Influence of separate feeding of calcium on nutrient digestibility, energy utilisation and performance of young broilers fed pelleted wheat-based diets

https://doi.org/10.1016/j.anifeedsci.2015.04.014Get rights and content

Highlights

  • The present study confirmed the previously reported Ca-specific appetite in modern broilers.

  • Feeding low Ca diets with access to a Ca source is advantageous in terms of growth performance.

  • When Ca sources are mixed in the diet, a substantial negative effect can be seen on P digestibility.

  • Provision of a separate Ca source may hold promise for reducing dietary P level in broiler chickens.

Abstract

Six broiler starter diets, based on wheat and soybean meal, were formulated to contain 1.1 2.0, 4.0, 6.0, 8.0 and 10.0 g calcium (Ca)/kg. All diets were equivalent in respect of total and non-phytate phosphorus contents (5.4 and 3.0 g/kg, respectively). The influence of dietary treatments on the growth performance, coefficient of apparent ileal digestibility (CAID) of nitrogen (N), starch, fat and phosphorus (P), Ca retention and apparent metabolisable energy (AME) in broiler starters was evaluated. A total of 288, one-day-old male broilers (Ross 308) were allocated to 36 cages (8 birds/cage), and cages were randomly assigned to 6 dietary treatments. Birds were also provided with a source of Ca in a separate feed trough. Birds fed the diet with 1.1 g Ca/kg gained more (P<0.05) weight and tended (P=0.08) to have higher feed intake than those fed the diets with 8.0 and 10.0 g Ca/kg. Increasing dietary Ca concentrations from 1.1 to 8.0 g/kg increased (P<0.05) feed per unit gain, but diets with 1.1 and 10.0 g/kg Ca resulted in similar (P>0.05) feed per unit gain. During d 8 to 14, d 15 to 21, and over the entire trial period of 21 d, birds fed Ca-deficient (6.0 g Ca/kg and less) diets consumed more (P<0.001) of the separate Ca source. During the third week and over the 21 d trial period, total Ca intake (Ca from feed plus Ca from separate source) of birds fed Ca-insufficient diets was higher (P<0.05) than those fed diets with higher dietary Ca concentrations. Diets with 1.1 g Ca/kg resulted in the highest (P<0.05) CAID of P. There was no effect (P>0.05) of dietary Ca on the retention of Ca and ash, AME and toe ash. The present data suggest that feeding broilers low Ca diets with access to a separate Ca source, is advantageous in terms of broiler performance, while maintaining bone mineralisation. The data also demonstrate that the provision of separate Ca source may hold promise for reducing the dietary P contents.

Introduction

Calcium (Ca) is an essential nutrient for many biochemical pathways, skeletal strength and integrity. Calcium deficiency can lead to skeletal deformation, rickets and tibial dyschondroplasia, bone fracture, neural weakness and poor feather condition in poultry. On the other hand, excessively high concentrations of dietary Ca may impede the availability of nutrients, specifically of other minerals and lipids, by the formation of non-absorbable complexes (Driver et al., 2005, de Matos, 2008, Selle et al., 2009). It has been shown that inclusion of an inorganic Ca source (Tamim and Angel, 2003, Tamim et al., 2004) or increasing dietary Ca concentrations (Plumstead et al., 2007) can impair the inherent ability of broilers to hydrolyse and utilise phytate-phosphorus (PP). Plumstead et al. (2007) reported that increasing the Ca concentration in broiler diets from 4.7 to 7.0, 9.3 and 11.6 g/kg, reduced the ileal digestibility of PP from 20.1 to 15.1, 8.6 and 5.9%, respectively. Precipitation of phytate, which makes the PP unavailable, accounts for this observation (Angel et al., 2002, Tamim and Angel, 2003). The result is a high level of P in poultry excreta, with a major environmental impact, and the need to add expensive inorganic phosphates in the diets. A new form or a delivery system of Ca to the poultry, which will not react with the PP, has been suggested as a potential approach to inhibit formation of Ca–phytate complex (Tamim and Angel, 2003). Another approach, to optimise the hydrolysis and availability of PP in broilers without compromising skeletal integrity usually associated with decreasing dietary Ca levels, might be the separation of major inorganic Ca sources from the diet.

Poultry are reported to have a specific appetite for Ca (Wood-Gush and Kare, 1966, Hughes and Wood-Gush, 1971, Joshua and Mueller, 1979) and can regulate their Ca intake according to their requirements, if they have access to Ca sources separated from the mixed diet (Wilkinson et al., 2013, Wilkinson et al., 2014). Wilkinson et al. (2013) removed a portion of the Ca from a maize-based diet and provided it separately as a supplement to study the effects of separate feeding of Ca on performance and nutrient digestibility of broilers. In this study, birds offered the diet with 2.5 g Ca/kg consumed the highest quantity of the separate source of Ca (CaCO3) compared to those fed the diet with 10.0 g Ca/kg which consumed the least, confirming that contemporary broilers have retained the specific appetite for Ca. Increased weight gain, a better feed efficiency and similar bone mineralisation were achieved when feeding diets with reduced Ca concentration and a separate Ca source.

Whereas several studies have demonstrated Ca preference in Ca-deprived chickens (Wood-Gush and Kare, 1966, Hughes and Wood-Gush, 1971, Joshua and Mueller, 1979), only limited published data are available on the effect of choice feeding of Ca on the utilisation of nutrients and energy in broilers (Wilkinson et al., 2013, Wilkinson et al., 2014), with no study investigating in pelleted diets. The main aim of the present study was to further investigate whether choice feeding of a Ca source influences the performance, nutrient utilisation, and apparent metabolisable energy (AME) in broiler starters fed a pelleted wheat-based diet.

Section snippets

Diets

Whole wheat was obtained from a commercial supplier and ground in a hammer mill (Bisley's Farm Machinery, Auckland, New Zealand) to pass through a screen size of 4.0 mm. Prior to formulating the diets, main ingredients (wheat and soybean meal) and monosodium phosphate, dicalcium phosphate (DCP) and Omyacal (CaCO3 grit, 387 g Ca/kg; Omyacal GL-TK, Omya, Auckland, New Zealand) were analysed for Ca and P contents and the data were used to formulate the experimental diets. Broiler starter diets,

Pellet durability index

Increasing the dietary Ca concentration above 6.0 g/kg resulted in lower PDI compared to 1.1, 2.0 and 4.0 g Ca/kg. The PDI values of 83.7, 82.7, 83.3, 78.5, 79.0 and 70.2 were obtained, respectively, with corresponding Ca concentrations of 1.1, 2.0, 4.0, 6.0, 8.0 and 10.0 g/kg.

Growth performance and Omyacal intake

Mortality during the performance experiment was low. Only seven out of the 288 birds died and the deaths were not related to any specific treatment.

Increasing dietary Ca concentrations resulted in lower (P<0.01; Table 2)

Discussion

The analysed dietary Ca and total P concentrations were in agreement with the expected values across all diets (Table 1). In a study involving Ca, it is important to analyse the major ingredients and Ca sources for Ca and P contents prior to formulating the diets. This will minimise the difference between determined and expected values. Soybean meal has been reported to have a large impact, due to the inclusion of limestone as an anti-caking and flow agent in some batches of soybean meal (Tamim

Conclusions

The present study confirmed the previously reported Ca-specific appetite in modern commercial broilers. The current study also demonstrated that feeding low Ca diets with birds having access to a separate Ca source while maintaining bone mineralisation is advantageous in terms of growth performance. Improved P utilisation and pellet quality, as a result of reducing dietary Ca concentrations, are possible explanations for the improved growth performance of young broilers. When Ca sources are

Conflict of interest statement

There is no conflict of interest.

References (32)

  • N.M. Tamim et al.

    Influence of dietary calcium and phytase on phytate phosphorus hydrolysis in broiler chickens

    Poult. Sci.

    (2004)
  • C.L. Walk et al.

    Influence of limestone and phytase on broiler performance, gastrointestinal pH, and apparent ileal nutrient digestibility

    Poult. Sci.

    (2012)
  • S.J. Wilkinson et al.

    Effect of dietary nonphytate phosphorus and calcium concentration on calcium appetite of broiler chicks

    Poult. Sci.

    (2014)
  • AOAC International

    Official Methods of Analysis

    (2005)
  • E.T. Champagne

    Effects of pH on mineral–phytate, protein–mineral–phytate and mineral–fiber interactions. Possible consequences of atrophic gastritis on mineral bioavailability from high fiber foods

    J. Amer. Coll. Nutr.

    (1988)
  • E. Delezie et al.

    Can choice feeding improve performances and N-retention of broilers compared to a standard three-phase feeding schedule?

    Br. Poult. Sci.

    (2009)
  • Cited by (7)

    • Effect of enzymatically hydrolyzed scallop visceral protein powder used as a replacement of fish meal on the growth performance, immune responses, intestinal microbiota and intestinal morphology of broiler chickens

      2018, Livestock Science
      Citation Excerpt :

      The main determination contents were as follows: dry matter (GB 6435-86 or AOAC, 2005), crude protein (GB/T6432-1994), crude fat (GB/T6433-1994), ash (GB/T6438-1992), Ca (GB/T6436-2002 or AOAC, 2005), P (GB/T6437-2002 or AOAC, 2005), and Cr (GB/T13088-1991 or AOAC, 2005). Then, apparent nutrient digestibility (AND) was calculated by the following formula (Abdollahi et al., 2015; Li et al., 2014): AND = 100 – Cr in feed/ Cr in excreta × nutrient content in excreta/nutrient content in feed × 100 At d 0 and 42, broiler chickens were weighed after feed deprivation for 12 h, and the feed intake was recorded to calculate average daily weight gain (g/d), average daily feed intake (g/d), and feed/gain ratios.

    • Investigation of the interaction between separate calcium feeding and phytase supplementation on growth performance, calcium intake, nutrient digestibility and energy utilisation in broiler starters

      2016, Animal Feed Science and Technology
      Citation Excerpt :

      Phytase recoveries in the experimental diets confirmed that in-feed phytase activity agreed with the expected values. The impaired PDI value due to increasing dietary Ca concentrations was unambiguous and consistent with our previous findings (Abdollahi et al., 2015), and may be attributed to increasing inclusion rates of soybean oil. The segregation characteristic of limestone also cannot be ruled out as a possible contributing factor.

    View all citing articles on Scopus
    View full text