Chick quality: an overview of measurement techniques and influencing factors

A conventional hatchery vs "on-farm" hatching of broiler chickens in terms of microbiological and microclimatic conditions

"On-farm hatching" is one of the proposed alternatives to conventional hatchery-hatching. This solution reduces distress and improves the welfare of the chicks around the hatching period. Therefore, it seemed interesting to compare conventional hatchery and "on-farm" hatching in terms of microbiological and microclimatic conditions. Hatching eggs (Ross 308) were incubated in a commercial hatchery. The control group (HH, 683 eggs) hatched in a conventional hatcher, while the other eggs were transported into the experimental chicken-hall for on-farm hatching, and set in pens directly on litter (OL, 667 eggs) or plastic trays (OT, 678 eggs). One-day-old chicks were also placed in the experimental hall. Microclimatic parameters were controlled every 12 h. The microbiological status of the surface of the eggshells and the litter was assessed based on the total number of aerobic mesophilic microorganisms and also the selected individual genus/species of bacteria. The hatchability of HH was 96.4% in comparison to 93.9% and 95.8% for OL and OT, respectively (P > 0.05). On the other hand, 2.1% of the HH chicks were found injured/dead, while only 0.2-0.3% of the on-farm groups were. The total number of aerobic mesophilic microflora on the surface of as-hatched shells was 4.93 ± 0.629 log CFU/g in HH, while only 1.14 ± 0.995 and 1.93 ± 1.709 log CFU/g in OL and OT, respectively (P < 0.001). Similarly, the total count of bacteria in the litter in the on-farm hatched pens was 1.9-fold lower than in pens set with HH chicks (P < 0.001). In summary, on-farm hatching results in hatchability that is no worse than in a conventional hatcher, while the microbiological status of as-hatched eggshells and litter is significantly better. Therefore, on-farm hatching seems to provide appropriate environmental conditions for newly hatched chicks and poses no epizootic risk.

The effects of exposure to cold during incubation on developmental stability, fear, growth, and carcass traits in Japanese quails

The aim of this study was to determine the effects of 6 h/day cold (35.0 °C) acclimatization between the 9^th and 15^th days of incubation of Japanese quail embryos on hatchability, livability, chick quality, developmental stability, fear response, live weight, and slaughter-carcass characteristics. Two homologous incubators and a total of 500 hatching eggs were used in the study. Randomly selected half of the eggs were exposed to cold according to the eggshell temperature. The cold acclimation of Japanese quail embryos had no adverse effects on all mentioned traits, except for chick quality. Chicks in the control group had higher Tona scores (99.46) than those exposed to cold (99.00) (P < 0.05). In addition, there were differences among the treatment groups in terms of the parameters of mature weight (β₀), instantaneous growth rate (β₂), and inflection point coordinates of the Gompertz growth model (P < 0.05 for all). It was found that exposing embryos to cold during the incubation changed the shape of the growth curve. As the development of embryos exposed to cold slows down, a compensatory growth occurs in the early posthatch period. Thus, the growth rate increased in the period before the inflection point of the growth curve.

An evaluation of the thermoregulatory potential of in ovo delivered bioactive substances (probiotic, folic acid, and essential oil) in broiler chickens

Mitigating the negative effects of heat stress (HS) is a critical challenge for the global poultry industry. This study evaluated the thermoregulatory potential of 3 in ovo delivered bioactive substances using selected gut health parameters. Eggs were incubated and allotted to 5 groups, and respective bioactive substances delivered. These groups included-the noninjected, in ovo saline, in ovo folic acid (FA), in ovo probiotics (P), and in ovo essential oil (EO). At hatch, chicks were assigned to 5 new posthatch treatment combinations, including A) Negative control (NC)-noninjected eggs offered a basal corn-wheat-soybean diet, B) Antibiotics-NC + 0.05% bacitracin methylene disalicylate, C) In ovo FA-eggs injected with FA + NC diet, D) In ovo probiotics-eggs injected with probiotics + NC diet, E) In ovo + in-water EO-eggs injected with EO and supplied EO via drinking water + NC diet. Birds were raised for 28 d in 8 replicate cages/treatment (6 birds/cage) and exposed to either a thermoneutral (24°C ± 0.2) or HS challenge (31°C) condition from d 21 to d 28. The in ovo delivered FA and EO treatments reduced (P < 0.001) hatchability by at least 26% compared to NC. Induced HS reduced (P < 0.001) total plasma protein, total antioxidant capacity, and villus width in the duodenum and jejunum. Independent of HS and compared to NC, the in ovo + in-water EO treatment resulted in (P < 0.05) at least a 15% increase in villus height: crypt depth across the 3 gut sections. The in ovo + in-water EO treatment also increased the relative mRNA expression of intestinal barrier-related genes (Claudin1,3,4, Occludin, Zona occludens-2, and Mucin 2). Under HS, the in ovo + in-water EO treatment recorded a 3.5-fold upregulation of amino acid transporter gene (SLC1A1), compared to NC. Subject to further hatchability optimization, the in ovo + in-water delivery of EO show potential to afford broiler chicken thermotolerance.

Impact of growth curve and dietary energy-to-protein ratio of broiler breeders on offspring quality and performance

The impact of growth curve (GC) and dietary energy-to-protein ratio of broiler breeder hens on chick quality and broiler performance was investigated. Pullets (n = 1,536) were randomly allotted to 24 pens and assigned to 1 of 8 treatments from hatch onwards, according to a 2 × 4 factorial arrangement with 2 GC (standard growth curve = SGC or elevated growth curve = EGC, +15%) and 4 diets, differing in energy-to-protein ratio (96%, 100%, 104%, and 108% AME_n diet). At 28 and 36 wk of age, 60 hatching eggs per maternal pen were selected for incubation and 768-day-old broilers were assigned to 32 pens according to maternal treatment.

Broilers from EGC breeders were 1.9 g heavier at hatch (P < 0.001) and 36 g heavier at slaughter (P = 0.001) than broilers from SGC breeders due to a 1.0 g/d higher growth rate (P = 0.003) and 1.5 g/d higher feed intake (P = 0.006) from hatch to 32 d of age. An increase in breeder dietary energy-to-protein ratio resulted in a linear decrease in embryonic mortality in the first 3 d of incubation (β = -0.2% per % AME_n; P = 0.05). At hatch, broiler BW decreased with an increasing breeder dietary energy-to-protein ratio (β = -0.1 g per % AME_n; P = 0.001), whereas at slaughter broiler BW increased with an increasing breeder dietary energy-to-protein ratio (β = 3.2 g per % AME_n; P = 0.02). This was due to a linear increase in growth rate (β = 0.1 g/d per % AME_n; P = 0.004) and feed intake (β = 0.1 g/d per % AME_n; P = 0.02). Additionally, an increase in breeder dietary energy-to-protein ratio resulted in a linear decrease in body weight corrected feed conversion ratio (β = -0.002 per % AME_n; P = 0.002). Overall, it can be concluded that a higher GC of breeders and an increase in breeder dietary energy-to-protein ratio enhances offspring performance.

Influences of Dietary Supplementation with Maca (Lepidium meyenii) on Performance, Parameters of Growth Curve and Carcass Characteristics in Japanese Quail

Simple Summary

It is known that the bioactive compounds (N-benzyl-palmitamide, benzyl isothiocyanate, glucosinolates and phenolics) in the maca plant are appetizing, as well as having antioxidant effects and improving reproductive ability. The aim of this study was to determine the effects of adding maca plant powder to the ration at different levels on growth, slaughter carcass, partial egg production and some reproductive characteristics of Japanese quail (Coturnix coturnix japonica). Addition of maca powder to the diet increased the feed consumption but did not affect growth, slaughter carcass, partial egg production or fertility. In addition, maca powder reduced embryonic deaths and improved chick quality. According to these results, the positive effects of short-term application of maca powder are not observed during the fattening period in Japanese quails.

Abstract

Maca plant contains rich nutrients and in addition, it has various bioactive substances (N-benzyl-palmitamide, benzyl isothiocyanate, glucosinolates and phenolics). It is used to improve reproductive properties and has antioxidant effects for both humans and animals. The aim of this study was to determine the effects of adding maca plant powder to the ration at different levels on growth, slaughter carcass, partial egg production and some reproductive characteristics in Japanese quail (Coturnix coturnix japonica). The experimental groups were formed by adding 0% (control), 0.05% and 0.1% maca powder to the diet, and a total of 300 birds were used. Growth (weekly body weights, parameters of Gompertz growth function), feed efficiency and carcass characteristics of quails in the 42-day fattening trial were determined. Reproductive characteristics were measured up to 22 weeks of age. Addition of maca powder to the diet increased the feed consumption (p < 0.05) but did not affect body weights at 35 and 42 days of age, β₀ and β₁ parameters or point of inflection weight of the Gompertz model, carcass traits, partial egg production or fertility. It may be advisable to add 0.1% maca powder to the diets of breeders. Besides, maca powder reduced embryonic deaths and improved chick quality (both p < 0.05). It is thought that different results for reproductive traits can be obtained if maca powder is used for a longer period in the diets of breeder quail flocks.