Effect of diet phase change, dietary Ca and P level and phytase on bird performance and real-time gizzard pH measurements

Abstract

In this study, a novel capsule technique was used to capture real-time pH readings from the gizzard over several hours, in response to different dietary treatments. 1. The first experiment was a preliminary study into capsule administration and pH recordings using 9 male Ross 308 broilers from 20 d. In the second experiment, broilers (576) were fed in two phases (0-21 and 21-42 d) with 4 treatment groups; low and adequate Ca and AvP diets with and without Quantum Blue phytase (1500 FTU/kg). Capsules were administered to 8 birds from each treatment group, pre and post diet phase change, with readings captured over a 2.5 h period. 2. Phytase addition improved body weight gain (BWG) and feed conversion ratio (FCR) of birds fed low dietary Ca, while having no significant effect on birds fed adequate Ca diets. Unexpectantly, diets with higher Ca levels gave a lower average gizzard pH compared to the low Ca diet. Phytase addition, irrespective of Ca level, increased average gizzard pH. Fluctuations in gizzard pH (0.6-3.8) were observed across all treatment groups. Higher frequencies of pH readings below pH 1.0 were seen in birds fed an adequate Ca diet and with phytase supplementation of a low Ca diet. 3. These results signify the potential use of capsule techniques to monitor real-time pH changes. The implication on gastric protein and fibre hydrolysis as a result of large fluctuations in pH should be considered.

Effect of phytase supplementation on plasma and organ myo-inositol content and erythrocyte inositol phosphates as pertaining to breast meat quality issues in chickens

“…This was an extension of a study published by Greene et al (2019). Some of the experiments formed partial studies (Lee et al, 2017(Lee et al, , 2018. For these latter experiments, the trials were reviewed by the Drayton Animal Health Welfare and Ethical Review Body and conducted according to the Animals (Scientific Procedures) Act 1986.…”

“…The design of the feeding trials from which blood, plasma, kidney, liver and muscle tissue were obtained for this study have been previously described (Greene et al, 2019;Lee et al, 2017Lee et al, , 2018.…”

“…Gizzard, kidney, liver and muscle tissue were obtained from Lee et al (2017), from 576 Ross 308 broilers, housed in 32 pens with 18 birds per pen from 1-42 d. Diets were fed in two phases (0-21 and 21-42 d) as four treatment groups; low and adequate levels Ca and AvP diets with and without QB at 1,500 FTU/kg. Eight samples of each tissue were taken from randomly selected birds in each of the treatment groups.…”

“…The effect of phytase on tissue inositol is rarely tested (Gonzalez-Uarquin et al, 2020). Analysis of samples obtained from Lee et al (2017), where four diets containing low or adequate Ca /AvP with zero or 1,500 FTU/kg of phytase was described (Table 7). Phytase reduced the InsP 6 content of the gizzard from 4,311 to 211 nmol/g in the low Ca/AvP diet and from 3,698 to 403 nmol/g in the adequate Ca/AvP diet.…”

A study on Indian Peafowl (Pavo cristatus) emphasising breeding season and feeding behaviour in captivity

“…To investigate the food habits of other birds, crop or gizzard contents are analysed which give more accurate results as compared to faecal analysis, as food items in faeces are more difficult to recognize as compared to bird's crop or gizzard contents (Mwalusanya et al, 2002;Hagen et al, 2003;Lee et al, 2017). The current study, in case of Indian peafowl which is considered as endangered species, analysis of crop or gizzard contents is not possible hence faecal analysis was carried out.…”