Effects of dietary rice bran, lasalocid, and sex of calf on postpartum reproduction in Brahman cows.

Abstract

To determine the effects of dietary lasalocid and increased dietary fat on reproduction, multiparous Brahman cows (n = 68), body condition score (BCS) of 6.2 +/- 0.7 and BW of 500.9 +/- 42.6 kg, were randomly assigned within sex of calf to receive one of four rations. All treatment groups grazed Coastal bermudagrass overseeded with rye-ryegrass and were given ad libitum access to hay and water. The control (n = 17) group received 4.17 kg x d(-1) x cow(-1) of 4:1 corn:soybean meal. The rice bran (n = 17) group received 4.35 kg x d(-1) x cow(-1) of 3:1:1 corn:soybean meal:rice bran (5.2% dietary fat). The lasalocid (n = 17) group received the Control diet with the addition of 200 mg of lasalocid x d(-1) x cow(-1). The rice bran-lasalocid (n = 17) group received the rice bran diet with the addition of 200 mg of lasalocid x d(-1) x cow(-1). Diets were fed once daily from d 1 after parturition through the detection of first estrus. Weight and BCS of cows and BW of calves were recorded at 14-d intervals from d 1 after parturition through detection of first estrus and at weaning. Cows were bled on d 1, 3, 5, 7, and 14 and at weekly intervals until estrus and on d 7 and d 10 after estrus. Ovarian follicular populations were monitored by transrectal ultrasonography weekly from d 14 after parturition through detection of first estrus. Plasma 13-14-dihydro-15-ketoprostaglandin-F2alpha (PGFM) and progesterone (P4) concentrations were quantified using RIA. Concentrations of PGFM from d 1 to 7 and P4 concentrations on d 7 and 10 after estrus were not influenced (P > 0.10) by diet or sex of calf. Changes in BW and BCS were not affected (P > 0.10) by diet. The number of medium-sized follicles tended to be greater (P < 0.06) in Controls than in cows on lasalocid or rice bran + lasalocid treatments on d 21. Cumulative return to estrus with a functional corpus luteum by d 60 postpartum was greater (P < 0.02) in the rice bran (70.6%) and lasalocid groups (76.5%) than in Controls (52.9%) or the group given rice bran + lasalocid (25.0%). Normal first estrous cycles were less likely (P < 0.07) to be exhibited in cows given rice bran + lasalocid than in other groups. Intervals from calving to corpus luteum formation, functional corpus luteum, and first P4 > or = 1 ng/mL were longer (P < 0.02) in cows given rice bran + lasalocid than in other cows. Combining increased dietary fat (5.2%) with lasalocid lengthened the time to reproductively important events.

Whole sunflower seeds as a source of polyunsaturated fatty acids for grazing dairy cows: Effects on metabolic profiles and resumption of postpartum ovarian cyclicity

“…This was consistent with Beam and Butler (1997) who reported that ovulation of the dominant follicle during the first follicular wave PP reduced ICOV length in comparison with cows where the first PP dominant follicle did not ovulate. Some studies have reported a decrease in the length of the ICOV due to supplementation with PUFA-rich lipids, both in grazing beef (Wehrman et al, 1991;Webb et al, 2001) and dairy cows (Beam and Butler, 1997), while others have not (Meier et al, 2006). Maximum DDF, the day in which this diameter was achieved and DSF did not follow the same pattern of response as ICOV to WSS supplementation.…”

Effects of prepartum supplementation of linoleic and mid-oleic sunflower seed on cow performance, cow reproduction, and calf performance from birth through slaughter, and effects on intake and digestion in steers1

“…Samples were centrifuged at 2,500 × g for 15 min, and plasma was stored at −20°C until progesterone was quantified. Cows with 1 or more plasma samples containing ≥0.5 ng/mL of progesterone were considered to have luteal activity (Webb et al, 2001;White et al, 2002;Ciccioli et al, 2003; interassay CV = 16%; intraassay CV = 24%). Cows were artificially inseminated from May 12 through June 13, 2003, followed by natural mating from June 13 through July 16, 2003, which resulted in a 65-d breeding season.…”

Effects of supplementation of whole corn germ on reproductive performance, calf performance, and leptin concentration in primiparous and mature beef cows1

“…In contrast, Webb et al (2001) reported greater cumulative numbers of cows returning to estrus within 60 d of calving when supplemented postpartum with 5.2% dietary fat from rice bran. Previous research noted that cows supplemented with fat postpartum did not have decreased postpartum intervals (Carr et al, 1994;Filley et al, 2000;Johnson et al, 2001a;Bottger et al, 2002) or increased pregnancy rate (Filley et al, 2000).…”

“…Fat supplementation during the postpartum period improved first-service conception rate (Bader et al, 2000), pregnancy rate (De Fries et al, 1998), and number of cows exhibiting estrus within 60 d after calving (Webb et al, 2001).…”