Effect of castration at 10 months of age on growth physiology and behavior of male feral beef cattle

Abstract

This study compared the growth performance, plasma testosterone and cortisol levels around castration at 10 months of age, and plasma insulin-like growth factor (IGF)-I concentration and flight speed, in intact bulls and steers from 10 to 21 months of age in a feral Spanish breed. Fourteen bulls (366.5 ± 48.5 kg live weight) were assigned at random to one of two treatments: surgically castrated (steers) or intact (bulls), and submitted to an identical fattening period. Steers reared until heavy live weights (21 months of age) grew slowly and had lower plasma IGF-I concentrations than intact bulls. These differences were mainly highlighted the month after surgery (11 months of age) and the last part of the fattening period (from 19 to 21 months of age). After surgical castration (11 and 12 months of age), steers showed a tendency to display greater flight speed values than intact bulls but baseline plasma cortisol concentration did not differ between groups at this time. At the end, steers and bulls reached nearly similar temperament, as flight speed did not differ between them. The results confirm the role of IGF-I as a key anabolic hormone in male beef cattle and thus it may reflect growth differences due to altered sex steroids production.

Effects of immunocastration performed at two live weights on the growth physiology, temperament and testicular development of feral beef bulls

“…neither the initial LW nor immunocastration had any effect on the chute score or flight speed tests, likely because of individual variability within this breed due to a lack of genetic selection(Álvarez- Rodríguez et al, 2017). In contrast to our results,Fina et al (2006) …”

“…Immunocastration reportedly reduces aggressiveness, male-male sexual behavior, and, in general, physical activity (Martí et al, 2015;Price, Adams, Huxsoll, & Borgwardt, 2003). In the current study, neither the initial LW nor immunocastration had any effect on the chute score or flight speed tests, likely because of individual variability within this breed due to a lack of genetic selection (Álvarez-Rodríguez et al, 2017). In contrast to our results, Fina et al (2006) described that temperament recorded during finishing depended upon initial weight in a feral breed, suggesting that older calves were less adaptable to intensive fattening systems.…”

“…In our study, plasma IGF‐1 concentrations were higher in LIGHT‐C than LIGHT‐VA animals, reflecting their distinct weight gains, although no differences were found between HEAVY‐C and HEAVY‐VA animals. Röpke, Schams, Schwarz, and Kirchgessner () and Álvarez‐Rodríguez et al () described lower plasma IGF‐1 concentrations during the fattening period in surgically castrated animals than in intact bulls, suggesting IGF‐1 may be increased by gonadal hormones, although Bruckmaier, Lehmann, Hugi, Hammon, and Blum () reported that this difference disappeared approximately 450 kg LW. In contrast, IGF‐1 is also related to reproductive function in males.…”

“…To ease handling, reduce sexual and aggressive behavior and improve their poor conformed carcasses during the finishing phase, Serrana de Teruel males are sometimes castrated (Sanz et al, 2013). Álvarez-Rodríguez, Albertí, Ripoll, Blasco, and Sanz (2017) described that physical castration causes pain and distress to the animals, triggering weight loss primarily in the month following castration and at the end of the fattening period. Therefore, other alternative methods should be explored.…”

Development of Marbling in Beef Cattle Can Be Modulated through the Control of Adipogenic Activity

“…This may be attributed to 30% less intramuscular fat levels in bulls than steers [21]. Castration practices are reported to reduce blood testosterone level [22]. Testosterone, a male reproductive steroid hormone, has been observed to suppress adipogenesis [23] [24].…”