Scielo RSS <![CDATA[South African Journal of Animal Science]]> http://www.scielo.org.za/rss.php?pid=0375-158920180002&lang=pt vol. 48 num. 2 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Enhancement of poultry meat: Trends, nutritional profile, legislation and challenges</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200001&lng=pt&nrm=iso&tlng=pt Poultry meat is a good source of animal protein, and is affordable for many low-income families in developing countries. It is also part of a balanced diet through contributing valuable nutrients for human health. The poultry industry implements an enhancement process to improve quality and add value to poultry meat. This process may be defined as the addition of a formulated solution or brine, which contains salt, phosphate, and flavour additives for meat. It reduces cooking loss, and improves the tenderness and juiciness of meat. Although enhancement is widely used in the poultry industry, literature on this topic is inadequate. This review aims to outline recent trends in poultry meat enhancement, the main ingredients, and the effects of these ingredients on enhanced poultry meat. The nutritional profile affected by enhancement, the challenges of the enhancement process, and the legislative background to enhancement in selected countries are also discussed. This review provides scientific information on poultry meat enhancement for authorities, food processors, and consumers to ensure accurate application of the process and to prevent adulterated meat products in the market. <![CDATA[<b>Production and profitability of a beef herd on transitional Cymbopogon-Themeda veld receiving three levels of lick supplementation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200002&lng=pt&nrm=iso&tlng=pt The purpose of the study was to investigate the effects of three levels of lick supplementation on the production and reproduction of cows grazing transitional Cymbopogon-Themeda veld. The study was conducted over three years (2011-2014). A total of 150 Drakensberger cows were randomly allocated to three supplementary treatment groups. These supplementation formulations are available commercially and are typical of levels used under farming conditions. In summer Treatment 1 (T1) consisted of a supplement containing 50 g phosphate (P)/kg and 150 g crude protein (CP)/kg. T2 and T3 both consisted of supplements containing 60 g P/kg and 0 g CP/kg. In winter, T1 consisted of a supplement containing 367 g CP/kg, 77.5% non-protein nitrogen (NPN) and metabolizable energy (ME) content of 5.25 MJ/kg. T2 had 466 g CP/kg, 88.7% NPN and a ME content of 4.4 MJ/kg. T3 had 475 g CP/kg, 95.9% NPN and an ME content of 2.4 MJ/kg. Traits were calf birth weight, 100-day and weaning weights of calves, cow weight at weaning, inter-calving period (ICP), conception rate and body condition score (BCS) of cows. Calf birth weight was affected by supplementation treatment only in year 3 and 100-day weight in year 2. However, weaning weight and reproductive performance were not influenced by treatment. It was concluded that the level of supplementation of each treatment group enabled the cows to operate within their target weight range; however, it was more profitable to use the T3 supplementation option. <![CDATA[<b>Quantification of the uterine involution and dimensions, hormonal response and reproductive performance of pyometric and healthy dairy cows treated with Dinoprost</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200003&lng=pt&nrm=iso&tlng=pt The aim of the present study was to investigate the effects of a PGF2αanalogue (Dinoprost) on involution of the puerperal uterus, especially with pyometra during 35 to 45 days postpartum in multiparous high yielding Holstein dairy cows. At days 40 ± 5 postpartum, 1250 cows were ultrasonographically examined. Fifty cows were diagnosed as pyometric. Fifty pyometric and 50 clinically healthy cows were assigned randomly to one of four groups. Groups were: 1.) Pyometric+Dinoprost cows (PD, n = 25 treated with 25 mg of Dinoprost), 2.) Pyometric+Saline cows (PS, n = 25 treated with saline), 3.) Healthy+Dinoprost cows (HD, n = 25 treated with 25 mg of Dinoprost), and 4.) Healthy+Saline cows (HS, n = 25 treated with saline). All treatments were given intramuscularly. Ultrasonography was performed at the time of examination and 7 days later to evaluate changes in uterine diameter. Treatment with Dinoprost significantly reduced gross uterine diameter in PD in comparison to the PS group in the presence or absence (P4 concentrations <1 ng/ml) of an active corpus luteum. Dinoprost treatment did not decrease gross uterine diameter in groups HD and HS. Luminal diameter was significantly smaller in the PD than in the PS group. Pregnancy rate of PD was greater than PS cows (36% vs 20%, respectively). Days to first service (110 d vs. 140 d) and open days (160 d vs. 190 d) were shorter in PD cows than PS cows. It was concluded that injection of 25 mg of Dinoprost to pyometric cows had uterotonic effects in presence or absence of functional corpus luteum. Therefore, this treatment can help uterine involution in puerperal dairy cows affected by pyometra and consequently improved reproductive performance. <![CDATA[<b>Layer performance, fatty acid profile and the quality of eggs from hens supplemented with <i>Moringa oleifera</i> whole seed meal</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200004&lng=pt&nrm=iso&tlng=pt The objective of the study was to determine how the partial supplementation of Moringa oleifera whole seed meal (MOWSM) would affect layer performance, egg quality and egg fatty acid profile. One hundred and forty-four Hy-Line hens in early-lay (20-weeks-old), with an average body weight of 1.45 kg were randomly allocated to four dietary treatments which were formulated to meet or exceed the National Research Council standards for brown-egg laying hens. Dietary treatments consisted of 0 (control), 1, 3, and 5% MOWSM. Layer performance was monitored over a period of 8 weeks. The inclusion of MOWSM in layer diets reduced feed intake, bodyweight, the rate of lay, egg weight, and egg mass. Yolk colour was significantly improved by 1, 3 and 5% inclusion levels, while the albumen height decreased. The albumen weight, yolk weight, eggshell weight, eggshell thickness, and egg shape index showed no statistical differences across all treatment groups. Similarly, the saturated fatty acid profile was also not affected. Palmitoleic acid decreased with the increase in MOWSM inclusion, whilst linolelaidic acid increased. The atherogenicity index was not affected by MOWSM inclusion, while the thrombogenicity index increased when compared to the control diet. It was concluded that, although MOWSM inclusion improved yolk colour, maintained external egg quality, and improved the fatty acid profile, the deleterious effect that it had on layer performance indicated that it may not be fed to early-lay hens at these respective levels. <![CDATA[<b>Effects of a fibrolytic enzyme and bacterial inoculants on the fermentation, chemical composition and aerobic stability of ensiled potato hash</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200005&lng=pt&nrm=iso&tlng=pt The study was conducted to evaluate the effects of adding a fibrolytic enzyme in combination with bacterial inoculants on the fermentation, chemical composition and aerobic stability of ensiled potato hash (PH). Potato hash silage (PHS) was produced by mixing 800 g PH/kg and 200g wheat bran (WB)/kg. The mixture was ensiled with either no additive or enzyme Celluclast (low or high dose) or bacterial inoculants (Emsilage and Silosolve). These treatment combinations were produced: i) no additive (control); ii) Celluclast low dose (CLD); iii) Celluclast high dose (CHD); iv) Emsilage (EMS); v) CLD + EMS; vi) CHD + EMS; vii) Silosolve (SLS); viii) CLD + SLS; and ix) CHD + SLS. These treatments were ensiled in 81 x 1 L anaerobic jars for 90 days with nine replicates per treatment. Three samples per treatment were collected before ensiling and after 90 days' ensiling, were analysed for fermentation characteristics and chemical composition. In addition, samples of day 90 were subjected to an aerobic stability test, where they were exposed for five days. Enzyme addition reduced fibre, thus making more sugar available for fermentation. The combination of CHD and EMS reduced silage pH, thus preserving the silage compared with other treatment combinations. Enzyme addition (used at low and high dose), and bacterial inoculants improved fermentation. Enzyme addition improved the chemical composition, but impaired the aerobic stability of PHS. Further work to test these findings on animal performance is warranted. <![CDATA[<b>Potential of white garlic powder (<i>Allium sativum </i>L.) to modify <i>in vitro </i>ruminal fermentation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200006&lng=pt&nrm=iso&tlng=pt The current study aimed to evaluate the effect of increasing doses of garlic powder (GaP) on in vitro fermentation characteristics. Two successive 24-hour incubations were run, and gas production was measured at the end of each incubation period. Liquid samplings for each dose were reserved to determine ammonia nitrogen (NH3-N) and true organic matter degradability (TOMD). Partitioning factor (PF) was estimated as the ratio between TOMD and the gas produced at 24 hours of incubation. Microbial biomass (MBM) was estimated on the bases of truly degraded substrate and PF. Results showed that gas production increased (P <0.001) with the addition of 32 and 64 mg GaP. An increase (P <0.0001) in NH3-N concentration was recorded with 4 mg and 8 mg GaP compared with control, whereas adding 32 and 64 mg resulted in a NH3-N concentration equivalent to control (averaged 39.25 mg/100 ml). The propionate (C3) increased with doses and the highest proportion was noted with the addition of 8 mg GaP (P <0.001). The TOMD was similar for all the doses except for 64 mg GaP, where a slight but significant (P <0.001) increase was noted (77.7%). GaP did not affect PF and MBM values until the dose of 64 mg. It was concluded that GaP added to a ration composed of 50% roughages and 50% concentrate did not result in drastic modifications of in vitro rumen fermentation parameters, except at the highest dose (64 mg), where an increase of gas production, TODM, PF and MBM were noted. <![CDATA[<b>Gene expression and maturation evaluation of sheep oocytes cultured in medium supplemented with natural antioxidant source</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200007&lng=pt&nrm=iso&tlng=pt Any improvements in assisted reproduction techniques at experimental level are important in in vitro production of large animal and human embryos. The in vitro embryo production system includes three major steps, namely in vitro maturation of the primary oocytes, in vitro fertilization of the matured oocytes, and in vitro culture of presumptive embryos. The success of in vitro fertilization and embryo culture depends on the success of in vitro maturation. Fenugreek seed extract (FSE) is an important source of steroid hormones, antioxidants, and anti-inflammatories. This study aims to investigate the effect of FSE on the maturation progression, glutathione (GSH) concentration, and expression of certain genes controlling maturation such as growth differentiation factor-9 (GDF-9), transforming growth factor beta receptor 1 (TGFβR1), activin A receptor type II-like 1 (ACVRL1), hyaluronan synthase 2 (HAS2), C-Myc, B-cell leukaemia/lymphoma gene-2 (BCL-2), and BCL2-associated X protein (Bax) of matured sheep oocytes. To carry out this study, cumulus-oocyte complexes (COCs) aspirated from sheep ovaries were cultured in TCM-199 medium supplemented with various concentrations of FSE (0, 1 and 10 µg/mL). The results indicated that the mean values of matured oocytes were 65.2 compared with 47.8 in the control group. Concerning the candidate genes, expression was improved in oocytes matured with FSE when compared with oocytes cultured without extract. In conclusion, the addition of FSE to the maturation medium at 1 or 10 µg/mL concentrations improved the maturation of oocytes. <![CDATA[<b>Effect of <i>Acacia angustissima</i> leaf meal on performance, yield of carcass components and meat quality of broilers</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200008&lng=pt&nrm=iso&tlng=pt The study determined the appropriate levels of including Acacia angustissima leaf meal in broiler diets for optimum performance, carcass part yield, and meat quality characteristics. One hundred and fifty broiler chicks were allocated to 0%, 5%, and 10% A. angustissima leaf meal-based diets in a completely randomized design, with five replicates per treatment. Weekly feed intake and live weights were measured. Weekly weight gains and feed conversion ratios were calculated. At six weeks, two birds per replicate were slaughtered and dressed. Carcass and portion yields were determined. Breast proximate components, CIELAB colour variations, cooking loss and shear force were estimated. Consumer preferences for colour, aroma, taste, flavour and tenderness were determined. Voluntary feed intake (VFI), weekly weight gain, weekly live weights and feed conversion ratios (FCR) were the same across treatments at two weeks. At weeks 4 and 6, the control and 5% groups outperformed the 10% group. Increasing dietary leaf meal had no effect on dressing out percentage, but decreased carcass weight from 1456 g to 1060 g, breast yield from 36.83% to 32.69%, breast meat to bone ratio from 4.77% to 2.94%, and proportion of drumstick skin from 11.57% to 7.92%. It also resulted in increased yield of thighs from 14.63% to 15.97%, proportion of thigh skin from 11.50% to 14.31% and breast skin proportion from 5.37% to 7.95%. The leaf meal had no effect on the proximate components of breast meat. The L* values decreased from 53.66 to 49.23; the b* values increased from 12.93 to 19.97; shear force increased from 14.14 N to 14.54 N; and cooking loss increased from 5.95% to 7.64% with increasing leaf meal levels. It was concluded that up to 5% A. angustissima leaf meal inclusion has no negative effect on performance, yield of carcass parts and meat quality characteristics of broilers. <![CDATA[<b>Feed intake, growth performance and carcass traits of broilers fed diets with various inclusion levels of baobab seed oilcake</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200009&lng=pt&nrm=iso&tlng=pt The effects of increasing dietary inclusion levels of baobab seed oilcake (BSOC) on the growth performance, carcass characteristics, and yield in Ross 308 broiler chicks were assessed. Dietary treatments (T) consisted of four levels of BSOC: T1, control (0% BSOC); T2, 5% BSOC; T3, 10% BSOC; and T4, 15% BSOC. Birds on T2 and T1 had the highest bodyweight (BW) on days 14 and 28, respectively. Feed intake (FI) was highest during the periods of 1 to 7 days and 15 to 21 days in T2 birds. From 15 to 21 days, Feed conversion ratio (FCR) was highest in T3 birds. Significant differences were noted in slaughter and carcass weights among the treatments. Although no significant differences were observed in dressing percentages among treatments, birds in T1 had a higher dressing percentage, followed by those on T2. There were no statistical differences in carcass yield among the treatments. Calculations for revenue and gross margin showed that feed costs were lower in T4 and higher in T2 in the starter phase. In in the grower phase, feed costs were lower in T4 and higher in T3. The gross margin was higher in T1 and lower in T2 in the starter phase. During the grower phase it was higher in T1 and lower in T4. It was concluded that the inclusion of 5% BSOC at most could improve growth performance. Additionally, increasing levels of BSOC reduced feed costs, with a reduction in the gross margin in the grower stage of broilers. <![CDATA[<b>The effect of beef production system on proximate composition and fatty acid profile of three beef muscles</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200010&lng=pt&nrm=iso&tlng=pt In this study the effects of animal age combined with feeding regime and the utilisation of a beta-agonist (within a grain-fed system) on proximate composition and fatty acid profile of M. longissimus lumborum (LL), M. biceps femoris (BF), and M. semitendinosus (ST) were determined. Eighty Bonsmara steers consisting of A-age (0 permanent incisors) grain-fed (AC) and grain-fed supplemented with a beta-agonist, zilpaterol (AZ) (n = 20) grass-fed AB-age (1 - 2 permanent incisors; AB) (n = 20), and B-age (3 - 6 permanent incisors; B) (n = 20) animals were used. These four groups are representative of cattle slaughtered in South Africa and were treated as four production systems. The chemical composition of all three muscles showed that zilpaterol increased protein and reduced muscle fat contents of meat. All the muscles of both grass-fed groups (AB and B) had significantly higher content of certain desirable fatty acids (FAs) such as conjugated linoleic acid (CLA), omega-3 (n-3) FAs, branched chain saturated phytanic acid, and a lower omega-6/omega-3 (n-6/n-3) ratio than the two grain-fed groups (AC and AZ). The FA composition of grain-fed beef muscle was generally not influenced by the use of zilpaterol except for a tendency towards higher n-6 polyunsaturated fatty acid (PUFA) in beta-agonist produced beef. This was mainly due to higher levels of linoleic acid in LL and ST muscles and higher CLA in BF muscle of AZ animals. Phytanic acid was also higher in BF muscle of the AZ group compared to AC. Differences in animal age among grass-fed animals (AB vs. B) had minimal effect on FA composition of grass-fed beef. We can conclude that differences in FA composition of the three muscles are influenced mainly by feeding regime and less by differences in production factors within feeding regimes. <![CDATA[<b>Sinai and Norfa chicken diversity revealed by microsatellite markers</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200011&lng=pt&nrm=iso&tlng=pt The present study aimed to outline the population differentiation of Sinai and Norfa chicken, native to Egypt, with microsatellite markers. Twenty microsatellite loci recommended by the Food and Agriculture Organization (FAO) were used. Fifty eight birds were sampled (29 for each strain: 12 males + 17 females). Data were collected and genetic diversity indicators were assessed utilizing the approaches implemented in FSTAT, Cervus 3.0.7 and GenAlEx 6.5 software programmes. A total number of 182 alleles were detected with an average value of 9.1 allele per locus. The expected heterozygosity was 6.625 and 6.343 in Norfa and Sinai chickens, respectively. Norfa chickens produced 15 private alleles, while there were 9 unique alleles detected in Sinai chickens (13.18% private alleles as a percentage of the total observed number of alleles). Fixation indices' (F ST, F IS, and F IT) values were 0.060, 0.410 and 0.438, respectively, across all 20 loci investigated. Results indicated that the studied populations were genetically differentiated. Consequently, they have high breeding potential. Efforts should be made to incorporate the other local chicken strains as unique genetic resources into conservation programmes. This should begin with proper management of these flocks to ensure the maintenance of their genetic diversity over time by avoiding inbreeding. Such information is likely to have a profound effect on the success of genetic improvement and completes information from phenotypes and biometric measurements of the domestic chickens in Egypt. <![CDATA[<b>Model system evaluation of the effects of pea and pH on the emulsion properties of beef</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200012&lng=pt&nrm=iso&tlng=pt The effects of dried ground pea (0 - 1%) and pH (4.80 - 7.20) on the emulsion properties of beef were investigated using the model system. The study was designed according to the central composite rotatable design using the Response Surface Methodology. Pea had significant effects on emulsion activity and stability. The effects of pH on emulsion capacity, stability, activity, density, viscosity and apparent yield stress were significant. In addition, the interaction of both factors (pea and pH) caused significant effects on emulsion density, apparent yield stress of emulsion and emulsion gel. Pea addition increased emulsion activity at low concentrations and decreased at high concentrations. This study suggests that pea can improve the properties of emulsion type meat products and may be considered as an alternative additive in such products. <![CDATA[<b>Effects of grape pomace and vitamin E on performance, antioxidant status, immune response, gut morphology and histopathological responses in broiler chickens</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200013&lng=pt&nrm=iso&tlng=pt We investigated the effects of grape pomace (GP) and vitamin E on the performance, antioxidant status, immune response, gut morphology and histopathological responses in broiler chickens. Two hundred and fifty male broiler chickens (Ross 308) were allocated to five dietary treatments (50 birds/treatment) in a completely randomized design. The experimental diets were as follows: i) Control corn-soybean meal diet (C); ii) C + Vitamin E (200 mg/kg of α-tocopherol acetate); iii) The diet containing 5%GP; iv) The diet containing 7.5% GP; v) The diet containing 10% GP. No differences were found in performance of the experimental birds. Birds fed 7.5% GP showed a significant increase in superoxide dismutase (SOD), glutathione peroxidise (GSH-Px) activity and reduced malondialdehyde (MDA) concentration. Antibody titer against Newcastle disease virus (NDV) at 42 days (d) of age in the control and 7.5% GP fed groups were lower than others. The primary IgM concentration of birds fed 10% GP was higher than the birds fed the control diet, the vitamin E supplemented diet or the diet containing 5% GP. The secondary titer against sheep red blood cells (SRBC) was increased significantly in the birds fed 10% GP and the secondary IgG concentration of birds fed 10% GP was higher than the birds fed the control diet and the diets containing 5% or 7.5% GP. In duodenum part of small intestine, villus height/crypt depth ratio and muscularis thickness were decreased. The results of the present study suggest that the inclusion of up to 10% GP in diets did not adversely affect broiler chickens' performance and improved the antioxidant and immune responses of broiler chickens. <![CDATA[<b>External stimuli help restore post-partum ovarian activity in Pelibuey sheep</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200014&lng=pt&nrm=iso&tlng=pt Post-partum anestrus is a problem on farms, and its duration depends on the frequency and intensity of suckling which affects reproduction and production efficiency to become a determining economic factor. The aim of this study was to determine the post-partum reproductive response in ewe to a "male effect" with an ovulation induction protocol of five days using progesterone and the application of a metabolic restorative (MR; Metabolase ®). One hundred and twenty females were randomly assigned to one of four treatments: T1: Continuous suckling (CS; n = 29), T2: CS + MR (n = 29), T3: CS + Male Effect (ME; n = 32), and T4: CS + MR + ME. The percentage of females in ovulation, weight changes among females and lambs, the onset of estrus, calving, fecundity, and prolificacy were also determined. The ovulation percentage was higher in CS + ME and CS + MR + ME (75.0 and 73.3%) than in the other treatments. Weight changes in females and lambs were different among periods. The onset of estrus was similar for CS and CS + MR (25.9 ± 1.9 and 25.7 ± 0.7 h, respectively). The calving percentage was higher for CS + MR (86.2%) than other treatments. Male presence positively affected the postpartum cyclic ovarian re-establishment and the metabolic restorative could even improve the fertility of hair ewes in continuous suckling with similar hormone protocol. <![CDATA[<b>Effect of management system and dietary yeast autolysate on the performance, slaughter and carcass characteristics of partridges (<i>Alectoris chukar</i>)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200015&lng=pt&nrm=iso&tlng=pt This study was conducted to determine the effects of management system (a floor housing (FH) versus a free-range housing (FRH) system) and dietary yeast autolysate (Saccharomyces cerevisiae) (1% versus 2% dietary supplement) on the performance, slaughter and carcass characteristics of partridges (Alectoris chukar). A total of 480 (240 for each management system) one-day-old male partridge chicks were randomly allocated to a control group and the two dietary groups per production system, each containing 80 chicks. Each dietary group was then divided into five replicate groups of 16 chicks. The study lasted 112 days. In terms of growth performance, partridges reared under FRH management system had a lower average daily live weight gain (ADG), a significantly higher feed intake (FI), and feed conversion ratio (FCR) compared to the control group. However, partridges fed diets with yeast autolysate had a significantly higher ADG, lower FI, and an improved FCR compared to the control group overall. The gizzard, leg, and wing percentages of the partridges reared in the FRH system were found to be significantly higher than those of partridges reared in the FH system, while the breast and abdominal fat percentages were found to be lower. Dietary supplementation with yeast autolysate significantly increased the cold carcass yield and breast percentage when compared to the control group, while wing and abdominal fat percentages were decreased. In general, best performance was observed in the dietary supplementation group of 1% yeast autolysate in terms of growth and carcass parameters. When considering the fact that partridges are gamebirds, that housing poultry in cage production systems has been prohibited in recent years and that there are positive effects associated with using yeast autolysate as a prebiotic, it is recommended that a free-range production system should be used for partridge breeding, with the addition of 1% yeast autolysate to the diet of the birds. <![CDATA[<b>Whole genome study of linkage disequilibrium in Sahiwal cattle</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200016&lng=pt&nrm=iso&tlng=pt The linkage disequilibrium (LD) is an important tool to study quantitative trait locus (QTL) mapping and genetic selection. In this study, we identified the extent of linkage disequilibrium (LD) in Sahiwal (n = 14) cattle using the bovine high density single-nucleotide polymorphisms (SNPs) BeadChip. After data filtering, 500,968 SNPs comprising 2518.1 Mb of the genome, were used for the LD estimation. The minior allele frequency (MAF) was 0.21 in a substantial proportion of SNPs and mean distance between adjacent markers was 4.77 ± 2.83 kb. The overall mean LD between adjacent markers was 0.18 (r²) and 0.55 (|D'|), respectively. The LD (r²) values reduced with the increase in distance between adjacent markers from 1 kb (0.35) to 100 kb (0.12) and |D'| specified distinct decay of the LD. Chromosomes 1, 27, 28 and 29 presented the LD at some distance between markers. The extent of LD was higher, except these four chromosomes, for markers separated by 20 kb. At < 3 kb distance, the upper value of the linkage disequilibrium (LD) was observed at 0.30. High level of the linkage disequilibrium (LD) between markers was observed at high minor allele frequency (MAF) threshold (0.15), at the short distance between markers. The results of this study revealed that the Bovine high density SNPs BeadChip will be informative for the estimation of breeding value in Sahiwal cattle. <![CDATA[<b>Milk progesterone on day 5 following insemination in the dairy cow: associated metabolic variables and reproductive consequences</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200017&lng=pt&nrm=iso&tlng=pt Despite the importance of progesterone on the fertility of lactating dairy cows, the factors that affect post ovulatory progesterone concentration are still unclear. Thus, the aim of the present study was to identify factors associated with the post ovulatory progesterone rise following 1st insemination in lactating dairy cows. Data collected across a number of complimentary studies were compiled to produce a single database of 168 lactating Holstein Friesian dairy cows maintained under commercial conditions. In all animals a number of variables were measured during the insemination period and related to milk progesterone measured on day 5 following 1st artificial insemination (AI). Overall, 44% of cows conceived to 1st AI and while mean day 5 progesterone was not significantly higher in these cows, there was a significant quadratic relationship between milk progesterone concentration and conception rate. While a number of variables showed some association with progesterone concentration, the only variable showing a strong and repeatable relationship was plasma leptin concentration. We conclude that adequate but not excessive progesterone levels on day 5 bring about a better fertility, and plasma leptin concentration may be a much better indicator of metabolic status in lactating dairy cows. <![CDATA[<b>Dose-dependent effects of luteinizing hormone and follicle stimulating hormone on <i>in vitro </i>maturation, apoptosis, secretion function and expression of follicle stimulating hormone receptor and luteinizing hormone receptor of sheep oocytes</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200018&lng=pt&nrm=iso&tlng=pt The present study compared the effects of follicle stimulating hormone (FSH) and luteinizing hormone (LH) on in vitro maturation (IVM), apoptosis, and secretion function in sheep oocytes, as well as gene expressions of the receptors (FSHR, LHR, and GnRHR) in cumulus-oocyte complexes (COCs). The COCs were recovered from sheep ovaries and pooled in groups. The COCs were cultured for 24 hours in IVM medium supplemented with various concentrations of LH (5-30 μg/mL) and FSH (5-30 IU/mL). They were allocated to LH-1 (5 µg/mL), LH-2 (10 µg/mL), LH-3 (20 µg/mL), and LH-4 (30 µg/mL) groups, and FSH-1 (5 IU/mL), FSH-2 (10 IU/mL), FSH-3 (20 IU/mL), and FSH-4 (30IU/mL) groups. The apoptosis of COCs was assessed by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). The maturation rates of oocytes improved gradually as LH and FSH concentration increased from 0 to 10 μg/mL(IU/mL), reaching a peak value of 44.1% of LH-2 and 48.5% of FSH-2 group. Oocyte apoptosis rates of LH-2 and FSH-2 groups were the lowest among LH- and FSH-treated groups, respectively. The germinal vesicle breakdown (GVBD) rate of the FSH-2 group was higher than that of the control group (CG) and FSH-4 groups. The GVBD rate of LH-2 group also increased in comparison with the CG group. FSH concentration of the FSH-2 group was greater than that of CG. Expression levels of FSHR, LHR, and GnRHR mRNAs of FSH-2, LH-3, and LH-3 group, respectively, were higher than CG. Levels of FSHR proteins in FSH-2 and FSH-3 groups were greater than CG. Levels of GnRHR proteins were increased with a maximum increment of FSH-4. The FSH and LH supplemented into the IVM medium could promote the maturation rate, reduce the apoptosis rate of sheep oocytes, and increase FSH concentrations in IVM medium fluid. Additionally, FSH and LH enhanced expression levels of FSHR, LHR, and GnRHR mRNAs of sheep COCs. <![CDATA[<b>Probiotic <i>Bacillus </i>species and <i>Saccharomyces boulardii</i> improve performance, gut histology and immunity in broiler chickens</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200019&lng=pt&nrm=iso&tlng=pt The aim of this study was to compare the effects of a new multispecies probiotic containing four Bacillus species and Saccharomyces boulardii (Microguard®) with a commercial probiotic (Protexin®) and a commonly used antibiotic in broilers. Six hundred one-day-old male Ross 308 broilers were randomized to six experimental treatments, with five replicates of 20 chicks each, for 42 days, receiving an ad libitum corn-soybean basal diet. Treatments were added to the basal diet and consisted of tetracycline as an antibiotic growth promoter (500 g/ton), three dosages of Microguard (50, 100 and150 g/ton) or Protexin (100 g/ton). The control group received the basal diet with no additive. The group fed with Microguard at 150 g/ton showed increased final bodyweight, weight gain, high density lipoprotein, triglyceride, and antibody titres against Newcastle disease (ND) and avian influenza (AI) levels. Improved feed conversion ratio, increased villus height, and villus highest crypt depth ratio, along with lower plasma gamma-glutamyl transpeptidase, alkaline phosphatase, alanine aminotransferase, were found in probiotic-supplemented broilers. Carcass yield, liver weights, breast muscle values, and abdominal fat weights were reduced in groups fed with 100 or 150 g/ton of Microguard. Caecal coliforms, Salmonella and Escherichia coli numbers decreased in groups fed with 100 or 150 g/ton of Microguard. These results show that Microguard at 150 g/ton is a promising probiotic to replace antibiotics in broiler feed as a growth-promoter while enhancing immune system responses and inducing beneficial modulations in the caecal microflora. <![CDATA[<b>Effect of different levels of sunflower meal and multi-enzyme complex on performance, biochemical parameters and antioxidant status of laying hens</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0375-15892018000200020&lng=pt&nrm=iso&tlng=pt This study was designed to evaluate the effects of different sunflower meal (Helianthus annus; SFM) levels and a multi-enzyme complex (Natuzyme P50) on performance, biochemical parameters and antioxidant status of laying hens. A total of 288 Hy-Line W-36 laying hens (39-wk-old) were divided into six groups with six replicates per group (eight birds per replicate) and fed one of the six experimental diets. A corn-soybean meal-based diet was formulated and used as control diet. The experimental treatments consisted of three levels of SFM (0, 10, and 20%) and two levels of multi-enzyme complex (0 and 250g/ton). The feeding trial lasted 10 weeks. The results showed that the egg production, egg weight and mass, egg specific gravity, shell strength and thickness, Haugh unit, shape index, triglyceride content, plasma glutathione peroxidase (GSH) activity, and malondialdehyde (MDA) were not influenced by dietary treatments; however, the feed consumption, yolk cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol were significantly affected by feeding SFM compared to the control. In conclusion, the supplementation of SFM up to 20% in diet with multi-enzyme complex in laying hens did not appear to cause any adverse effects on egg production and quality as well on antioxidant status in laying hens.