By Rick Kleyn, SPESFEED (Pty) Ltd

Poultry feed makes up slightly more than 70% of the feed manufactured by the members of the South African Feed Manufacturers Association (AFMA). Not surprisingly, the South African feed industry has grown at a pace similar to that of the poultry industry. During the past decade however, this has not been the case. The South African Poultry Association (SAPA) data for both broilers and laying hens shows considerable growth, while the feed industry has lagged behind somewhat (Table 1 and Figures 1 and 2).

From this table it can be seen that in the 10 year period ending in 2002, the estimated broiler output in the country rose by 68%, yet the amount of broiler feed manufactured by AFMA’s members only increased by 36%. During the same period egg output has increased by about 28% and layer feed production by only 10%. It should be borne in mind that the figure for the feed production for laying birds includes the feed consumed during rear.

It is true that not all feed sold in South Africa is manufactured by AFMA members but I estimate that less than 5% of the broiler feed and about 15% of the layer feed used in the country is manufactured by non AFMA members. These represent relatively small amounts. Whilst the amount of broiler feed being manufactured by non AFMA members has remained fairly constant, there has been some growth in the volumes of layer feed manufactured by non AFMA members.

The reason why the feed industry has lagged behind the poultry industry can only be ascribed to the improvements in technical efficiencies that have occurred in both the broiler and layer industries. Not only has there been a dramatic improvement in the genotype of the birds that are used, but there have also been changes, particularly in broiler husbandry, that have had an impact on feed usage. It is true that it is often difficult to separate these two effects from each other, but some data does exist in this regard.

In the case of laying hens it can be shown that modern layer breeds are constantly changing through genetic selection and improvement. The principle aim of the primary breeding companies is to ensure that the birds sold to their clients are more efficient. From table 2, it can easily be seen just how successful they have been in this endeavour.

These improvements have been achieved through a number of mechanisms, which include an increased egg output potential, a reduced age at sexual maturity and perhaps most importantly an improvement in feed conversion efficiency. Selecting for smaller birds with a higher egg output together with an active program to select against birds with a high Residual Feed Intake (RFI) has brought about improvement in feed efficiency. RFI is intake that can not be explained by measurable parameters such and egg output or body weight.

*The manual only shows 17-week weights.

From a feed perspective the parameter that has the greatest impact on feed usage is the FCR (kg feed/kg eggs). This is perhaps the most dramatic in rear, where as can be seen the birds are reaching sexual maturity 8 days earlier than they were a decade ago. As already mentioned the AFMA data does not distinguish between rearing diets and laying diets so the impact of this is difficult to calculate.

Using Hy-line data (table 2), it can be shown that the FCR in laying hens has improved by between 6.63% (at worst) and 17.6% (at best) over the last decade. By comparison, I estimated the FCR of the national laying flock from table 1, using the assumption that an egg weighs 60 grams. The FCR in 1992 was 2.75 and that calculated for 2002 was 2.36. This represents an improvement of 13.8%. From table 1 it can be seen that layer feed production rose by 10% during the decade. If we were to assume that FCR improved by 14% during the same period it can be shown that the increase in feed sales would have been in the order of 24%, as opposed to an increase in egg output of 28%. The "missing" 4% could easily be explained by the increase in layer feed production by non-AFMA members.

The situation with regards the improvement in broilers has been more dramatic than that of laying hens. The true scope of the improvements that have occurred in the broiler industry have recently been demonstrated by work done in the Department of Poultry Science, North Carolina State University (Havenstein et al., 2003). These workers compared production between the 1957 Athens Canadian Random Bred Control (ACRBC) strain and the 2001 Ross 308, using feeds from each era. The ACRBC strain is a valuable tool for measuring genetic change over time as it has be shown that there has been no measurable genetic improvement since it was established.

The trial was conducted for a period of 85 days, with measurements being taken at 21, 42, 56, 70 and 84 days of age. A summary of the results obtained for 21, 42 and 84 days are shown in the table 3. Mortality was approximately twice as high in the modern strain in the current study, as it was in the ACRBC strain, but is still at a modest level at market age.

From these data a number of things can be concluded. Genetics, nutrition and management changes over the last 44 years have resulted in a broiler that required one-third the time (32 vs. 101 d) and threefold decrease in the amount of feed consumed (estimated FC of 1.47 vs. 4.42) to produce an 1,815-g broiler. It was also shown that 85% of the improvement in broiler production was as a result of genetic improvement and that feed was only responsible for 10 to 15% of this advance.

In other recent work, McKay (2000) showed how the incidence of conditions such as leg problems and ascities have declined with time. Interestingly, he was also able to show (figure 3) how the mortality rate of the modern broiler (Ross 308) had not changed as compared to a 1972 reference flock.

When one looks at the commercial data compiled by Ross Breeders, South Africa (Gericke, 2003), it is possible to see just how much improvement has occurred in the broiler industry in South Africa during the last 10 years. Understandably the feed conversion efficiency has improved as both growth rate, lean deposition rate and the age at slaughter have all improved.

* Estimated

What is of specific interest, is the fact that the mortality rate of the birds has improved during the same period, this despite McKay’s evidence that the bird has shown no real change with regards this trait. This can only mean that the level of husbandry on South African farms has improved. It is true that the almost universal swing to nipple drinker lines from bell drinkers will be responsible for much of this improvement, but it is obvious that our farmers have simply become better managers. It should be remembered that this improvement in mortality would by default be included in the feed conversion ratio in terms of feed usage.

It is true that the age at slaughter and the mortality levels incurred have a direct impact on the efficiency of broiler production, these improvements are measured by the FCR in terms of feed usage. Sadly the 1992 data is not complete and it is not know how representative of the industry at large the data was. For this reason it was decided to extrapolate the more accurate 1995 data for a 10-year period. Accordingly, I estimated that the FCR in the national broiler flock improved by about 12%. When I made the assumption that all of the broilers produced during the last decade consumed feed produced by AFMA members, the FCR dropped from 2.87 to 2.33, which is a 19% improvement (data in Table 1).

Even if I use the higher figure of 19% improvement in FCR it is still only possible to account for 55% of the 68% increase in broiler output in terms of feed production. It is true that there has been a small improvement in carcass yield over the past decade, but this would only account for a percent or two.

When comparing the data supplied by SAPA (Table 1) for the year 2002 (829 000 tons) with the value published by the Agricultural Marketing Service of the USDA (www.ffas.usda.gov) for South Africa (745 000 tons) some doubts arise. The respective figures for 2001 were 772 000 and 730 000 tons, which are very much more in line with each other. Using a mean of the two figures would give a broiler production figure for 2002 of 787 000 or a 60% increase over the last decade, which would leave only 4 or 5% unaccounted for. This is still unlikely to be explained by feed being manufactured by non-AFMA members.

This article has shown how feed production in South Africa has lagged behind growth in the poultry industry. In the case of laying hens, most of these differences can be explained. However, in the case of broilers this has not been entirely possible. There are two possible reasons for this. Either the data with regards the size of the broiler industry is less than accurate, or the real improvements in efficiency that have been achieved on farm are significantly better than we realise.

It has however been clearly demonstrated that as the poultry industry continues to expand so will the feed industry. The implication of the improvements in both genotype and technical efficiencies on farm is that growth in the poultry industry will continue to outstrip growth in the feed industry. The feed industries major responsibility in the future will be to ensure that the feed that is delivered to farms will sustain optimum growth for the improved genotypes being used.