Age Of Castration Research Articles

The effects of age of castration on carcass characteristics, meat quality and fatty acid profile of finishing South African Mutton Merino lambs

This study compared the effect of either keeping South African Mutton Merino (SAMM) ram lambs intact, or castrated with age applicable methods on their carcass characteristics, meat quality and fatty acid composition of subcutaneous fat (SCF) and intramuscular fat (IMF). Ten lambs per treatment were castrated early at one week of age (EAR) with an elastrator band (4.4 kg ± 0.78 kg: mean ± SD), another 10 lambs at eight weeks of age (late castration - LAT) with a burdizzo (23.6 kg ± 2.26 kg: mean ± SD), whereas another ten lambs were left intact (CON). The two castration methods used were based on cost, ethical prescriptions and to mimic commercial operations. The lambs were housed individually in 30 pens (1.404 m2) for the duration of the study. Animals were housed on an elevated slatted wooden floor in the same metabolic building with an extractor fan to promote ventilation. At the start of the feeding trial, the age of the lambs was on average two and a half months with a live weight of 24.3 kg ± 4.10 kg (mean ± SD). The lambs were fed a standard commercial finishing diet for 67 days and slaughtered when they reached approximately 44.2 kg ± 6.35 kg (mean ± SD) live weight. After slaughter, carcass characteristics (cold carcass) and meat quality were evaluated. The left 3-rib cut was dissected (9th through 11th rib) and the muscle percentage for CON lambs was higher compared to both EAR and LAT lambs. Therefore, CON lambs produced leaner carcasses compared to EAR and LAT lambs. Castration status had no effect on meat Warner-Bratzler shear force (WBSF), consumer sensory analysis nor colour. For proximate composition, CON lambs had higher moisture compared to LAT lambs while LAT had higher dry matter compared to CON lambs. Both, EAR and LAT lamb’s meat had higher organic matter compared to CON lamb’s meat, but these differences were negligible. For IMF in the longissimus thoracic et lumborum muscle, CON lambs’ meat had higher total PUFA, α-linolenic acid, total PUFA n-6, linoleic acid, PUFA:SFA ratio and PUFA:MUFA ratio than meat from both EAR and LAT lambs. Eicosapentaenoic acid (EPA) and total PUFA n-3 were both higher for meat from CON lambs than LAT lamb’s meat, while palmitic acid and conjugated linoleic acid (CLA) were higher for EAR lamb’s meat than CON lamb’s meat and EAR lambs than LAT lamb’s meat, respectively. For SCF, CON lambs had higher heptadecenoic acid and linolelaidic acid than LAT lambs. The calculated atherogenicity index (AI) of SCF was higher for LAT lambs compared to CON lambs. Limited effects of castration age on the possible health benefits of SAMM lamb meat were proven in the current study. It is however suggested that for a higher production response and carcass muscle content, to either keep SAMM rams intact or at least postpone castration for as long as possible.

Studi Literatur Implementasi Kastrasi pada Anjing

Castration is one of the important aspects in the management of maintain and care for animals. The purpose of this study was to determine the age of castration in small and large breed dogs, to know purpose of carrying out castration in dogs, to know the techniques of castration in dogs. This literature study is obtained from searching and collecting various library sources from Google Scholar with the help of the Mendeley application. Based on the results of the study, age is the most important risk factor for most diseases. Castration age in large breed dogs should be done at a minimum age of 15-18 months and in small breed dogs at a minimum age of 5 months because in large breed dogs castration before 1 year can cause osteosarcoma and if castration under 6 months has a significant risk factor for the emergence of a tibial plateau angle. The aim of implementing castration in dogs is to control the population, prevent aggressive behavior, roaming and congenital abnormalities, and to prevent the occurrence of diseases such as Sertoli cell tumors in dogs with cryptorchid. Dog castration techniques that can be used are open prescrotal or scrotal castration, closed prescrotal or scrotal castration, perineal castration and scrotal ablation. The open castration technique is preferred in larger dogs because the ligation can be placed directly around the vascular pedicle and provides a safer ligation. Closed castration techniques are preferred over open techniques. This method is usually performed on small or young dogs. Based on the results of open castration studies, it shows a higher complication rate than closed castration. The closed castration technique has the disadvantage that the binding is less secure because the vessel is tied while it is surrounded by the tunica and cremaster muscles attached rather than directly tied.

Distinguishing female, male and castrated sheep using linear metrics and geometric morphometrics: Application on an archaeological assemblage

Although as a species sheep are commonly found in archaeological deposits and occupy a major position in the history of animal husbandry, it remains difficult to discriminate the sexual type (male, female or castrate) of individuals from observation of the remains. However, understanding sheep husbandry through sex ratio analysis, contributes to a better understanding of the history of animal husbandry. Current criteria for determining are limited to visual characters on coxal and skull. This study explores the variability of sheep skeletons according to their sex to submit hypotheses for methods capable of individual sexing. Using 58 complete skeletons and 428 isolated Soay sheep bones from the collection of the Natural History Museum (UK), we initially tested the sexual distinction using the so-called classical methods: the estimates of shoulder heights and the slenderness index. We then evaluated the influence of sex on the shape and size of selected bones with geometric morphometric, using a protocol that we had previously developed and validated. Finally, we classified these data using the K-Nearest Neighbors (KNN) method, quantifying the reliability of sex attribution. We were able to test its application on an archaeological sample, after selecting bones with the best rate of sexual assignment. Our results demonstrate the difficulty of using traditional methods to sex sheep whilst proposing solutions for sex assignment (88% reliable) using geometric morphometric and KNN. In addition, we were able to highlight the influence of sex according to bone type, though this is strongly qualified by various criteria (such as the age of castration). By characterising and quantifying the sex ratio within archaeological assemblages, we may better understand herd management, procurement strategies and feeding habits, and therefore improve our global knowledge of animal husbandry history.

Farming practices and breeding objectives identification of farmer in north shoa and south wello zones of Amhara region

The study aims at assessing the production systems and identifying the traits preferred by farmers in the study areas to establish community-based breeding and sustainable utilization programs. The study was conducted in the four purposively selected districts of North Shoa and South Wello zones of Amhara region (Merehabete, Wereillu, Moretena Jiru and Mojaena Wedera). A total of 120(30 farmers from each district) purposively selected farmers participated in their own flock ranking experiment. Furthermore, 216 (i.e., 54 farmers from each district) were interviewed about their goat production systems and trait preferences to be improved. The chi-square test was used to analyze qualitative data, and analysis of variance was used to analyze quantitative data generated by the survey. For the rank data, indexes were calculated using Microsoft Excel 2010. Income was the main objective of goat rearing in all the study areas. Doe has a larger proportion than other flock structures in all the study areas. Mostly, the age of castration was above one year in all the study areas. The breeding buck selection criteria were growth, shape, size, and color. Body size, litter size, and mothering ability were identified as important traits in all study areas. Early selling of fast-buck kids is practiced in all study areas for their immediate cash. This results in the use of poor-performing bucks for breeding and may result in negative selection. To address such issues, it is critical to create and implement a community-based breeding program that takes into account body size, litter size, mothering capacity, puberty age, and longevity.

Diferencias de pesos entre terneros Braford enteros y castrados a diferentes edades

<p>Se compararon terneros braford machos enteros y castrados, con diferentes edades de esterilización, con el objetivo de evaluar este efecto en el crecimiento mediante la ganancia total y diaria de peso. Se utilizaron 28 terneros al pie de madre en campo natural. Se dividieron<br />aleatoriamente en grupos de 7 individuos: C45: castrados a los 45 días de edad; E45: enteros<br />con 45 días de edad; C90: castrados a los 90 días de edad y E90: enteros con 90 días de edad.<br />Los pesos se registraron individualmente el día 0 (día de la castración) y posteriormente los<br />días 15, 30 y 45. La técnica de castración se realizó por cirugía cruenta. Las variables estudiadas para el peso vivo fueron: ganancia total (GT, kg) y ganancia media diaria (GMD, kg/<br />día). Se obtuvieron estadísticas descriptivas, análisis de varianza (ANOVA) y test de Duncan<br />(p<0,05), tomándose como efecto principal la edad de castración (45 y 90 días), obrando los<br />enteros como testigos. Las medias para GT fueron: C45: 34,86 kg; E45: 37,29 kg; C90: 51,14<br />kg y E90: 44,29 kg. Para GMD fueron: C45: 0,58 kg; E45: 0,62 kg; C90: 0,85 kg y E90: 0,74<br />kg. El ANOVA arrojó diferencias significativas para ambas variables: GT (p=0,0156) y GMD<br />(p=0,0157), siendo C90 superior al resto de los grupos. Por su parte, E90 obtuvo valores<br />intermedios entre C90 y los terneros de 45 días. Entre C45 y E45 no se hallaron diferencias<br />significativas en ambas variables. Se concluye que el momento elegido para la castración<br />debe ser cercano a los tres meses, ya que a los 45 días el peso vivo resultó más afectado por<br />la cirugía.</p>

What we know that just ain’t so

It is well documented that castration, regardless of age or method (surgical or band) causes pain in beef cattle. At the same time, consumer concern and awareness regarding painful routine management procedures in livestock is at an all-time high. Developing pain mitigation strategies that are practical and cost effective for producers is also important to facilitate their adoption by the beef industry. The goal of this paper is to review current pain assessment and mitigation strategies for knife and band castration in pre-weaned calves with focus on the influence of the age and method of castration, including a summary of recent studies assessing the effects of meloxicam in controlling calf pain and improving calf comfort.

Castration age and growth, meat production and meat quality of Nellore male cattle

Castration in beef cattle production has been proposed to reduce sexual and aggressive behaviour, increase carcass fat deposition, and improve meat quality traits, such as tenderness and juiciness. The aim of the present study was to evaluate the effects of the age of castration on performance, subprimal yield and meat quality of Nellore cattle raised on a pasture system. A total of 24 Nellore males were raised in a grass-fed system with Brachiaria brizantha since birth until slaughter (at 30 months old). Three treatments were assigned: castration at weaning (CW); castration at 20 months old (C20); and intact bulls (NoC). Males were weighed, and muscle and fat thickness were periodically evaluated by ultrasonography. The cold carcass weight, dressing and carcass pH (pH 24), and subprimal cut weights were recorded after 24 h of chilling. Samples of Longissimus lumborum (LL) were taken to measure meat quality traits. Animals that were castrated at weaning had lower bodyweight after 10 months of age with no changes in the supplement intakes, average daily gain, hot carcass weight and cold carcass weight compared with NoC. Intact males had greater cooking losses and carcass yield compared with others, with no differences for LL pH 24 according to the treatments. The castration did not change the LL muscle area, but decreased total forequarter, chunk, shoulder and eye of round weights, and increased the back fat over LL and rump fat. Animals castrated at weaning had higher marbling compared with others. In addition, regardless of age, castration improved tenderness, increased LL total lipids and decreased moisture compared with NoC. For sensory property, steers castrated at 20 months of age had lower juiciness, and NoC had a greater global sensory property compared with steers castrated at 20 months old. In conclusion, steers castrated at weaning had lower growth rate, final bodyweight and meat production compared with intact males. However, when castration was performed at 20 months, animals did not differ in most cases from castration at weaning and NoC. Tenderness was improved by castration, but sensory traits did not differ between groups.

Effects of weaning and castration ages on growth performance, blood metabolites, and carcass characteristics in Hanwoo steers

BackgroundRecently, as production costs have been increasing owing to rising feed prices worldwide, shortening the age of slaughter has been recognized as a way to increase farm income. In Korea, the raising period for Hanwoo steers is over 31 months with the delay of weaning and castration stated as one of the reasons for the increase in the raising period. Thus far, studies on age of weaning and castration have been conducted individually, and there have been no studies on the combined effects of weaning and castration ages on the growth performance and carcass characteristics in Hanwoo steers.MethodsWeaning ages were calculated at 80 or 130 days of age, and castration ages were calculated at 90 days and 180 days of age. Calves were allocated to one of the four treatment groups: W80C90 (weaning at 80 days of age and castration at 90 days of age), W80C180, W130C90, and W130C180.ResultsFor the entire experimental period, weaning and castration ages did not significantly affect growth performance of Hanwoo steers. In addition, weaning and castration ages did not affect the overall yield and quality traits of carcass in Hanwoo steers.ConclusionWeaning and castration ages had small effects on growth performance and carcass characteristics in Hanwoo steers. Therefore, the early weaning and castration ages are recommended to reduce the slaughter age without any negative effects on meat quality grade.

Infrared Thermography and Metabolic Changes in Castrated Piglets due to the Effects of Age and the Number of Incisions in the Testicles

The objective of the study was to evaluate infrared temperature and metabolic responses in different-aged piglets castrated surgically with one or two incisions. The piglets were divided into groups according to age (5- and 13-day old) and the number of incisions: simulated castration; castration with one incision (C1I5 and C1I13); and castration via two incisions (C2I5 and C2I13). Temperature evaluations were performed with an infrared thermal thermography camera in the eyes, the thorax and the scrotal area, at 24 h before castration (RV), immediately after castration (PC), 24 and 48 h post-surgery. The study also evaluated plasma glucose and lactate concentrations. The thorax presented lower infrared temperature in the groups C1I13 and C2I13 than those in C1I5 and C2I5 (p<0.05). Regardless of age and type of castration, plasma lactate values increased PC (P=0.0001). The piglets castrated at 5 days of age were less susceptible to presenting temperature changes regardless of the number of incisions, while the animals castrated at 13 days with two incisions showed lower temperatures and imbalances in plasma glucose and lactate concentrations. Castration in piglets of 13 days causes a decrease in temperature in the lacrimal caruncle immediately after performing surgery. The physiological responses caused by castration are less marked in 5-day-old piglets.

The age of surgical castration affects the healing process in beef calves.

Castration is painful for calves. Castrating at an earlier age is often recommended, but little is known about how this affects the healing process or the pain experienced. We compared incision closure, swelling and pain sensitivity of beef calves surgically castrated at 3 (range 0 to 8 d; n = 16) or 73 (range 69 to 80 d; n = 15) d of age. Closure of the incision, as measured with a 5-point scale (1 = fresh wound, 5 = no longer visible), weight gain, and inflammation (skin temperature and swelling, as measured by scrotal circumference) were recorded on d 1, 3, 7, 11, 15, 18, 21, 25, 32, 39, 45, 61, and 77 after the procedure, until all incisions were fully healed. On these same days, pain sensitivity was assessed by applying a known and increasing force with von Frey hairs (0.02 to 300 g-force) at the edge of the castration wound and at a control site, approximately 2 to 5 cm anterior to the teats, until animals showed a behavioral response or the highest force was reached. The incisions of younger calves healed more quickly than older ones [fully healed, median (95% confidence interval); 39 (32 to 61) vs. 61 (61 to 77) d; P = 0.002], however, they had relatively more swelling in the days after castration (P < 0.001). Younger animals reacted to lighter pressure of von Frey hairs compared to older calves especially in the first stages of healing process (P < 0.001), and there were other signs indicative of inflammation processes in this region at this time. However, there was no difference in the control site for either age group. In addition, it took longer for older calves to recover their daily weight gain after the procedure (P < 0.001). Taken together, these results paint a mixed picture about the effects of age of surgical castration. Calves castrated soon after birth experience more tissue swelling and show more signs of pain, but their incisions heal sooner and their weight gain is less affected, when compared to animals castrated around 73 d of age.

Carcass physical composition and physic-chemical characteristics of meat from Nellore cattle

Assessment of carcass physical composition and physicochemical characteristics of meat from Nellore males distributed randomly into three treatments: males castrated at 13 months of age at puberty (n=26); castrated at 18 months of age, 15 days before confinement (n=26); and young bulls (n=25). For the evaluation of meat chemical characteristics, we used samples of 12 animals taken at random from each treatment. The experimental design was completely randomized. Animals were slaughtered at 22 months of age after 100 days of confinement. The carcasses of young bulls showed higher contents of muscle (66.46 %) and bone (16.03 %), and lower fat content (17.66 %), in relation to that of steers castrated at 13 (62.83,15.28, and 22.11 %, respectively) or 18 months (63.99, 15.29, and 21.53%, respectively), which did not differ amongst themselves. The meat of young bulls was darker (3.07 points) than the meat from those castrated at 13 months of age (3.43 points), while the meat from those castrated at 18 months displayed an intermediate color (3.29 points), not differing from the others. Young bulls yielded meat with lower content of intramuscular fat (3.18 points) and lipids (3.81%) in relation to those castrated at 13 (4.58 points and 6.77%, respectively) or 18 months (4.52 points and 5.66%, respectively). Protein content was higher (P 0.05) by the age of castration, with young bulls having lower values in relation to the castrated males. Castration of Nellore young bulls in early puberty increases the edible portion of the carcass due to the higher body fat deposit.

Effects of castration age, protein level and lysine/methionine ratio in the diet on colour, lipid oxidation and meat acceptability of intensively reared Friesian steers

A total of 64 intensively reared Friesian steers were used in a 2×2×2 design to study the effects of age of castration (15 days old v. 5 months old), dietary protein level (14.6% v. 16.8%; DM basis) and lysine/methionine (lys/met) ratio (3.0 v. 3.4) on meat quality. The lys/met ratio of 3.0 was reached with supplementation of protected methionine. Animals were slaughtered at a live weight of 443.5±26.2 kg at around 12 months of age. Colour and lipid oxidation were measured in the longissimus thoracis muscle throughout the 14 days of display under modified atmospheric and commercial display conditions. A panel of 17 consumers assessed daily the visual acceptability of the meat on display. A consumer acceptability eating test was also performed with 120 consumers in meat aged for 7 days under vacuum conditions. Lipid oxidation was not influenced by castration age and the protein level in the diet. Castration age did not affect meat colour, but meat from the low protein level diet and the low lys/met ratio showed higher redness (a*) from 3 days of display onwards. Nevertheless, from 6 days onwards, consumer visual acceptability was below the level of acceptance in all treatments, and even from 5 days onwards in those animals that underwent early castration and were fed either a high protein diet or a combination diet low in protein content and high in lys/met ratio. The best accepted treatments throughout the display period were those from late castrated animals fed a low protein diet, probably related to other visual aspects. However, the best accepted meat after consumption was that from late castrated animals fed high protein and high lys/met. The addition of protected methionine to reach lys/met levels of 3.0 did not improve beef acceptability, with the high protein diet being preferred by consumers in terms of palatability in late castrated animals.

Veterinary attitudes towards pre-pubertal gonadectomy of cats: a comparison of samples from New Zealand, Australia and the United Kingdom

AIM: To compare the attitudes and practices of a sample of veterinarians in New Zealand, Australia and the United Kingdom (UK) towards pre-pubertal gonadectomy of cats. METHODS: Respondents' demographics were gathered using an electronic questionnaire distributed via professional veterinary associations in the target countries, as were minimum age at gonadectomy and typical age of puberty. Desirability of prepubertal gonadectomy was gauged using three response categories (‘yes’, ‘no’ or ‘sometimes’), respondents were then able to justify the response given. Two-way Analyses of Variance (ANOVA) followed by post hoc Tukey HSD tests were used to test whether there were differences in minimum ages for gonadectomy within and between countries and between providers and non-providers of services to pounds (or animal welfare centres). Views on the desirability of prepubertal gonadectomy relative to demographics were explored using a Likelihood Ratio Test. RESULTS: The survey received 717 responses. Most respondents believed pre-pubertal gonadectomy was either entirely or ‘sometimes’ desirable (556/621), few thought it was undesirable (65/621). Minimum age at gonadectomy was significantly affected by country surveyed and provision or non-provision of services for pounds. Post hoc Tukey HSD analysis indicated the mean age of both spaying and castration (4.3 months) in the UK was significantly different from both Australia (spaying: 3.4 months, castration: 3.2 months) and New Zealand (spaying: 3.4 months, castration: 3.2 months) (all p<0.001). Mean ages at spaying and castration were also significantly different (p= 0.008; p= 0.019, respectively) for non-providers (spaying: 3.9 months, castration: 3.8 months) of services to pounds when compared to providers (spaying and castration: both 3.6 months). Likelihood Ratio Tests indicated significant effects amongst countries and between genders relative to the desirability of pre- pubertal gonadectomy. Respondents from the UK were more likely to answer ‘no’ (p = 0.004) or ‘sometimes’ (p = 0.050) as compared to those from New Zealand or Australia. Females were more likely to respond with ‘sometimes’ as opposed to ‘yes’ than males. Reasons for considering pre-pubertal gonadectomy desirable or sometimes desirable focussed on reducing unwanted pregnancies and improving population control, as well as improving rates of adoption, owner compliance and cat behaviour and health. CONCLUSIONS AND CLINICAL RELEVANCE: In general, pre-pubertal gonadectomy is considered a desirable procedure by those practitioners that responded to the survey. However age at which any such procedure occurs differs depending upon a number of factors. Differences among countries may relate to the specific veterinary association's guidelines or possibly differences in social discourse which affect perception of cats. There is substantial overlap between the reported minimum age of gonadectomy and the age at which cats can enter early puberty, allowing a window for unintentional pregnancy when pre-pubertal gonadectomy does not occur.

Male pre- and post-pubertal castration effect on live weight, components of empty body weight, estimated nitrogen excretion and efficiency in Piemontese hypertrofic cattle

To evaluate the effect of sexual neutering and age of castration on empty body weight (EBW) components and estimated nitrogen excretion and efficiency, a trial was carried out on 3 groups of double-muscled Piemontese calves: early castrated (EC, 5th month of age), late castrated (LC, 12th month of age) and intact males (IM, control group). Animals were fed at the same energy and protein level and slaughtered at 18th month of age. Live and slaughtering performances and EBW components were recorded, whereas N excretion was calculated by difference between diet and weight gain N content. In live and slaughtering performances, IM showed higher final, carcass and total meat weight than EC and LC (P<0.01). In EBW components, IM showed higher blood and head weight than EC and LC (P<0.01 and 0.05 respectively), and differences were found between EC and LC for head weights (P<0.01). IM showed higher body crude protein (BCP) than EC and LC (P<0.01 and 0.05 respectively), but BCP/EBW ratio was higher only in IM than EC (P<0.05). Estimated N daily gain was higher in IM than EC and LC (P<0.01). Only LC showed higher excretion than IM (P<0.05), and N efficiency was higher in IM than EC and LC (P<0.05 and 0.01 respectively). In conclusion, for the Piemontese hypertrophied cattle castration significantly increases N excretion (+7%) and reduces N efficiency (−15%), leading to a lower level of sustainability.

220 EFFECTS OF FOLLICLE-STIMULATING HORMONE AND 6-N-PROPYL-2-THIOURACIL ON BOAR SPERMATOGENESIS

Currently, swine biotechnologies related to reproduction increase considerably. Investments are made in order to improve the reproductive rates and performance of breeding stock. Understanding the physiology of spermatogenesis will help increase sperm production and improve boar efficiency. Sertoli cells are the only somatic cells present in the seminiferous tubules. Their function is to guarantee proper sperm formation and maturation. Each Sertoli cell is responsible for nursing a finite number of spermatogonia. At puberty, Sertoli cell maturation and lumen formation have occurred within the seminiferous tubules and germ cells have proliferated rapidly followed by the onset of spermatogenesis. At least two hormones are known to play a role in Sertoli cell proliferation and maturation: follicle-stimulating hormone (FSH) and thyroid hormone. FSH secretion has been assumed to be the stimulus for proliferation. The thyroid hormone is responsible for normal postnatal growth and development. Alterations in thyroid activity have frequently been associated with changes in male reproductive functions, since hypothyroidism, induced with 6-N-propyl-2-thiouracil (PTU) soon after birth, is associated with a marked delay in sexual maturation and development. The goal of this study was to report the effect of FSH and PTU on the stages of sperm cell development of young pigs. Six piglets of 1, 7, 14, 25, and 55 days of age were castrated and their testes were sectioned to grafts of 5 mm3. The grafts were then transplanted subcutaneously into the dorsum of 12 castrated nude mice per age group. Two days post-surgery mice were randomly assigned to one of four treatment groups: control, FSH (5 IU rFSH), PTU (0.015% solution), and FSH + PTU. Following 14 days of treatment, testicular tissue pieces were allowed to grow for 2 additional weeks. Tissues were then harvested, immersion-fixed in neutral buffered formalin, and embedded in paraffin. Five-micron-thick sections were stained using hematoxylin and eosin. Slides were evaluated under light microscopy and the oldest germ cell type present in each section was recorded. Germ cell types were recorded as spermatogonium, spermatocyte, early spermatid, and late spermatid. Statistical differences between all groups were detected using paired Student t-tests. There were no differences noted between control groups and those treated with PTU or FSH alone. No effect concerning age of castration on grafts development was observed. There was a slightly significant increase (P = 0.05) in the number of spermatocytes observed in the groups treated with FSH+PTU. These data suggest that there is a potential synergistic effect of FSH and PTU on sperm cell development. Based on these results, further studies need to be performed to completely understand the effect of these two hormones on Sertoli cells.

Effect of pre- and post-pubertal castration on Piemontese male calves: I. Live and slaughtering performances

Abstract To evaluate the effect of different age of castration on live and slaughtering performances in Piemontese males a study was carried out on 24 cattle divided in 3 groups: EC—early castrated (5th month of age), LC—late castrated (13th month) and IM—intact males, reared under the same environmental condition until the same fattening degree, then slaughtered at 18 month of age. The animals were fed at the same energy and protein level. Live weight was recorded monthly and 18 linear body measurements were recorded at 18th month of age. Live performances and slaughtering data were recorded or calculated. Differences were found in live weight (higher in IM than EC and LC; P P P P P

Comparison of fatty acid profiles of edible meat, adipose tissues and muscles between cocks and capons

The effect of caponisation on fat composition by parts (wing, breast, thigh, and drumstick) and tissues (skin, subcutaneous adipose tissue, intermuscular adipose tissue and muscle) was examined in the present study and fatty acid profiles of abdominal fat and edible meat by parts and tissue components were determined. The sample was made up of twenty-eight castrated and twenty male Penedesenca Negra chicks reared under free-range conditions and slaughtered at 28 wk of age; the birds were castrated at four or eight weeks. Caponisation significantly increased (P < 0.01) the chemical fat content in all parts (16.31% to 37.98% in breast; 21.98% to 34.13% in wing; 21.09% to 49.57% in thigh; 14.33% to 24.82% in drumstick) and led to minor modifications in fat haracteristics, particularly in the thigh and the drumstick, where the unsaturated vs. saturated fatty acid ratio increased from 1.31 to 1.76 ( P < 0.01) and from 1.48 to 2.07 (P < 0.01), respectively. Delaying the age of castration from 4 to 8 weeks increased this ratio by 0.35 in the edible meat. Even though the profile of the abdominal fat is less saturated in capons, all changes occurring on fat quality after caponisation indicate that increased fatness after castration does not imply worse fat nutritional properties.

Comparison of carcass composition by parts and tissues between cocks and capons

The effect of caponisation on carcass composition by parts and tissues was examined. Twenty-eight castrated and twenty male Penedesenca Negra chicks reared under free-range condi- tions were slaughtered at 28 weeks of age. The birds were castrated at 4 or 8 weeks. The left sides of the carcasses were quartered (wing, breast, thigh and drumstick), and the parts dissected into the tis- sue components (skin, subcutaneous fat, intermuscular fat, muscle, bone and tendons). Capons showed more abdominal, intermuscular and subcutaneous fat than the cocks, both at the same slaugh- ter age and at the same weight. The breast and thigh were heavier in the capons than in the cocks. However, the whole muscle mass in the breast was increased by caponisation. This favourable effect was achieved at the expense of decreasing the carcass yield. The age of castration up to 8 weeks did not affect the carcass composition of the parts and tissues. chicken / capon / carcass / tissue composition

Effect of delayed castration on the growth rate, behaviour and serum insulin-like growth factor-1 concentration of beef cattle on tropical pasture

AbstractMale beef calves in northern Australia are generally castrated under 6 months of age as an aid to management of animal behaviour and for the purpose of producing sufficiently fat carcasses at slaughter. It is also common for beef producers to administer hormone growth promotants, such as oestradiol, to increase the growth rates of steers at pasture. This experiment tested the hypothesis that delaying castration by 9 months would produce an increase in growth rate for the period while the cattle are retained as bulls without compromising management of animal behaviour. Bulls of three genotypes were castrated at 7 months or 16 months of age and half were treated with oestradiol after castration. Body weight (BW) and serum insulin-like growth factor-1 concentrations (IGF-1) were measured and behaviour was observed before and after the 16 month castration. At both 7 and 16 months of age, surgical castration of bulls caused no animal welfare problems. BW gain was affected by genotype with Bos taurus types having a lower BW gain than Bos indicus and F1-cross cattle. IGF-1 was similarly affected by genotype. Oestradiol treatment increased growth of the steers (early castrates) during the 9 months between castration times compared with non-implanted steers and bulls. Oestradiol implanted steers had similar BW gain from the late castration to slaughter, regardless of age at castration, which was greater than non-implanted early castrates which, in turn, was greater than the late castrates. Similar differences were observed for IGF-1 concentrations. Behaviour was not affected by genotype, oestradiol treatment or age of castration but this may have been an artefact of the design where all treatment groups were grazed together. Although delayed castration resulted in no behavioural or management problems, it did not produce a commercially useful increase in growth rate.

Effect of age of castration, oestradiol treatment and genotype on the fat colour of beef cattle raised at pasture

AbstractIt is hypothesized that the fat colour of steers raised at pasture can be manipulated by altering animal growth patterns using the effects of post-pubertal surgical castration and oestradiol treatment. The fat colour of 151 steers of three genotypes of beef cattle, castrated at approximately 9 months or 18 months of age and treated, or not treated, with oestradiol after castration, was studied.Surgical castration of beef cattle at both 9 months of age or 18 months of age caused no readily apparent animal welfare problems. The combined effects of early or late castration and oestradiol treatment produced varying growth patterns with early castrates exposed to two post-castration episodes of growth associated with carotene-rich forage and late castrates only one such episode of growth.Late castrates and early castrates treated with oestradiol had a less yellow fat than early castrates not treated with oestradiol. The proportion of carcasses with commercially significant yellowness in the fat was decreased by either late castration or by oestradiol treatment. There was no effect of genotype on fat colour.