Jaime Gallegos-Sánchez

Effect of litter material and stocking density on bone and tendon strength, and productive performance in broilers

Abstract: Litter material and stocking density were evaluated on welfare-related variables and productive performance in broilers. Male chicks (n = 744, “Ross 308” strain) were raised on either tezontle (TEZ) or wood shavings (WS) litter, with a stocking density of either 13 (LDe) or 18 (HDe) birds m?2. Twenty-four birds per treatment were randomly selected to assess: tibia breaking strength (TiBS) and tendon breaking strength (TeBS) at day 45, and foot pad lesions (FPL) and valgus/varus angulation (VAng) at days 25, 32, and 39 of age. The TiBS was higher in birds housed at LDe than in those housed at HDe. Chickens on WS litter showed higher TeBS than those on TEZ litter. Birds in the TEZ–LDe group had lower values of FPL and VAng at day 32 than birds in the other groups. Birds in the WS–LDe group had less VAng at days 25 and 39 compared with birds in the other groups. Productive performance was higher (P < 0.05) in birds housed at LDe than in those housed at HDe. In conclusion, TEZ along with low stocking density reduced FPL, however, TEZ negatively affected TeBS, whereas WS litter improved TeBS and VAng.

Effect of a single-reduced dose of equine follicular fluid on the timing of oestrus and reproductive performances in goats

To evaluate the use of equine follicular fluid (EFF) in a single-reduced dose on the synchronisation of oestrus in Boer×Nubian goats, the following experimental treatments were applied: Goats in group T1 (FGA, n=10) were synchronised in oestrus by intravaginal sponges impregnated with 45 mg FGA (Chronogest-MSD) for 12 days; group T2 (T2, FGA + eCG, n=16) goats were synchronised as in T1, plus 400 IU eCG, 48 h before sponge withdrawal; T3 goats (FGA + PGF2α, n=11) received the sponge as T1 plus an i.m. dose of PGF2α (1 ml, Prosolvin-MSD) 48 h before sponge withdrawal; T4 (FGA + EFF, n=19) animals received the sponge as T1 plus 2 ml EFF at sponge withdrawal and finally, group T5 (FGA + PGF2α + EFF, n=10) was like T3 plus 2 ml EFF at sponge withdrawal. Presentation: onset and duration of oestrus were recorded, and fertility, prolificacy and fecundity were calculated. All females showed oestrus. The onset of oestrus was different (P < 0.01), T4 and T5 goats showing a delay (50.5±4.9 and 48.2±2.0 h for T4 and T5 groups, respectively). Litter size (2.10±0.11 kids/kidding) and fecundity (1.90±0.23 kids/goat) were higher (P<0.01) in T5 goats compared to T1 and T4, with no differences with T2 and T3. The combination of EFF with FGA and PGF2α in goats produces a delayed onset of oestrus and improves prolificacy and fertility in comparison with the use of FGA and EFF.