Marco Antonio López-Carlos

Zilpaterol Hydrochloride on Performance and Sperm Quality of Lambs Fed Wet Brewers Grains

Abstract Aguilera-Soto, J.I., Ramirez, R.G., Arechiga, C.F., Mendez-Llorente, F., Lopez-Carlos, M.A., Silva-Ramos, J.M., Rincón-Delgado, R.M. and Duran-Roldan, F.M. 2008. Zilpaterol hydrochloride on performance and sperm quality of lambs fed wet brewers grain. J. Appl. Anim. Res., 34: 17–21. Forty Rambouillet × elibuey male lambs were grouped as light-weight (LW; n =20; 28±1.2 kg BW) and heavy-weight (HW; n = 20; 40.5±1.6 kg BW) to be fed a finishing diet containing 60% wet brewers grain with or without 6 mg kg1 DM ofβ-adrenergic agonist zilpaterol hydrochloride (ZH). On d 60 of the feeding trial, ZH was removed and semen collection was measured by electroejaculation. Further, on d 63 animals were slaughtered for carcass and meat quality evaluation. On d 15 of the feeding trial, lambs fed ZH gained significantly (about 25%) more weight. However, at the end of feeding trial (60 d period), ADG, DMI and feed efficiency were unaffected by ZH consumption. Sperm motility was significantly reduced by ZH only in HW lambs; but, sperm concentration was not affected. Conversely, storage loss at 96 h, cooking loss and drip loss were significantly higher and water holding capacity was significantly lower in animals fed ZH. It appears that ZH addition to diet of lambs had not caused positive performance effects during long period of feeding, however, it affected the reproductive performance of rams.

Effect of Fermentable Liquid Diets Based on Wet Brewers Grains on performance of Growing Pigs

Abstract Aguilera-Soto, J.I., Ramirez, R.G., Arechiga, C.F., Gutierrez-Bañuelos, H, Mendez-Llorente, F., Lopez-Carlos, M.A., Piña-Flores, J.A., Rodriguez-Frausto, H. and Rodriguez-Tenorio, D. 2009. Effect of fermentable liquid diets based on wet brewers grains on performance and carcass characteristics by growing pigs. J. Appl. Anim. Res., 36: 271–274. To evaluate growth and carcass characteristics of pigs fed graded levels of fermentable liquid diets (FLD) based on wet brewers grains (WBG), 32 Landrace × York male pigs (32±4 d; 9.7±1.2 kg) were allotted to one of the four treatment diets containing 0, 15, 30 and 45% WBG (dry matter basis). Animals were weighed every 20 d and dry matter intake (DMI) by pen was recorded daily. At 95 kg pigs were slaughtered and carcass characteristics were measured. Average daily gain of pigs was significantly different among treatments being higher for 0% WBG (660 g day−1) followed by 15% (553), 30% (537) and 45% (507), similar trend was observed for DMI (1895 g day−1, 1881, 1823 and 1771, respectively). Moreover, carcass dressing was significantly different among treatments (71.5%, 70.1, 68.9 and 67.8, respectively). Even though, growth performance was negatively affected by FLD, feeding costs were reduced even when the fattening period was longer. It is suggested that animals may be fed on 30% WBG diets in post-weaning periods and 30 or 45% during growing and finishing periods.

Superovulatory response and embryo development in ewes treated with two doses of bovine somatotropin

This study evaluated whether the administration of 50 and 100mg bovine somatotropin (bST) at the start of synchronization and at the time of natural mating in ewes improves the ovulation rate, embryonic development and pregnancy rate of transferred embryos. Forty-eight donors were assigned to three treatments: the bST-100 treatment (n=15) received 100mg bST at the start of synchronization and at natural mating, the bST-50 treatment (n=15) received 50mg bST on the same schedule as the previous group, and the control (n=18) did not receive any bST. Two embryos were transferred to each recipient (n=121): 35 received embryos from bST-100; 50 received embryos from bST-50, and 36 received embryos from the control. The superovulatory rate, percentage of recovered structures, cleavage rate, percentage of transferable embryos, embryo quality and development and pregnancy rate were analyzed using the GENMOD procedure of SAS. The number of corpora lutea and the cell number were analyzed using the GLM procedure of SAS. The insulin and IGF-1 concentrations were analyzed with ANOVA for repeated measures. The bST application did not affect the superovulatory rate, number of corpora lutea and recovered structures (P>0.05). The numbers of transferable embryos and embryos reaching the blastocyst were higher (P≤0.01) in the bST-50 (96.4±3.6% and 69.0±7.8%) than the bST-100 (93.0±4.5% and 27.2±38.9%) and control (87.7±5.4% and 50.4±6.4%) groups. The insulin and IGF-1 concentrations were higher (P<0.05) in the bST-treated groups, but the insulin concentration was higher (P<0.05) in the bST-100 group than in the bST-50 group. The pregnancy rate was similar (P=0.21) in ewes receiving embryos from the two treatments [bST-50, (70.0%); bST-100, (62.5%), and control, (56.6%)]. The administration of 50mg bST at the start of synchronization and at natural mating in superovulated ewes was concluded to enhance the proportion and development of transferable embryos. However, bST did not affect the pregnancy rate of transferred embryos.

The male effect stimulus positively increased the ovarian and reproductive seasonality in Criollo goats irrespective of a controlled photoperiodic regime

Present study evaluated the presence of a sexually active male buck upon the onset of reproductive activity and estrous cycle progression in Criollo goats exposed to a 6-month long controlled photoperiod in a range of 13.4–10.6 light-hours per day. Mexican-native (Criollo) goats (n=10) were randomly assigned into 2 groups: (1) goats exposed to a male buck (n=5); (2) goats not exposed to a male buck (n=5). Blood samples were taken weekly to quantify serum-progesterone levels through radioimmunoanalysis. Male exposure increased luteal activity and estrous cycle progression reflected as a higher number of days in luteal activity (44±9.05 vs. 32.3±20.6); a reduced number of days in anestrous (4.0±4.8 vs. 51.9±28) and a greater number of luteal phases (15.7±4.4 vs. 11.3±8.7) without compromising serum progesterone levels (6.8±0.8 vs. 7.3±0.5). In conclusion, presence of a sexually active male induced a greater ovarian activity in Criollo goats, shortening seasonal anestrous irrespective of the controlled photoperiodic regime.

The male effect stimulus positively influences luteinising hormone secretion in ovariectomised Criollo goats irrespective of a controlled photoperiodic regime

Present study evaluated the presence of a sexually active male buck upon the influence of an estradiol implant in ovariectomised (OVX) goats exposed to a 6-month-long controlled photoperiod in a range of 13.4–10.6 light-hours per day. Mexican-native (Criollo) goats (n=20) were randomly assigned into 2 groups: (1) goats exposed to a sexually active male buck (n=10); (2) goats not exposed to a male buck (n=10). Each experimental group of goats included ovariectomised goats (OVX, n=5), and ovariectomised and estradiol-implanted goats (OVX + E2, n=5). Blood samples were taken from OVX and OVX + E2 goats, every four weeks, during 6 h at 15 min intervals (i.e., 24 samples/day). Frequency, amplitude, and concentration of luteinising hormone (LH) were determined. While the OVX + E2 goats depicted an increased LH pulse frequency (2.0±0.5 vs. 0.7±0.1), the presence of a sexually active male increased frequency, amplitude and concentration of LH in OVX goats compared to goats not exposed to males (frequency: 3.2±0.4 vs. 0.7±0.1 pulses/6 h; amplitude: 1.6±0.1 vs. 0.8±0.3 ng/mL; concentration: 5.3±0.6 vs. 2.0±0.9 ng/mL) (P<0.001). In conclusion, the presence of a sexually active male increase LH pulse frequency, amplitude and concentration in OVX-goats (Criollo), irrespective of a controlled photoperiodic regime.

Effect of Feed Additives on Digestibility and Milk Yield of Holstein Cows Fed Wet Brewer Grains

Abstract Aguilera-Soto J.I., Ramirez, R.G., Arechiga, C.F., Mendez-Llorente, F., Lopez-Carlos, M.A., Piña-Flores J.A., Medina-Flores C.A., Rodriguez-Frausto, H., Rodriguez-Tenorio, D. and Gutierrez-Bañuelos, H. 2009. Effect of feed additives on digestibility and performance of Holstein cows fed wet brewers grains. J. Appl. Anim. Res. 36: 227–230. To evaluate different feed additives in cows fed wet brewers grain, 5 ruminal-cannulated Holstein cows (470±45 kg; 18±3 kg d−1 milk), were allotted to a 5x5 Latin-square design. A total-mixed diet containing 33% wet brewers grains (WBG) was provided including: 1) no additives (Control), 2) 1% sodium bicarbonate, 3) 1% sodium bentonite, 4) 33 mg kg−1 sodium monensin and 5) 200 mg kgfibrolityc enzymes. Cows fed bicarbonate or enzymes had significantly higher dry matter intake (DMI). However, apparent digestibility of different nutrients did not differ (P>0.05) among dietary treatments. Similarly except acetate propionate ratio (A:P) none of the ruminal parameters differed among groups. A:P followed the same pattern as DMI. Cows given monensin, enzymes and bicarbonate yielded more milk than control or those given bentonite. Except bentonite all additives increased milk yield.