Page 12 - National Poultry Newspaper

Pressure for chicken meat industry
AS the Australian Com- petition and Consumer Commission observed in a December 2020 re- port, pressures face the chicken meat industry with processing domi- nated by two compa- nies – the stock market listed Inghams and the privately owned Baiada, owner of the Steggles brand and processing
Supply farmers warned of likely changes for the Baiada Beresfield plant.
While the ACCC views Beresfield’s future as an internal company matter,
plant at Beresfield. Currently under a cloud, Baiada said no decision had been made on the Be- resfield plant, but in a Jan- uary letter warning supply farmer of likely changes, ‘total closure’ was the first
existing maximum output and add another 682 jobs to a current workforce of 494 – the Meat Workers Union said it was confi- dent the Beresfield plant would not close any time soon.
Australia, with consump- tion rising by 5 percent a year over the past decade.
its December 2020 report acknowledged concerns for chicken farmers pos- sibly facing unfair contract terms in relations with the big processing companies.
of four options listed. Though Baiada has won approval for a new $200 million plant at Tamworth – which could triple the
With plants at Hanwood and Tamworth, Baiada quotes government figures showing chicken as the most consumed meat in
With this growth in mind, the fears for Beres- field stem from the greater capacity of the new Tam- worth plant, indicating a potential cutback else- where.
With the nominal ex- piry date of an enterprise agreement in September, the future is uncertain for the 1000 Beresfield plant employees and supplying farmers.
Figure 1. A significant treatment interaction of feed grain and dietary crude protein concentration on feed conversion ratio of broiler chickens in the present study (P < 0.001).
Figure 2. Quadratic relationship (r = 0.882; P < 0.001) between dietary non-bound amino acid inclusions and FCR in broiler chickens (y = 1.383 - 0.001*NBAA + 0.00007263*NBAA2).
Table 1. Experimental design in the present study.
On the other hand, glu- cose from rapidly digest- ible wheat starch may be disposed of by direct oxi- dation.
Crude protein reductions in broiler diets
n Major factor in quest for sustainable production
Shemil P MacElline
A STUDY, ‘A compari- son of wheat and sor- ghum-based diets with two crude protein levels on the performance of broiler chickens’, car- ried out by Shemil Ma- celline, Peter Chrystal, Mehdi Toghyani, Shiva Greenhalgh, Peter Selle and Sonia Liu, was pre- sented recently at the 2022 Australian Poultry Science Symposium.
supported higher weight gains than wheat-based diets by 4.84 percent (2232 versus 2129g/bird; P = 0.002) independent to dietary crude protein reduction.
capacity of avian species to store glycogen in mus- cle is limited.
Wheat and sorghum are the two major feed grains used in Australia for broiler diets, however wheat is more common and is usually considered better quality than sor- ghum.
the quest for sustainable production.
In contrast, at 170g/kg CP, the sorghum-based diet supported a better FCR than wheat by 4.90 percent (1.437 versus 1.511).
The wheat-based 170g/ kg CP diet contained substantially more non- bound amino acids (51.4 versus 37.2g/kg) than the corresponding sorghum- based diet.
The local chicken meat industry may have to in- crease by 60 percent to meet demand in 2050, so strategies are needed to promote sustainable chicken-meat production to meet this anticipated demand.
Reduced-CP diets have the potential to lower nitrogen excretion and ammonia emissions, im- prove litter quality and bird welfare, and reduce our dependence on im- ported soybean meal.
Therefore, reducing dietary CP from 210 to 170g/kg compromised FCR in wheat and sor- ghum-based diets by 8.94 percent and 4.97 percent respectively.
The genesis of this dif- ference was simply be- cause the protein content of wheat exceeded that of sorghum.
Crude protein reduc- tions in broiler diets could be a major factor in
However, growth performance of broiler chickens is often com- promised by reductions in dietary CP, and the growth response to the reduction of dietary protein was inconsist- ent among different feed grains.
Dietary CP reductions increased relative fat-pad weights by 16.7 percent (10.35 versus 8.34g/kg/ bird, P = 0.010) and sor- ghum-based diets gen- erated heavier fat-pad weights than wheat by 31.8 percent (10.99 ver- sus 8.34g/kg/bird, P < 0.001).
Non-bound amino ac- ids are more rapidly absorbed than protein- bound amino acids and it follows that this differ- ence could trigger post- enteral amino acid im- balances, resulting in the deamination of surplus amino acids and excre- tion of uric acid – a pro- cess that requires energy.
Wheat-based reduced- CP diets depressed broil- er growth performance, while in contrast maize- based diets performed well when dietary CP was reduced.
The interaction between dietary CP and feed grain for FCR suggests that sorghum is superior to wheat as the basis of reduced-CP broiler diets.
The balance between non-bound and protein- bound amino acids in reduced-CP diets may be pivotal and a point may be reached where non-bound amino acid inclusions become ex- cessive and compromise performance.
The protein structure and functional properties are similar in sorghum in comparison to maize, and sorghum contains less soluble non-starch poly- saccharides and relatively slow starch digestion rate than wheat.
Alternatively, sorghum generated 42.1 percent (12.15 versus 8.55g/kg) heavier fat-pad weights than broilers offered 170g/kg CP wheat-based diets, which is disadvan- tageous.
In the present study, increasing dietary non- bound amino acid inclu- sions were associated with compromised FCR in a quadratic manner (r = 0.882, P < 0.001), as shown in Figure 2.
Table 2. Composition and nutrient specification of experimental diets.
Sorghum-based diets
Excess glucose may be stored as glycogen in liver and muscle but the
Page 12 – National Poultry Newspaper, April 2022
www.poultrynews.com.au
Therefore, the present study was designed to compare wheat and sor- ghum-based diets in the context of reduced CP diets.
These conflicting out- comes present an obsta- cle to the development of reduced-CP broiler diets.
In conclusion, broiler responses to wheat and sorghum-based diets con- taining 170g/kg CP were divergent in that sorghum generated better efficien- cy of feed conversion but somewhat paradoxically, greater fat deposition.
A total of 392 off-sex male Ross 308 broilers were randomly distrib- uted into 28 floor pens with 14 birds per pen and seven replicates for each treatment from 14-35 days post-hatch.
In reduced-CP diets, wheat has a lesser pro- pensity to increase ab- dominal fat-pad weights and by extension overall fat deposition than maize and, in the present study, sorghum.
In this and other com- parative studies, the im- pact that the feed grain selected as the basis of a reduced-CP diets has on broiler performance is of tremendous importance.
The arrangement of di- etary treatments is shown in Table 1 and their com- position and nutrient specifications are shown in Table 2.
It is probably salient that the starch digestion rate of wheat is more rapid than maize or sor- ghum, which has been demonstrated under in vitro and in vivo condi- tions.
The genesis of these differences between feed grains appears to be related to both starch properties and protein contents, which dictate the extent of non-bound amino acid inclusions.
In the present study, di- etary CP reduction com- promised weight gain by 8.98 percent (2292 versus 2086g/bird; P < 0.001) and feed intake by 2.72 percent (3157 versus 3071; P = 0.031) regard- less of the feed grain.
It appears that slowly digestible maize and sorghum starch and the more gradual and sus- tained intestinal uptakes of glucose promotes in- creased fat deposition via de novo lipogenesis.
A better comprehension of both factors is needed if reduced-CP broiler di- ets are to be developed successfully.
Shemil MacElline
As shown in Figure 1, a significant treatment interaction (P = 0.033) was observed for FCR as broilers offered 210g/kg CP wheat and sorghum- based diets had statisti- cally similar feed conver- sion ratios.
Once glycogen stores are saturated, glucose is effectively converted into fat by de novo lipogenesis in the liver.