Milk supplementation: effect on piglets performance, feeding behavior and sows physiological condition during the lactation period

The present study aimed to investigate the effect of milk liquid and powder supplements on piglets' performance, drinking behavior, and sow back-fat thickness change during the lactation period. There were four experimental groups (n = 24), and in the control group (n = 6), the piglets were suckled from the sow. For the supplemental groups (n = 18), milk powder (MP), milk liquid by feeding trough (MLFT), and milk liquid feeding by the bucket (MLFB). Data were collected with the weight of a total of 252 piglets measured at birth, at 14 days and at weaning (28 days), respectively. Sow back-fat thickness was measured 3 days before farrowing, 14 days after farrowing and at weaning. There were significant differences in average daily weight gain between day 14 and weaning age for the MP and MLFT (P < 0.05) but not in MLFB (P > 0.05). For approaches to the feeder, there were significantly higher in MP and MLFT groups (P < 0.05). Based on the examination of sow back-fat thickness, the back-fat loss was minimal (P < 0.05) in the MP and MLFT compared to the MLFB and the control. Giving the milk supplement as powder and liquid by feeding trough has increased the piglets' average daily gain and body weight on day 14th and the weaning day. Moreover, the back-fat thickness reduction of sows in the supplemental groups is lower compared to the control group.

Weaning and concentrate supplementationon the characteristics of carcass cuts and longissimusmuscle of Suffolk lambs finished on pasture

The aim of this study was to evaluate the influence of weaning and concentrate supplementation on the characteristics of carcass cuts and longissimusmuscle of Suffolk lambs finished ona Tifton 85 (Cynodonspp.) pasture. Weaning and concentrate supplementation strategies were evaluated in four finishing systems: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding;iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate. In the systems with weaning, lambs were weaned at 46 ± 6 days of age. In the systems with supplementation, the concentrate was offered daily at 2% of lambs body weight. Weaning led to a decrease, whereas supplementation led to an increase in carcass cut weights. Supplemented lambs had lower yields of neck and uncovered ribs, and higher yields of breast + flank and loin. The characteristics of loin eye and fat thicknessover the longissimusmuscle presented lower values in weaned lambs and higher values in supplemented lambs. Keeping lambs with their dams and offering concentrate supplementation until slaughter are strategies recommended to obtain heavier cuts with increased muscularity and fat content.(AU)

Effect of rearing, season of birth, and father on labyrinth behaviour of dairy heifers

Objective of this study was to test the hypotheses that heifer's behaviour after 12 months (M) are impacted by rearing (feeding/housing) before weaning, seasons of birth, and father lineage. Fifty-one Holstein heifers (born in year seasons SB1, SB2, SB3, and SB4, originating from 4 fathers) were assigned to one of three rearing treatments: restricted suckling (RS), calf in pen with mother to 21st day, suck three times daily, then group pen (6 kg milk) to weaning; unrestricted suckling (US), calf in pen with foster cows (6 kg milk) to weaning; conventional rearing (CR), calf in the hutch to 56th day, then group pen to weaning (milk replacer 6 kg). After weaning at the 84th day, heifers were kept in groups with the same ration. The labyrinth behaviour was tested in the 12th and 19th M of the age. In the evaluation factors rearing and season of birth, groups US and SB3 solved the passage of the labyrinth the fastest (868.0 s, 857.4 s), the slowest were CR and SB1 (1148.2 s, 1257.5 s). The results show that the manner (housing/feeding) used to rear heifers and season of birth may impact their later labyrinth behaviour.(AU)

Effect of rearing, season of birth, and father on labyrinth behaviour of dairy heifers

Objective of this study was to test the hypotheses that heifer's behaviour after 12 months (M) are impacted by rearing (feeding/housing) before weaning, seasons of birth, and father lineage. Fifty-one Holstein heifers (born in year seasons SB1, SB2, SB3, and SB4, originating from 4 fathers) were assigned to one of three rearing treatments: restricted suckling (RS), calf in pen with mother to 21st day, suck three times daily, then group pen (6 kg milk) to weaning; unrestricted suckling (US), calf in pen with foster cows (6 kg milk) to weaning; conventional rearing (CR), calf in the hutch to 56th day, then group pen to weaning (milk replacer 6 kg). After weaning at the 84th day, heifers were kept in groups with the same ration. The labyrinth behaviour was tested in the 12th and 19th M of the age. In the evaluation factors rearing and season of birth, groups US and SB3 solved the passage of the labyrinth the fastest (868.0 s, 857.4 s), the slowest were CR and SB1 (1148.2 s, 1257.5 s). The results show that the manner (housing/feeding) used to rear heifers and season of birth may impact their later labyrinth behaviour.

Body mass index at calving on performance and efficiency of Zebu cow herds / Índice de massa corporal ao parto no desempenho e eficiência de rebanhos de vacas Zebuínas

This study examines the impact of the body mass index (BMI) at calving on the development and postpartum efficiency of cows of Zebu origin. The study involved 87 cows and their calves [pure Nellore (N) or predominant Nellore composition in a cross with Charolais (C) (3/4N1/4C and 5/8N3/8C)]. The mothers were grouped into classes according to their BMI at calving, namely, 'small', 'moderate' and 'large'. Body mass index was determined by dividing the body weight of the cows by their length and by hip height and then dividing the result by 10. Cows were weighed at calving, at weaning, at the end of the breeding period and at the diagnosis of pregnancy. Calves were weighed at birth, at early weaning (63 days) and at 210 of age. To evaluate milk yield and quality, milk was collected at 21, 42 and 63 days after calving. Milk yield was measured by the direct method, with manual milking, followed by analysis of the lactose, fat, total solids and crude protein contents. Pregnancy rate was similar between the three BMI groups; however, cows with a lower BMI were more efficient at calving in producing kilograms of calf per kilogram of cow kept. Higher BMI provide higher milk yields, without affecting its quality, as well as heavier calves at early weaning and at 210 days of age.(AU)

O objetivo dessa pesquisa foi avaliar o impacto do índice de massa corporal (IMC) ao parto no desenvolvimento e eficiência pós-parto de vacas de origem zebuína. Utilizou-se 87 vacas e seus bezerros [Nelore (N) puros ou com predominância em cruzamento com Charolês (C) (3/4N1/4C e 5/8N3/8C)], agrupadas em classes segundo o seu IMC ao parto, em 'pequenas', 'moderadas' e 'grandes'. O índice de massa corporal foi determinado através da divisão do peso corporal das vacas pelo seu comprimento e pela altura de quadril e posteriormente o resultado dividido por 10. As vacas foram pesadas no parto; ao desmame; final da monta e no diagnóstico de gestação. Os bezerros foram pesados ao nascimento, na desmama precoce (63 dias) e aos 210 dias de idade. Para a avaliação da produção e qualidade do leite das vacas foram realizadas três coletas aos 21, 42 e 63 dias após o parto. A medida da produção de leite foi realizada pelo método direto, com ordenha manual, seguida de análise do teor de lactose, gordura, extrato seco total e proteína bruta. A taxa de prenhez foi similar para os três índices de massa corporal, no entanto vacas de menor IMC foram mais eficientes ao parto na produção de quilogramas de bezerros por quilograma de vaca mantida. O IMC alto propicia maior produção de leite sem que a qualidade seja alterada e bezerros mais pesados no desmame precoce e no peso aos 210 dias.(AU)

Effects of milking system in suckling period on growth, reproduction traits, and milk yield of East Friesian-cross dairy sheep

The main objective of this study was to determine the effects of milking system on growth, reproduction, and milk yield and composition of East Friesiancross (Tahirova) dairy sheep that were milked in the evening during the suckling period. A total of 43 Tahirova ewes and 58 lambs were used in the present study. One of the groups was milked in the evening (evening milked; EM) before coming together with their lambs, and the other group was not (not milked in the evening; NEM). Morning milking was performed in both groups during the study. Lambs in both groups were individually weaned at the age of 60 days. There was no statistical difference between the lambs' live weight at weaning in the EM and NEM groups, determined to be 23.46 and 24.11 kg, respectively. Live weight values of lambs were similar in the groups at ages of up to 180 days. The reproductive characteristics of ewe lambs in the EM and NEM groups, having similar growth rates and a similar live weight and body condition in the first estrus stages, were also similar. The return rate and frequency of return were close in both groups of ewe lambs. Milk yield of the NEM group was significantly higher than that of the EM group before and after weaning. However, in groups with similar lactation milk yield and length, the total marketable milk yield was higher in the suckling period of the EM group. The milking system in suckling period of Tahirova ewes does not significantly affect growth, average daily gain, and reproductive characteristics. Milk yield in the NEM group before and after weaning was significantly higher than the EM group, but the total marketable milk yield was higher in the EM group.(AU)

Weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on pasture

The aim of this study was to evaluate the influence of weaning and concentrate supplementation on the characteristics of carcass cuts and longissimus muscle of Suffolk lambs finished on a Tifton 85 (Cynodon spp.) pasture. Weaning and concentrate supplementation strategies were evaluated in four finishing systems: i) non-weaned and non-supplemented lambs; ii) non-weaned lambs supplemented with concentrate in creep feeding; iii) weaned and non-supplemented lambs; and iv) weaned lambs supplemented with concentrate. In the systems with weaning, lambs were weaned at 46 ± 6 days of age. In the systems with supplementation, the concentrate was offered daily at 2% of lambs' body weight. Weaning led to a decrease, whereas supplementation led to an increase in carcass cut weights. Supplemented lambs had lower yields of neck and uncovered ribs, and higher yields of breast + flank and loin. The characteristics of loin eye and fat thickness over the longissimus muscle presented lower values in weaned lambs and higher values in supplemented lambs. Keeping lambs with their dams and offering concentrate supplementation until slaughter are strategies recommended to obtain heavier cuts with increased muscularity and fat content.(AU)

Effect of growth and carcass traits on likelihood of early pregnancy in Nellore heifers raised at intensive nutritional plan

This study evaluated the influence of the quantitative traits measured by real-time ultrasound (adjusted longissimus muscle area [AdjLMA], adjusted rump fat thickness [AdjRFT], and adjusted marbling [AdjMAR]) as well as age at first breeding [AFB] and adjusted weight [AdjWeight], on the probability of occurrence of early pregnancy (EP) in 55 Nellore heifers, and also performed an economic analysis. All calves received supplementation in creep-feeding (ad libitum), and at weaning (average age= 210 ± 30 days; average weight= 241 ± 33 kg) until first breeding by artificial insemination (May to November) all heifers were managed in the same group (two paddocks of 25 ha each evenly covered with Urochloa Marandu Grass) and received protein-energy supplementation (1% of average BW per animal/day). The quantitative variables were collected immediately after timed artificial insemination (average age= 392 ± 27 days; average weight= 431.90 kg), and the pregnancy diagnosis was completed at 30 days following insemination. For economic analysis, two systems were compared (age at first breeding at 13 and 24 months). The greater adjusted weight on the first breeding increased the probability of occurrence of early pregnancy, while the greater adjusted longissimus muscle area reduced. In addition, intensive meat production systems provide greater economic return throughout cow-calf operation.(AU)

Fertility disorders in male dogs

Male dog fertility disorders are usually troublesome and challenging for a practicing veterinarian. It may be generally assumed, that reproductive potential in this species is lower than in farm animals and it is still decreasing. This situation starts to be similar to human medicine, where we observe dramatic drop of reproductive capacity, which resulted in the need of implementation of Assisted Reproductive Technologies (ART). Situation in dogs is more complicated owing the fact, that the use of ART meets many obstacles. Low fertility potential in dogs appears to be the result of variable factors such as: specific criteria of selection for reproduction in which fertility performance in not a priority, lack of periodical obligatory fertility check, species specific predisposition for many reproductive diseases and no age limit for reproductive use of males. Dogs are kept in human environment and exposition for civilizational byproducts influences negatively not only on our health, but also on health our 'minor brothers'. It should be bear in mind, that reproductive organs are very sensitive for environmental factors disrupting homeostatic balance. The decline in male dog fertility over the past decades was proved, with potential link to environmental contaminants (4). They were found in pet foods and were also detected in the sperm and testes of adult dogs causing a detrimental effects on sperm function. Over the 26 years of the study of Lea et al. (4), authors found a decrease in the percentage of normal motile sperm. Between 1988 and 1998, sperm motility declined by 2.5 per cent per year. Then from 2002 to 2014 sperm motility continued to decline at a rate of 1.2% per year. In addition, the male pups had an increased incidence of cryptorchidism. Basics of physiology of reproduction of male dogs. Normally the puberty in males is associated with presence of normal sperm cells in genital organs. It is reached in male dogs at age around 5-6 months. Such a young dog obviously cannot be used for reproduction. Reproductive maturity is associated later, with development of normal sexual behavior and production of sufficient number of normal, fertilizing competent spermatozoa. It corresponds with 12-18 months of animal age. Testicular descent is completed usually before weaning period, but sometimes testicles may reach scrotum later, but never after the end of 6 month of age. That time inguinal canals start to be so narrow, that caudal passing of gonads is unlikely. Male dogs have only one accessory sexual gland - prostate, which produces vast portion of seminal plasma.(AU)

Effect of parity segregation on Mycoplasma hyopneumoniae infection dynamics and pneumonic lesions in pigs / Efeito da ordem de parto segregada sobre a dinâmica de infecção de Mycoplasma hyopneumoniae e lesões pulmonares ao abate

Gilts represent a group risk for Mycoplasma hyopneumoniae vertical transmission in swine herds. Therefore, parity segregation can be an alternative to control M. hyopneumoniae infections. The study evaluated the effect of parity segregation on M. hyopneumoniae infection dynamics and occurrence and severity of lung lesions at slaughter. For that, three multiple site herds were included in the study. Herd A consisted of the farm where gilts would have their first farrowing (parity order (PO) 1). After the first farrowing PO 1 sows were transferred to herd B (PO2-6). Herd C was a conventional herd with gilt replacement (PO1-6). Piglets born in each herd were raised in separated nursery and finishing units. Sows (n = 33 (A), 37 (B), 34 (C)) in all herds were sampled prior to farrowing and piglets (n = 54 (A), 71 (B), 66 (C)) were sampled longitudinally at 21, 63, 100, 140 days of age and at slaughter for M. hyopneumoniae detection by PCR and lung lesions scoring. M. hyopneumoniae prevalence in sows did not differ among herds. Prevalence of positive piglets was higher at weaning in the PO1 herd (A) (P < 0.05). However, prevalence of positive pigs from 100 days of age to slaughter age was higher in the PO2-6 herd (B) (P < 0.05). Lung lesion occurrence and severity were higher in herd B. The authors suggested that the lack of a proper gilt acclimation might have influenced the results, leading to sows being detected positive at farrowing, regardless of the parity.

As leitoas consistem em um grupo de risco na transmissão vertical de Mycoplasma hyopneumoniae dentro do sistema de produção de suínos. Dessa forma, a segregação de partos poderia ser utilizada como alternativa para controlar as infecções por M. hyopneumoniae. O objetivo deste estudo foi avaliar o efeito da segregação de partos sobre a dinâmica de infecção de M. hyopneumoniae e a ocorrência e severidade das lesões pulmonares ao abate. Para isso três sistemas de produção de suínos com três sítios cada foram incluídos no estudo. A granja A consistia da unidade onde as leitoas tem o primeiro parto, ou seja, alojava somente de fêmeas de ordem de parto 1 (Granja OP1). Após o primeiro parto as fêmeas OP1 foram transferidas para a granja B (Granja OP2-6), ou seja, consistia de fêmeas de ordem de parto 2 a 6, e a granja C consistiu em uma granja convencional com reposição de leitoas (Granja OP1-6), com fêmeas de ordem de parto 1 a 6. Os leitões nascidos de cada granja foram transferidos e criados em creches e terminações segregadas. As matrizes (n = 33 (A), 37 (B), 34 (C)) de todas as granjas do estudo foram amostradas previamente ao parto e os leitões (n = 54 (A), 71 (B), 66 (C)) foram amostrados longitudinalmente aos 21, 63, 100 e 140 dias de idade e ao abate. Em todos os momentos de coleta, as amostras foram avaliadas por PCR para detecção de M. hyopneumoniae. As lesões pulmonares foram avaliadas e escores de lesão foram atribuídos ao abate. A prevalência de matrizes positivas para M. hyopneumoniae não diferiu entre as granjas (P > 0,05). A prevalência ao desmame foi maior na granja A (OP1) (P < 0,05). No entanto, dos 100 dias de idade até o abate a prevalência de leitões positivos para M. hyopneumoniae foi maior na granja B (OP2-6) (P < 0,05). A ocorrência e severidade de lesões pulmonares foram maiores na granja B. Os autores sugerem que a falta de uma aclimatação adequada das leitoas pode ter influenciado nos resultados, levando à detecção de matrizes positivas ao parto, independente da ordem de parto.

Influence of non-genetic factors on the maternal ability of Santa Inês ewes / Influência de fatores não-genéticos na habilidade materna de ovelhas Santa Inês

ABSTRACT: The aim of this study was to evaluate the influence of different non-genetic effects on indicator traits for maternal ability in Santa Inês ewes. Data included performance records of 100 lambs (males and females) born from 59 dams, from 2009 to 2012. The analyzed traits were birth weight (BW), weaning weight (WW), average daily gain from birth until weaning (ADGBW), total litter weight at birth (TLWB), and total litter weight at weaning (TLWW). The effects analyzed were the year of birth of the lamb, birth season, dam age at lambing, dam weight at lambing, sex of the lamb, lamb birth type, interaction between sex and birth type, and interaction between sex and birth season. SAS® software (SAS University Edition, USA) was used for calculation of the analysis of variance, means, and Pearson correlation coefficients. With the exception of the birth season, all the other environmental effects evaluated had a significant influence on at least one of the studied traits. The correlation estimates ranged from low to high and were either positive or negative. Birth weight was negatively correlated with the birth type and influenced positively all the other performance traits evaluated. The maternal ability of Santa Inês ewes was more clearly influenced by the age and weight of the dam at lambing, and the lamb birth type.

RESUMO: O objetivo deste estudo foi avaliar a influência de diferentes efeitos não-genéticos sobre características indicadoras de habilidade materna em ovelhas da raça Santa Inês. Os dados utilizados incluíram registros de desempenho de 100 cordeiros (machos e fêmeas) filhos de 59 ovelhas, nascidos de 2009 a 2012. As características analisadas foram peso ao nascimento (PN), peso ao desmame (PD), ganho médio diário do nascimento ao desmame (GMND), peso total das crias ao nascer (PTCN) e peso total das crias ao desmame (PTCD). Os efeitos analisados foram ano de nascimento da cria, estação de nascimento, idade da mãe ao parto, peso da mãe ao parto, sexo da cria, tipo de nascimento da cria, interação entre sexo e tipo de nascimento, e interação entre sexo e estação de nascimento. O programa SAS (SAS University Edition, EUA) foi utilizado para o cálculo de análise de variância, médias e coeficientes de correlação de Pearson. Com exceção da estação de nascimento, os demais efeitos avaliados exerceram influência significativa sobre pelo menos uma das características estudadas. As estimativas de correlação variaram de baixa a alta magnitude e foram tanto positivas quanto negativas. O peso da cria ao nascimento foi negativamente correlacionado com o tipo de nascimento e influenciou positivamente todas as outras características de desempenho avaliadas. A habilidade materna de ovelhas Santa Inês foi mais claramente influenciada pela idade e peso da mãe ao parto e pelo tipo de nascimento da cria.

Influence of non-genetic factors on the maternal ability of Santa Inês ewes / Influência de fatores não-genéticos na habilidade materna de ovelhas Santa Inês

The aim of this study was to evaluate the influence of different non-genetic effects on indicator traits for maternal ability in Santa Inês ewes. Data included performance records of 100 lambs (males and females) born from 59 dams, from 2009 to 2012. The analyzed traits were birth weight (BW), weaning weight (WW), average daily gain from birth until weaning (ADGBW), total litter weight at birth (TLWB), and total litter weight at weaning (TLWW). The effects analyzed were the year of birth of the lamb, birth season, dam age at lambing, dam weight at lambing, sex of the lamb, lamb birth type, interaction between sex and birth type, and interaction between sex and birth season. SAS® software (SAS University Edition, USA) was used for calculation of the analysis of variance, means, and Pearson correlation coefficients. With the exception of the birth season, all the other environmental effects evaluated had a significant influence on at least one of the studied traits. The correlation estimates ranged from low to high and were either positive or negative. Birth weight was negatively correlated with the birth type and influenced positively all the other performance traits evaluated. The maternal ability of Santa Inês ewes was more clearly influenced by the age and weight of the dam at lambing, and the lamb birth type.(AU)

O objetivo deste estudo foi avaliar a influência de diferentes efeitos não-genéticos sobre características indicadoras de habilidade materna em ovelhas da raça Santa Inês. Os dados utilizados incluíram registros de desempenho de 100 cordeiros (machos e fêmeas) filhos de 59 ovelhas, nascidos de 2009 a 2012. As características analisadas foram peso ao nascimento (PN), peso ao desmame (PD), ganho médio diário do nascimento ao desmame (GMND), peso total das crias ao nascer (PTCN) e peso total das crias ao desmame (PTCD). Os efeitos analisados foram ano de nascimento da cria, estação de nascimento, idade da mãe ao parto, peso da mãe ao parto, sexo da cria, tipo de nascimento da cria, interação entre sexo e tipo de nascimento, e interação entre sexo e estação de nascimento. O programa SAS (SAS University Edition, EUA) foi utilizado para o cálculo de análise de variância, médias e coeficientes de correlação de Pearson. Com exceção da estação de nascimento, os demais efeitos avaliados exerceram influência significativa sobre pelo menos uma das características estudadas. As estimativas de correlação variaram de baixa a alta magnitude e foram tanto positivas quanto negativas. O peso da cria ao nascimento foi negativamente correlacionado com o tipo de nascimento e influenciou positivamente todas as outras características de desempenho avaliadas. A habilidade materna de ovelhas Santa Inês foi mais claramente influenciada pela idade e peso da mãe ao parto e pelo tipo de nascimento da cria.(AU)

Effect of raising method of calves during liquid milk nutrition on their open-field and maze behaviour after weaning

The objective was to find whether calf behaviour is affected by it rearing to weaning in 84 days, gender, and the sire lineage. 99 Holstein calves were assigned to 1 of 3 treatments: artificially reared in hutches (A), suckling of a foster cow (F), or suckling of the mother (M). After weaning (84 days), all calves were kept separately by sex in age-balanced groups. The speed of traversing the maze was recorded at 6 months of age. The open-field observation was performed at 10 months. The average time of traversing the maze facility was no significantly different among treatment groups. The average time of traversing the maze for 6 tasks was the highest in A and the lowest in the F group (P 0.05). At the open field test, the difference compared to the grid (square) crossings was significant at the 1st minute of the 1st test (P 0.05). The average of the grid crossings in all tests was highest in M (139.5) and the lowest in A (123.1) (P 0.05). There were no significant differences between sex in behaviour in the maze or the open field tests. Sire lineage significant effect was found in vocalisation and defecation behaviour. The results show that the method used to rear calves and sire lineage may have an impact on their later behaviour.(AU)

Effect of raising method of calves during liquid milk nutrition on their open-field and maze behaviour after weaning

The objective was to find whether calf behaviour is affected by it rearing to weaning in 84 days, gender, and the sire lineage. 99 Holstein calves were assigned to 1 of 3 treatments: artificially reared in hutches (A), suckling of a foster cow (F), or suckling of the mother (M). After weaning (84 days), all calves were kept separately by sex in age-balanced groups. The speed of traversing the maze was recorded at 6 months of age. The open-field observation was performed at 10 months. The average time of traversing the maze facility was no significantly different among treatment groups. The average time of traversing the maze for 6 tasks was the highest in A and the lowest in the F group (P 0.05). At the open field test, the difference compared to the grid (square) crossings was significant at the 1st minute of the 1st test (P 0.05). The average of the grid crossings in all tests was highest in M (139.5) and the lowest in A (123.1) (P 0.05). There were no significant differences between sex in behaviour in the maze or the open field tests. Sire lineage significant effect was found in vocalisation and defecation behaviour. The results show that the method used to rear calves and sire lineage may have an impact on their later behaviour.

Estimation of genetic parameters for weaning and yearling weights in a composite population used to form the Purunã breed

We aimed to evaluate the effects of sex and the linear and quadratic components of age of dam at calving, as well as apply a mixed model including maternal effect for the genetic evaluation of weaning (WW) and yearling (YW) weights. The phenotypic database was composed by Charolais, Caracu, Aberdeen Angus, and Canchim purebred and crossbred animals. Single-trait analyses were performed using models that included the maternal effect for WW and YW traits, and a model ignoring this effect on YW (YWNM). The Deviance Information Criterion (DIC), model posterior probabilities (MPP), accuracy of breeding values (ACC), and Spearman's rank correlation were applied to compare the models including and ignoring the maternal effect on YW. Sex and age of dam at calving had significant effects on WW and YW. The direct heritability estimates were 0.21±0.03 and 0.05±0.02, and the maternal heritabilities were 0.11±0.02 and 0.02±0.01 for WW and YW, respectively. The heritabilities estimated for YW may have been influenced by the several genetic groups in the population and by used conventional animal model, which may not have been the better fit model to evaluate YW in this population. The DIC, MPP, and ACC values indicated that YW outperformed the YWNM model, but the rank correlation and percentages of individuals selected in common suggested that the best animals would be selected independently of the model chosen.

The effects of tryptophan and pyridoxine supplied orally to nursing piglets on weight loss and social behavior after weaning / Os efeitos do triptofano e da piridoxina fornecidos por via oral aos leitões em amamentação sobre a perda de peso e o comportamento social após o desmame

This study evaluated the effect of oral supplementation with tryptophan (Trp) and pyridoxine (Pyr) on the growth performance and social behavior of suckling piglets before and after weaning. At day 14, six suckling piglets per sow were distributed into three treatments and allotted in a randomized block design, with eight replicates and two piglets per experimental unit. Treatments consisted of a Control - oral supplementation with L-alanine (1.70 g), D-glucose (1.74 g) and distilled water (3.44 mL); Trp - oral supplementation with Trp (3.5 g/d) and distilled water; and Trp + Pyr - oral supplementation with Trp (3.5 g/d) + Pyr (0.0095 g/d) and distilled water. Each treatment was supplied orally five times per day (2.5 mL each treatment), from 14 to 21 days old. Piglets were monitored continuously in the nursing phase for 24 h at 21, 28 and 33 days of age to assess the behavior (standing, lying, eating, socializing, sitting and drinking). Piglets receiving oral Trp + Pyr showed a decreased weight loss on the first day after weaning (P = 0.03). Performance was not affected (P > 0.05) by treatments in each studied period, such as in overall period (21 to 34 days) after weaning. Piglets receiving Trp supplementation visited the feeders more frequently from days 21 to 22 (P < 0.01) and from days 28 to 29 (P < 0.02), as well as in the overall period (P < 0.01). It is concluded that high doses of tryptophan with or without high doses of pyridoxine, supplied orally to nursing piglets, reduced the weight loss on the first day after weaning and increased the frequency of visits to the drinkers on the first day after weaning and also to the feeders, mainly from weaning until 7 days after.(AU)

Este estudo avaliou o efeito da suplementação oral de triptofano (Trp) e piridoxina (Pyr) para leitões em aleitamento sobre o desempenho produtivo e comportamento social, antes e após o desmame. No 14º dia de vida, seis leitões por porca foram divididos em três tratamentos e foram distribuídos em um delineamento experimental de blocos ao acaso, com oito repetições e dois leitões por unidade experimental (16 leitões/ tratamento). Os tratamentos foram os seguintes: Controle - suplementação oral de L-alanina (1.70 g), D-glicose (1.74 g) e água destilada (3.44 ml); Trp - suplementação oral de Trp (3.5 g / d) e água destilada; Trp + Pyr-Trp (3.5 g / d) + Pyr (0.0095 g / d) e água destilada. Cada tratamento foi fornecido oralmente por cinco vezes ao dia (2.5 ml em cada suplementação), do 14º até o 21º dia de idade. Durante a fase de creche os leitões foram monitorados durante 24 horas no 21º, 28º e 33º dia de idade para avaliação do comportamento (em pé, deitado, comendo, sociabilizando, sentado e bebendo). Leitões suplementados oralmente com Trp + Pyr apresentaram uma redução na perda de peso (P=0.03) no primeiro dia após o desmame. O desempenho não foi influenciado (P > 0.05) pelos tratamentos nos períodos estudados, assim como no período total após o desmame (21 a 34 dias). Leitões que receberam suplementação de Trp, com ou sem Pyr, visitaram os comedouros mais frequentemente do 21º ao 22º dia (P < 0.01) e do 28º ao 29º (P < 0.02) assim como no período total (P < 0.01). Conclui-se que altas doses de Trp associadas ou não com altas doses de Pyr fornecidas oralmente aos leitões em aleitamento reduziram a perda de peso no primeiro dia após o desmame e aumentaram a frequência de visitas aos bebedouros no primeiro dia após o desmame e aos comedouros principalmente do desmame até 7 dias após ao desmame.(AU)

Selection indexes for Nellore production system in the Brazilian Pantanal

The objective was to develop selection indexes for Nellore cattle raised in full-cycle production system in the Brazilian Pantanal. The resulting offspring are retained as replacements or sold at two years of age. Preliminary analyses explored effects of scale on economic values (EV). However, given the available data, these effects were very small. Presented herein are results from a simulated system consisting of 5,000 cows with all animals maintained on pasture as is typical in Pantanal. The EV were determined by approximating the partial derivatives of the profit function, changing one trait at a time, by one unit, while keeping the other traits constant. Traits in the breeding objective were mature cow weight, direct and maternal weaning weight, postweaning average daily gain, subcutaneous fat depth, longissimus muscle area, and stayability. Economic values were calculated on the basis of number of animals (per head), number of animal units, and arroba of carcasss weight. Regardless of the basis, maternal weaning weight and subcutaneous fat depth made negligible contributions to the breeding objective. Proportions of variation in the breeding objectives (per head, per animal unit, per arroba) explained by cow weight, direct weaning weight, postweaning average daily gain, stayability, and longissimus muscle area were: 13, 13, 17; 6, 1, 5; 3, 3, 4; 67, 67, 61; and 11, 17, 13, respectively. These indexes may aid Nellore breeders in their selection decisions, thus facilitating the genetic progress and increased productivity and profitability of Pantanal herds.

Effect of different rearing condition on early age in the maze, open-field, and aversive behaviours in the dairy cow during the first lactation

The aim of the study was to tested hypotheses that the primiparous cows behaviour is impacted by the method of rearing from the second day of life to weaning. 53 Holstein primiparous cows were used. They were reared in different ways during milk nutrition. Calf-heifers were assigned to one of five rearing groups on the second day after having nursed their mothers for 24 hours: H) hutch; HA) hutch, from 7 days pen with an automated drinking machine (ADM); MA) with mother, from 7 days pen with an ADM; MH) with mother, from 7 days hutch; MN) with mother, from 4 days with nursing cows. After weaning (56 days), all heifers were kept in group pens, after calving in free-stall housing. Maze learning ability was tested in the third month of lactation. In the 5th month, cows were observed in the open-field, in the seventh month they were subjected to an aversion test (AT). Group MN was the slowest in solving all tasks and HA the fastest. Differences were recorded among groups in the first-day evaluation (P < 0.01). No differences in open field tests were found. In the AT traversing, the slowest were groups H and HA, the fastest MH and MA (P < 0.01). The time of the first return was different (P < 0.001). On the first day, the most vocalized cows of the MN group (P < 0.05). The results show that the method used to rear heifers may have a significant impact on their maze and aversive behaviour.(AU)

Effect of different rearing condition on early age in the maze, open-field, and aversive behaviours in the dairy cow during the first lactation

The aim of the study was to tested hypotheses that the primiparous cow’s behaviour is impacted by the method of rearing from the second day of life to weaning. 53 Holstein primiparous cows were used. They were reared in different ways during milk nutrition. Calf-heifers were assigned to one of five rearing groups on the second day after having nursed their mothers for 24 hours: H) hutch; HA) hutch, from 7 days pen with an automated drinking machine (ADM); MA) with mother, from 7 days pen with an ADM; MH) with mother, from 7 days hutch; MN) with mother, from 4 days with nursing cows. After weaning (56 days), all heifers were kept in group pens, after calving in free-stall housing. Maze learning ability was tested in the third month of lactation. In the 5th month, cows were observed in the open-field, in the seventh month they were subjected to an aversion test (AT). Group MN was the slowest in solving all tasks and HA the fastest. Differences were recorded among groups in the first-day evaluation (P < 0.01). No differences in open field tests were found. In the AT traversing, the slowest were groups H and HA, the fastest MH and MA (P < 0.01). The time of the first return was different (P < 0.001). On the first day, the most vocalized cows of the MN group (P < 0.05). The results show that the method used to rear heifers may have a significant impact on their maze and aversive behaviour.

Heifer management characterization in dairy herds from the west of Buenos Aires, Argentina / Caracterização da gestão de novilhas em rebanhos leiteiros do oeste de Buenos Aires, Argentina

The replacement program in a dairy farm represents the second or third largest cost in a dairy operation. This study aimed to characterize and typify the practices related to the dairy heifer replacement program and describe the growth, development, and health parameters during this period in commercial dairy herds in Trenque Lauquen. A cross-sectional observational study was carried out, including 54 randomly selected dairy farms that were visited once to collect data about facilities and management through a semi-structured survey. Cluster and principal coordinates analysis were applied to classify the farms based on all variables collected, grouped in four main areas: pre-fresh cows, colostrum management, pre-weaning calf 's management, and personnel. Additionally, growth, development, and health status were also recorded and described for calves and breeding heifers. Two similar-sized farm clusters were identified with differences in management and facilities in different areas of calves rearing. In one cluster there was a greater proportion of farms having a pre-fresh group, implementing appropriate health (colostrum, vaccination) and feeding management. Also, differences in personnel and technical support were relevant. The estimated body gain was 452 and 774 g/d for calves younger or older than 60 d of age, respectively. The age and weight farm averages in breeding heifers were 21.0 mo (range: 16.7-27.5) and 416.3 kg (range: 336.7-519.3), respectively. Diarrhea and respiratory affections were the major problems in pre-weaning calves and heifer rearing, respectively. The median mortality was 7.3, 7.6, and 2.9% at the calving, pre-weaning, and heifer rearing period, respectively. The results showed an improvement opportunity for producers, the design of precise and high impact programs that could lead to an improved replacement program.(AU)

Nos rebanhos leiteiros, o programa de reposição representa o segundo ou o terceiro maior custo da atividade de produção de leite. O objetivo do presente trabalho foi caracterizar e tipificar as práticas relacionadas ao programa de reposição de novilhas leiteiras e descrever o crescimento, desenvolvimento e parâmetros de saúde durante este período em rebanhos leiteiros comerciais localizados em Trenque Lauquen, oeste de Buenos Aires, Argentina. Foi realizado um estudo observacional transversal incluindo 54 fazendas de produção de leite selecionadas ao acaso e visitadas uma única vez para a colheita de dados relacionados a instalações e manejo empregando-se um questionário semi-estruturado. Foi efetuada a análise dos agrupamentos e das coordenadas principais para classificar as fazendas com base em todas as variáveis colhidas e agrupadas em quatro principais áreas: vacas pré-parto, manejo de colostro, manejo pré-desmame de bezerros e recursos humanos. Os dados referentes ao crescimento, desenvolvimento e estado de saúde dos animais também foram registrados e descritos para bezerros e novilhas. Dois grupos de fazendas de tamanho semelhante foram identificados com diferenças no manejo e instalações em distintas áreas de recria de bezerros. Em um grupo houve uma maior proporção de fazendas que tinham um grupo de vacas pré-parto, com implementação de adequado manejo de saúde (colostro, vacinações) e manejo alimentar. Também foram relevantes as diferenças em termos de pessoal e suporte técnico. O ganho de peso estimado foi de 452 e 774 gramas por dia, respectivamente, para os bezerros jovens e os com idade superior a 60 dias. As médias das fazendas da idade e do peso das novilhas de reprodução foram, respectivamente, 21,0 meses (variação de 16,7 a 27,5) e 416,3 kg (variação de 336,7 a 519,3). A diarreia e as afecções respiratórias foram os maiores problemas de saúde, respectivamente, nos bezerros em pré-desmama e novilhas em recria. A média de mortalidade foi de 7,3; 7,6 e 2,9%, respectivamente, ao parto, na pré-desmama e durante a recria de novilhas. Os resultados obtidos demonstraram a existência de oportunidades de melhoria para os produtores, com o delineamento de programas precisos e de alto impacto que poderão propiciar um programa de reposição aprimorado.(AU)