Insects for Income Generation Through Animal Feed: Effect of Dietary Replacement of Soybean and Fish Meal With Black Soldier Fly Meal on Broiler Growth and Economic Performance.

The ever-increasing animal feed costs are driving many vulnerable communities involved in animal husbandry out of business. The high cost is mainly driven by the protein source, which represents the most expensive component in animal feed. In conventional feed, protein is obtained mainly from soybean and fish meal (SFM). The present study explored potential of partially replacing this SFM with black soldier fly prepupae meal (BSFPM) in Cobb 500 broiler chicken diets. A SFM-based diet was compared to three experimental diets formulated by partially substituting SFM with BSFPM at 13.8, 27.4, and 42.0% of the crude protein (CP) in the starter feed and 11.0, 37.2, and 55.5% of the CP in the finisher feed of diets D1, D2, and D3, respectively. Dietary effects on average daily feed intake, average daily body weight gain, feed conversion ratio, carcass characteristics, breast meat sensory attributes, and the economic implication of their use in broiler production were evaluated. Replacement of SFM with BSFPM did not affect daily feed intake, daily body weight gain, feed conversion ratio, aroma or taste of cooked breast meat. A 16.0% higher Cost Benefit Ratio and 25.0% better Return on Investment was recorded when the birds were reared on the highest concentration of black soldier fly (D3) compared to the conventional diet which was 19.0% more expensive. The implication of these findings for the promotion of insect mass production enterprises for animal feed protein, and their potential for income generation and job creation particularly in developing countries is discussed.

Effects of dietary n-3 polyunsaturated fatty acids, breed and dietary vitamin E on the fatty acids of lamb muscle, liver and adipose tissue.

The effect of feeding n-3 PUFA on the fatty acid composition of muscle, adipose tissue and liver of lambs was investigated. Groups of eight ram lambs per breed, SuffolkxLleyn (24 kg live weight) and Scottish Blackface (18 kg live weight), were each fed one of six diets containing one of three fat sources (50 g fatty acids/kg DM; Megalac((R)) (calcium soap of palm fatty acid distillate; Volac Ltd, Royston, Herts., UK) and formaldehyde-treated whole linseed (Trouw Nutrition UK, Northwich, Ches., UK) either alone or with fish oil (1:1, w/w) and either 100 or 500 mg alpha-tocopheryl acetate/kg DM. Feed was offered ad libitum until slaughter at approximately half breed mature live weight. The type of dietary fat had no effect on intake, growth rate or feed conversion ratio. The 3.0-fold higher concentration of 18 : 3n-3 in the linseed compared with the Megalac((R)) diet approximately doubled (P<0.001) the concentration in the neutral and polar lipid fractions of musculus semimembranosus and liver, and in adipose tissue it increased 2.5-fold. Feeding protected linseed also increased (P<0.001) concentrations of 20 : 5n-3 and 22 : 5n-3 in muscle polar lipids and both lipid fractions of liver. The linseed-fish oil raised the 20 : 5n-3 concentrations above those for the linseed diet and also increased 22 : 6n-3. Scottish Blackface lambs had lower concentrations of 18 : 3n-3 in all lipids compared with Suffolk x Lleyn lambs, but more 20 : 5n-3 in the polar lipids of muscle and liver. High levels of dietary vitamin E were associated with small decreases in the concentration of monounsaturated fatty acids and increases in PUFA. Linseed raised the PUFA : saturated fatty acid ratios in liver and adipose tissue but not in muscle, and improved the n-6 : n-3 fatty acid ratio, as did the linseed-fish oil. Different combinations of dietary fatty acids and better protection against rumen biohydrogenation are required to improve muscle PUFA : saturated fatty acids ratios.

Effects of dietary fat source and breed on the carcass composition, n-3 polyunsaturated fatty acid and conjugated linoleic acid content of sheep meat and adipose tissue.

Seventy-two 8-week-old ram lambs from three breeds, Suffolk, Soay and Friesland, were offered one of four diets based on dried grass and formulated to have a similar fatty acid content (60 g/kg DM) and containing: Megalac (high in 16 : 0, control; Volac Ltd, Royston, Herts., UK), whole linseed (18 : 3n-3), fish oil (20 : 5n-3 and 22 : 6n-3) or whole linseed plus fish oil. The lambs were slaughtered at approximately half of their mature live weight (43, 21 and 43 kg for Suffolk, Soay and Friesland lambs, respectively). Fish oil reduced DM intake and lamb live-weight gain (P<0.001), while DM intake, live-weight gain and subcutaneous fat content were highest in Suffolk and lowest in Soay lambs. Linseed feeding doubled the proportion (x100) of 18 : 3n-3 in the longissimus dorsi from 1.4 to 3.1 and in the subcutaneous adipose tissue from 1.2 to 2.6 (P<0.001). Suffolk and particularly Soay lambs contained higher proportions of 18 : 3n-3 than Friesland lambs in the longissimus dorsi, while in the adipose tissue, Suffolk lambs had the highest level. Feeding fish oil increased the muscle proportion (x100) of 20 : 5n-3 from 0.7 to 2.3 and 22 : 6n-3 from 0.3 to 0.8 (P<0.001). By contrast, the proportions of the longer-chain n-3 polyunsaturated fatty acids were similar across all three breeds. All three lipid supplements containing n-3 polyunsaturated fatty acids increased the content of muscle trans-18 : 1 relative to the control values, but conjugated linoleic acid (cis-9,trans-11-18 : 2) only increased in the muscle of lambs fed linseed. Feeding linseed or fish oil lowered the n-6 : n-3 ratio in sheep meat, but neither diet nor breed had much effect on the polyunsaturated fatty acid: saturated fatty acid ratio.

The growth performance of indigenous Kenyan chickens fed diets containing different levels of protein during rearing.

A study was conducted to investigate the growth response of indigenous chickens in Kenya offered ad libitum diets with 18%, 20%, 22% or 24% crude protein. The body weights of the birds were recorded weekly and used in statistical analysis to determine the effect of the diets, using covariance analysis to adjust for the effect of the proportion of males in each pen. There was a significant effect only in the early growth stages, when diets of a higher protein level gave better growth than diets with less protein. This advantage was later lost. Adjusting for the differences in the proportion of males was important for determining the dietary effect.