Effect of hatching time on time to first feed intake, organ development, enzymatic activity and growth in broiler chicks hatched on-farm

Effects and Interactions of Incubation Time and Preplacement Holding Time on Mortality at Placement, Yolk Sac Utilization, Early Feeding Behavior and Broiler Live Performance

The effects and interactions of incubation time and chick preplacement holding time on mortality at placement, utilization of yolk sac, crop filling rate, early feeding-drinking behavior, and broiler live performance were investigated. Ross 308 broiler hatching eggs from a 39-week-old flock were set in two identical setters in a commercial hatchery, with the setting time 12 h earlier in one machine. At the end of incubation, chicks were removed from the hatchers at the same time. Thus, the incubation times were either 504 h (normal incubation time (NIT) treatment) or 516 h (longer incubation time (LIT) treatment). After the pull time, chicks from each incubation time group were subjected to either 6, 24, 48, 60, or 72 h preplacement holding times. At placement, chicks were given access to feed and water. In total, 19,200 chicks were randomly assigned to a total of 10 subtreatment groups (2 incubation times × 5 preplacement holding times). Therefore, a total of 1920 chicks were used in each subtreatment group for the grow-out period in a commercial broiler house. For the first week of the experiment, 160 randomly selected as-hatched (not sexed) chicks were placed in 12 replicate floor pens (120 total pens). From the second week of age onward, chicks from two pens were combined into six replicate pens, with 320 chicks per replicate (60 total pens). An interaction was found between incubation time and preplacement holding time for residual yolk sac (RYS) weight (g, %) (p < 0.001). RYS weight was greater at pull time and at 6 and 24 h of preplacement holding in the NIT treatment compared to the LIT treatment, while differences were no longer evident at 48-72 h. The lowest percentage of chicks with full crops and eating activity was observed in the shortest preplacement holding time (6 h) group at 3 h after placement. As expected, the initial BW at placement clearly decreased with increasing duration after the pull time (p < 0.05), with the highest and lowest weights found in the 6 and 72 h holding time treatments, respectively. This BW difference was still evident at 35 d after placement and chicks held for the longest period after the pull time (72 h) showed the lowest BW (p < 0.001). However, there was no significant difference between the 6 and 60 h preplacement holding times. Mortality during the first 7 d after placement increased only when the preplacement holding time was extended to 72 h (p = 0.031). Similarly to the 7 d results, chicks held for 72 h exhibited higher 0-35 day mortality compared to those held for 6 or 24 h (p = 0.028). Neither BW nor mortality was affected by incubation time treatment at 35 d after placement (p > 0.05). It can be concluded that there were no significant differences in average BW and mortality, up to and including a 60 h holding time under thermal comfort conditions, but a 72 h preplacement holding time resulted in final BW and mortality being negatively affected. In addition, LIT tended to have a beneficial effect on BW and mortality compared to NIT when the preplacement holding time was shorter (6-24 h) but had a negative effect for extended holding times (48-72 h).

Effects of algal supplementation in feed to broiler breeders on transfer of nutrients and antibodies to chicks and quality of hatchlings

Breeder nutrition is an important factor for chick quality since the chick embryo relies on nutrients available in the egg for growth and development. In addition, the egg is providing the chick with important antibodies that are vital during the first weeks of life. Brown algae contains several bioactive compounds, and dietary supplementation with algal extracts have shown improved gut health and immune responses in both pigs and poultry. The aim of this study was to investigate if feeding the brown algae Saccharina latissima, intact or as an extract, to broiler breeders can affect breeder hens' antibody responses to vaccination, egg quality and transfer of antibodies and nutrients to the egg and thereby improve the quality of newly hatched chicks. Forty-five hens and nine roosters of the parent lines of the fast-growing broiler Ross 308 were included in the experiment where hens were 31 weeks at the start. The hens were housed individually and fed one of three dietary treatments for seven weeks; (a) control, (b) addition of 0.6% algal meal or (c) addition of 0.08% algal extract. The hens were given a booster vaccination against infectious bronchitis virus (IBV) 21 days after the start of experiment. During experimental days 32-42, hens were naturally mated every 5th day and hatching eggs were collected. A total of 255 chicks were hatched, and chick quality was assessed. Moreover, on chick day three, blood was collected from 48 focal chickens and total immunoglobulin Y levels and specific titres to IBV in serum were determined. The results showed that feeding the brown algae Saccharina latissima, intact or as an extract to broiler breeders did not affect egg production, egg quality, antibody responses to vaccination or transfer of antibodies from hen to chick. However, feeding intact algae significantly increased the levels of iodine and decreased the level of selenium in the eggs and resulted in a lower proportion of chicks with maximum quality score. Interestingly, algal feeding, both intact and as an extract, increased the abdominal fat pad in broiler breeders by about 17% without affecting BW. In conclusion, supplementation of broiler breeder diets with algal extract from Saccharina latissima, but not intact algal meal is a promising dietary strategy to increase the abdominal fat pad without causing any adverse effects on nutrient level in eggs or chick quality.

Effects of access to feed, water, and a competitive exclusion product in the hatcher on some immune traits and gut development in broiler chickens

This study evaluated the effect of access to feed, water, and the competitive exclusion (CE) product Broilact®, administered in the hatcher, on broiler performance, caecal microbiota development, organ development, intestinal morphology, serum levels of IgY and vaccine-induced antibody responses.In total, 250 chicks were hatched in a HatchCare^TM hatcher and divided into four groups, given access to feed, water and the CE product sprayed on the chicks (CEs); access to feed, water, and the CE product in water (CEw); access to feed and water (Cpos); or no access to feed and water (Cneg) in the hatcher. At the research facility, 10 chicks per hatching treatment were euthanized for organ measurements. The remaining 200 chicks were randomly distributed to 20 pens. On d 11, all birds were vaccinated against avian pneumovirus (APV). Three focal birds per pen were blood-sampled weekly for quantification of IgY and serum antibodies to APV. On d 11 and 32, two birds per replicate pen were euthanised for organ measurements and sample collection. Feed intake and body weight were recorded weekly.Delayed access to feed and water reduced weight gain and feed intake early in life. At the end of the study, no differences in body weight remained.There were some early effects on organs, with depressed intestinal development and higher relative gizzard weight for the Cneg group at placement. No treatment effects on the immune traits measured were detected. The relative abundance of seven bacterial genera differed between treatment groups at d 11 of age. The results suggested that chickens are capable of compensating for 40 h feed and water deprival post-hatch. Provision of Broilact® did not have any persistent performance-enhancing properties, although different outcomes under rearing conditions closer to commercial production cannot be ruled out.

Influence of the preplacement holding time and feeding hydration supplementation before placement on yolk sac utilization, the crop filling rate, feeding behavior and first-week broiler performance

This study investigated the effects of the broiler chick preplacement holding time and feeding hydration supplementation before placement on yolk sac utilization, the crop filling rate, feeding–drinking behavior and first-wk broiler performance. Broiler hatching eggs were obtained from a commercial broiler breeder flock of Ross 308 at 37 wk of age and incubated in a commercial hatchery. At 510 h of incubation, all chicks were removed from the hatcher and separated into cardboard chick boxes containing 80 chicks each. The chick boxes were randomly separated into two groups with either added commercial hydration supplementation (gel: Hydrogel-95) or the control (no gel). Then, the chicks were randomly distributed into 5 groups with different holding times across each hydration supplementation treatment (gel and control). The preplacement holding times were 6, 24, 48, 60, and 72 h from the pull time from the hatchers in the hatchery to placement in the broiler house on the farm, at which point the chicks were able to access feed and water. There were 10 subtreatment groups comprising 5 chick preplacement holding time groups × 2 hydration supplementation groups. There were 12 replicates (160 chicks per pen) per holding period × gel treatment, with a total of 19,200 chicks placed. The feed and water access time did not influence yolk sac utilization, but the absolute or relative residual yolk sac (g, %) decreased linearly with the duration after the pull time (P < 0.001). Longer preplacement holding times were associated with a higher percentage of chicks with full crops at 3 h after placement (P < 0.001). Chicks with the shortest (6 h) preplacement holding time had a lower percentage of feed-seeking activity compared to the 24, 48, and 72 h holding time groups at 3 h after placement (P < 0.001). The highest chick eating and drinking activity was observed in the 72 h group at both 3 and 8 h after placement. Chick weight at placement was significantly reduced linearly with the duration after the pull time (0.106 g/h; R² = 0.775), and as expected, the highest and lowest BW were found in the 6 (41.51 g) and 72 h (34.50 g) preplacement holding time groups, respectively. However, BW and BW gain were higher in the 24 h group than in the other preplacement holding time groups (P < 0.001) at 7 d after placement. Mortality within the first 3 d after placement increased only when the preplacement holding time was extended to 72 h (P = 0.002). Mortality during 4 to 7 d postplacement was not affected by the holding time at all, but the 72-h holding time group still had statistically significantly higher mortality cumulatively from 0 to 7 d (P = 0.024). Neither BW nor mortality was affected by feeding the hydration supplement at placement, and the lack of effect persisted through 7 d after placement (P > 0.05).

It can be concluded that the BW at 7 d after placement was greater in the 24 h holding time group than in shorter (6 h) or longer (48, 60, and 72 h) preplacement holding time groups. In the present study, a greater number of chicks were raised, and it was clearly demonstrated that mortality, as a direct indicator of flock health and welfare, was not affected by preplacement holding times up to and including a 60 h after take-off under thermal comfort conditions, but holding for a further 12 h to 72 h, mortality at 7 d of age after placement was increased. On the other hand, holding chicks in a short period (6 h) did not improve mortality and the BW at 7 d, suggesting that some delay to placement can be beneficial. In addition, feeding hydrogel during the preplacement holding period had no positive effect on BW gain and cumulative mortality during the first week of the growing period.

Effect of Acetic Acid and Sodium Bicarbonate Supplemented to Drinking Water on Water Quality, Growth Performance, Organ Weights, Cecal Traits and Hematological Parameters of Young Broilers

To evaluate the effect of acetic acid and sodium bicarbonate supplemented to drinking water on water quality, growth performance, relative organ weights, cecal traits and hematological parameters of broilers, a total of 456 one-day-old Cobb MV × Cobb 500 FF mixed broilers were randomly placed in three experimental treatments, with four replicates per treatment and 38 birds per replicate, for 10 days. The treatments consisted of the use of acetic acid (0.4%; T1) as acidifier, an apparently neutral pH (T2) and sodium bicarbonate (1%; T3) as alkalizer of the drinking water. T3 showed the highest values (p < 0.05) for total dissolved solids, electrical conductivity, salinity and pH. T1 and T2 showed the same productive response (p > 0.05); however, T3 decreased (p < 0.05) body weight, feed intake and the relative weight of the pancreas and immune organs and increased (p < 0.05) water intake, mortality and relative weight of the heart and liver. Likewise, T3 increased (p < 0.05) the cecal pH, although without changes for the cecal lactic cecal bacteria count and blood parameters (p > 0.05). The acid pH of the drinking water had no effect on the biological response of broilers compared to T2; however, the T3 provoked high mortality, ascites, low productivity and abnormal growth of some organs.