The Master´s thesis is focus on intensity of growth of Aberdeen Angus breed in organic breeding's. In thesis is observed influence of sire, year, sex and breeding on weight of descendants. The animal weights were gained from yield inspections of beef cattle. Descendants were observed in four organic breeding's which are situated in region Zlín. Influence of sire on birth weight descendants very often reach highly important differences (p < 0,01). Effect of sire on weight (at birth, 120, 210 and 365 days) was influenced by number of descendants from particular father. In individual breeding's were used different number of sires. In 2011 was manifested significant decline of birth weight (p < 0,01) on all farms and average birth weight was 35,96 +- 1,96 kg. Weights in rest of check periods mostly reached the highest values in last four years. The birth weight of all breeding's was quite equable 37,28 - 39,37 kg. At farms A (404,09 kg), B (416,18 kg) and C (416,28) was annual weights of animals over 400 kg and at farm D was the lowest annual weight of animals 336,13 kg. The weights were influenced by number of weighted animals in 365th day of life

As pesquisas com utilização de adubação nitrogenada em papuã têm avaliado principalmente as características do pasto e a produção animal. Este trabalho foi realizado com o objetivo de estudar a eficiência de uso do nitrogênio em papuã por meio de informações sobre características da pastagem e consumo de forragem de novilhas de corte. O experimento foi desenvolvido na Universidade Federal de Santa Maria (UFSM), de janeiro a maio de 2014. Os tratamentos foram constituídos por doses de zero, 150 ou 300 kg/ha de nitrogênio (N), na forma de ureia. O método de pastejo foi o de pastoreio rotacionado, sendo utilizadas 16 novilhas-teste Angus, com idade e peso corporal (PC) médio inicial de 15 meses e 276,0 ±17,4 kg, respectivamente. Foi utilizado como critério de manejo do pasto a altura do dossel na ocasião da saída dos animais dos potreiros, mantendo-os em 30 cm de altura. A avaliação do consumo de forragem foi realizada dosificando duas novilhas-teste por piquete, com óxido de cromo (Cr2O3) como indicador externo da produção fecal, fornecendo-o por 11 dias (sete dias para adaptação e quatro dias para coleta fecal). O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo, com três tratamentos e duas repetições de área. Para as avaliações de consumo foram utilizadas quatro repetições por tratamento, onde cada animal foi considerado uma unidade experimental. A massa de forragem, lâminas foliares e colmos nos piquetes com 300 kg/ha de N foram 23,7%, 18,6% e 28,8% superiores, respectivamente, quando comparado a dose zero. O teor de PB foi 3,4% superior quando utilizado adubação nitrogenada de 300kg/ha em relação a dose de 150kg/ha de N (18,7%). Independente das doses de N utilizadas, as novilhas consumiram 2,2±0,09 kg MS/100kg PC de forragem. A adubação nitrogenada em papuã modifica a estrutura do pasto, aumentando a produção total e a qualidade da forragem. O uso de 150 e 300kg/ha de N aumenta a massa de lâminas foliares. Novilhas em pastejo em papuã adubado com 300kg/ha de N colhem forragem com maior teor de proteína bruta. A mudança na estrutura do dossel faz com que as novilhas reduzam o consumo de forragem ao final do ciclo de utilização do papuã. / Several researches on nitrogen fertilization in Alexandergrass have mainly assessed pasture characteristics and animal production. The efficiency of nitrogen in Alexandergrass through information on the features of pasture and forage intake by beef heifers was analyzed. This study was carried out at the Universidade Federal de Santa Maria (UFSM), Santa Maria RS Brazil, from January to May 2014. Treatments comprised doses of 0, 150 and 300 kg/ha of nitrogen (N), in form of urea. Experimental animals were sixteen Angus heifers with initial age and body weight (BW) of 15 months and 276.0 ± 17.4 kg, respectively. The grazing method was rotational with variable number of animals. Pasture management criterion comprised canopy height of 30 cm at the output of the animals from the paddocks. Forage intake was estimated in two heifers per paddock using chromium oxide (Cr2O3) as an indicator of fecal output. The dosing period was 11 days, with seven days for adaptation and four days for feces collection. The experimental design was completely randomized with repeated measurements over time, with three treatments (0, 150, 300 kg/ha N) and two area replications. Forage intake assessment comprised four replications per treatment in which each animal was the experimental unit. Forage, leaf blades and stems mass in paddock with 300 kg/ha of N were 23.7%, 18.6% and 28.8%, respectively, higher when compared to dose zero. Crude protein content (CP) was 3.4% higher at 300 kg/ha nitrogen fertilization when compared to dose 150kg/ha of N (18.7%). Regardless of N doses, heifers consumed 2.2±0.09 kg DM/100kg BW of forage. Nitrogen fertilization of Alexandergrass modified the pasture structure, increased total production and forage quality. Doses 150 and 300 kg/ha of N increased the leaf blades mass. Heifers grazing on Alexandergrass fertilized with 300 kg of N/ha harvest forage with the highest CP content. Changes in canopy structure makes reduce the forage intake at the end of the Alexandergrass cycle.

The aim of this diploma work was to analyse the results of the Aberdeen Angus meet oxherd breeding in an ecological farming with the welfare relationship to the animals and at the same time to compare the efficiency after the system change of the farming at the farm Angus, Rančice, owned by Šebelka. The research was done in the period of years 2006 ? 2011. The survey range includes 65 heads of thorough-bred cows as well as 204 heads of Aberdeen Angus calves born in the tracked period. The number of births, the birth process, and the age before lay out and related reasons were recorded by the cows. By the calves we noted the live mass and average daily gain in the growth process. The range of the calves was then sorted our by year of the birth, gender, rank of the birth, by genitors and by the way of farming. The data entries were elaborated in the MICROSOFT EXCEL and evaluated in STATISTICA 7 CZ. The number of spontaneous birth without cowman assist equals 94,12%, only 4,41% of births required the necessary support. By the monitored number of calves no matter of the gender was noted the lowest and the highest live mass by the birth in the year 2007 (36,81 kg resp. 38,77 kg). The group of calves born in 2010 reached the highest average weight in 120 days as well as in 210 days (192,27 kg resp. 309,04 kg). The lowest average weight in 120 days was noticed in year 2009 (168,96 kg), in 210 day in 2008 (262,31 kg). The best growth ability from the birth to 120 days was by the group of calves born in 2010 (1,409 kg) compared to the lowest result in 2009 (1,099 kg). The average daily gain from 120 till 210 days reached its minimum in 2009 (1,171 kg), the maximum numbers were noted in 2010 (1,412 kg). The growth intensity from the birth till 210 days circulated in the range of 1,071 kg (2008) and 1,377 kg (2010). In the ecological agriculture system were noted statistical better efficiency results (live mass, growth intensity) compared to conventional agriculture system.

The purpose of this thesis was to evaluate the level of performance of Aberdeen Angus beef cattle breed bred in Less-favoured areas in southern Bohemia. This evaluation was carried out on Mr. Lepša?s farm in the years 2010 and 2011. 74 basic herd cows and 108 purebred calves born during this period were selected for this purpose. The date of birth, number of births, age at first calving and the average time interval between calving were checked on cows and the date of birth, the weight at birth and the weight in the age of 120 and 210 days were checked on calves. Average daily increments in the interval from birth to 120 days of age, from 120 to 210 days of age and from the day of birth to 210 days were calculated. The group of calves was sorted out by following parameters. Year of birth; sex and year of birth; month of birth; order of calving of the mother. Microsoft Excel was used for processing the statistic data. Basic statistical characteristics for the monitored parameters were calculated and differences between groups were verified by single-factor analysis of variance (F-test) and paired t-tests for the corresponding levels of significance. Breeding cows were evaluated by age and number of births. Cows with 1 (23%) or 2 (17.6%) births are represented in the largest number in the herd including even the cows with 15 births. Cows at first calving reached an average age of 813 days and average length of the interval between calving was 393 days. Calves regardless of sex reached the average birth weight of 33.72 kg in the year 2010, 33.31 kg in 2011, in 120 days of age the average live weight reached 207.95 kg in 2010, 202.94 kg in 2011 and calves in 210 days of age reached an average weight of 309.61 kg in 2010 and in 2011 306.09 kg. Average daily gain of calves from birth to 120 days reached 1451 g in 2010, 1.413 g in 2011, between 120 and 210 days of age the average daily gain was 1413 g in 2010, 1169 in 2011 and in the period from birth to 210 days of age it was 1314 g in 2010 and 1299 g in 2011. Analysis of breeding from economic perspective by comparing revenues (including subventions) and expenditures in each year resulted in findings that the breeding is moderately profitable and it follows that without subventions which constitute an important part of the revenue would be difficult to realize this breeding.

Made available in DSpace on 2015-01-26T13:21:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-03Bitstream added on 2015-01-26T13:30:31Z : No. of bitstreams: 1 000795832.pdf: 314304 bytes, checksum: b6077bd7a50cb6eb686277acd319024f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O oviduto possui papel essencial na reprodução de mamíferos, promovendo um microambiente favorável para a maturação oocitária, estocagem e capacitação do espermatozoide, fertilização, transporte dos gametas e desenvolvimento inicial do embrião. Anatomicamente e funcionalmente, o oviduto é dividido em três regiões principais: infundíbulo, ampola e istmo. O oócito e o espermatozoide entram nos lados opostos do oviduto, respectivamente no infundíbulo e istmo, e são transportados até a ampola, local onde ocorre a fertilização. O sucesso reprodutivo está diretamente ligado a temporização apropriada do transporte dos gametas ao local da fertilização, bem como, a precisão no tempo de transporte do embrião até o útero, para a aquisição da capacidade de implantação. A coordenação e regulação das funções do oviduto são complexas e estão sob efeitos endócrinos, parácrinos e autócrinos, os quais alteram temporalmente e espacialmente a transcrição e tradução de diversos fatores. Diante disso, o presente trabalho visou avaliar o efeito de biotecnologias reprodutivas, especificamente da superestimulação ovariana, bem como de características genéticas e fisiológicas reprodutivas no perfil transcricional de diversos fatores no oviduto bovino. Para tanto, foram avaliados os efeitos da indução de múltiplas ovulações em vacas da raça Nelore (dados apresentados no primeiro manuscrito), bem como os efeitos da influência da seleção genética de animais com alta contagem folicular em novilhas da raça Nelore e Aberdeen Angus, no período inicial pós ovulação (dados apresentados no segundo manuscrito), na expressão de genes relacionados ao transporte de gametas e fertilização. Os resultados demonstram que a superestimulação ovariana modula a expressão de alguns genes relacionados à contratilidade do oviduto em vacas da raça Nelore e que a ovulação é principal fator responsável por controlar ... / The oviduct has an important role in mammal reproduction, promoting a favorable microenvironment for oocyte maturation, sperm storage and capacitation, fertilization, transport of gametes and early embryo development. Anatomically and functionally, the oviduct is divided in three regions: infundibulum, ampulla and isthmus. The oocyte and the sperm enter in opposite sides of the oviduct, respectively infundibulum and isthmus, and are transported to the fertilization site, the ampulla. Reproductive success is directly related to appropriate timing of gamete transport to the fertilization site, as well as a precise time of embryo transport to the uterus, to obtain the capacity of implantation. The coordination and regulation of oviductal functions are complex and under endocrine, paracrine and autocrine effects, which temporally and spatially alter the transcription and translation of several factors. Therefore, this study aimed to evaluate the effect of reproductive biotechnologies, specifically ovarian superstimulation, as well as genetic and physiological reproductive characteristics in the transcriptional profile of several factors in the bovine oviduct. To do so, we evaluated the effects of inducing multiple ovulation in Nelore cows (data presented in the first manuscript), and the effects of the influence of genetic selection of animals with high follicle count in Nellore and Aberdeen Angus heifers, in the initial period post-ovulation (data presented in the second manuscript), in gene expression related to gametes transport and fertilization. The results demonstrated that ovarian superstimulation modulates the expression of some genes related to oviductal contractility in Nelore cows and ovulation is the main factor responsible for transcriptional control in bovine oviduct, with less or no impact of breed and ovarian follicle count / FAPESP: 12/09498-9

Made available in DSpace on 2014-06-11T19:27:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-12Bitstream added on 2014-06-13T20:56:42Z : No. of bitstreams: 1 santos_ct_me_botfmvz.pdf: 295424 bytes, checksum: 2c14969a0776e097a0cbbffb9d4632d0 (MD5) / A qualidade da carne está diretamente ligada as exigências do consumidor, que considera dureza, amora, sabor, suculência e coloração. Desta forma o presente trabalho tem por objetivo verificar o efeito da imunocastração na composição centesimal, análise sensorial e perfil de ácidos graxos da carne de bovinos Nelore e cruzados ½Nelore x ½Aberdeen-Angus, 60 animais distribuídos em um delineamento em esquema fatorial 2 x 3, sendo grupos genéticos e condições sexuais, com castração cirúrgica, imunocastração e não castrados, totalizando 6 tratamentos com 10 animais . Os animais foram abatidos e as carcaças resfriadas. Após 24 horas, foram utilizadas amostras do M. longissimus thoracis da 11ª à 13ª costela da carcaça direita, embaladas a vácuo e congeladas. Entre as condições sexuais estudadas, não foram encontradas diferenças nos valores médios de proteína, extrato etéreo e resíduo mineral fixo, sendo apenas a umidade diferente. Entre os grupos genéticos, os valores médios da composição centesimal apresentaram diferença para umidade, extrato etéreo e resíduo mineral fixo, sendo a umidade elevada para a carne dos animais cruzados, o extrato etéreo e o resíduo mineral fixo com maiores teores para a carne dos animais Nelore. As variáveis, sabor, maciez, mastigabilidade e suculência apresentaram melhores valores para a carne de animais cruzados. No perfil de ácidos graxos, entre as condições sexuais, foram encontradas diferenças no ácido miristoléico (C14:1), no ω6 (ômega 6) e na proporção de ácidos graxos poliinsaturados/ácidos graxos saturados, com maiores resultados... / The quality of meat is directly linked to consumer demands, which considers hardness, blackberry, flavor, juiciness and color. Thus, the present study aims to determine the effect of immunocastration proximate composition, sensory analysis and fatty acid profile of meat from Nellore and is crossed Nellore x ½ Aberdeen-Angus, 60 animals were allotted to a factorial 2 x 3 with genetic conditions and sex groups, with surgical castration, immunocastration and unneutered, totaling 6 treatments with 10 animals. The animals were slaughtered and the carcasses chilled. After 24 hours, samples were used of M. longissimus thoracis from the 11th to the 13th rib on the right casting, vacuum packed and frozen. Between sexual conditions studied, no differences were found in mean values of protein, lipids and fixed mineral, with just different humidity. Among genetic groups, the mean values of centesimal composition showed differences for moisture, ether extract and fixed mineral residue, and high humidity for the meat of crossbred animals, ether extract and fixed mineral with higher levels for the meat of Nellore . Variables , taste, tenderness , juiciness and chewiness showed better values for beef and crossbred animals . In the fatty acid profile between sexual conditions , differences were found in myristoleic acid ( C14 : 1 ) , the ω6 ( omega 6 ) and the ratio of polyunsaturated / saturated fatty acids fatty acids with greater results found in the flesh of animals not castrated . Among genetic groups the results differed due to the influence of racial characteristics , with the best values in meat from Nellore , because the selection of forage taken by animals . The use of immunocastration proved effective in aspects related to composition , sensory analysis and meat fatty acid profile when compared with surgically... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-23Bitstream added on 2014-06-13T20:28:01Z : No. of bitstreams: 1 vieira_ldc_me_jabo.pdf: 386143 bytes, checksum: ef616fd81495dd161b9f57bba8ca738c (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Avaliou-se o efeito de diferentes períodos de maturação (1, 7, 14 dias) sobre a qualidade da carne de dois músculos (Longíssimus dorsi e Tríceps braquii) de bovinos cruzados, criados em confinamento no sistema “superprecoce”. Foram utilizados 40 bovinos machos não castrados, divididos em quatro cruzamentos, oriundos do acasalamento de fêmeas cruzadas ½ angus + ½ nelore e ½ simental + ½ nelore com touros das raças Angus e Wagyu. Os animais foram confinados em lotes de 4 animais por baia divididos por grupo genético. Após o abate e estabelecimento do rigor-mortis (24 horas) coletou-se amostras dos músculos Longíssimus dorsi e Tríceps braquii, que foram embalados a vácuo e submetidos à maturação (0, 7 e 14 dias). Foram avaliadas características qualitativas (capacidade de retenção de água, cor, pH, perdas de peso por cozimento e força de cisalhamento) e sensoriais (sabor, odor, suculência, fibrosidade, maciez, sabor de gordura e aceitação global). Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 4 x 3 x 2 (4 cruzamentos x 3 períodos de maturação x 2 músculos) com 10 repetições. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste Tukey com 5% de significância. A maturação é eficiente na melhoria da maciez da carne dos animais avaliados. Os animais filhos de touro Wagyu apresentaram carne com sabor de gordura mais acentuado através da avaliação sensorial. O músculo Tríceps brachii foi considerado mais macio e mais suculento tanto na análise sensorial como nas análises físicas, contudo, o músculo Longíssimos dorsi apresentou maior aceitação global / We evaluated the effect of different periods of maturation aged (0, 7 and 14 days) on meat quality of two muscles (Longíssimus dorsi and Triceps braquii) of crossbred beef cattle, reared in confinement in the system “youngbulls”. We used 40 bulls divided into four crossbred from the mating of cows crossbred ½ Angus + ½ Nelore e ½ Simental + ½ Nelore with bulls Angus and Wagyu. The animals were confined in collective stalls 4 animals for pen divided by genetic groups. After slaughter and establishment of rigor mortis (24 hours) samples were collected from muscles Longíssimus dorsi e Triceps braquii, which were vacuum packed and submitted of maturation aged (0, 7 and 14 days). We evaluated quality characteristics (water-holding capacity, color, pH, weight loss for cooking and shear force) and sensory (flavor, scent, juiciness, fibrousness, softness, fat flavor and global acceptance). It was used a 4 x 3 x 2 factorial arrangement (4 crossbred x 3 maturation aged x 2 muscles) with 10 replicates. The dates submitted analysis of variance and the means were compared by Tykey's test (5%). The maturation aged is proved effective improvement the meat in the animals evaluated. The animals crossbred Wagyu bull presented meat-flavored fat sharper through sensory evaluation. The muscle Tríceps brachii was considered more soft and juicy both in sensory evaluation as in physical analysis, however, the muscle Longíssimus dorsi showed higher global acceptance

As pesquisas com utilização de adubação nitrogenada em papuã têm avaliado principalmente as características do pasto e a produção animal. Este trabalho foi realizado com o objetivo de estudar a eficiência de uso do nitrogênio em papuã por meio de informações sobre características da pastagem e consumo de forragem de novilhas de corte. O experimento foi desenvolvido na Universidade Federal de Santa Maria (UFSM), de janeiro a maio de 2014. Os tratamentos foram constituídos por doses de zero, 150 ou 300 kg/ha de nitrogênio (N), na forma de ureia. O método de pastejo foi o de pastoreio rotacionado, sendo utilizadas 16 novilhas-teste Angus, com idade e peso corporal (PC) médio inicial de 15 meses e 276,0 ±17,4 kg, respectivamente. Foi utilizado como critério de manejo do pasto a altura do dossel na ocasião da saída dos animais dos potreiros, mantendo-os em 30 cm de altura. A avaliação do consumo de forragem foi realizada dosificando duas novilhas-teste por piquete, com óxido de cromo (Cr2O3) como indicador externo da produção fecal, fornecendo-o por 11 dias (sete dias para adaptação e quatro dias para coleta fecal). O delineamento experimental foi o inteiramente casualizado, com medidas repetidas no tempo, com três tratamentos e duas repetições de área. Para as avaliações de consumo foram utilizadas quatro repetições por tratamento, onde cada animal foi considerado uma unidade experimental. A massa de forragem, lâminas foliares e colmos nos piquetes com 300 kg/ha de N foram 23,7%, 18,6% e 28,8% superiores, respectivamente, quando comparado a dose zero. O teor de PB foi 3,4% superior quando utilizado adubação nitrogenada de 300kg/ha em relação a dose de 150kg/ha de N (18,7%). Independente das doses de N utilizadas, as novilhas consumiram 2,2±0,09 kg MS/100kg PC de forragem. A adubação nitrogenada em papuã modifica a estrutura do pasto, aumentando a produção total e a qualidade da forragem. O uso de 150 e 300kg/ha de N aumenta a massa de lâminas foliares. Novilhas em pastejo em papuã adubado com 300kg/ha de N colhem forragem com maior teor de proteína bruta. A mudança na estrutura do dossel faz com que as novilhas reduzam o consumo de forragem ao final do ciclo de utilização do papuã. / Several researches on nitrogen fertilization in Alexandergrass have mainly assessed pasture characteristics and animal production. The efficiency of nitrogen in Alexandergrass through information on the features of pasture and forage intake by beef heifers was analyzed. This study was carried out at the Universidade Federal de Santa Maria (UFSM), Santa Maria RS Brazil, from January to May 2014. Treatments comprised doses of 0, 150 and 300 kg/ha of nitrogen (N), in form of urea. Experimental animals were sixteen Angus heifers with initial age and body weight (BW) of 15 months and 276.0 ± 17.4 kg, respectively. The grazing method was rotational with variable number of animals. Pasture management criterion comprised canopy height of 30 cm at the output of the animals from the paddocks. Forage intake was estimated in two heifers per paddock using chromium oxide (Cr2O3) as an indicator of fecal output. The dosing period was 11 days, with seven days for adaptation and four days for feces collection. The experimental design was completely randomized with repeated measurements over time, with three treatments (0, 150, 300 kg/ha N) and two area replications. Forage intake assessment comprised four replications per treatment in which each animal was the experimental unit. Forage, leaf blades and stems mass in paddock with 300 kg/ha of N were 23.7%, 18.6% and 28.8%, respectively, higher when compared to dose zero. Crude protein content (CP) was 3.4% higher at 300 kg/ha nitrogen fertilization when compared to dose 150kg/ha of N (18.7%). Regardless of N doses, heifers consumed 2.2±0.09 kg DM/100kg BW of forage. Nitrogen fertilization of Alexandergrass modified the pasture structure, increased total production and forage quality. Doses 150 and 300 kg/ha of N increased the leaf blades mass. Heifers grazing on Alexandergrass fertilized with 300 kg of N/ha harvest forage with the highest CP content. Changes in canopy structure makes reduce the forage intake at the end of the Alexandergrass cycle.

Researchers have investigated several factors that could alter fetal growth, including nutrient restriction (Valiente et al., 2021), hair shedding (Gray et al., 2011), and extreme hot and cold temperatures (Davidson et al., 2022). Hot temperatures and increased humidity percentages in the southeast United States caused researchers to investigate the hair coats of Angus cattle in the commercial production setting. An improvement in fiber digestibility and calf birth and weaning weights has been observed in Angus dams that shed 50% of the winter hair coat by May (Gray et al., 2011; Burnett et al., 2021). Our objective of this experiment was to investigate the nutrient digestibility of Angus calves born to cows that on average, shed early compared to calves from cows that shed later. Newly weaned, purebred Angus bull calves (early; n = 6, late; n = 6) were housed in metabolism crates for 10 d. Prior to the trial, calves had a 14 d adaption period to a 14% CP textured feed (CPC 14% Developer, CPC Commodities, Fountain Run, KY) and offered ad libitum Cynodon dactlyon hay and water. After 3 d crate acclimation period, urine, feces, orts, and hay samples were collected for 7 d. Concentrate was offered at 0.25% of average BW. Approximately 5% samples were taken of feces, and urine samples had 1-1.5% of 25% metaphosphoric acid added to prevent ammonia volatilization, and both collections were composited by animal. Orts were collected at 0600 h daily, dried, and composited by animal. Laboratory analysis included dry matter (DM), organic matter (OM), Ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), Kjeldahl N (CP), and fat. Data were analyzed using the GLM procedure of SAS 9.4 in a completely randomized design with calf as the experimental unit. Significant (P ≤ 0.05) means were separated using Fischer’s protected LSD. The model for intake included average daily DM and OM (kg) and adjusted by body weight (BW%). For digestibility analysis, the model included: DM, OM, ash, NDF, ADF, hemi-cellulose (HC), CP, and fat. The N retention model included: N retained (g/d), N retained/consumed (%), and N retained/DM intake (%). There were no differences between early or late calves for DM intake (5.502 ± 0.2774 kg/d; 2.251 ± 0.1247 %BW), or OM intake (5.199 ± 0.2591 kg/d; 2.128 ± 0.1166 %BW). There were no differences in digestibility for either group for DM, OM, Ash, NDF, ADF, HC, CP, or fat (Table 1.). There were also no differences in N retention in either group of calves (3.686 ± 2.0242 g/d; 4.366 ± 2.3964 %; 0.064 ± 0.0355 %). Replication and further research are needed in this area to adequately understand factors influencing nutrient digestibility in calves born from early and late shedding dams.

Congenital hypotrichosis in cattle is commonly referred to as "rat-tail" syndrome and is characterized by a dilution of black coat color and morphological changes to the hair shaft and tail switch. Two loci are involved in the inheritance of the rat-tail phenotype, the "extension locus" (MC1R) and an unknown locus. In order to express the rat-tail phenotype the animal must inherit at least one black allele at MC1R and be heterozygous at the unknown locus. The rat-tail locus was previously mapped to an 8.7 cM region of Bos Taurus autosome (BTA) 5. Pmel17 is known to be involved in the expression of pigmentation and maps to the same region of BTA5 as the rat-tail locus. Cattle from a population segregating for the rat-tail syndrome were sequenced at Pmel17 in order to identify putative causative mutations. Two mutations were detected, a three base pair (bp) deletion in exon 1 at codon 18 removing a leucine residue, and a single nucleotide polymorphism (SNP) at codon 612 resulting in an amino acid substitution (A?E). The 3-bp deletion in exon 1 of Pmel17 is in 100% concordance with the rat-tail phenotype in this research population and may be causative of the rat-tail phenotype.