• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.667-673
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• 2009

Ninety six intact male sheep (12 months old with mean live weight of about 35 kg) were used to assess the effects of restricted feeding on intake, digestion, nitrogen balance and metabolizable energy (ME). The animals were selected from two known Iranian small and large body size breeds: 48 Sangsari (S) and 48 Afshari (A), and were divided into two equal groups: restricted (R) and a control (C). Each group had 48 sheep (24 each breed). The experiment had a duration of 15 and 75 days adaptation and treatment periods, respectively. The animals were individually placed in metabolism cages and fed a diet based on pelleted concentrate mixture consisting of alfalfa, barley grain, cottonseed meal and barley straw. The animals in group C were fed ad libitum, while animals in group R were fed at maintenance level and maintained a relatively constant live weight. During the experiment, the average daily weight gain (ADG) of S and A animals in R group was 0.34 and -0.25 g/d (0.02 and -0.02 $g/kg^{0.75}/d$), respectively. While that of S and A animals in C group was 174.4 and 194.4 g/d (10.16 and 11.48 $g/kg^{0.75}/d$), respectively. Nitrogen (N) was determined by both measured and regression methods. Animals of R group stayed at about zero N balance (0.01 and -0.00 g $N/kg^{0.75}/d$ for S and A animals, respectively). The N retention of animals of both S and A breeds in C group were similar (0.45 and 0.46 g $N/kg^{0.75}/d$, respectively). Digestible organic matter intake (DOMI) and ME requirement for maintenance (MEm) were measured by both constant weight technique and regression method by regressing N balance on DOMI and ME intake on ADG. The measured DOMI during constant weight was 24.61 and 24.27 g $DOMI/kg^{0.75}/d$ and the calculated DOMI from regression equation was 24.24 and 24.22 g $DOMI/kg^{0.75}/d$, for S and A animals, respectively. The measured MEm was 402 and 401 kJ $ME/kg^{0.75}/d$ and the calculated MEm from regression analysis was 398 and 400 kJ $ME/kg^{0.75}/d$ for S and A breeds, respectively. There were no significant differences between both measured and regression techniques. There was no significant difference between S and A breeds for DOMI, N retention, MEm, digestibility and metabolizability values. Digestibility values for OM, GE and CP and metabolizability were significantly (p<0.05) higher in restricted feeding sheep compared with that of sheep fed ad libitum.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1642-1649
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• 2003

An experiment was conducted to evaluate the effects of phytase supplementation on the growth performance, nutrients utilization and bone mineralization in broiler chickens. Day-old broiler chicks (n=480) were equally devided into eight treatment groups and fed maize or wheat based isocaloric, isonitrogenous and isocalcium diets having two non phytate phosphorus (NPP) concentrations (0.50% and 0.30%) and two phytase levels (0 and 500 phytase units/kg diet) in a 42 days growth trial. Maize based dietary treatments were MC (NPP 0.50%, MN (NPP 0.30%), MNP (MN+500 units of phytase) and MCP (MC+500 units of phytase), whereas wheat based experimental diets were WC (NPP 0.50%), WN (NPP 0.30%), WNP (WN+500 units of phytase) and WCP (WC+500 units of phytase). The NPP levels were maintained by dicalcium phosphate. Reduction in dietary NPP depressed live weight gain and feed intake and increased feed conversion ratio (FCR). Phytase supplementation to low NPP (0.30%) diets significantly (p<0.05) improved the growth performances of broilers. The supplementation to low NPP diets allowed complete, safe and economic replacement of dietary inorganic P (dicalcium phosphate) to reduce feed cost per kg live weight gain of broilers. Reduction in dietary NPP did not affect retention of nutrients except phosphorus (P) but had a significant (p<0.05) depression in tibia ash and minerals (Ca, P) concentration in serum and tibia ash. Phytase supplementation at low NPP level was effective (p<0.05) in improving the retention of dry matter, Ca and P and Ca and P concentration in serum and tibia ash. However, the supplementation was not effective at high level of NPP (0.50%). There were no significant (p>0.05) differences in carcass quality among dietary treatments. The response of phytase was greater in low NPP and maize based diets as compared with high NPP and wheat based diets, respectively. The results show that phytase supplementation to low NPP (0.30%) diets improved the growth performance, relative retention of nutrients (N, Ca and P) and minerals (Ca, P) status of blood and bone in broiler chickens, with a better efficacy in maize based diets.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.3
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• pp.232-238
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• 2020

This study used adult wistar-based rats to observe the sexual cycle as a morphological characteristic of vaginal epithelial cells by vaginal smearing, and investigated the fetal number through mating with male rats of the same strain. The target animal was a 12 to 13-week-old Wistar-based mature unlighted rat (weight 220 g to 240 g), room temperature 23 ± 2℃, 14 hours artificial lighting (05:00 to 19:00 hours), 10 hours Adapted individuals were used for rearing for at least 2 weeks under the conditions of the darkroom (19:00 to 05:00). The feed was managed for free feeding of pellet feed for animals and water. The vaginal smearing method was used for the experiments by observing the sexual cycle every morning and confirming that the normal sexual cycle of 4 or 5 days was repeated at least 2 cycles or more. As a result, the proestrus was found to have few red blood cells, the cells and nuclei were rather large and round, and many nucleated cells were identified. In the case of the estrus, the cells were large and the nuclei were not stained, and most of the keratinocytes were found. In addition, in the metestrus and diestrus, there were many white blood cells, and it was confirmed that nucleated epithelial cells and keratinocytes were significantly reduced. The pregnancy period was 21 ± 1.8 days, and the number of live births per delivery was 11.9 on average. The number of fetuses on the 8th and 10th days of pregnancy were 15.2 ± 0.4 and 15.4 ± 0.3, respectively. On the contrary, the number of fetuses on the 12th day of pregnancy was 12.9 ± 0.6, which was significantly (p < 0.05) decreased compared to the 10th day of pregnancy, and the number of fetuses was similar until delivery. As a result of investigating the change of body weight according to the birth weight and growth stage after delivery, the birth weight of female and male was 9.2 ± 2.0 g and 9.8 ± 2.5 g, respectively. After that, until the 16th day, the female and the male showed similarly moderate weight gain, and then showed a rapid weight gain until the 21st day of lactation. With reference to the results of this study, it is expected to be used as basic data for determining the mating time of rodents and controlling pregnancy and fetal number.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1540-1544
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• 2003

This study chiefly aimed to ascertain the effect of age at weaning on caecal content characteristics, post-weaning performance and health of rabbits. A secondary aim was to study the effect of dietary restriction on performance and health of rabbits. After delivery, 30 litters of 8 pups each, were housed in separate cages. Fifteen litters were weaned 24 days from birth (group W 24) while the other 15 were weaned at 28 days (group W28). After weaning, 53 rabbits of group W24 and 56 of group W28 were fed ad libitum (group LIB), while 53 rabbits of group W24 and 57 of group W28 were restricted (group RES). All the rabbits were kept in individual cages. Fourteen other rabbits of groups W24 (7 fed ad libitum and 7 restricted) and 7 of group W28 were sacrificed to obtain data regarding caecum weight and caecal content. Age at weaning affected neither the state of health nor the final live weight. In comparison with those of group W28, the rabbits weaned at 24 days had a lower daily gain until 35 days of age but gain was higher subsequently. From the 28th day, however, the feed intake and the feed conversion ratio of the group W24 rabbits were always better than those of W28. The restricted diet until 42 days resulted in a lower weight both at 42 days (1,078 vs. 1,164 g) and at 70 days (2,192 vs. 2,294 g). Indeed, from the 42nd day, despite receiving feed ad libitum the rabbits of the restricted group continued to ingest less feed (120.8 vs. 127.2 g) than those of the ad libitum group, and had a slightly lower daily gain (39.8 vs. 40.3 g). The measurements carried out on the caecum highlighted significant differences among the groups in caecal content (33.1 vs. 31.7 vs. 25.3 g respectively for groups W24LIB, W28 and W24RES), for total volatile fatty acids (53.2 vs. 50.6 vs. 44.5 mmol/l respectively for groups W24LIB, W28and W24RES) for ammonia (7.0 vs. 7.2vs 8.8 mmol/l respectively for groups W24LIB, W28 and W24RES), for propionate (5.7 vs. 6.3 vs. 8.1% respectively for groups W24LIB, W28 and W24RES) and for propionate/butyrate (0.33 vs. 0.36 vs. 0.49 respectively for groups W24LIB, W28 and W24RES).

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.13-18
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• 2000

An experiment was conducted to evaluate feeding values of food and other organic wastes, and to determine their dietary effects on performance and carcass yield in ducks. A total of 156 meat type ducklings at the age of 25 days were housed in 12 pens and assigned to 4 treatments, in which the birds were fed for 21 days. One of 4 diets, commercial duck feed, raw food waste (RFW), fermented food waste(FFW) and mixture of 50% RFW and 50% FFW (R+FFW). Feed consumption was significantly higher (p＜0.05) in the RFW groups. Body weight gain showed no significant differences between the control and other treatments. The feed consumption ratio was significantly higher in the RFW groups (p＜0.05) than that of the other groups. Carcass yield was significantly higher in the R+FFW groups (p＜0.05) than the other groups. The weight of liver per live body weight showed significant differences among the treatment groups (p＜0.05). The length of intestine was significantly different from those of the treated groups(p＜0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.394-400
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• 2013

A total of 192 broiler chicks were used to evaluate the influence of dietary ${\alpha}$-lipoic acid (ALA) on growth performance, carcass characteristics and meat quality of broiler chickens with the purpose of developing a strategy to prevent the occurrence of pale, soft, and exudative (PSE) meat and to improve the meat quality of broilers. At 22 d of age, birds were allocated to 4 ALA treatments (0, 400, 800, and 1200 ppm). The results showed that dietary ALA significantly decreased average feed intake (AFI), average daily gain (ADG), final live body weight (BW) and carcass weight (p<0.05), while no difference in feed conversion ratio (FCR) was detected among chickens fed with and without ALA. Abdominal fat weight significantly decreased (p<0.05) for broilers fed 800 and 1200 ppm ALA. However when calculated as the percentage of carcass weight there was no significant difference between control and ALA treatments. Meat quality measurements showed that dietary ALA regulated postmortem glycolysis and improved meat quality as evidenced by increased muscle pH and decreased drip loss of meat (p<0.05). Although ALA did not change the tenderness of meat as indicated by meat shear force, dietary ALA decreased collagen content and mRNA expression of COL3A1 gene (p<0.05). In conclusion, the results indicate that dietary ALA may contribute to the improvement of meat quality in broilers.

• Animal Bioscience
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• v.35 no.10
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• pp.1524-1534
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• 2022

Objective: The objective was to test if creep feeding (CF) improves the average daily gain (ADG) and weaning weight of calves submitted to temporary weaning (TW) and if the combination of CF and TW improves conception and pregnancy rates of cows. Methods: Primiparous (n = 74) and primiparous and multiparous (n = 104) cows grazing native grasslands were used in experiment 1 and 2; respectively. The experimental design was in plots divided into complete random blocks with two replications. The CF was the big plot and TW the small plot, thus four experimental groups were formed: i) -CF-TW (n = 21 and 27); ii) -CF+TW (n = 16 and 24); iii) +CF-TW (n = 20 and 26); iv) +CF+TW (n = 17 and 27) with cow-calf pairs for experiments 1 and 2; respectively. Nose plate application for TW had a duration of 14 and 15 days for experiment 1 and 2: respectively. In experiment 1, calves were fed at 1% of live weight for 112 days using a commercial supplement with 18.4% crude protein. In experiment 2, the supplementation lasted 98 days, and was carried out with corn dried distillers grains with soluble (DDGS) at 40% of the potential intake on a daily basis. Results: The TW reduced ADG during the TW period and the following 14 days, but the negative effect of TW was maintained until the final weaning only in experiment 2. The CF increased ADG during TW period in both experiments. The TW promoted an earlier conception of the dams (12 days in -CF treatment and 19 days in +CF treatment, p<0.01) and CF increased pregnancy rate in experiment 1, being the effects not consistent between experiments. Conclusion: The CF consistently promoted an increase in ADG during the period of TW and increased final weaning weight of calves, therefore it is economically viable.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.500-506
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• 2017

To investigate the potential applications of bacterial heme, aminolevulinic acid synthase (HemA) was expressed in a Corynebacterium glutamicum HA strain that had been adaptively evolved against oxidative stress. The red pigment from the constructed strain was extracted and it exhibited the typical heme absorbance at 408 nm from the spectrum. To investigate the potential of this strain as an iron additive for swine, a prototype feed additive was manufactured in pilot scale by culturing the strain in a 5 ton fermenter followed by spray-drying the biomass with flour as an excipient (biomass: flour = 1:10 (w/w)). The 10% prototype additive along with regular feed was supplied to a pig, resulting in a 1.1 kg greater increase in weight gain with no diarrhea in 3 weeks as compared with that in a control pig that was fed an additive containing only flour. To verify if C. glutamicum-synthesized heme is a potential electron carrier, lactic acid bacteria were cultured under aerobic conditions with the extracted heme. The biomasses of the aerobically grown Lactococcus lactis, Lactobacillus rhamosus, and Lactobacillus casei were 97%, 15%, and 4% greater, respectively, than those under fermentative growth conditions. As a potential preservative, cultures of the four strains of lactic acid bacteria were stored at $4^{\circ}C$ with the extracted heme and living lactic acid bacterial cells were counted. There were more L. lactis and L. plantarum live cells when stored with heme, whereas L. rhamosus and L. casei showed no significant differences in live-cell numbers. The potential uses of the heme from C. glutamicum are further discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.550-556
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• 2009

This study was designed to evaluate the effects of dietary prebiotic (mannan oligosaccharide = MOS) and probiotic (Saccharomyces cerevisiae = SC) in finishing turkey diets on carcass, cut yield, meat composition and colour. A total of 72 ten-weeksold Big6 male turkey poults were used in the trial. There were eight replicate floor pens per floor with three birds in each. The experiment lasted up to 20 wks of age. The trial was set up as a completely randomized design with 3 dietary treatments. The treatments were: i) negative control (C, no additive); ii) MOS 1 g per kg of diet and iii) SC 1 g per kg of diet (strain SC47, $300{\times}10^{10}$ CFU/kg). Body weight (BW) and feed intake were determined for each of the two week intervals. Twenty-four birds were slaughtered and eviscerated to determine carcass, carcass parts and internal organ weights at 20 wks of age. Meat colour and pH levels were measured 24 h after slaughter. The dietary treatments did not affect BW and average daily gain during the trial (p>0.05). The average daily feed intake and feed conversion ratio of turkey toms fed with MOS were higher than those of control and SC groups during the overall period (p<0.05). The dietary treatments did not affect carcass yield, breast meat, thigh, wing, liver, heart, empty gizzard, intestine, and abdominal fat pad proportions and meat pH, composition and pigmentation (p>0.05). These results suggest that the addition of MOS and SC is not likely to produce any performance or carcass characteristics in finishing turkeys at 10 to 20 wks of age.

• Korean Journal of Veterinary Service
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• v.28 no.4
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• pp.367-373
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• 2005

Coccidiosis of domestic fowl is a parasitic disease that infects poultry drastically and can cost the pastured poultry producer much in the course of a year. Two hundred forty, day-old-broiler chicks were purchased and were randomly divided in eight groups, containing thirty birds in each group. Decoquinate $6\%$, maduramicin ammonium $2\%$, monensin sodium $13.2\%$, salinomycin sodium $12\%$, a live attenuated vaccine, and trivalent live attenuated vaccine, was provided to the day chicks of six groups, respectively. The chicks of last two groups served as infected non-medicated and uninfected non-medicated, respectively. Feed consumption, weight gain, feed conversion ratio, mortality and oocyst count per gram feces were recorded during the conduction of the experiment. Among treated groups, performance of salinomycin group was significantly better (p<0.05) in all aspects. Salinomycin acts against the sporozoites, trophozoites and first generation schizonts and is highly effective against the economically important species of Eimeria. The present study confirms that use of salinomycin, as an anticoccidial, is a drug of choice.