Scielo RSS <![CDATA[South African Journal of Animal Science]]> vol. 41 num. 2 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[<b>Evaluation of faba bean (<i>Vicia faba </i>cv. Fiord) as a protein source for broilers</b>]]> An experiment was conducted, using 960 sexed broiler chicks between 7 and 21 d of age, to measure their response to increasing contents of faba bean in the feed. The experimental design consisted of two sexes, six levels of faba bean (0 to 250 g/kg feed), two feed forms (mash and pellets) and two levels of methionine supplementation (0 and 1.5 g DL methionine/kg feed). Each treatment was replicated twice, using 96 pens and 10 chicks per pen. The responses were the same between sexes and between methionine levels. Where feeds were offered in a mash form, growth rate and feed conversion efficiency (FCE) declined linearly, and food intake increased linearly, with increasing faba bean content, but when the feeds were pelleted, performance was the same on all levels of faba bean, suggesting that heat generated during the pelleting process may have destroyed some heat labile anti-nutritional factor present in the faba bean. As most broiler feeds are pelleted, it would appear that faba beans could be used successfully as an alternative protein source in feeds for broilers, up to an inclusion level of 250 g/kg, when geographic, agronomic and economic conditions favour the use of these beans. <![CDATA[<b>Nutritional evaluation of dehulled faba bean (<i>Vicia faba </i>cv. Fiord) in feeds for weaner pigs</b>]]> The objective of this experiment was to determine whether faba bean could successfully be used in feeds for weaner pigs in the period 10 to 25 kg liveweight. An experiment was conducted using 48 weaner pigs (average weight 10 ± 0.42 kg) to determine the nutritive value of dehulled faba bean meal (Vicia faba cv. Fiord) in comparison with full-fat soy. Two basal feeds were formulated, the first containing no faba bean but with full-fat soy (FFS) as the protein source, while the second contained 300 g faba bean/kg feed (FB). These feeds were blended to produce a series of five feeds (T1 to T5) containing a range of faba bean contents. In addition, a choice feeding treatment was included in the experiment to determine whether pigs showed preferences for or against faba bean. The experimental feeds were: 1) 1.0 FFS; 2) 0.75 FFS + 0.25 FB; 3) 0.5 FFS + 0.5 FB; 4) 0.25 FFS + 0.75FB; 5) 1.0 FB and 6) choice between FFS and FB. Feeds were formulated to meet or exceed NRC (1998) nutrient requirements of weaner pigs. Diluting full-fat soya with dehulled faba bean meal had no effect on growth rate (ADG), feed intake (ADFI), feed conversion efficiency (FCE) or time taken to attain final weight. Male pigs had a numerically higher ADFI (1150 vs. 992 g/d) and ADG (553 vs. 539 g/d) than females, and reached the final liveweight on average 3 d before the females. When given a choice between the two basal feeds, no preference was shown for either feed. It may be concluded that a feed for weaner pigs may contain as much as 300 g dehulled faba bean/kg without causing any deleterious effects on performance as long as the quality of the faba beans is the same as that used in this trial. <![CDATA[<b>Evaluation of dehulled faba bean (<i>Vicia faba </i>cv. Fiord) as a protein source for laying hens</b>]]> Dehulled faba beans were evaluated as an alternative to soybeans as a protein source for laying hens using 240 individually caged birds, 50 weeks of age. Two basal feeds were formulated to the same nutrient specifications but with one containing no faba beans and the other containing 200 g dehulled faba bean meal/kg. The experiment was divided into two parts: a dilution series, and a choice feeding treatment. The dilution series consisted of increasing concentrations of faba beans, the five levels in the series being 0, 50, 100, 150 and 200 g/kg of food. The sixth treatment was a choice between the two basal feeds. Although food intake increased linearly with faba bean inclusion, reflecting a need by the hens to consume more in an attempt to obtain sufficient of some unidentified limiting nutrient, laying performance was the same on all feeds in the dilution series. Hens consumed the same amount of each basal feed when given a choice between the two, suggesting that no anti-nutritional factors were present in the faba beans used in this trial. It can be concluded, from a nutritional point of view, that dehulled faba bean meal may be used successfully as an alternative to soybeans as a source of amino acids for laying hens as long as the levels of antinutritional factors present are very low, as was the case in this trial, and as long as accurate estimates of the AME and the digestible amino acid contents of the ingredient are used when formulating feeds containing faba beans. If faba beans can be grown and then used locally in areas unsuitable for soybean production, the reduced transport cost could make this an attractive alternative to soybeans. <![CDATA[<b>Nutrient intake, acid base status and weight gain in water buffalo calves fed different dietary levels of sodium bicarbonate</b>]]> The impact of different dietary levels of sodium bicarbonate (NaHCO3) on nutrient intake, acid-base status, nitrogen balance and weight gain was examined in growing male buffalo (Bubalus bubalis) calves exposed to hot summer conditions. In a complete randomized block design 60 animals of similar age and weight were divided into five treatment groups of 12 per group. Five isonitrogenous and isoenergetic diets were formulated and randomly allocated to a treatment group. The control diet (0SB) contained no NaHCO3, while diets 4SB, 8SB, 12SB and 16SB contained 0.4, 0.8, 1.2 and 1.6% NaHCO3, respectively. An increase in nutrient intake was recorded with increasing dietary NaHCO3 level while the reverse was true for nutrient digestibility. Calves fed the 12SB and 16SB diets had higher nitrogen retentions than those fed the 0SB and 4SB diets. Significant increases in blood pH, serum HCO3 and urine pH were recorded with increasing NaHCO3 levels, with the highest in calves receiving the 16SB diet. Calves fed the 14SB and 16SB diets gained more weight than those fed the 0SB and 4SB diets. These results indicate that the best nutrient intake, acid-base status, nitrogen retention and weight gain occurred in the calves receiving the diet containing 1.2% NaHCO3. <![CDATA[<b>Comparison and evaluation of mathematical lactation curve functions of Iranian primiparous Holsteins</b>]]> Describing lactation in mammals using a lactation curve aims to provide a concise summary of the pattern of milk yield and valuable information about the biological and economic efficiency of the animal or herd under consideration. A total of 106 581 monthly test-day milk records collected from 12 677 Tehran Province primiparous Holstein cows from 151 herds, were used in this study. Using the General Linear Model procedure in SAS, the effect of herd, calving year, age at calving, season of production, age and days in milk were found to be significant on daily milk yield. The suitability of seven mathematical models (with three, four and five parameters) for describing the 305-day milk yield lactation curve of Holstein cows, were examined in this study. Comparisons of the models were made based on the coefficient of determination, root mean square error, Durbin Watson coefficient and sum of daily deviations, by using nonlinear (NLIN), regression (REG) and autoregression (AUTOREG) procedures in SAS. The best three, four and five parameter functions with respect to these criteria were the Incomplete Gama, Dijkstra and Grossman functions. With regards to the Wilmink model, the best results obtained were from models with the constant of 0.05 and 0.065. The Wood function was selected as the best model for prediction of daily milk yield, due to parameters in the function and less computational limitation. <![CDATA[<b>Modelling growth of five different colour types of mink</b>]]> The objective of this study was to estimate and compare the growth curve parameters for live weight of standard black, brown, mahogany, Hedlund white and sapphire minks. The data were collected from five colour types in the period from seven days to 24 weeks of age. Three hundred mink (about 60 of each colour types) were used. Six different non-linear models, namely Logistic, Gompertz, Brody, Richards, Bridges, and Janoschek were used to define the growth curves of the mink. Models were compared using coefficients of determination (R² values), the Akaike's information criterion (AIC) and the Bayesian information criterion (BIC). The R² were high for all models, ranging from 0.923 to 0.985 for different breeds of mink. Comparing the models by AIC, BIC values and the residuals showed the following results. Three of the models fitted the growth curves very well. Colour type differences were observed in the growth parameters of mink. The brown, mahogany and sapphire was observed to be late maturing and lighter at maturity, while the standard black and Hedlund white had a higher growth rate, reached maturity earlier and attained a heavier mature weight <![CDATA[<b>Use of anise seed and/or </b><b>α</b><b>-tocopheryl acetate in laying Japanese quail diets</b>]]> An experiment was conducted to investigate the possible use of anise (Pimpinella anisum) and/or α-tocopheryl acetate as dietary supplements on the performance and some egg quality characteristics of laying Japanese quail. One hundred and eight Coturnix japonica quail (72 females and 36 males), 149 days old, were randomly allocated to four equal groups with three subgroups of nine birds each (six females and three males). A commercial laying diet was fed to the control group (Group A). The remaining three groups received the same diet supplemented with anise seed at 10 g/kg (Group B) or 20 g/kg (Group C), or additional 600 mg α-tocopheryl acetate/kg (Group D). The birds were given feed and water ad libitum for a period of 29 days, while being kept under commercial conditions. During the experiment, egg production, feed consumption and mortality were recorded daily. Also, at the end of experiment, egg weight, egg yolk, albumen and shell weight percentages, egg yolk colour (using the L*a*b* colour space), blood serum total cholesterol and triglycerides concentrations were determined. Neither the supplementation of anise nor that of α-tocopheryl had any effect on the performance of the birds or the quality of their eggs, except for a significant change of the colour of the egg yolk. Cholesterol concentration in the serum tended to decrease with the addition of anise to the diet. <![CDATA[<b>Effects of supplementing humates on rumen fermentation in Holstein steers</b>]]> Humates have nitrogen-binding qualities that could prove to be beneficial in the retention of ammonia nitrogen in the rumen of Holstein steers fed a high-concentrate finishing diet. Therefore, four ruminally fistulated Holstein steers were used in a 4 x 4 Latin Square design to determine the effects of humates (HA) on serum urea nitrogen, rumen pH, rumen ammonia nitrogen and volatile fatty acid (VFA) production. Steers were randomly assigned one of four treatments; a control (0), 5.0, 10.0 or 15.0 g/kg HA (DM basis). Steers were fed ad libitum for 21 days prior to sample collection with dry matter intake (DMI) determined from days 14 to 21. For DMI, a quadratic response was observed; lowest for 5.0 and 10.0 g/kg HA and highest for 15.0 g/kg HA compared to control. Treatment by time interactions was not observed. No treatment differences were observed for total VFA concentrations (mM), or molar proportions of acetate, propionate, butyrate or valerate, but there was a quadratic response observed for butyrate. It was determined that HA do not alter rumen fermentation of Holstein steers fed high-concentrate diets. <![CDATA[<b>Nutrient content of uncooked and cooked meat from South African classes A2 lamb and C2 mutton</b>]]> The study compared the nutrient content of selected joints of South African mutton (Class C2) (n = 18) and lamb (Class A2) (n = 18) carcasses of fat code 2 in both classes. South African sheep carcasses are classified according to age by dentition: Lamb carcasses of class A2 show the ruction of no incisors and mutton carcasses of class C2 of more than six incisors. Fatness is assessed by the thickness of subcutaneous fat. Chilled carcass sides were subdivided into the primal cuts. The cuts were dissected into meat (muscle, intermuscular and intramuscular fat), bone and subcutaneous fat (SCF). The soft tissue of the carcass was analysed for selected nutrients. It was found that South African lamb and mutton contain less fat than the nutrient values previously assumed as scientifically correct and presented in the National Food Composition Tables of the Medical Research Council (MRC), USDA. The results from this study emphasize the importance of country specific nutrient data on own food commodities. <![CDATA[<b>Photostimulation of male broiler breeders to different photoperiods</b>]]> The effect of photostimulation of male broiler breeders (n = 144) to different photoperiods (8-h control and 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 14 and 18 h) applied at 20 weeks of age, on age at first semen production, testis weights, as predicted by comb area, and semen characteristics at the reported age at first egg of females provided the same photostimulation photoperiods, as well as semen characteristics during the production cycle and comb area and testis weights at 51 weeks, was investigated. Photostimulation photoperiod did not affect age at first semen production, sperm motility, morphology or predicted testis weights. Sperm concentration, at the reported age at first egg of females on the same photostimulation photoperiod, decreased with increasing photostimulation photoperiod. Large variation in the male response to photostimulation was observed, however, photostimulation to 12 h or higher resulted in reduced variation in the age at first semen production. Males provided with the longer photostimulatory photoperiods had smaller testis weights at 51 weeks of age, although this was not associated with decreased sperm concentration, increased abnormal sperm morphology or reduced comb area. When male and female broiler breeders are reared on the same lighting regimen, initial male reproductive potential is not adversely affected, provided that the photostimulation photoperiod does not exceed the saturation daylength of 13 h, above which, sperm concentration is lower at the reported female age at first egg, which could negatively affect egg fertility near peak production, and the onset of adult photorefractoriness appears to be advanced, which could negatively affect egg fertility towards the end of production. <![CDATA[<b>The effect of dosing <i>Megasphaera elsdenii </i>NCIMB 41125 (<i>Me</i>) on lactation performance of multiparous Holstein cows</b>]]> The objective of the study was to determine whether early post-partum dosing of Megasphaera elsdenii NCIMB 41125 (Me) will be beneficial to performance of high producing TMR-fed cows. Sixty multiparous Holstein cows were randomly allocated to four treatments (60% or 70% concentrate diet and placebo or Me [single oral dose of 1011 cfu in 250 mL suspension on day of calving and Days 10 and 20 post-partum, respectively]). Observations were recorded between calving and 80 days post-partum. Performance data were analysed for all 60 cows combined and for the 40 highest producing cows only, since they were considered more susceptible to ruminal acidosis. For all 60 cows, body weight, condition score and milk yield tended to increase with Me, but data for the 40 highest producing cows suggested that this response could be ascribed primarily to higher producing cows on the higher concentrate diet. Dry matter intake and milk protein were not affected by Me, whereas milk fat percentage increased with Me but only in cows on the 60% concentrate diet. Results support the hypothesis that dosing with Megasphaera elsdenii is most likely to benefit higher producing cows with greater risk of acidosis. <![CDATA[<b>Non-genetic factors affecting growth performance and carcass characteristics of two South African pig breeds</b>]]> A study was conducted to establish non-genetic factors affecting growth and carcass traits in Large White and Landrace pigs. This study was based on 20 079 and 12 169 growth and 5 406 and 2 533 carcass data collected on performance tested pigs between 1990 and 2008 from Large White and Landrace breeds respectively. The traits analyzed were backfat thickness (BFAT), test period gain (TPG), lifetime gain (LTG), feed conversion ratio (FCR), age at slaughter (AGES), lean percentage (LEAN), drip-free lean percentage (DLEAN), drip loss (DRIP), dressing percentage (DRESS), carcass length (CRLTH) and eye muscle area (AREA). Significant effects were determined using PROC GLM of SAS. Herd of origin, year of testing and their interaction significantly affected all traits. Most traits were not affected by season of testing in both breeds, while all traits in both breeds were significantly affected by sex. Testing environment (station, farm) affected all growth traits except for LTG. Backfat thickness and AGES increased with increasing total feed intake, while other traits decreased as total feed intake increased. Improved test centre management did not compensate for pre-test underperformance. Castrates produced higher carcass yields of lower quality than females, while performance testing showed the best results when done at testing centres. This study showed the importance of adjusting for fixed effects when performing genetic evaluations in the two pig populations.