Established bird maintenance and production req. based on:

Energy (carbohydrates and  Fat), Protein, Vitamins and Minerals. 

 Recent Trends:    Subdivision of major nutrients into more specific subclasses, e.g.,

          Carbohydrates:   Structural and Non-structural

          Protein:               Amino acids (Lysine and methionine)

         Minerals:             Macro and Micro (on the basis of quantity)

Minerals Importance:

Part of all biological functions;

• structural role
• expression and regulation of genes
• hormone and enzyme systems
• osmotic balance, and
• acid base balance

AIM: Focus on the balance of fixed dietary cation and anions on acid-base balance and its potential effects on performance in poultry birds reared in thermoneutral and heat stress environments.

AIM: 

Focus on the balance of fixed dietary cation and anions on acid-base balance and its potential effects on performance in poultry birds reared in thermoneutral and heat stress environments

ELECTROLYTES

Substances which when added to the neutral water, produces a conductor solution.

• Strong electrolytes (HCl, NaCl, NaOH)
• Weak electrolytes (NH₃, CH₃COOH, HgCl₂)

Electrolyte Concentrations in Body Fluids

	Extracellular	Intracellular
Cations(+)	mEq/l	mEq/l
Na+	142	10
K+	5	140
Ca2+	5	0.1
Mg2+	3	30
Anions(-)
HCO3–	27	10
Cl–	103	4
HPO42-	2	60
SO42-	1
Organic acids	6	NA
Proteins	2	16

(Gamble, 1954)

Diet and Electrolyte Balance:

High concentrate diet?

High forage diet?

                                      (Roby et al., 1987)

Ration Cation-Anion Balancing

Ill defined terminology:

          Anion gap, alkali-alkalinity,          acidity-alkalinity,        and

          dietary cation- anion balance (DCAB)

Concept of balancing DCAB in poultry was given by Mongin (1981).

 

Fixed cations and anions

Bioavailable ions which can not be metabolized or broken down further during digestion/metabolic processes.

 

– Fixed ion balance determines the acid base balance in biological fluids.

(Stewart, 1978)

Sodium, Potassium and Chlorine are considered as Fixed ions because;

• Osmotic balance
• Acid base balance
• Pumping mechanism of cell membranes

Fixed dietary ion balance: (mEq) (Na⁺+K⁺)-(Cl^–)

 

DCAB:      Does not determine dietary acido- or alkalo-genic properties.

But affect metabolic processes by;

                       –  Kidney function, buffering system & cellular maintenance.

 

Relationship Between Acid Base Balance

and Mineral Balance in Practice

When animal in steady a state

(Blood pH 7.4, Plasma carbonate 25 mEq/l, BE=0)

(An-Cat)_in + H⁺_endo – (An-Cat)_out = 0…………..1

 

(An-Cat)_in + H⁺_endo – (An-Cat)_out + BE = 0………2

(Cat-An)_in – (Cat-An)_out – H⁺_endo = BE ……………3

(Cat-An)_in = mEq (Na⁺ + K⁺ + Ca²⁺ + Mg²⁺) – mEq (Cl^–

+ SO₄^2- + H₂PO^4- + HPO₄ ^2-)…………………….4

(Cat-An)_in = mEq (Na + K -Cl) + mEq (Ca + Mg – SO – H₂PO – HPO₄)…..5

(Na + K – Cl) = (Cat-An)_out + H⁺_endo + BE……………..6

Practical Importance of Mineral Balance

 

1. Acid base balance and its relationship to the (Na+K-Cl) balance

          Blood acid base balance µ Ionic balance of the diet

Relationship between the (Na+K-Cl) content of the diet and plasma bicarbonate concentrations in growing chicks

                                                (Mongin and Sauveur, 1973)

2. Mineral Balance and Body Growth

Maximum body weight gain at DACB 250 mEq/100g

 

Effect of (Na+K-Cl) content of the diet of body weight at 4 weeks of age in chicks.

 

(Meilliere and Forbes, 1966; Hurwitz et al., 1973; Mongin and Sauveur, 1973, 1977)

3. Endogenous Acid Production and Protein Source

 

 

1. The composition of the nitrogen products varies
2. Organic phosphate increases the H⁺ production
3. Mineral composition of natural protein sources is highly variable

Variation in the (Na+K-Cl) content of the diet when part of the soya is substituted by another protein source

Protein sources used	Percentage of soya/percentage of other protein source in the overall diet
	20/0	17/2	14/4	8/8
	(Na+K-Cl) content of the diet (mEq/100g)
Soybean meal (50%)/ Fish meal (75%)	17.42	16.35	15.27	13.13
Soybean meal (50%)/ Meat meal (50%)	17.42	16.42	15.41	13.41
Soybean meal (50%)/ Sunflower meal (42.5%)	17.42	16.82	16.26	15.10

(Mongin, 1980)

Divalent Cation Intake and Bird Performance

Effects of Hydrochloride and Chloride Salts on Feed Consumption and Growth

Treat.	Dietary additive	Chloride added	Cat/An	Feed cons/ chick/d (g)	Gain/d (g)
1	none	–1	1.2	18.0	11.5
2	HCl	0.28	1.1	16.5	10.6
3	HCl	.58	1.0	16.3	9.7
4	HCl	2.41	0.6	6.8	1.1
5	CaCl2.2H2O	2.41		8.3	2.1
6	MgCl2.6H2O	2.41		13.2	6.3
7	NaCl+KCl	2.41		16.9	10.9

¹ Basal diet with 1.047% chloride and DCAB 150 meq/kg

(Melliere and Forbes, 1966)

Effects of Excess Dietary Na, K or the Combination on Feed Consumption and Growth

Treat.	Dietary additive	Cat/An	Feed cons/ chick/d (g)	Gain/d (g)
1	none1	1.2	18.0	11.5
2	Na (0.279)	1.4	18.1	12.4
3	Na (0.972)	1.8	17.3	12.0
4	Na (1.649)	2.2	14.1  (3)	9.4
5	K (0.477)	1.4	17.7	11.4
6	K (1.560)	1.8	17.6	10.9
7	K (1.649)	2.2	15.6	9.0
8	Na+K2	1.4	17.6	11.6
9	Na+K	1.8	18.0	11.0
10	Na+K	2.2	17.1	10.9

¹ Basal diet with 1.047% chloride and DCAB 150 meq/kg

² added as carbonate in equimolar conc.

(Melliere and Forbes, 1966)

Effect of Chloride, Sulphate and Phosphate on Blood Acid-Base Variables

Anion added	Amount added	Body wt.	Feed intake	Blood variables H+          HCO3         pCO2
	mEq/kg	(g)	g/chick	(10-8 M)	(mM)	(mm Hg)
None	0	95.6ab	94.4a	4.02 (7.40)1	17.2	28.3
Cl	160	87.5bc	76.0	5.29 (7.28)**	12.8**	27.5
Cl	240	83.5c	71.0c	5.88 (7.23)**	11.1**	25.8
SO4	120	101.5a	92.1a	4.50 (7.35)*	14.6**	30.0
SO4	240	101.6a	90.9ab	4.52 (7.34)*2	13.8**2	26.4
PO4	120	99.7a	86.3abc	4.29 (7.37)	16.1	29.2
PO4	240	98.6ab	90.4ab	7.06 (7.39)2	16.62	28.6

¹ pH in parenthesis                        

² Significantly different form 240 mEq/kg Cl treatment (P<0.05)

^* Significantly different from 0 mEq/kg treatment (P<0.05).

^**Significantly different from 0 mEq/kg treatment (P<0.01).

                                                                                                (Austic et al., 1993)

Effects of Electrolyte on Growth of Heat Distressed broilers

Adverse Effects of High Temp Includes;

1. Reduced feed intake
2. Reduction in weight gain
3. Increased mortality

(Teeter et al., 1994; Reece et al., 1985)

Which are due to changes in ;

1. Intestinal flora (Suzuki et al., 1983)
2. Amino acid digestibility (Wallis and Bawlnave, 1984)      
3. Immune function (Thaxton and Siegel, 1970)
4. Blood acid base balance (Mitchel and Siegell, 1973)

How to counteract these changes

1. Addition of electrolytes in water (KCl, NaCl, NaHCO₃,)
2. Addition of electrolytes in feed (KCl, NaCl, NH₄Cl, NaHCO₃,)

Effect of Electrolytes Addition in Water on Broiler Performance Reared at Elevated Temperature  (22C to 35C) from 22 to 49 d of Age

Parameters	Control	KCl (0.48%)	NaCl (0.376%)
BW gain (g/d)	44.0b	45.3ab	46.7a
Feed consump. (g/d)	118	113	119
Water consump. (ml/d)	210b	247a	255a
Body temp. (C)	43.1	43.0	43.1
Carcass weight (g)	1398	1400	1467
Carcass yield (%)	68.7	69.1	69.5
Abdominal fat   (%)	1.76	1.84	1.87
pH	7.3	7.2	7.29
Survivability	88c	97a	93b

^a,b,cMeans within the same row differ significantly (P<0.05)

(Smith, 1994)

(Deyhim and Teeter, 1991)

High Chronic Ambient Temperature Stress and Birds Response to Supplemental NH₄Cl, KCl and K₂CO₃

	K+ (%)	NH4Cl        0                   0.1                0.3                0.5
Av.daily gain, g
	0	17.9efg	19.2cde	18.5def	16.8fg
	0.05	18.5def	21.6ab	19.0cde	16.4b
	.1	19.8bcd	21.7ab	20.6bc	14.5h
	.5	21.2b	23.1a	17.1fg	12.6i
Gain/feed	0	0.29a	0.31a	0.27a	0.291a
	0.05	0.30a	0.32a	0.29a	0.27a
	.1	0.30a	0.29a	0.32a	0.25a
	.5	0.31a	0.31a	0.27a	0.18b
Blood pH	0	7.45a	7.33bc	7.25cde	7.17efg
	0.05	7.39ab	7.27cd	7.23de	7.14fgh
	.1	7.41ab	7.27cd	7.19def	7.16fg
	.5	7.40ab	7.17efg	7.09gh	7.07h

^a-iMeans within a parameter with unlike superscript differ significantly (P<0.05)

Water Suppl. K+ (%)	Av.daily gain (g)	Gain/feed
0	23.1b	0.26
.15 K+ as KCl	27.4a	0.32
.15 K+ as K2CO3	18.6c	0.24

(Teeter and Smith, 1986)

Heat Stress and Layer Performance

Egg shell formation:

Dietary calcium + Bone —— (PTH)——-> Egg shell formation

During Shell formation —- > ¯ in blood & uterine fluid pH—- > carbonate formation by shell glands — > acidosis — > hyperventilation and acidic urine.

NaHCO₃ improve the situation but not improve shell quality.

When (Na + K) -Cl >1.5   ——– > no drop in pH but at ratio 2 respiratory alkalosis. Increasing Cl improved the shell quality.

Under heat stress (32-40C):

Panting —– > loss of CO₂ — > respiratory alkalosis — (negative Na and K balance)…..Blood ionined calcium level decreases —-> disturbed acid base balance —- > poor shell formation.

Remedies

Sodium bicarbonate supplementation (water @ .2-.5%/feed @ .5-1.5%)  and/or 0.6% KCl in water will improve the situation.

Whereas KHCO₃ aggravated respiratory alaklosis.

Intake of Ions and Wetness of Droppings

Water intake and weight of wet droppings as a function of

potassium intake

Sodium and Sodium Bicarbonate Utilisation by Broiler Chicks

Trt	Supp. Na	Final BW	Av. daily intake Feed           Water       Sodium			Faecal moisture
(%)	(mg/kg)	————(g)———-			(mg)	(%)
NaCl
0	0	99a	11.2a	15.4a	3.3a	33.6a
.05	196	170b	19.9b	28.4bc	9.9b	64.7b
.10	392	247c	24.1c	34.7cd	16.7c	72.7b
.15	588	347d	29.4d	46.4ef	26.2d	74.7b
NaHCO3
.072	196	177b	19.1b	25.8b	9.5b	75.7b
.144	392	279c	26.1cd	39.6de	18.0c	76.1b
.216	588	347d	28.1cd	49.5fg	25.0d	76.3b

^a-gMeans in the same column without common letter differ significantly. (P<0.05)

(Damron et al., 1986)

Limitations 

• Where the rate of inclusion in the diet of one of the minerals in question is less than the birds minimum requirements.

• DCAB have little effect when one of the minerals is present in such excess that it becomes toxic.

• The ratio of K/(Na-Cl) must be higher than unity in order to avoid mortality in chicks.
• DCAB must be kept as close as possible to 250 mEq/kg of the diet to met K/(NA-Cl) >1.