T.S. Brand

The effect of dietary energy and protein levels on production in breeding female ostriches

1. In a study spanning two breeding seasons, we assessed the effect of different dietary energy and protein levels on body mass, body condition, and egg production of female ostriches. 2. During the first breeding season, groups were given diets with energy concentrations of 8·5, 9·5 and 10·5 MJ/kg dry mass (DM) metabolisable energy (ME) and protein concentrations of 135, 150 and 165 g/kg. In the second breeding season, groups were given diets with ME of 7·5, 8·5 and 9·5 MJ/kg and protein contents of 105, 120 and 135 g/kg. 3. Body mass of birds on diets of 7·5 and 8·5 MJ/kg ME decreased significantly in the course of the breeding season compared with birds fed on diets with higher energy contents and body measurements decreased, suggesting a loss of body condition. 4. Females fed on diets containing only 7·5 MJ/kg ME produced significantly fewer eggs at significantly longer intervals, resulting in fewer chicks hatched. 5. There was no significant difference in egg mass, initial chick mass, chick survival to one month of age and body mass of chicks at one month. 6. Dietary protein concentrations had no effect on egg production, egg mass, hatchability, initial chick mass, chick survival or chick mass at one month old. 7. The female ostriches regained their original body mass during the 4-month rest period between breeding seasons, but significant differences in some parameters during the second breeding season suggest that they may not have fully recovered their body condition. 8. A dietary energy content of 7·5 MJ/kg proved to have an adverse effect on egg production by breeding female ostriches, and it may be concluded from this study that a diet containing 8·5 MJ ME/kg DM and 105 g/kg protein should be regarded as the minimum that can be used for breeding female ostriches without compromising egg production.

The effect of dietary fish oil rich in n − 3 fatty acids on the organoleptic, fatty acid and physicochemical characteristics of ostrich meat

The effect of different levels of unrefined fish oil in the diet on ostrich Musculus iliofibularis was evaluated in a completely randomised experimental design, where a supplementary energy rich feed, containing 6.7% fish oil, was fed at four different levels over a 7-month period. An increase in the amount of fish oil consumed was found to have had no significant effect on the sensory characteristics of ostrich meat, although there was a tendency towards an increase in fishiness, for both aroma and flavour. Increased concentrations of fish oil, however, did have a significant effect on the aroma and flavour of the abdominal fat pads. The muscle pH(f) and muscle lightness (L*) revealed a significant reduction, with increased energy intake. However, the increased energy intake had no effect on the chemical composition (moisture, protein, fat, and ash content) of the meat. The fatty acid profile of both adipose tissue and muscle was altered as a result of the consumption of fish oil. The SFA concentration increased, while the PUFA concentration decreased with increasing dietary levels. The MUFA concentration remained constant for all four groups.

Naked oats (Avena nuda) as a substitute for maize in diets for weanling and grower-finisher pigs

Abstract The naked oat ( Avena nuda ), cultivar Bandicoot (145.6 g kg −1 crude protein (CP), 35.6 g kg −1 crude fibre (CF) and 94.3 g kg −1 ether extract (EE)), was evaluated in the diets of weanling and grower-finisher pigs (Large White × Landrace). Four diets for weanling pigs were formulated on an iso-nutrient basis [approximately 16.3 MJ kg −1 dry matter (DM) digestible energy (DE), 207.2 g kg −1 CP, 15.4 g kg −1 lysine, 8.0 g kg −1 methionine plus cystine and 2.8 g kg −1 tryptophan on a DM basis] so that maize-meal was substituted by increasing levels of naked oats (0%; 33%; 67% and 100%). Similarly four diets for grower-finisher pigs were formulated on an iso-nutrient basis (approximately 15.1 MJ kg −1 DM DE, 200.5 g kg −1 CP, 11.3 g kg −1 lysine, 8.0 g kg −1 methionine and cystine and 2.8 g kg −1 tryptophan on a DM basis), where maize was substituted in the same way. Weanling pigs ( n = 52) were fed ad libitum from 8.7 to 21 kg live weight. Piglets were kept in pairs (one gilt and one castrated boar combined at random), in cages (1.5 × 1 m) with solid floors, fitted with a self-feeder and equipped with an automatic water nipple. Grower-finisher pigs ( n = 52), individually housed in flat deck-type cages (1.6 × 1 m), fitted with a self-feeder and equipped with an automatic water nipple, were fed ad libitum from 25.7 up to 89.2 kg, whereafter pigs were slaughtered and carcass characteristics determined. In a digestion trial, maize-meal and naked oats were supplied as sole sources. Although the DM digestibility of maize was slightly higher ( P ≤ 0.05) in comparison to naked oats, both sources were nearly equal in DE content (respectively 17.7 and 17.9 MJ kg −1 DM). Crude protein digestibility was higher ( P ≤ 0.05) for naked oats (83.7%) in comparison with maize (79.3%). No significant effect of the inclusion of naked oats in the diets of weanling pig was observed on feed conversion ratio (FCR) or growth rate, but piglets receiving 100% oat as grain source consumed 17.5% ( P ≤ 0.02) less feed day −1 than piglets receiving diets where 33% and 67% of the maize was replaced. Grower-finisher pigs on the diets with 67% and 100% replacement of maize by naked oats consumed 6.8% less ( P ≤ 0.05) feed day −1 than pigs on the 100% maize diet. DM intake decreased by 57.8 (SE b = 21.3) g day −1 ( P ≤ 0.01) with every increment of maize replacement. No significant effect on the diet on average daily gain (ADG) or feed conversion was observed, although ADG was reduced by 11.8 (SE b = 8.3) g day −1 (NS) with every increment of oat inclusion. No significant differences in dressing percentage (mean of 76.7%), percentage meat in the carcass (67.3%) or P 2 back fat thickness (mean of 17.2 mm) were observed. It appears from the results that naked oats can provide a successful alternative to maize in the diets of pigs, although the amount of naked oats in the diets of weaned piglets should not exceed 492.5 g kg −1 . Naked oats can replace a large portion of the protein sources conventionally associated with maize-based diets.

Triticale (Tritico secale) as substitute for maize in pig diets

Abstract An experiment was conducted to quantify the effect of the inclusion of triticale (cv. Usgen 19) in the diets of pigs, on certain metabolism and production parameters. Three diets were formulated on an iso-nutrient basis (approximately 13.9 MJ kg −1 dry matter (DM) metabolizable energy, 17.2% crude protein, 1.00% lysine, 0.69% methionine and cystine and 0.23% tryptophan on a DM basis) so that maize meal was substituted by increasing levels of triticale meal (0%, 33% and 67%). In a metabolism and nitrogen (N) balance study with 18 SA Landrace × Great White boars, DM digestibility, apparent N digestibility, digestible energy (DE) and metabolizable energy (ME) contents were largely independent of the substitution of maize by triticale. Apparent N retention tended ( P ≤ 0.09) to be better on the triticale-containing diets. The diets were evaluated according to a 2 (sex) × 3 (diet) factorial arrangement of treatments in terms of dry matter intake (DMI), average daily gain (ADG) and feed conversion ratio (FCR), in a growth study with 13 SA Landrace × Large White pigs per diet. Mean (± SE) initial live mass of the pigs was 23.4 ± 0.3 kg. Pigs were fed ad libitum. The experiment ended when the pigs were slaughtered at a live mass of 90.6 ± 0.2 kg, and carcass characteristics were determined. Daily DMI of pigs decreased linearly ( P ≤ 0.01) by 198 (SE b = 71) g day −1 per unit substitution of maize by triticale. Daily gain was similarly affected, with a corresponding linear ( P ≤ 0.01) decline of 95 (SE b = 34) g day −1 . The substitution of maize with triticale up to 67% did not affect FCR significantly; the mean FCR was 2.72 kg DMI required per kg live mass gain. Mean dressing percentage, eye muscle area or back fat thickness did not differ significantly between diets (means of 80.5%, 38.8 cm 2 and 17.6 mm), although pigs on the 100% maize diet tended ( P ≤ 0.07) to have thicker back fat than pigs on the triticale diets. Efficiency was thus largely unaffected by the substitution of maize by triticale. Triticale may therefore be used to substitute maize up to 67% provided that the lower DMI and resultant poorer growth rate is taken into consideration.

Effect of cottonseed oilcake inclusion on ostrich growth performance and meat chemical composition

This study investigated the effect of replacing dietary soybean oilcake meal with increasing levels of cottonseed oilcake meal (CSOCM) on the growth performance and meat (Iliofibularis muscle) chemical composition of ostriches in order to decrease total feed costs. A total of 105 ostriches were divided into five feeding groups according to the CSOCM inclusion level in the whole diet: Control (0% CSOCM), 3%, 6%, 9% and 12% CSOCM (of the whole diet), and fed with experimental diets from 6 to 13 months of age. As a result of feeding CSOCM, the final live weight and the average daily gain significantly increased in the 12% CSOCM group. The proximate composition, cholesterol content, mineral and fatty acid profile of the meat remained unaffected. Thus CSOCM may be used as an alternative protein source to the more expensive soybean oilcake meal in ostrich nutrition.

The development of ratite production through continued research

This paper summarises research on farmed ratites and their industries over the past 100 years. Commercial ratite products include meat, skins, feathers and oil. Research on ratites has attempted to enhance the quantity and quality of these products by focusing on the disciplines of breeding and genetics, reproduction and incubation, assisted reproduction, nutrition and animal welfare. Advances in these disciplines are discussed, and directions for future research are provided.

Effect of transportation on ostrich (Struthio camelus) weight loss and meat quality

The purpose of this study was to compare the effect of different transport distances on ostrich meat quality parameters, weight loss, and dressing percentage. Twenty-four ostriches were transported for 0 (T0), 60 (T60) and 600 (T600) km before being slaughtered. There was a significant difference (P = 0.038) in the percentage liveweight loss during transport and lairage between T60 km (2.4 ± 2.185%) and T600 km (8.13 ± 1.156%), respectively. There was also a significant difference (P = 0.003) in dressing percentage (farm weight to cold carcass weight) between the two abovementioned groups (T60 = 49.77%; T600 = 46.86%). Treatments also had a significant effect (P 0.05) were found in shear force and percentage cooking loss between the treatments, although all three treatments differed significantly (P 0.05) in a* and chroma values. A significant correlation was found between hue angle (r = 0.528; P = 0.008) and pHu. The results of this study indicate that ostrich transport distance influences liveweight loss and meat quality.

The effect of dietary energy concentrations on production variables of ostrich chicks (Struthio camelus var. domesticus)

Abstract The effects of different dietary energy concentrations on ostrich production variables were examined in two separate trials. The first trial tracked changes in production variables from the pre-starter phase through the starter phase and grower phase. The second trial was based on the finisher phase per se. In both trials, the influence of dietary energy on feed intake, feed conversion ratio (FCR) and growth variables was investigated. Additionally, basic abattoir weights were recorded, and measurements of the feathers and skin were performed. In both trials, three diets with different concentrations of dietary energy were given during each phase where the low-, medium- and high-energy concentrations for each phase were as follows: 13.5, 14.5 and 15.5 MJ ME/kg feed pre-starter; 12.5, 13.5 and 14.5 MJ ME/kg feed starter; 10.5, 11.5 and 12.5 MJ ME/kg feed grower and 9.5, 10.5 and 11.5 MJ ME/kg feed finisher. Feed and water were available ad libitum in both trials. Overall, it was found that the best performance for growth, FCR, skin size and grade, live weight, carcass weight and thigh weight were obtained on the medium-energy diet during the pre-starter, starter and grower phases. During the finisher phase, improved growth rate and tanned skin size was found in birds given the diet with the highest energy concentration (11.5 MJ ME/kg feed). Carcass weight, growth rate and certain feather variables were also significantly influenced by gender.

Prediction of the chemical composition of winter grain and maize with near infrared reflectance spectroscopy

Near infrared reflectance spectroscopy (NIRS) was evaluated as a tool for the fast and inexpensive prediction of nutritional values of feedstuffs. NIRS calibrations were developed for winter grain samples collected over three years in the Western Cape region of South Africa. Winter grains used in the study include oats, barley, triticale and wheat. Calibrations were also developed for maize samples collected throughout South Africa. Win- ter grain samples were analysed for ash, dry matter (DM), crude protein content (CP), fat content, acid detergent fibre (ADF), neutral detergent fibre (NDF), in vitro organic matter digestibility (IVOMD), lysine and methionine. The digestible energy (DE) content of winter grain samples was determined by the mobile nylon bag technique on pigs. Maize samples were analysed for ash, DM, CP, IVOMD and TDN (total digestible nutrients). Standard errors of prediction (SEP) and multiple correlation coefficients (r) for the different winter grain constituents were respectively; ash (0.22%; 0.87), DM (0.67%; 0.68), CP (0.60%; 0.93); fat (0.19%; 0.99), ADF (0.88%; 0.98), NDF (2.13%; 0.97), IVOMD (2.06%; 0.97), DE (0.76%; 0.91), lysine (0.04%; 0.93) and methionine (0.01%; 0.90). SEP and r values for the maize calibrations were, ash (0.08%; 0.49), DM (0.12%; 0.95), CP (0.12%; 0.95), IVOMD (0.55%; 0.92) and TDN (0.39%; 0.92). These results suggested that NIRS can be developed as a rapid and accurate tool for the prediction of the nutritional value of feedstuffs, which makes it an attractive technique for routine quality control in the industry.

Field peas (Pisum sativum) as protein source in diets of growing-finishing pigs.

Abstract Brand, T.S., Brandt, D.A., van der Merwe, J.P. and Cruywagen, C.W. 2000. Field peas (Pisum sativum) as protein source in diets of growing-finishing pigs. J. Appl. Anim. Res., 18: 159–164. The field pea (Pisum sativum) cultivar Glenroy (187g/kg CP) was evaluated as an alternative protein source in diets of grower-finisher pigs. Four diets were formulated on iso-nutrient basis (≈14.4 MJ/kg DE, 160 g/kg CP, 9.3 g/kg lysine, 5.3g/kg methionine and cystine, 2.1g/kg tryptophan) so that soybean oilcake meal and maize meal were substituted by increasing levels of fieldpeas (16%, 32%, 48% and 64%). Forty castrated pigs (78 d, 21.7±2.6 kg) were individually housed and 10 pigs were fed on each diet ad libitum for 84 days. DM intake, average daily gain and feed conversion efficiency, all depressed on the highest peas level in the diet. The DE content and N-retention of the 64% peas diet were significantly (P<0.05) lower than those of the 16% and 32% pea diets. Though dressing percentage was not affected by dietary treatment, P2 back fat thickness was significantly decreased in the 64%peas inclusion group resulting in leaner carcasses. This was mainly due to lower slaughter weights. It was concluded that up to 32% of the field pea cultivar Glenroy in the diets of growing pigs can be recommended.