Effect of Pasture and Feed Additives on Performance and Egg Quality in Ranging Laying Hens
Free-range egg production is rapidly growing in Australia with an estimated retail value market share of 48% (AECL, 2014). Laying hens exposed to pasture range may experience reduced performance, poor enteric health and increased mortality (Ruhnke et al., 2014). In addition, egg quality can also be affected, indicated by the increased number of damaged and misplaced eggs as well as decreased egg shell quality (Kijlstra et al., 2009). These effects may be related to excessive fiber digestion and reduced nutrient uptake. The addition of multi-enzymes or organic acids to free-range layer diets may improve the digestion of nutrients, thus increasing performance, gut health and egg quality. A study was conducted to investigate the effect of range types and feed additives on performance and egg quality of ranging laying hens.
Impact of on-range choice feeding with black soldier fly larvae (Hermetia illucens) on flock performance, egg quality, and range use of free-range laying hens
Semi-intensive free-range farm systems are common in Australia, and these systems frequently practise on-range feeding. The objective of this study was to investigate the benefit of on-range choice feeding on flock performance, egg quality, and range use of free-range laying hens using black soldier fly larvae (Hermetia illucens, BSF). A total of 160 mature ISA brown laying hens, previously determined to range daily, were allocated to a control group (control) or a treatment group (BSF) with various replicates depending on the parameter investigated. All hens were fed ad libitum indoors with a wheat-soy based diet formulated according to breed requirements. Black soldier fly hens were offered dried BSF larvae ad libitum on the range. Body weight, feed intake, BSF intake, egg production, feed conversion ratio, internal and external egg quality parameters, and individual range use using radio-frequency identification (RFID) technology was evaluated. Black soldier fly hens consumed on average 15 ± 1.7 g BSF larvae/hen per day. There were no differences between BSF and control hens for any of the performance parameters obtained (P > 0.05). Egg weight, shell weight, and shell thickness of eggs from BSF hens were significantly lower (P = 0.003, P = 0.001, and P = 0.004, respectively) than those of eggs from control hens. Egg yolk colour was significantly paler in eggs from BSF hens (P < 0.001). No significant ranging differences between the BSF and control hens were observed (P > 0.05) except for BSF hens showing longer total maximum time for a single visit to the range (P = 0.011). In conclusion, the average intake of BSF larvae indicated a good level of acceptance. Feed formulation should be adjusted for the intake of the choice fed source. The impact of choice-feeding on range use was minor.
The addition of feed enzymes to layer diets based on wheat or wheat plus rye
Four different commercial enzyme products were added to either a standard commercial wheat-based layer diet or the same diet with 20% of the wheat substituted with cereal rye. Diets were fed to Isa Brown laying hens from 50 to 65 weeks of age. Measurements of egg and egg shell quality, apparent metabolisable energy and excreta moisture were conducted at five-weekly intervals. Digesta viscosity was measured at the end of the trial. The AME of the diets was similar and relatively stable. Excreta moisture was not affected by the addition of feed enzymes. Egg and egg shell quality varied significantly as the birds grew older and was significantly better for the wheat+rye diet as compared with the wheat diet. There were few effects of enzymes on egg and egg shell quality except that Kemzyme resulted in lower albumen quality and lighter shell colour. Production was not affected by type of diet but the Roxazyme treatment had the highest production. Both type of diet and the addition of enzymes affected egg and egg shell quality.
Pasture, multi-enzymes, benzoic acid and essential oils positively influence performance, intestinal organ weight and egg quality in free-range laying hens
1. The objective of this study was to investigate the effect of range type, multi-enzyme applications, and a combination of benzoic acid (BA) and essential oils (EO) on the productive performance, organ weight and egg quality of free-range laying hens. 2. Three hundred laying hens were evaluated for the short-term (6 weeks) and long-term (12 weeks) effects of range type (G = no pasture, P = pasture) and feed additives (T1 = control; T2 = betaglucanase/pectinase/protease; T3 = BA/EO). Body weight, feed intake (FI), feed conversion ratio (FCR), egg production (EP), digestive organ weight, and egg quality (EQ) were evaluated. Data were analysed using SPSS 2.2 in a 2×2×3 factorial arrangement. 3. Hens that ranged on pasture were significantly heavier (2043 g vs. 1996 g; p < 0.001), laid heavier eggs (61.9 g vs. 60.3 g; p < 0.001) and produced darker yolk colour (4.3 vs. 7.0; p < 0.001) compared to hens ranged on gravel. Hens fed T2 were significantly heavier (2050 g) compared to hens fed T1 (2005 g) or T3 (2008 g). Organ weights (gizzard, liver and pancreas) were significantly heavier in hens ranged on pasture (16.8 g/kg BW, 22.3 g/kg BW and 1.89 g/kg BW, respectively) compared to hens ranged on gravel (14.2 g/kg BW, 21.7 g/kg BW and 1.83 g/kg BW, respectively). Over time, body weight (1970-2070 g; p < 0.001) and egg weight (59.5-62.8 g; p < 0.001) increased, FI (123-120 g; p = 0.024) was reduced and FCR (2.36-2.10; p = 0.002) improved 4. In conclusion, hens housed on pasture and fed multi-enzyme supplemented diets had significantly heavier body weight and produced heavier eggs with darker yolk colour. Pasture intake and enzyme supplementation increased digestive organ weight significantly.
The impact of choice feeding with the black soldier fly larvae ('Hermetia illucens') on egg quality in free range laying hens
Introduction: Insects, such as the Black Soldier Fly larvae ('Hermetia illucens', BSF), could be considered as an alternative protein sources as they have high crude protein content (De Marco et al, 2015). In Australia, free-range egg production is a rapidly growing sector, with an estimated retail market value share of 51%. Extensive hen housing, on-range feeding and choice feeding are all common practices in smaller enterprises (Ruhnke et al., 2016). The hypothesis of the present study was that choice feeding with black soldier fly larvae would not affect egg quality in free range laying hens.
Feed enzymes and wheat-based diets in laying hens
In Trial 1, four different commercial enzyme products were added to standard commercial layer diets, based on two different types of wheat, "normal" wheat and "pinched" wheat. Diets were fed to Isa Brown laying hens from twenty-five weeks of age. In Trial 2 (50 to 65 weeks of age), all diets were based on pinched wheat or pinched wheat containing 20% cereal rye. Measurements of egg and egg shell quality were conducted at five-weekly intervals. Apparent metabolisable energy and excreta moisture were measured every 5 weeks from 30 to 65 weeks of age. The AME of the diets was similar for the two types of diet in both trials. AME increased to 40 weeks of age, remained relatively stable and then decreased slightly. Excreta moisture was not affected by enzymes in either trial. Egg and egg shell quality varied significantly as the birds grew older and was significantly better for normal wheat than pinched wheat and for wheat+rye versus wheat. Shell breaking strength was slightly lower for Biofeed Wheat and Avizyme, shell reflectivity was higher for Roxazyme and Kemzyme, and percentage shell and shell thickness was higher for Kemzyme. Yolk colour showed minor variation among the enzyme treatment groups. Production was not affected by type of diet or enzymes in either trial. Both type of grain and the addition of enzymes have the potential to affect egg and egg shell quality.
Diet type, apparent metabolisable energy and digesta viscosity in laying hens of two different ages
Diets based on wheat, barley or sorghum were fed to younger and older laying hens for a period of 12 weeks. Production and weekly egg mass were higher for the younger birds and feed intake and feed conversion efficiency were higher for the older hens, with no effect of diet. Egg shell quality and egg internal quality were better for the younger hens. The sorghum diet resulted in eggs with better shell quality but lighter shell colour and lower albumen quality. AME was higher for the older birds and differed among diets, with sorghum the highest and barley the lowest. Excreta moisture was higher for the wheat and barley diets than the sorghum diet, and higher for the older birds. The digesta viscosities of the jejunum and ileum were higher for the wheat and barley diets than for the sorghum diet and not different between the younger and older hens.
Effects of commercial enzyme preparations on egg and eggshell quality in laying hens
1. Four different commercial enzyme products were added to standard commercial layer diets, based on barley, wheat or triticale. 2. Diets were fed to 4 different strains of commercial laying hen: ISA Brown, Hy-Line CB, Tegel SB2 and Tegel HiSex. 3. Diets were given for 5 weeks prior to measurements of egg and eggshell quality. 4. The inclusion of commercial enzyme products in the diets had no effect on egg weight. 5. Positive effects of the enzymes were: improved eggshell breaking strength, shell weight, percentage shell and shell thickness for the barley-based diet and increased eggshell breaking strength for two of the enzymes with the wheat-based diets. 6. Negative effects of the enzyme products were slightly lighter coloured eggshells and reduced albumen quality for the barley-based diet and for two enzymes with the wheat-based diet. 7. The addition of commercial enzyme preparations had no main effect on egg and eggshell quality for the triticale-based diet, except for effects on yolk colour. 8. Yolk colour was lower than control for enzyme 3 in all diets and for enzyme 4 with the barley- and wheat-based diets. 9. Further investigation is required to elucidate the specific enzyme components that influence egg quality.