Growth performance, carcass characteristics and meat sensory evaluation of broiler chickens fed diets with fermented cassava leaves

Objective

The objective of the study was to determine the effects of feeding fermented cassava leaf meal (FCLM) on growth performance, carcass characteristics and meat sensory evaluation of broiler chickens.

Methods

A total of 160 Cobb-500 chickens were used during the phases of growing (21 days of age; initial weight 0.39 ± 0.025kg/bird) and finishing (35 days of age; initial weight 1.023 ± 0.164 kg/bird). The whole experiment lasted for four weeks. The FCLM was included in starter and finishing diets at 0, 50, 100, and 150 g/kg inclusion levels. Total feed intake (TFI), weight gain (WG), feed conversion ratio (FCR) and nutrient digestibility were recorded. Sensory evaluation of breast meat was used to determine the eating quality of the meat prepared using roasting and boiling methods.

Results

The total feed intake (TFI) and weight gain (WG) decreased (P < 0.05) with increasing inclusion levels of FCLM in the diets of growing chickens. Crude protein digestibility for chickens fed 0 and 50g/kg FCLM was higher (P < 0.05) than for chickens subjected to a diet with 150 g/kg FCLM. During the finishing phase, TFI increased linearly (P < 0.05) with increasing inclusion level of FCLM in chicken diets, while WG decreased (P < 0.05) with inclusion level of FCLM. Treatment diets had no effect (P > 0.05) on the eating qualities of breast meat. However, juiciness was significant (P < 0.05) for the cooking method and treatment interaction. At 50 g/kg inclusion level, boiled meat had a higher (P < 0.05) juiciness score than roasted meat. Tenderness, on the other hand, was significant (P < 0.05) for the interaction of gender and treatment. Females considered the boiled meat to be more tender than the males at 150g/kg inclusion level. Using principal component analysis (PCA), a positive correlation was observed between teeth adhesion and fibrousness, flavour and juiciness, and springiness and tenderness.

Conclusion

From the study, it can be concluded that FCLM can be used as an ingredient in the diets of broiler chickens. Inclusion level of 50g/kg can be used in chicken diets during the growing phase, whereas in the finishing phase, inclusion level of 150g/kg FCLM can be used. The FCLM did not affect the eating quality of breast meat.

Lactobacillus buchneri and molasses can alter the physicochemical properties of cassava leaf silage

In developing countries where feed resources are scarce, cassava leaves can be used as feed for animals. However, the use of cassava leaves is limited mainly because of their high fibre content and overall acceptability by animals. The resolution to this problem is to process the cassava leaves by ensiling and using additives. Therefore, the objective of the study was to determine the effects of including different inclusion levels of molasses and bacteria concentration on the physicochemical properties of cassava leaf silage. Molasses was added at inclusion levels of 0, 3, 5 and 7 g/100g of the chopped cassava leaves, and Lactobacillus buchneri was mixed with chopped cassava leaves at different concentrations of 0, 3.1 × 106 cfu/ml, 3.1 × 108 cfu/ml and 3.1 × 1010 cfu/ml. The effects of inclusion level of molasses on the colour, smell and texture of cassava leaf silage were significant (P < 0.05). Inclusion of bacteria concentration also influenced the smell of silage (P < 0.05). Effects of the inclusion level of molasses and bacteria concentration resulted in decreased pH, crude protein and crude fibre of silage (P < 0.05). There was a quadratic relationship between Ca and K with inclusion level of molasses in cassava leaf silage (P < 0.05). A positive linear relationship was observed between Mg and molasses inclusion levels in cassava leaf silage (P < 0.05). Using principal component analysis (PCA), molasses had a strong positive correlation with PCA 1, whereas crude fibre, pH and crude protein had a positive correlation with PCA 2. The inclusion level of bacterial concentration was negatively correlated to Ca, CP, P and CF. From the study, the use of molasses and L. buchneri can greatly improve the physicochemical qualities of cassava leaf silage.

Relationships between litter size, sex ratio and within-litter birth weight variation in a sow herd and consequences on weaning performance

Routine selection for litter size has resulted in an increase in the proportion of lightweight piglets. There is a need to balance prolificacy with litter uniformity to maximize profit. A total of 3,465 piglets from 310 litter records obtained from 2016 until 2019 at the Pig Industry Board research unit, Arcturus, Zimbabwe were used to determine the relationships between litter size, sex ratio, and within-litter birth weight variation in the sow herd and consequences on performance at weaning. The regression procedure of SAS was used to determine the relationships between litter size, sex ratio, and within-litter birth weight variation. The regression procedure was also used to determine the relationships between number born alive, within-litter birth weight variation, and sex ratio, and litter performance traits at weaning. Parity of sow, year, and month of farrowing did not affect sex ratio (P > 0.05). The number born alive and number of piglets born had no relationship with sex ratio (P > 0.05). As the sex ratio increased, percent survival of piglets at weaning also increased linearly (P < 0.05). As the proportion of males in litters increased, within-litter birth weight variation and within-litter weaning weight variation increased reaching maximum as the proportion of males in litters approached 0.5 and then decreased onwards. As the proportion of males in litters approached 1, within-litter birth weight variation and within-litter weaning weight variation reached their least values. In conclusion, within-litter sex ratio does not vary with parity, year, and month of farrowing. Within-litter weight variation is highest in litters with equal number of male and female piglets and lowest in unisex litters. This implies that the production of unisex litters can help to reduce the variation in the weight of pigs at birth, weaning, and marketing which is one of the biggest economic challenges faced by pork producers.

A review of limitations to using cassava meal in poultry diets and the potential role of exogenous microbial enzymes

Cassava (Manihot esculenta), a crop grown in the tropics, is increasingly becoming a vital feed resource for human beings and livestock. Traditionally, cassava has been used primarily as a source of food for humans. However, it is becoming an increasingly important ingredient in livestock feed. The use of cassava leaves and roots in poultry diets is limited because of nutrient imbalances and toxins (hydrogen cyanide (HCN)) found in them. High HCN is reduced to innocuous levels by processing the ingredient using a simple sun drying method. Plant fibre content can be reduced and made available for use by poultry through the use of exogenous enzymes. More recent innovative interventions in biotechnology have brought about various exogenous enzymes that can help improve the digestibility of fibrous diets. These include, among others, carbohydrases, proteases and phytases. The extent to which the animals utilise nutrients is influenced by the type of enzyme and the physicochemical properties of the feed ingredient. This review aims to collate information on the current state of knowledge on the use of exogenous microbial enzymes in diets containing cassava and how the enzymes that target carbohydrates might be useful in making nutrient available for poultry.

Effect of Varying Inclusion Levels of Fossil Shell Flour on Growth Performance, Water Intake, Digestibility and N Retention in Dohne-Merino Wethers

Simple Summary

With the recent negative public opinion on chemical-based feed additive in many nations of the world (for the health implication and environmentally hazard it posed), naturally occurring feed additive are urgently needed to replace and support the sustainable development in livestock production. The potential of Fossil shell flour as performance enhancer was investigated in this study. The major finding was that fossil shell flour increased growth performance, apparent nutrient digestibility, N retention and make minimum use of water in Dohne-Merino wethers. Hence it could be an alternative to chemical-based feed additive in livestock production.

Abstract

This study was carried out to determine the effect of varying levels of Fossil shell flour (FSF) supplementation on growth performance, water intake, digestibility and N retention in Dohne Merino sheep pursuant to establishing the optimum inclusion rate of this supplement in Dohne Merino diets. Sixteen Dohne-Merino wethers (18 ± 1.5 kg body weight) were used in a complete randomized design with four animals per treatment. Sheep were fed a basal diet without FSF addition (control, T1), or with the addition of FSF (2%, T2), (4%, T3) or (6%, T4) of the diet for 105 days. Treatment 3 (4% FSF) has the highest values of dry matter intake, total weight gain, N retention and for most of the apparent digestibility nutrients (CP, EE and Ash) compared to treatment T1, T2 and T4(p < 0.05). The urinary and fecal N excretion also significantly decreased in the FSF treated diets compared to the control (p < 0.05). Water intake values were highest in control and were significantly (p < 0.05) different from those in treatments 2 and 4, but not to treatment 3. It is concluded that 4% inclusion rate of FSF will give the best improvement on growth performance, diet digestibility and N retention of Dohne-Merino sheep. Also, the addition of FSF in the diets of sheep is a safe natural additive that can help to reduce environmental pollution by reducing fecal and urinary N excretion.