The Combined Effect of Melatonin Implant and Removal of Buck Seminal Plasma on Cryopreservation During the Nonbreeding Season.

This study aimed to determine how melatonin (MT) and seminal plasma affected the freezability of buck sperm during the nonbreeding season. Semen was collected from eight bucks before (pre-MT) and after (post-MT) MT application in the nonbreeding season. Individual ejaculates were collected from the bucks, split into two equal groups according to the removal of seminal plasma (SP) (-) or nonremoval of SP (+). For washing, the groups of ejaculates were centrifuged, and the supernatant was separated, SP (-) and SP (+) ejaculates were diluted, then frozen. Semen samples were examined for sperm motility, plasma membrane integrity, defective acrosomes, DNA fragmentation, and mitochondrial membrane function at the native and post-thaw stages. When the general average post-thaw motility (p < 0.01), plasma membrane (p < 0.05), acrosome (p < 0.05), and DNA integrity rates (p < 0.05) and mitochondrial membrane potential (MMP) (p < 0.01) were evaluated, it was seen that MT administration caused a statistically significant improvement. The dramatic effect of nonremoval of seminal plasma on motility and plasma membrane integrity is more clearly observed in individual semen samples frozen in the pre-MT group (p < 0.05). Also, it was observed that removing seminal plasma in the post-MT group caused even milder post-thaw acrosome damage compared with the SP (+) group (p < 0.05). The effect of removing seminal plasma was not observed in terms of DNA integrity and MMP rates in pre- and post-MT groups. As a result, it was concluded that MT application and removal of seminal plasma in the nonbreeding season result in improvement in the freezability of buck semen.

Administration time of misoprostol affects fertility rate in artificially inseminated Kivircik ewes with frozen-thawed ram semen.

The aim of this study was to determine the effects of the administration time of misoprostol (11 h (Miso11) and 6 h (Miso6) before artificial insemination) on fertility rates in Kivircik ewes (control: n = 41, Miso11: n = 32 and Miso6: n = 33) during breeding season. Artificial insemination (AI) was performed 48 h after sponge removal using frozen-thawed semen (150 million sperm per dose in 0.25 ml straws). Estrus synchronization parameters (onset and duration) and lambing rate were evaluated. No significant difference was observed among groups for the estrus onset and duration hours (P > 0.05). The lambing rates in the control, Miso11 and Miso6 groups were 39.0, 62.5 and 54.5%, respectively. There were significant differences among the control, Miso11 and Miso6 groups according to lambing rates (P < 0.05). In conclusion, misoprostol treatment significantly improved fertility in ewes when using frozen-thawed semen in AI. Administration of misoprostol 11 h before AI resulted in a higher lambing rate than that at 6 h before AI; therefore, treatment of misoprostol 11 h before AI can effectively be used.

The effect of body weight on some welfare indicators in feedlot cattle in a hot environment.

Heat stress has important effects on the welfare of livestock. The effects of heat stress in cattle include changes in biological functions and behaviors. The aim of this study was to investigate the behavioral differences between light and heavy feedlot cattle reared in a hot environment. Sixteen male Holstein feedlot cattle were allocated to light (353.8 ± 15.5 kg, n = 8) and heavy (737.1 ± 15.8 kg, n = 8) groups according to their live weight and were kept in a semi-open feedlot barn. The individual behavioral response variables measured were standing, lying, feeding, drinking, ruminating, locomotor activity and elimination (urinating and defecating). The effects of group, day, observation time, replicate and all interactions were included in an explanatory statistical (GLM) model. The data were analyzed using the PROC GLM procedure of SAS. Overall, the heavy cattle spent more time standing (P < 0.001), lying (P < 0.001), and eliminating (P < 0.05) compared to the light group. In contrast, the light group spent more time eating, drinking and ruminating (P < 0.001). Locomotor activity did not differ significantly between groups (P > 0.05). During the day, heavy cattle spent more time standing (at 1600 hours) and less time eating in comparison with the light cattle (P < 0.001) (at 1300 and 1600 hours). Light and heavy feedlot cattle behaved differently in a hot environment. The findings of the study indicate that the welfare of the heavy Holstein feedlot cattle was impacted negatively when the ambient temperature was high (at 1300 hours).

The effect of shearing in a hot environment on some welfare indicators in Awassi lambs.

The aim of this study was to analyze the effects of shearing on the individual behaviors and rectal temperature profile during the day at hot environment in Awassi lambs. Twenty Awassi male lambs were randomly allocated into shorn (n = 10) and unshorn (n = 10) groups (28.8 ± 0.7 and 29.9 ± 0.7 kg, respectively) and were kept indoor during the experiment. The physiological and behavioral response variables measured were rectal temperature, standing, lying, feeding, ruminating, drinking, locomotor activity, and elimination. The effect of day, time of day, and all interactions on rectal temperature were found significant (P < 0.001). The effect of shearing on the rectal temperatures of lambs was tend to be significant (P = 0.06). Overall, unshorn lambs showed more frequencies of locomotor activity (P < 0.05) and there was a tendency of less standing behavior (P = 0.08) when compared to the lambs in shorn group. The difference of the other behaviors was not significant (P > 0.05). Within the observation hours, there was a tendency of difference for behavioral frequencies between groups especially early in the day and late at night (P = 0.07). But during the day, the difference of behavior type between groups was highly significant at 1300 and 1600 hours (P < 0.01 and P < 0.001, respectively). The findings of the current study showed that the behavior of shorn lambs changed with the changing of environmental heat and showed more behavioral differences at 1300 hours but they tend to cope with heat stress better than unshorn lambs in a hot environment when their rectal temperatures were compared.

The assessment of carcass composition of Awassi male lambs by real-time ultrasound at two different live weights.

The accuracy of ultrasonography to measure fat thickness (FT) and longissimus dorsi muscle (LM) traits (area, depth and width) in live Awassi male lambs and predict carcass FT and LM traits was studied. Twenty six Awassi male lambs were randomly divided into light (L) (n=13) and heavy (H) (n=13) finishing lambs. Slaughter weight of lambs in L and H groups were 40 and 45kg, respectively. FT and LM traits, cross-sectional area between the 12th and 13th rib were measured using real-time ultrasound in vivo and on the carcass after slaughter. All ultrasound and carcass measurements were the same except live weight (LW) (P<0.001), cold carcass weight (CCW) (P<0.001) and carcass LM width (P<0.05). Overall, correlation coefficients between ultrasound and carcass FT, LM depth, width and area were 0.79, 0.82 (P<0.001); 0.60, 0.58 (P<0.05); 0.48, -0.17 (P>0.05) and 0.89, 0.87 (P<0.001), respectively, for lambs in L and H groups. The introduction of ultrasound FT and ultrasound LM area as independent variables in addition to LW in the multiple regression equations further improved the variations for carcass FT (84%, 71%), carcass LM area (79%, 79%), CCW (72%, 65%) for lambs in light and heavy groups whereas no improvement was observed for carcass yield. These results indicate that in vivo ultrasound FT and measurement of the LM area in association with LW could be used to estimate carcass FT, carcass LM area and CCW in different LW Awassi lambs.