This review provides an overview of the published data on the canola meal and its suitability for duck as an alternative plant-origin protein source to soybean meal. Canola meal is a legume origin protein source containing comparable amino acid profile to soybean meal and rich in essential minerals and vitamins. Nonetheless, it is known to contain less in energy content than soybean meal. Factors like field conditions and processing methods creates compositional variations among canola meal. Presence of anti-nutritional factors such as phenolic substances, phytate and glucosinolates which are known to reduce growth performance in livestock animals, are the major drawbacks for canola meal to be a competitive plant-origin protein source in the feed industry. This review is focused to address i) nutritional characteristics and feeding value of canola meal for ducks and ii) impacts of feeding canola meal on performances of ducks.

The aim of this study was to investigate the effect of dietary emulsifiers and lipase supplementation on growth performance, blood metabolites, intestinal organ weight, gut morphology, nutrient digestibility, carcass measurements, and meat quality in broiler chickens. A total of 384, 1-day-old Ross 308 broiler chicks were randomly allocated to one of eight dietary treatments arranged in a completely randomized design with 6 replications per treatment and 8 birds per cage. Diets were corn-soybean meal-based and formulated to meet the nutritional requirements for Ross 308 specifications. Beef tallow used as the fat source in all diets. Dietary treatments were as follows, (1) positive control (PC; energy sufficient diet); (2) negative control (NC; energy deficient,−100 ME, kcal/kg); (3) NC+POL (0.1%, Polysorbate-20); (4) NC+CET (0.1%, Ceteth-20); (5) NC+POL+TLL (0.1%, Thermomyces lanuginosus lipase); (6) NC+POL+CRL (0.1%, Candida rugosa lipases); (7) NC+CET+CRL and (8) NC+LL (0.05%, Lysolecithin). Growth performances were measured weekly. One bird per pen was selected and sacrificed to collect blood, ileal digesta, jejunum sample, viscera organ weight, and meat samples on day 21 and 35. Results revealed that birds fed NC+POL+CRL diet had higher (P < 0.05) body weight, weight gain, and the improved (P < 0.05) feed efficiency compared to birds fed other low energy diets, and the effect was more prominent at the grower phase from day 21 to 35. Similarly, higher (P < 0.05) villi height and lower (P < 0.05) crypt depth commensurate with higher (P < 0.05) V:C ratio were observed with the broiler chickens fed NC+POL+CRL diet compared to broiler chickens fed NC diet on day 21 and 35. Moreover, broiler chickens fed NC+POL+CRL diet showed improved fat and energy digestibility compared NC diet counterpart on day 35. This study, therefore indicated that Polysorbate-20 together with Candida rugosa lipases had promising ability to improve growth performance of broiler chickens fed with low energy diet and curtail the growth depression without affecting blood metabolites, carcass, and visceral organs weights.

No abstract

Chicken NK-lysin peptide 2 (cNK-2) is a natural lytic peptide with direct cytotoxicity against many apicomplexan parasites including Eimeria. Developing an effective oral delivery strategy to express cNK-2 in the intestine, where Eimeria parasites interact with the host's gut epithelial cells, may effectively reduce the fecundity of parasites and minimize intestinal damage. Furthermore, cNK-2 modulates gut immune responses to decrease local inflammation elicited by Eimeria infection in the intestine. Therefore, we developed a stable strain of Bacillus subtilis (B. subtilis) that carries cNK-2 to the gut to determine its effectiveness in ameliorating the negative impacts of coccidiosis and to replace the use of antibiotics in controlling coccidiosis in commercial broiler chicken production. Chickens were randomly allocated into eight treatment groups: two control groups (NC: E. acervulina infected non-B. subtilis control; CON: non-infected control); three B. subtilis-empty vector (EV) groups (EV6: 106 cfu/day/bird; EV8: 108 cfu/day/bird; EV10: 1010 cfu/day/bird), and three B. subtilis-cNK-2 groups (NK6: 106 cfu/day/bird; NK8: 108 cfu/day/bird; NK10: 1010 cfu/day/bird). All chickens, except those in the CON group, were challenged with 5,000 freshly sporulated E. acervulina oocysts through oral gavage on day 15. Chickens were given an oral dose of B. subtilis on days 14, 15, and 16. Body weight, weight gains, and fecal oocyst shedding were measured. To investigate the efficacy of oral B. subtilis-cNK-2 against coccidiosis, gene expression of gut health-related biomarkers was measured using RT-PCR. Markers included SOD1, CAT, and HMOX1 for oxidative stress in the spleen and intestinal mucosa, OCLN, ZO-1, and JAM2 for tight junction proteins, and MUC2 for mucin gene expression in the gut. The results showed that oral treatment of young chickens with B. subtilis-cNK-2 improved growth performance, enhanced gut integrity, and reduced fecal oocyst shedding. Altogether, these results confirm B. subtilis-cNK-2 treatment as a promising and effective alternative strategy to replace antibiotics against coccidiosis based on its ability to reduce parasite survival, to reduce coccidiosis-induced body weight loss, and to decrease gut damage based on the enhanced expression of proteins associated with gut integrity and intestinal health.

“Gut health” refers to the physical state and physiological function of the gastrointestinal tract and in the livestock system; this topic is often focused on the complex interacting components of the intestinal system that influence animal growth performance and host-microbial homeostasis. Regardless, there is an increasing need to better understand the complexity of the intestinal system and the various factors that influence gut health, since the intestine is the largest immune and neuroendocrine organ that interacts with the most complex microbiome population. As we face the post-antibiotic growth promoters (AGP) era in many countries of the world, livestock need more options to deal with food security, food safety, and antibiotic resilience to maintain agricultural sustainability to feed the increasing human population. Furthermore, developing novel antibiotic alternative strategies needs a comprehensive understanding of how this complex system maintains homeostasis as we face unpredictable changes in external factors like antibiotic-resistant microbes, farming practices, climate changes, and consumers’ preferences for food. In this review, we attempt to assemble and summarize all the relevant information on chicken gut health to provide deeper insights into various aspects of gut health. Due to the broad and complex nature of the concept of “gut health”, we have highlighted the most pertinent factors related to the field performance of broiler chickens.

Probable maximum precipitation (PMP) is widely used as an input in rainfall-runoff modelling to estimate probable maximum flood (PMF), which is required for the design of spillways of large dams. In relation to dam safety studies at 32 dam sites, an analysis was done of extreme rainfalls in Sri Lanka, which is influenced by the Asian monsoon system and cyclonic effects. Accordingly, the Hershfield's statistical method, which is one of the recommended procedures of the World Meteorological Organization (WMO), was used for estimating PMP. It is also a technique that can be readily used in design office practice. However, it is of significant value and scientific interest to explore what the outcome would have been if the physically based hydro-meteorological procedure had been adopted. For this purpose, long series of annual maximum daily rainfall data from seven stations were analysed. The research shows that the maximum moisture and corresponding wind run or the use of maximum moisture alone are two scenarios, which yield results compatible with the statistical PMP. Although globally there is a tendency to exclude wind maximization, this does not automatically apply to a country like Sri Lanka, which experiences cyclonic rainfall and special attention should be paid to precipitation efficiency. These results are further confirmed by a frequency analysis based on the generalized extreme value (GEV) distribution. An approximate value of PMP could be in the order of 2.0-3.0 times the maximum observed daily rainfall. However, this aspect needs further investigation when observed maxima are near PMP storms.

In this study, we investigated the effect of methionine isomers (D-and L-methionine) on growth performance, blood metabolite levels, nutrient digestibility, intestinal morphology, and foot pad dermatitis in broilers challenged with acute heat stress. In total, 240 broilers were randomly allocated in a 2×2 factorial arrangement consisting of two dietary treatments (D-vs. L-methionine) and two thermal environmental conditions (thermo-neutral vs. acute heat stress). Methionine isomers were added to the diet as an ingredient according to the diet formulation. The broilers were exposed to acute heat stress at 33℃ for 5 h on day 14. The average daily gain and feed conversion ratio of birds fed L-methionine were higher than those fed D-methionine (P＜0.05) from the time of hatching till 21 days. Induced acute heat stress impaired (P＜0.05) the daily gain and feed intake of the broilers on day 21. Furthermore, the blood urea nitrogen levels of birds subjected to acute heat stress on days 14 and 21 were higher (P＜0.05) than those of their counterparts. Longer villi (P＜0.05) were observed in broilers fed L-methionine-supplemented diet than in those fed D-methionine-supplemented diet on day 14, irrespective of thermal environmental conditions. Heat stress reduced (P ＜0.01) nutrient digestibility of the broilers on days 14 and 21. Higher incidence and severity of foot pad dermatitis were observed (P＜0.05) in broilers fed diet containing D-methionine than in those fed L-methionine-supplemented diet. In conclusion, L-methionine-supplemented diet improved growth performance, overcame growth depression, and reduced the incidence of foot pad dermatitis when broilers were exposed to acute heat stress in the starter period.

A study was conducted to determine the apparent metabolizable energy (AME) requirement of Korean native ducklings for hatch to 21 d of age. A total of 336 one-day-old male Korean native ducklings were used in a completely randomized design having 8 dietary treatments to provide a range of AME content from 2,600 to 3,300 kcal/kg (i.e., 100 kcal/kg disparity). Eight experimental diets containing varying levels of AME were formulated to meet the NRC (1994) nutrient specifications. Ducklings were randomly allocated to 48 pens (6 replicates per treatment and 7 ducklings per pen) and were offered their respective diets on an ad libitum basis for the period of study. Body weight and feed intake were measured weekly to calculate feed conversion ratio, energy intake, and protein intake. Two ducklings per pen (n = 6) were euthanized via cervical dislocation to weigh empty body and drumsticks at the conclusion of the experiment. Data were fitted to both linear-plateau and quadratic-plateau models for estimation of the AME requirements for Korean native ducklings for hatch to 21 d of age. The estimated AME requirements were 2,953, 3,007, and 2,950 kcal AME/kg diet for maximum daily gain, daily feed intake, and for minimum feed conversion ratio, respectively.