2018
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Item Open Access Rumen degradability and gas production as influenced by different strains of Bacillus thuringiensis(Canadian Science Publishing, 2018-10-24) Campos, Fernanda C; Abdalla Filho, Adibe Luiz; Corrêa, Patricia Spoto; Nazato, Carina; Monnerat, Rose G; McManus, Concepta M; Tsai, S.M.; Abdalla, Adibe Luiz; Louvandini, HelderThe effect of six Bacillus thuringiensis (Bt) strains on diet degradability was evaluated using an in vitro gas production technique. Spores (5.7 x 106 spores) of different Bt strains (907, 1192, 2036, 2493, 2496 and S1185) plus a Control (no spores) were used as treatments with four replicates (inocula) in duplicate. Fermentation processes were evaluated and ruminal microorganisms were quantified. Compared to the Control, the Bt907 strain decreased dry matter (DM) and organic matter (OM) degradability without affecting the F. succinogenes population, while the other strains reduced this population without altering DM and OM degradability.Item Open Access Feeding and post-ruminal infusion of calcium gluconate to lactating dairy cows(Canadian Science Publishing, 2018-12-12) McKnight, Leslie; Doelman, John; Carson, Michelle; Waterman, Douglas; Metcalf, John A.Gluconic acid was proposed as a prebiotic for non-ruminants; however, a ruminant application is undescribed. The first experiment was a 5 x 5 Latin Square with five test doses of calcium gluconate (CaG): 0, 5, 17, 32 and 46 g/d. Treatments were infused into the omasum of lactating dairy cows for 28 d and milk was collected on d 26, 27 and 28. The second experiment was a cross-over where cows (N = 30) were fed a TMR with (0.2 % of DM) and without CaG for 28 d. Milk (d 26, 27 and 28) and blood (d 28) were collected from all cows and rumen fluid (d 28) from a subset of 6 rumen cannulated cows. Infusion of CaG into the omasum increased milk fat yield and decreased DMI resulting in improved feed efficiency. In contrast, cows fed CaG in the TMR had decreased milk yield and milk protein and lactose yields compared to CON. In the subset of rumen cannulated cows, the proportion of butyric acid was decreased and acetic acid increased relative to total VFA in cows fed the CaG. These findings suggest that CaG utilization may be different in the rumen and lower gastrointestinal tract.Item Open Access Assessment of the Canadian model predicting daily milk yield and milk fat percentage using single-milking dairy herd improvement samples(Canadian Science Publishing, 2018-12-21) Duplessis, Mélissa; Lacroix, René; Fadul-Pacheco, Liliana; Lefebvre, Daniel; Pellerin, DorisThe use of adjustment factors with alternate morning (AM)-evening (PM) milk-tests to predict daily milk yield and fat percentage from single milking could lead to erroneous daily data. The aims of this study were to evaluate the relationship between predicted daily milk yield or milk fat percentage, calculated using single milking samples and Canadian adjustment factors, and the actual daily milk yield or milk fat percentage as well as to explore feeding and management variables that could improve daily predictions. A total of 4277 Holstein cows in 100 dairy herds were enrolled. Separate PM and AM milk samples were collected for each cow using in-line milk meters. Daily milk yield and milk fat percentage predictions were computed from single-milking samples using adjustment factors taking into account milking interval and milking time. Concordance correlation coefficients between actual daily milk yields and daily milk yield predictions from PM (0.970) and AM (0.974) milkings were higher than those between actual daily milk fat percentages and daily milk fat percentage predictions from PM (0.897) and AM (0.917) milkings. There were only slight prediction improvements when days in milk, parity and some feeding management variables were entered in models aiming to explain residuals.Item Open Access Effects of dietary protected organic acids on growth performance, nutrient digestibility, fecal microflora, diarrhea scores and fecal gas emission in weanling pigs(Canadian Science Publishing, 2018-12-11) Yang, Yi; Lee, Kwang Yong; Kim, I.H.A total of 112 weanling pigs with an average body weight of 6.70 ± 1.31 kg were allotted to one of four experimental diets for a 6 wk feeding trail to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, and fecal microbial counts. Diets consisted of basal diet (CON), CON + 0.2% unprotected organic acid (UOA), CON + 0.1% protected organic acid (POA1), and CON + 0.2% POA (POA2). Feeding POA diets to weanling pigs increased (P < 0.05) the average daily gain (ADG) during 0–2 wk and overall experimental period, and it also increased (P < 0.05) the apparent total tract digestibility (ATTD) of dry matter (DM) compared with UOA. The addition of increasing levels of POA showed greater (linear effect, P < 0.05) ADG, gain/feed ratio, and ATTD of DM. In addition, dietary inclusion of increasing levels of POA linearly increased (P < 0.05) the fecal Lactobacillus counts, whereas the Escherichia coli and Salmonella counts, diarrhea score, fecal ammonia, and acetic acid emissions were reduced (linear effect, P < 0.05). In conclusion, dietary supplementation of 0.2% POA to weanling pigs has the potential to improve growth performance and reduce diarrhea incidence while balancing microbial counts.Item Open Access Serum metabolites and weights of internal organs of broilers fed on varying levels of Acacia angustissima leaf meal(Canadian Science Publishing, 2018-08-04) Gudiso, Xolile; Hlatini, Vuyisa; Ncobela, Cyprial; Chimonyo, Michael; Mafongoya, ParamuThe objective of this study was to determine the relationship between inclusion levels of Acacia angustissima leaf meal against nutritionally related blood metabolites, activity of liver enzymes, and scaled internal organs in broilers. A total of 120 Ross 308 broiler chicks with initial body weight of 0.90 ± 0.043 kg were randomly allotted to six diets containing different inclusion levels, namely 0, 30, 60, 90, 120, and 150 g kg−1 dry matter of A. angustissima leaf meal. Each inclusion level of A. angustissima leaf meal was replicated four times. Five birds were randomly assigned to each replicate. There was a linear decrease in cholesterol (P < 0.05) with increasing levels of A. angustissima leaf meal. There was a linear increase in scaled gizzard weight (P < 0.05), scaled heart weight (SHW; P < 0.001), and intestine weight (P < 0.001). Scaled spleen weight (P < 0.01) had a positive quadratic relationship with levels of A. angustissima leaf meal. There was a positive quadratic response in alkaline phosphatase (ALP) activity with increasing levels of A. angustissima leaf meal (P < 0.001). The concentration of cholesterol and liver enzymes demonstrates the potential of leaf meals to be incorporated in poultry diets. The optimum inclusion level of A. angustissima was attained at 60 g kg−1 for ALP and 90 g kg−1 for SHW.Item Open Access Effects of repeated exposure to an estrus synchronization protocol on reproductive parameters in dairy goats(Canadian Science Publishing, 2018-12-05) Sun, Shuang; Liu, Shimin; Luo, Jun; Chen, Zhi; Yang, Yang; Shi, Huaiping; Li, Cong; Luo, JianingRepeated exposure to estrus synchronization (ES) protocol might have detrimental effects on reproductive function. Therefore, we examined the effects of repeated exposure to a gonadotropin-based ES protocol on hormonal profiles in 47 female Xinong Saanen dairy goats. Goats were randomly assigned to receive an ES protocol either three consecutive times with 14 d interval between each protocol (3 × ES group), or once (1 × ES group) starting concurrently with the third protocol of the 3 × ES group. The estradiol concentrations in 1 × ES group were significantly lesser than those of 3 × ES group at 0, 24, 36, 60 h after controlled internal drug release withdrawal. The progesterone, luteinizing hormone, and follicle-stimulating hormone concentrations did not differ between 1 × ES and 3 × ES groups. No differences (P > 0.05) were observed in the estrus interval, estrus duration, gestation length, birth weight of kids, and the incidences of estrus, pregnancy, single birth, twinning birth, triplet birth between 1 × ES and 3 × ES groups. Litter size was smaller in goats of the 3 × ES group than in 1 × ES goats, and there were more female offspring in 3 × ES group than 1 × ES group (P < 0.05). The differences in reproductive parameters warrant further investigation in a larger population of goats subjected repeated ES.Item Open Access Morphology, membrane integrity, and mitochondrial function in sperm of crossbred beef bulls selected for residual feed intake(Canadian Science Publishing, 2018-10-02) Bruinjé, Tony C.; Ponce-Barajas, Patricio; Dourey, Antoine; Colazo, Marcos; Caldwell, Timothy R; Wang, Zhiquan; Miller, Stephen P.; Ambrose, Divakar JThe objectives of this study were to compare morphology, plasma and acrosome membrane integrities, and mitochondrial function in sperm of bulls selected for low- vs. high- residual feed intake (RFI). Semen samples obtained from 10 low- and 8 high-RFI yearling crossbred beef bulls were evaluated. Assessment of sperm morphology was performed by microscopy, and sperm membrane integrity and mitochondrial membrane potential were evaluated by flow cytometry. Parameters of sperm morphology evaluated did not differ between low- and high-RFI bulls. Compared to high-RFI bulls, low-RFI bulls had an increased proportion (LSM ± SE) of sperm with actively respiring mitochondria (54.2 ± 2.9 vs. 43.6 ± 3.3%, P = 0.03). However, a greater proportion of sperm from low-RFI bulls had low mitochondrial membrane potential (34.4 ± 4.2 vs. 19.0 ± 4.7%, P = 0.03). Results indicate that selection for improved feed efficiency do not compromise bull sperm morphology and viability. However, despite greater mitochondrial activity, the increased proportion of mitochondria with low membrane potential in sperm of low-RFI bulls warrants further investigation to rule out any potential negative effects on fertility.Item Open Access A novel polymorphism in the 3′ untranslated region of rabbit TAS1R1 is associated with growth performance and carcass traits but not meat quality(Canadian Science Publishing, 2018-11-19) Wu, Zhoulin; Hu, Yongsong; Chen, Shiyi; Jia, Xianbo; Deng, Feilong; Lai, SongjiaThe aim of this study was to investigate the relationship between polymorphisms of the 3′ untranslated region of TAS1R1 and growth traits, carcass traits, and meat quality traits in rabbit. We detected one single nucleotide polymorphism located at 9120 bp (g.9120A>C) in the 3′ untranslated region of TAS1R1 gene by using polymerase chain reaction sequencing. The novel mutation g.9120A>C was subsequently genotyped by MassArray system (Sequenom iPLEX assay) in 249 samples of three breeds (Hyla, 91 animals; Champagne, 84 animals; Tianfu Black, 74 animals). Association analysis suggested that the individuals with AC genotype showed greater body weight at 70 d of age (P < 0.01), body weight at 84 d of age (P < 0.05), and average daily weight gain from 28 to 84 d of age (P < 0.05) than AA. In addition, the individuals with AC genotype had a lower eviscerated slaughter percentage (P < 0.05) and semieviscerated slaughter percentage (P < 0.05). However, association of the genotypes with other production traits was not observed. The results indicate TAS1R1 is one of the candidate genes affecting growth performance and dressing percentage in rabbits, and this may be of potential use in marker-assisted selection for meat quality traits in rabbits.Item Open Access Nutritional recommendations and management practices adopted by feedlot cattle nutritionists: the 2016 Brazilian survey(Canadian Science Publishing, 2018-10-16) Pinto, Ana Carolina Janssen; Millen, Danilo DominguesThe feedlot industry in Brazil is still evolving and some nutritional recommendations or management adopted by nutritionists changes from year to year. The main objective of this survey was to provide a snapshot of current nutritional management practices adopted in Brazilian feedlots. The 33 nutritionists surveyed were responsible for approximately 4,228,254 animals. Corn remained as the primary source of grain used in feedlot diets by the participants, whereas fine grinding was the primary grain processing method. Corn silage was the primary roughage source indicated by nutritionists, and for the first time physically effective neutral detergent fiber (NDF) was the preferred fiber analysis method. The average dietary fat recommended was 50 g kg-1 of dry matter (DM), which is about 10% higher than values reported in previous surveys. The use of truck-mounted mixers increased, which may have increased the percentage of feedlots using programmed feed delivery per pen, allowing the increase of energy content of finishing diets. Feedlots did not increase their capacity and nutritionists reported an improvement in feeding management. Results reported in the current study provide a baseline that can be used to improve practices and aid in the development of feedlot industry in Brazil and similar tropical climates.Item Open Access Typologie des élevages bovins laitiers de la région de Souk-Ahras (Algérie)(Canadian Science Publishing, 2018-09-17) Yozmane, Rania; Mebirouk-Boudechiche, Lamia; Houd-Chaker, Kahina; Abdelmadjid, SadekL’étude typologique mise en place a pour but de caractériser les différents types d’élevages bovins laitiers dans la wilaya de Souk-Ahras à vocation laitière en Algérie. Pour ceci, nous avons analysé les données d’une enquête qui a porté sur 91 exploitations : analyse des correspondances multiples, suivie d’une Classification ascendante hiérarchique. L’analyse a démontré que le foncier, la taille de cheptel et la race sont les principales caractéristiques qui discriminent les trois groupes identifiés (G1, G2 et G3). Les résultats ont en outre démontré une très faible productivité des élevages malgré l’importance du potentiel génétique du cheptel. Ainsi une surface agricole utile et une taille du cheptel importantes dans les deux premiers groupes (G1 et G2) n’ont pas contribué à l’amélioration de la productivité qui reste similaire au (G3) dans lequel la contrainte foncière est plus accentuée. Cette situation est attribuée principalement à la faible production fourragère en raison de la faible pluviométrie et des surfaces irriguées, réservées principalement aux cultures céréalières jugées plus rentables. Devant ce constat, la forte dépendance envers les approvisionnements en concentré dans la ration des vaches peut s’expliquer par les faibles quantités des fourrages disponibles dans les exploitations étudiées.Item Open Access Expression patterns of PPARγ2, PGC-1α, and MEF2C and their association with intramuscular fat content and skeletal muscle tenderness of crossbred Simmental bulls(Canadian Science Publishing, 2018-09-19) Yang, Li-Qin; Li, Jian; Wang, Chun; Wu, Qiu-Ying; Chen, Xuan-Yu; Lai, Song-Jia; Song, Tian-Zeng; Zhang, MingPPARγ2, PGC-1α, and MEF2C play an important role in skeletal muscle development and fat deposition. This study aimed to determine their mRNA expression levels in longissimus dorsi (Ld), semitendinosus (Se), and soleus (Sol) muscles of crossbred Simmental bulls and estimate their association with intramuscular fat (IMF) content and meat shear force (MSF). We measured the muscle fiber (MF) density and area, IMF content, and MSF of 6-, 12-, and 36-mo-old bulls. We found that the expression patterns differed with age: the PPARγ2 expression in the three muscles of 36-mo-old bulls was greater than that in the muscles of 6- and 12-mo-old bulls (P < 0.05). Furthermore, PGC-1α expression in Sol of 36-mo-old and MEF2C expression in Ld of 12-mo-old bulls were higher than those in the respective muscles of 6- and 12-mo-old bulls, and 6- and 36-mo-old bulls, respectively (P < 0.05). The MF area, IMF content, and MSF increased with age (P < 0.05). The PPARγ2 mRNA expression in Ld, Se, and Sol was positively correlated with MF area and IMF content (P < 0.05) and negatively correlated with MF density (P < 0.05). Thus, PPARγ2 might be a candidate marker, which is positively correlated with IMF content and MF area.Item Open Access Influence of β–glucanase supplementation on growth performance, nutrient digestibility, blood parameters, and meat quality in broilers fed wheat-barley-soybean diet(Canadian Science Publishing, 2018-10-12) Sun, Hao Yang; Ingale, Santosh Laxman; Rathi, Piyush; Kim, I.H.A total of 600 one-day-old male Ross 308 broiler chickens with an average body weight of 43.00 ± 0.42 g were used in a 35 d growth assay to investigate the supplemental effects of three levels (600, 1200, and 1800 β-glucanase units kg−1) of β-glucanase on growth performance, nutrient digestibility, blood parameters, and meat quality in wheat–barley–soybean-meal-based broiler diet. During days 19–35 and overall period, chickens’ body weight gain and feed conversion ratio were significantly (P < 0.05) improved linearly following the levels of β-glucanase supplementation. The digestibility of crude protein and gross energy were significantly (P < 0.05) increased linearly with the levels of β-glucanase supplementation. Significant linear increase (P < 0.05) due to increasing β-glucanase supplementation was observed for blood urea nitrogen (BUN) concentration. Increasing β-glucanase supplementation did not influence (P > 0.05) the meat quality. In conclusion, broiler diets supplementation with increasing β-glucanase could improve the growth performance, enhance the digestibility, and modulate the concentrations of BUN linearly. Meat quality was not influenced.Item Open Access Effects of oral administration of essential oils on anti-immune stress, antimicrobial and repairing the intestinal damage in broilers challenged by lipopolysaccharide(Canadian Science Publishing, 2018-10-10) Liu, Shu Dong; Song, M. H.; Yun, Won; Lee, JiHwan; Kim, Hyeun Bum; Cho, Jin HoThe aim of the present study was to evaluate the effects of oral administration of essential oils (carvacrol, thyme, and oregano) on anti-immune stress, antimicrobial properties, and repairing the intestinal damage caused by Salmonella enterica lipopolysaccharides (LPS) in broilers. A total of 100 Ross 308 broilers (21-d-old; 1.10 ± 0.11 kg) were randomly allocated to five groups: T1, basal diet + saline; T2, basal diet + LPS; T3, basal diet + 200 μL carvacrol oils + LPS; T4, basal diet + 200 μL thyme oils + LPS; T5, basal diet + 200 μL oregano oils + LPS, with 20 replicates each, and one chicken per replicate per cage. Those challenged by LPS resulted in an immune stress, which manifests as the abnormal growth (P < 0.05) in immune organs, and the content of immunoglobulin G (P < 0.05), tumor necrosis factor-α (P < 0.05), and the rectum temperature (P < 0.05) increased compared with other groups. The oral administration of essential oils controlled the immune stress to a certain extent. The essential oils could reduce harmful bacteria, such as Escherichia coli (P < 0.05) and Salmonella enumeration (P < 0.05), in vivo of broilers. Meanwhile, the essential oils repaired the intestinal damage, which showed a reduction in the villi height (P < 0.05) and goblet cell (P < 0.05) caused by LPS. In conclusion, the essential oils (carvacrol, thyme, and oregano essential oils) controlled the stress reaction and maintained intestinal health to a certain extent.Item Open Access The effect of age and ultimate pH value on selected quality traits of meat from wild boar.(Canadian Science Publishing, 2018-10-03) Stanisz, Marek; Ludwiczak, Agnieszka; Składanowska-Baryza, Joanna; Bykowska-Maciejewska, MartaThe meat from hunted wild boar juveniles (N=18) and yearlings (N=17), was analysed to assess the influence of age, and to assess the ultimate pH value on selected quality traits. The analysed meat of 55.56 % of the juveniles and 64.71 % of the yearlings was characterised with normal pH. The pH had been measured 24 h and 48 h post-mortem. More cases of high ultimate pH (pHu>5.8) and high maximal pH (about 6.2) have been noted in the meat of younger animals compared to older ones. We found no effect of pHu on the colour coordinates of analysed wild boar meat. A slight effect of age was observed for the L* coordinate. The post-mortem time was the most important factor influencing meat colour (L*, b* and hue-angle). A high pHu was related to lower drip loss (P=0.001), lower percentage of free water (P=0.036), lower cooking loss (P=0.001), and lower plasticity (P=0.042). The meat from juveniles showed higher plasticity than meat from yearlings. Summing up, both the pHu level and the age of wild boars may affect some qualitative patterns of meat, changing the technological usability of this raw animal product.Item Open Access Influence of the sex and type of tissue on the basic chemical composition and the content of minerals in the sirloin and offal of fattener pigs.(Canadian Science Publishing, 2018-10-03) Babicz, Marek; Kasprzyk, Anna; Kropiwiec-Domańska, KingaThe aim of the study was to determine the basic chemical composition and mineral content in the sirloin and offal of fattener pigs, taking their sex into consideration. In addition, comparative analysis of the content of chemical and mineral components in the sirloin and offal was performed. The experimental material included 24 crossbred (Polish Landrace × Polish Large White) fatteners, from which samples of sirloin (musculus longissimus lumborum), liver, heart, and kidneys were collected for the analysis. A significant effect of the sex on the fat content in the sirloin and liver and on the level of magnesium (Mg), zinc, and iron (Fe) in the sirloin was demonstrated. Significant differences were found in the basic chemical composition and mineral content between the sirloin and the offal. In comparison with the liver, the sirloin contained lower amounts of protein and fat and higher potassium and Mg contents. In turn, the offal was shown to be a rich source of sodium, calcium, and trace elements (Fe, manganese, and copper). The mean cadmium concentration in the sirloin and offal was significantly lower than the threshold values for these elements, i.e., it accounted for 26% and 6.2% (liver)–19.5% (heart) of the allowable content of this element in pork meat and offal.Item Open Access The cholesterol deficiency-associated mutation in APOB segregates at low frequency in Chinese Holstein cattle(Canadian Science Publishing, 2018-09-04) Li, Yanhua; Fang, Lingzhao; Liu, Lin; Zhang, Shengli; Ma, Zhu; Sun, DongxiaoCholesterol deficiency (CD) is a recessive genetic defect in Holstein cattle, which affects the rearing success of calves. We investigated whether CD has been spread into China. A total of 138 Holstein bulls and 90 cows were screened for CD using polymerase chain reaction amplification(PCR) and then seven bulls (5.07%) and one cow (1.11%) were identified as CD carriers. Pedigree analyses revealed that all seven CD carrier bulls were traced back to MAUGHLIN STORM and CD spread into China might through his daughter, Braedale Baler Twine. Our results demonstrated that the CD defect exists in the Chinese Holstein population.Item Open Access Effect of dietary chelated copper and Methionine + Cysteine on performance, egg quality and nutrient balance in brown laying hens from 20 to 49 weeks old(Canadian Science Publishing, 2018-09-21) Trindade Neto, Messias Alves; Saccomani, Ana Paula O.; TSE, Marcos Livio Panhoza; Dadalt, Julio CezarUsing 960 brown laying hens from 20 to 48 wk of age, in a 4 × 5 factorial arrangement, the effects on production, quality of eggs, and nutrient balance of analysed 18, 41, 61, and 111 mg kg−1 of copper (Cu) and of 0.550%, 0.679%, 0.793%, 0.845%, and 0.948% of methionine and cysteine (Met + Cys) were evaluated. Treatments were administered to six replicate cages (eight hens per cage). At the 49th wk of age, 320 of these hens were kept under the same experimental conditions to evaluate the nutrient balance, and each treatment was allocated to four replicate cages (four hens per cage). The trend of interaction effect between Cu and Met + Cys levels was observed on egg weight and mass. The interaction between mineral and amino acid was characterized on egg quality variables. Quadratic equations indicated that increasing the dietary level of Cu reduced the estimate requirement of Met + Cys for hens. Across the entire experimental period, the total estimated Met + Cys level was 0.755% ± 0.021% based on the performance variables. As Cu increased in the diet, it decreased the estimated Met + Cys level to ensure egg weight, mass, and egg quality. Level of chelated Cu above 23 mg kg−1 may negatively affect the egg quality.Item Open Access Effects of artificial sweeteners on feed palatability and performance in weaned pigs(Canadian Science Publishing, 2018-09-29) Lee, Chang Hee; Yun, Won; Lee, Ji Hwan; Kwak, Woo Gi; Oh, Han Jin; An, Ji Seon; Liu, Shu Dong; Cho, Jin HoIn experiment 1, a total of 30 weaning pigs were allotted to three dietary treatments to check the palatability of the dietary feed. Diet treatments were as follows: reference diets = basal diets + 0.05% saccharin (50% Saccharin-natrium), TRT1 = 0.03% saccharin–neotame mix (50% Saccharine-natrium + 2% Neotame), TRT2 = 0.02% neotame (10% Neotame), and TRT3 = 0.02% saccharin–neotame mix (10% Saccharine-natrium + 10% Neotame). TRT2 group was significantly higher than other treatments in palatability (P < 0.05). In experiment 2, a total of 52 weaning pigs were allotted to four dietary treatments. In the average daily gain and average daily feed intake over 1 wk, the TRT2 group was significantly higher than the TRT1 and TRT3 groups (P < 0.05). The concentration of triglyceride in the blood was highest in the TRT1 treated group and the lowest in the TRT2 group (P < 0.05). The Lactobacillus was significantly higher in the TRT2 and TRT3 treatments compared with 0.05% saccharin (50% Saccharine-natrium) (P < 0.05). There was no significant difference in the number of Escherichia coli (P < 0.05). In conclusion, diets supplemented with neotame could improve palatability, and artificial sweeteners can affect nutrient digestibility, blood characteristic, and fecal microbiota.Item Open Access Performance, carcass characteristics, and centesimal composition of meat from Santa Inês lambs and Texel crossbred lambs (Santa Inês × Texel)(Canadian Science Publishing, 2018-04-04) Nunes, Iolanda Aparecida; Alessandro Martins Brito, Ricardo; de Morais, Letícia Aparecida; Silva, Vanessa Souza; da Silva, Marco Antônio Pereira; Carmo, Ruthele MoraesThis study evaluated the performance, carcass characteristics, and centesimal composition of the meat of intact and castrated lambs of the Santa Inês breed and of the crossbred animals: one-half Santa Inês × one-half Texel. Thirty-four lambs were used, nine intact and nine castrated males of the Santa Inês breed, and seven intact and nine castrated crossbred males, all aged between 6 and 7 mo and with an average live weight of 18.2 kg. The design was completely randomized in a 2 × 2 factorial (two crossing and two sexual conditions), with statistical analyses performed in the STAT version 9.4 program. There was a significant difference the Santa Inês and the Texel and Santa Inês crossbred animals in feed conversion and average daily gain, with superiority of the latter group. Castration of animals aged <12 mo had no significant effect on the performance and on the carcass traits of the Texel and Santa Inês crossbred animals, whereas the genotype had a great influence on weight gain and on subjective and quantitative carcass characteristics, demonstrating that crosses in sheep are needed to explore the complementarity of breeds, and heterosis is needed to achieve better performances and carcass characteristics.Item Open Access Associations between prolactin receptor (PRLR) polymorphisms and milk production traits in dairy buffalo(Canadian Science Publishing, 2018-09-04) AL-KAL, Abakar; Jiang, Qin Yang; Qin, Guang Sheng; Pan, Bin; Chen, Bao Jian; Jiang, He ShengBuffalo milk is economically important, and an understanding of the genetic basis of milk production traits may therefore facilitate buffalo breeding. In this study, polymerase chain reactionâ single-strand conformation polymorphism was used to analyze polymorphisms in prolactin receptor (PRLR) exons 3, 5, 7, and 10 in Murrah, Nili-Ravi, and crossbred buffaloes and Holstein cows. A site in PRLR exon 3 exhibited variation in all three buffalo breeds and cows, and the three genotypes GG, GT, and TT were detected. In PRLR exon 5, nucleotide differences were detected between buffalo and Holstein dairy cow populations; the genotypes AA, AG, and GG were observed. In PRLR exon 7, polymorphisms were not detected. In PRLR exon 10, at 9637 bp, the TT, TC, and TT genotypes were observed. At the three polymorphic loci, Hardyâ Weinberg equilibrium was reached in the crossbreed buffalo population for exons 3 and 5 and in all three buffalo populations for exon 10. In an analysis of the associations of the three polymorphisms with milk production traits, only PRLR exon 10 in Murrah buffaloes was associated with milk yield, with a significant difference between the TT and CC genotypes.