Neither avUCP nor TBARS concentrations were significantly influenced by TM or dietary fat source. Downregulation of avUCP was observed following AHS, concurrent with an increase in TBARS concentration. Male birds exhibited higher levels of both avUCP expression and TBARS compared to females and a significant interaction was noted for heat stress by sex, with avUCP expression being greatest in males prior to AHS. The increase in avUCP expression and TBARS concentrations in male birds may be associated with an increased susceptibility to stress arising from the increased growth rate noted for male broilers.https://www.journals.elsevier.com/poultry-sciencedm2022Animal and Wildlife Science

Dietary protein and energy requirements of Venda village chickens

The objective of this study was to determine the dietary protein and apparent metabolisable energy (AME) requirements of local chickens. Freshly laid eggs of scavenging chickens collected in rural villages were hatched and randomly distributed to 27 floor pens, 10 chicks per pen. Chicks were fed 9 experimental diets that were combinations of three CP levels (140, 170 and 190 g kg−1 DM) and three AME levels (11.0, 11.7 and 12MJ kg −1) during the starter phase (0–6 weeks) and combinations of three CP levels (120, 150 and 180 g kg −1 DM) and three ME levels (11.3, 12.0 and 12.4MJ kg−1) during the grower phase (7–17) weeks. Significant differences within means on CP ×AME interaction effect were observed in all parameters measured, except feed intake during starter period and dressing percentage (%) and breast yield of 17 weeks old chickens. The results of the present study indicated that during the starter and grower phases, unsexed chickens would require dietary combinations of 170 g CP kg −1 and 11.0 AMEMJ kg−1 and 150 g CP kg−1 and 12 AMEMJ kg−1 in their diets to optimise weight gain and FCR, and 150gCPkg−1 and 11.3MJ kg−1 to optimise ash content of muscles, protein content of the breast and fat content of the leg muscle. Supplementation of 27 g CP kg−1 feed to grower scavenging chickens would be enough to improve chicken production in the rural villages.We are grateful to the National Research Foundation (NRF) for financial support of the present study, indigenous chicken’s farmers and the Limpopo Department of Agriculture and Rural Development officials for their assistance in this study.The National Research Foundation (NRF)http://www.jarts.infoam2018Animal and Wildlife Science