During 2008 ABN, manufacturers of Sportsman Game Feeds, commissioned us to carry out a feeding trial on the rearing field at Fordingbridge. The protein content of the feed and whether fishmeal is included are commercially-important issues; both add to the cost, but are perceived to be important in terms of bird performance. Furthermore, some feed manufacturers (those that also make cattle feed) are regulated against using fishmeal in their game feeds. However, the effects that these factors have on performance had not been clearly defined.
This trial investigated the effects of dietary protein level and fishmeal inclusion on the performance of pheasants grown to seven weeks of age. Feeds with either lower or higher protein content were formulated with either no fishmeal or standard levels of fishmeal. We replicated the resulting four feed treatments four times, so we used 16 pens, involving a total of 2,400 pheasants.
The protein levels chosen for the ‘high’ treatment were typical of those used in the game feed industry (28.5% in the starter and 23.5% in the grower). In the ‘low’ protein feeds, the starter and grower were formulated to 25.5% and 21.0% protein respectively. The protein levels used reflected differences in the digestible amino acid contents of the feeds, which were reduced by 10% in the low protein feeds.
The fishmeal levels used were either typical levels for commercial game feeds or with no fishmeal inclusion at all.
The effects of protein and fish were almost completely independent of each other. Both protein and fish had a positive effect on growth and this was most significant in the 21-49 day period. This suggests it is important not to reduce the protein levels of the feed too quickly as the bird gets older, and not to introduce whole wheat feeding too early as wheat is low in protein (typically 10-11%).
|Grams per day||Low protein||High protein||Significance (p=)||No fish||Standard fish||Significance (p=)|
|Weight gain 21-49 days||10.56||11.29||0.011||10.64||11.21||0.072|
|Feed intake 0-14 days||7.56||7.74||ns||6.53||8.76||0.011|
|Feed intake 28-49 days||31.52||32.78||0.050||31.62||32.68||0.085|
Both treatments increased feed intake from 28-49 days and fish, but not protein, also significantly increased feed intake from 0-14 days. The effect of fishmeal in young pheasants is perhaps not surprising as pheasants are not naturally vegetarian. Getting birds off to a good start and encouraging food consumption is essential for good long-term performance. The results are shown in Table 1.
In addition, there was a numerical trend (p=0.135) for mortality to be reduced (by 3.13% at 49 days) on the high protein feeds. This treatment also gave a small but statistically significant (p=0.027) improvement in skin condition at 21 days.
These effects would be very important to both the game farmer and shoot manager. Overall, the best liveweights were obtained on the higher protein feeds with fish and the poorest liveweights were obtained on the lower protein feeds without fish (see Figure 1). The birds that were fed higher protein and fishmeal were more evenly sized and would therefore be easier to rear and manage.
This trial confirms the important link between protein nutrition, the inclusion of fishmeal and the performance of growing pheasants. Higher protein feeds including fishmeal cost more, but give better performance.
|Figure 1. Average live weight gain of pheasants in feed trial at 21 days (right axis) and 49 days (left axis)|