Scielo RSS <![CDATA[South African Journal of Animal Science]]> vol. 50 num. 3 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>Association of polymorphisms of vasoactive intestinal peptide and its receptor with reproductive traits of turkey hens</b>]]> The aim of this study was to identify variations of vasoactive intestinal peptide (VIP) and VIP receptor-1 (VIPR-1) genes that might be associated with turkey reproductive traits. One hundred twenty turkey hens were recorded for age at first egg (AFE), first egg weight (FEW), egg number (EN), total egg weight (TEW), laying period (LP), and broodiness. The DNA was isolated from blood samples and subjected to PCR amplification of the meleagrine VIP and VIPR-1 genes. The SNPs were detected by single-strand conformation polymorphism and the variant DNA fragments were sequenced. One mutation in 3'-UTR of VIP (G5846A) and two SNPs in intron 2 of VIPR-1 (C17687T and A17690T) were found, all of them novel. The associations of the three detected SNPs with the reproductive traits of turkeys were evaluated. The detected polymorphisms were used for marker-trait association analyses. The results of association analysis showed that G5846A on 3' UTR of VIP has a significant association with LP, EN, TEW, and AFE. The G allele of G5846A was the favourable SNP allele for LP, EN, and TEW traits. The AA genotype of A17690T on intron 2 of VIPR-1 was significantly associated with higher LP, EN, and TEW. AGAA haplotype showed association with higher EN and TEW. These results suggest that the SNPs in 3'-UTR of VIP and intron 2 of VIPR-1 genes may influence egg production traits in turkey hens. <![CDATA[<b>Antibiotic-free diet supplemented with live yeasts decreases inflammatory markers in the ileum of weaned piglets</b>]]> Emerging bacterial resistance to antibiotics increases the need for effective alternatives to control intestinal inflammation and thus gut disorders in piglets. This study evaluated the effects of including Saccharomyces cerevisiae (strain 1026) and Saccharomyces boulardii (CNCM I-1079) as antibiotic alternatives in the starter diets of pigs on the concentrations of ileal inflammatory markers (nuclear factor-KB (NF-kB)), interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), and interleukin-12 subunit p40 (IL-12p40), and villus height. Forty piglets were assigned to four experimental diets, namely basal diet (C-), basal diet with antibiotics (C+), basal diet with S. cerevisiae (Sc), and basal diet with S. boulardii (Sb). At 7 and 14 days post weaning, five piglets per diet group were euthanized to quantify the inflammatory markers and to measure villus height. The C- group exhibited the highest concentration of inflammatory markers and the most atrophied villi. The Sc group had intermediate values for both variables. The C+ group had the lowest values for inflammatory markers and the highest villus height was similar to that of the Sb group, which showed low concentrations of inflammatory markers, although not so low as those of the C+ group. Both yeasts could be used as antibiotic alternatives to reduce the use of antibiotics in pig starter diets. However, S. boulardii CNCM I-1079 supplementation controls inflammation and preserves intestinal mucosa more effectively than S. cerevisiae strain 1026. <![CDATA[<b>Genetic effects from an Afrikaner, Bonsmara, and Nguni three-breed diallel and top-crosses of Angus and Simmental sires</b>]]> Individual and maternal breed additive effects and heterosis exist for most economically important traits in cattle. Crossbreeding may therefore be valuable for emerging and commercial beef farmers in improving the productivity of their herds. Calves were produced by mating Afrikaner, Bonsmara and Nguni cows to Afrikaner, Bonsmara, Nguni, Angus and Simmental bulls. The cows used were from Vaalharts Research Station or were purchased from other herds. Data were collected over three years. Individual and maternal additive effects and individual heterosis were estimated simultaneously as continuous linear variates. The estimated genetic effects were then used to predict production levels that may be achieved through implementation of top-cross, two-breed rotation, and terminal sire crossbreeding systems. The individual estimates of the genetic effects were relatively small and in most cases were not different from zero, with the exception of the maternal additive effects of Nguni on preweaning traits and their individual additive effect on cow weight, which were less than those of Bonsmara. However, the alternative crossbreeding systems differed across traits. The straight-bred breeding system was least efficient, followed by the crisscross system (+2%) and the terminal sire system that utilized Simmental (+4%), with the terminal sire system utilizing Angus being on average most efficient (+8%). The inter-generational genetic differences in cow weight that resulted from the use of different breeds of sire increased its standard deviation by 5 to 6% in rotational crossing. Despite the relatively small magnitude of the genetic effects, advantages of crossbreeding systems became evident. <![CDATA[<b>Evaluation of three fast- and slow-growing chicken strains reared in two production environments</b>]]> The present study evaluated performance, physiological response and economics of commercial fast growing (CFG), commercial slow growing (CSG), and Rhode Island Red (RIR) chickens under intensive and free-range rearing environments. After 21 days of rearing under the same intensive environment 240 birds from each strain were subjected to free-range and intensive rearing until they were 56 days old. Each treatment was replicated six times with 20 birds in each replicate. Body surface and cloacal temperatures, respiration and heart rates, feed intake, bodyweight and weight gain, feed conversion efficiency, growth efficiency, and liveability were recorded. Significant differences among strains were detected in physiological response and growth performance (except liveability). Rearing environment also caused significant differences in physiological parameters (except body surface temperature) and growth performance (except liveability). Significant interactions of the strains and production systems were detected. The CFG strain grew most rapidly under the intensive system with differences between strains being reduced in the free-range system. The RSG and CSG strains had similar respiration rates under the two production systems but differed significantly from each other. However, the CFG strain had a significantly elevated respiration rate in the free-range system. Total input cost of rearing CFG under the intensive system was highest ($3.54) among the treatments, whereas CSG under a free-range environment generated the highest profit ($0.37 per bird). In conclusion, rearing CSG under free range was the most economic farming strategy in today's scenario. <![CDATA[<b>Use of phosphatidylcholine in Tris-based extender with or without egg yolk to freeze Bapedi ram semen</b>]]> Traditionally, egg yolk is a protective agent that is used to freeze semen in various species. However, the addition of egg yolk in extender risks the introduction of disease. Therefore, an alternative cryoprotective agent should be found to preserve ram semen. The aim of this study was to evaluate the effect of phosphatidylcholine (PC) as a protective agent in extender with or without egg yolk on semen characteristics and acrosome integrity of frozen then thawed Bapedi ram semen. Semen was collected from four mature Bapedi rams, in the Agricultural Research Council (ARC) Germplasm Conservation Programme, using an artificial vagina. Following collection, semen samples were randomly diluted into Tris-based extender (1: 2), with and without egg yolk, and supplemented with four concentrations of PC liposome (0 mg/ml), 0.25 mg/ml, 0.5 mg/ml and 0.75 mg/ml). Supplementation of PC liposome in extender with or without egg yolk did not improve the semen total motility (TM), progressive motility (PM) and rapid motility (RM) rate. The sperm cell membrane integrity in extender with or without egg yolk was not influenced by the supplementation of PC liposome after thawing (P >0.05). The addition of PC liposome to Tris-based extender with egg yolk had a similar result to control (Tris-based extender with egg yolk) on sperm cell acrosome integrity. In conclusion, supplementation of PC liposome to Tris-based extender without egg yolk had lower sperm cell viability and motility rates compared with the extender with egg yolk, regardless of concentration. <![CDATA[<b>Short Communication - Oxalate and silica contents of seven varieties of Napier grass <i>(Pennisetum purpureum)</i></b>]]> Oxalate and silica are considered antinutrients. Large quantities of oxalate and silica in plants can interfere with the uptake of essential minerals in ruminants. Therefore, the aim of this study was to compare the total silica and oxalate contents of seven varieties of Napier grass to find out which is best for cultivation. Taiwan, Zanzibar, Pakchong, Purple, Kobe, Indian, and Dwarf Napier grass were grown in a completely randomized design with three replications to determine their soluble oxalate, total oxalate, and silica contents. Plants were harvested at two months of plant maturity. Whole plant of the Dwarf Napier grass contained significantly higher soluble oxalate content than tall varieties. Total oxalate content in whole plant differed significantly among varieties. Dwarf showed the highest total oxalate content (3.23% dry matter (DM)) followed by Kobe (2.61%), Zanzibar (2.60%), Purple (2.44%), Taiwan (2.43%), Indian (2.15%), and Pakchong (1.95%). Regardless of variety, leaf tissue contained significantly higher soluble oxalate and total oxalate than stem tissue. There were no differences in silica content among them. In conclusion, the tall varieties could produce lower levels of soluble oxalate than the Dwarf variety, whereas silica content might not vary among them. <![CDATA[<b>Incorporating oldman saltbush hay and prickly pear in diets for red Sindhi calves</b>]]> This study was designed to evaluate the nutrient intake, digestibility, degradability, and ruminal characteristics of Sindhi heifers fed diets that contained a combined total of 75% oldman saltbush hay (hereafter saltbush hay) and prickly pear cactus. Eight 12-month old intact male red Sindhi calves (four fistulated and four non-fistulated) with an initial mean weight of 170 ± 5 kg were assigned to 4 * 4 Latin squares, where factors consisted of four diets, namely 15% hay and 60% cactus; 30% hay and 45% cactus; 45% hay and 30% cactus; and 60% hay and 15% cactus, and four times at which rumen fluid was collected. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes in kg/day and NDF in percentage live weight (LW), water intake, salinity, and conductivity increased with hay level. Intake and digestibility of non-fibrous carbohydrates were curvilinear with higher values in diets containing 30% saltbush hay. The apparent digestibility of dry matter (DM) and organic matter decreased linearly as the concentration of saltbush hay increased in the diet. The pH of the rumen fluid was within the acceptable range for favourable microbial growth. The low temperature and high salinity and conductivity indices in the diets should be viewed with caution at higher concentrations of saltbush hay, because of a possible decrease in nutrient absorption and the development of health problems in the animals. Apparent degradability coefficients of DM and NDF were affected significantly by inclusion of prickly pear and saltbush hay in the diets. <![CDATA[<b>Effect of arbuscular mycorrhizal inoculation on the quality and in vitro gas production of einkorn wheat straw</b>]]> The purpose of this study was to determine the effects of arbuscular mycorrhizal (AM) inoculation on the quality of einkorn wheat straw (EWS) and in vitro gas production (GP). It was found that AM inoculation of EW seed before sowing caused significant increases in crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), zinc (Zn), copper (Cu), and iron (Fe) levels of straw, and a (P <0.05) decrease in crude ash (CA), metabolizable energy (ME), and organic matter digestibility (OMD) compared with the straw of non-inoculated EW. The observed difference in the average GP among the between EWS from plants grown from inoculated seed and those from the untreated control was significant at all times between the third and 96th hour. However, when the GP kinetics of the groups was examined after 96 hours' incubation, only the difference in the gas amount of the easily soluble fractions of feeds was significant. The GP from the slowly fermented part, the GP rate constant and the potential GP of the straws were not affected by the AM inoculation (P &gt;0.05). Thus, inoculation of einkorn wheat with AM altered the nutritional value of the straw produced creating a roughage with decreased value for feeding ruminant livestock. <![CDATA[<b>Effects of supplementing geese with green sweet sorghum stalks on microbiota in segments of the gastrointestinal tract</b>]]> To explore the effects of supplementing a basal diet with green sweet sorghum stalks on the gut microbiota in geese, one hundred and twenty 28-day-old geese were divided into two groups. Group 1 was fed a basal diet and group 2 was fed 92% of the same basal diet with green sweet sorghum stalks ad libitum for 42 days. Three male geese from each group were killed at 70 days old, four gastrointestinal tract segments (duodenum, jejunum, ileum, and caecum) were collected, and the hypervariable V4 region of the bacterial 16S rRNA gene was sequenced. There were obvious changes of microbiome in the caecum compared with the other three intestinal segments after green sweet sorghum stalks were added to the diet. Group 2 had significantly higher alpha diversity in the caecum compared with group 1 (P <0.05). The phyla of bacterial communities in the caecum differed. Group 2 had more abundant Bacteroidetes and Firmicutes, but Proteobacteria were more abundant in group 1. At genus level, Bacteroides was more prevalent in group 2, as were Prevotella and YRC22 (P <0.05). Functional analysis revealed that the carbohydrate metabolism, membrane transport, endocrine system and digestive system metabolic pathways were overrepresented in group 2. In conclusion, caecal microbes might play an important role in digesting green sweet sorghum stalks in geese. <![CDATA[<b>Effect of parity on reproductive performance sows of different breeds</b>]]> The aim of this study was to determine the effect of parity on reproductive performance by sows of different breeds. The sows were raised on three farms, and had seven or more litters of not fewer than seven piglets. A total of 1511 litters from various parities of Lithuanian White (N =721), Large White (N = 162) and Landrace (N = 628) sows were contained in the data that were used in this study. Multiparous sows had larger litters than primiparous sows. Piglet survival rate declined from parity 7. An increase in litter size was observed until parity 5 in Large White and until parity 6 in improved Lithuanian White (P <0.05). In comparison with parity 1, Landrace sows up to parity 5 showed not only increased prolificacy, but also increased number and litter weight of piglets at 21 days old, and the number and litter weight of weaned piglets (P <0.01). The current findings indicate that sows of these breeds can be used effectively in breeding herds until parity 5 and parity 6. <![CDATA[<b>Supplementation of Holstein dairy calves fed two levels of crude protein with methionine and lysine</b>]]> This study aimed to investigate various levels of crude protein (CP) in starter diets and their supplementation with amino acids (AAs) on efficiency, health, and serum metabolites of dairy calves. Ninety-six newborn Holstein calves were allocated to eight treatments, namely T1) 18% CP unsupplemented starter, T2) T1 supplemented with additional 20% methionine, T3) T1 with additional 20% lysine and 20% methionine, T4) T1 with additional 20% lysine, T5) 22% CP unsupplemented starter, T6) T5 supplemented with additional 20% methionine, T7) T5 supplemented with additional 20% lysine and 20% methionine, and T8) T5 supplemented with additional 20% lysine. Consumption of the starter was not influenced by the level of CP. Calves that received the unsupplemented 22% CP starter had higher average daily gain (ADG) and final weight. But no significant differences among diets were found in feed efficiency. Skeletal growth did not exhibit a clear trend. Calves that received T3 had fewer bouts of diarrhea and reduced body temperature. However, there were no significant dietary effects on immunoglobin G (IgG) or total protein concentration in blood. T1-T3 decreased serum urea concentration. Thus, use of T3 resulted in an improved amino acid balance, and was less expensive than the 22% CP starter. <![CDATA[<b>Determination of the best non-linear function to describe the growth of Kajli sheep</b>]]> The aim of the present study was to determine the best non-linear growth function to describe the growth of Kajli sheep. For this aim, the Brody, von Bertalanffy, Logistic, and Gompertz models were used to describe the sigmoidal relationship between bodyweight and age of the Kajli sheep. The records obtained from the Livestock Experiment Station, Khushab, were collected between 2007 and 2018. The records comprised 9864 age-weight observations (300 for male, 9564 for female, 7392 for single, 2388 for twin, and 84 for triplet lambs), which extended from birth to 12 months old. Candidate non-linear functions were fitted and the curve parameters were estimated by nlsfit (fit non-linear models) function in R statistical package, version 3.6.1. Goodness of fit criteria that were used to evaluate predictive performances of candidate models were adjusted coefficient of determination (R²adj), Akaike's information criterion (AIC), Bayesian information criterion (BIC) and root means square error (RMSE). The Brody model was the best non-linear function that described the biological growth pattern of all, male, female, single, twin, and triplet lambs. Differences in curve parameter estimates between male and female suggested a definite pattern of sexual dimorphism. Moreover, a higher estimate of rate of maturity in female lambs reflects their early maturity compared with male Kajli lambs. Similarly, the single-born Kajli animals with highest maturity rate were maturing at an earlier age than twins and triplets. This is the first report on the non-linear pattern of visible changes in bodyweight of Kajli sheep from birth to 12 months old. <![CDATA[<b>Effect of partial replacement of soybean and corn with raw or processed chickpea</b>]]> This study was conducted to investigate the effects of using raw and processed chickpeas in various ways and levels in rations of egg-laying quail on egg yolk fat content, egg yolk fatty acid profile and some blood parameters. Chickpeas were used raw, autoclaved, and microwaved, and were included in the rations on two levels (20% and 40%). The treatments were designed as seven groups, consisting of control, 20% and 40% raw, 20% and 40% autoclaved, and 20% and 40% microwaved. Each group was designed as three repetitions. Quail were housed in multi-storey cages for nine weeks. As a result, the differences between the control and treatment groups were significant (P <0.05, P <0.01) in terms of the ratios of linoleic acid, a-linoleic acid, total saturated fatty acids, and palmitic acid among the egg yolk fatty acids and significant in the ALT levels of the blood parameters (P <0.01), and not significant for the other parameters. <![CDATA[<b>Forage allowances offered to pregnant ewes until middle and late gestation</b><b>: </b><b>Organ priorities on foetus development</b>]]> Effect of forage allowance before conception and until mid or late gestation was evaluated for effects on foetal and neonatal weights, carcass, nervous systems, metabolic and reproductive organ weights, body dimensions, and variation in intensity of the effects among organs. Effects of two forage allowances, HFA: high forage allowance (2.9 - 3.8 kg of dry matter (DM)/kg bodyweight (BW)) and LFA: low forage allowance (1.4 - 2.6 kg DM/kg BW) were evaluated from 23 days before conception until 70 or 122 days postpartum. On gestation day 70, nine ewes per treatment, each carrying one male foetus, were euthanized and their foetuses were removed. The foetuses were weighed, their carcass and organ weights were recorded, and their external genitalia dimensions were measured. Nine additional lambs per treatment were euthanized 12 hours after birth and the same data were recorded. Hearts from day 70 LFA foetuses were lighter, their external genitalia were smaller, and their foetal weight tended to be less than in HFA. Newborn lambs from LFA ewes had lighter carcasses, livers, kidneys, adrenal glands and testes, shorter penises, but higher brain to liver weight ratios than in HFA. The cerebellum, brain, and heart weights of LFA and HFA newborn lambs did not differ. Low forage allowance until late gestation influenced both foetal and lamb weights and affected organ weights differentially. Thus, the treatments induced differences in prioritization of nutrients, with the central nervous system receiving the highest priority, and carcass and external genitalia the lowest. <![CDATA[<b>Defatted yellow mealworm larvae <i>(Tenebrio molitor </i>l.) meal as possible alternative to fish meal in quail diets</b>]]> The effects of replacing fish meal (FM) in the diet with defatted mealworm larvae meal (DMLM) on growth, carcass, and biochemical constituents of serum of Japanese quail chicks were investigated. A total of 600 unsexed one-day-old chicks were allotted to five dietary treatments with six replicates of 20 chicks each. The diets were formulated by replacing FM with DMLM at the levels of 25% (D25), 50% (D50), 75% (D75), and 100% (D100). The FM, D25 and D50 diets resulted in greater final bodyweight, higher bodyweight gain, and improved feed conversion ratio compared with the other diets. Diets that contained DMLM decreased the feed intake compared with the FM diet. The FM and D25 diets increased the hot and cold carcass yields compared with the other diets, whereas the D75 and D100 diets significantly enhanced the relative weight of the small intestine and abdominal fat compared with FM, D25, and D50. The replacement of FM with DMLM reduced the serum globulin, total cholesterol and triglyceride levels, and the albumin to globulin ratio significantly. The best protein and energy efficiency ratios and European efficiency factor were obtained with the D25 and D50 diets. In conclusion, the replacement of FM with DMLM at the levels of 25% and 50% produced positive results in growth performance, in serum albumin to globulin ratio, and in nutrient use efficiency in quail.