Linking oceanographic conditions, migratory schedules and foraging behaviour during the non‐breeding season to reproductive performance in a long‐lived seabird

Abstract This study evaluated the effect of heifer development system on body weight (BW), body condition score (BCS), fescue toxicosis symptoms, reproductive performance, and subsequent calf growth of fall-calving beef heifers. Angus × Simmental heifers [n = 399; 240 ± 20.0 kg initial BW; age = 252 ± 20 d] were stratified by BW and BCS and assigned to 1 of 12 groups in each of the 2 production years. The study utilized a stratified randomized design. Pens were randomly assigned to 4 treatments: drylot (DL) development (fed ad-libitum diet consisting of 90% hay and 10% DDGS on a dry matter basis), grazing endophyte-infected fescue supplemented daily (2.3 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/S), grazing endophyte-infected fescue and supplemented from the midpoint of treatment period until breeding (4.5 kg as-fed/heifer/d; 50:50 mix of soybean hulls and DDGS; E+/LS), and grazing novel endophyte-infected fescue with no supplement (NE+/NS). Treatments ceased on d 168 [time of artificial insemination (AI)] and heifers were commingled and managed as a group through second breeding season. Heifers in DL had greatest (P ≤ 0.05) BW and BCS from d 28 until d 254. Furthermore, E+/S heifers had greater (P ≤ 0.05) BW and BCS than both E+/LS and NE+/NS from d 28 until d 168. On d 56 and 84, E+/LS heifers had lower (P ≤ 0.05) BW and BCS compared to NE+/NS, but on d 148 treatments reranked and E+/LS remained at a greater (P ≤ 0.05) BW and BCS compared to NE+/NS through the first breeding season. Drylot heifers had greatest (P ≤ 0.05) percentage cycling and percentage of mature BW at AI (66.6%) and had greater (P ≤ 0.05) AI and overall pregnancy rates compared to E+/LS and NE+/NS. The E+/S (55%) and E+/LS (53.7%) heifers were developed to a greater (P < 0.01) percentage of mature BW than NE+/NS (49.3%). A greater (P ≤ 0.02) percentage of DL and E+/S heifers were pregnant at the end of the first breeding season (89.3 and 85.1%; respectively) compared to NE+/NS (61.5%). In summary, DL heifers had the greatest BW and BCS at AI, percentage cycling, and AI pregnancy rate. However, this strategy did not result in differing overall pregnancy rates between DL, E+/S, and E+/LS and there were no differences in milk production, rebreeding reproductive performance, and calf performance between all treatments. Finally, the poorest AI and overall pregnancy rates of the NE+/NS heifers suggests this is not a viable development strategy for fall-born heifers.

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Effects of body condition score at initiation of the breeding season on reproductive performance and overall productivity of Bos taurus and B. indicus beef cows

Animal Reproduction Science ◽

10.1016/j.anireprosci.2021.106820 ◽

2021 ◽

pp. 106820

Author(s):

R.F. Cooke ◽

G.C. Lamb ◽

J.L.M. Vasconcelos ◽

K.G. Pohler

Keyword(s):

Breeding Season ◽

Body Condition ◽

Reproductive Performance ◽

Bos Taurus ◽

Body Condition Score ◽

Beef Cows ◽

Condition Score

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Variations in the feeding success and behaviour of Galápagos sperm whales (Physeter macrocephalus) as they relate to oceanographie conditions

Canadian Journal of Zoology ◽

10.1139/z93-283 ◽

1993 ◽

Vol 71 (10) ◽

pp. 1991-1996 ◽

Cited By ~ 23

Author(s):

Sean C. Smith ◽

Hal Whitehead

Keyword(s):

Surface Temperature ◽

Significant Variation ◽

Foraging Behaviour ◽

Geographic Area ◽

Sea Surface ◽

Physeter Macrocephalus ◽

Sperm Whales ◽

Feeding Success ◽

Galapagos Archipelago ◽

Oceanographic Conditions

The feeding success of sperm whales off the Galápagos Islands, Ecuador, was examined over 5 study years; 1985, 1987, 1988, 1989, and 1991. A total of 160 days were spent following sperm whales at sea. The defaecation rates of sperm whales were used as an indication of feeding success. The recorded acoustic click rates of sperm whales were used as an indication of aggregative and foraging behaviour. Significant variation in feeding success occurred temporally over periods of days, months, and years. Feeding success also varied spatially with geographic area. Feeding success was inversely related to sea surface temperature (SST). The foraging and associative behaviour of sperm whales also varied with feeding success, SST, and by year. Variations in the feeding success and behaviour of Galápagos sperm whales can likely be attributed to changing oceanographic conditions in the waters surrounding the Galápagos archipelago.

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The effect of prostaglandin and gonadotrophins (GnRH and hCG) injection combined with the ram effect on progesterone concentrations and reproductive performance of Karakul ewes during the non‐breeding season

Veterinary Medicine and Science ◽

10.1002/vms3.353 ◽

2020 ◽

Author(s):

Mohammad Ayaseh ◽

Abdolah Mirzaei ◽

Alidad Boostani ◽

Mansur Mehrvarz

Keyword(s):

Breeding Season ◽

Reproductive Performance ◽

Ram Effect

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Reproductive performance of scottish blackface gimmers trained to eat supplements as ewe hoggs and offered feedblocks during mating

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600015658 ◽

1986 ◽

Vol 1986 ◽

pp. 54-54

Author(s):

A. Waterhouse

Keyword(s):

Breeding Season ◽

Reproductive Performance ◽

Supplementary Feed ◽

The Hill

Hill gimmers typically perform below the flock average and are reluctant to take supplementary feed. This paper reports an attempt to evaluate the effects in the first breeding season of training young flock replacements to eat supplementary feed in the form of either concentrate pellets or feedblocks.Four hundred and fifty-five ewe hoggs were allocated to two groups on return from away-wintering on 1 April. Untrained hoggs (U) were put to the hill immediately. The remainder were trained to feed (T) for one week before rejoining their contempories. Training and subsequent mating treatments are summarised in Table 1.

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Diving behaviour during the breeding season in the terrestrially breeding male grey seal: implications for alternative mating tactics

Canadian Journal of Zoology ◽

10.1139/z03-085 ◽

2003 ◽

Vol 81 (6) ◽

pp. 1025-1033 ◽

Cited By ~ 8

Author(s):

Damian C Lidgard ◽

Daryl J Boness ◽

W Don Bowen ◽

Jim I McMillan

Keyword(s):

Nova Scotia ◽

Reproductive Success ◽

Breeding Season ◽

Foraging Behaviour ◽

Diving Behaviour ◽

Halichoerus Grypus ◽

Phenotypic Traits ◽

Alternative Mating Tactics ◽

Grey Seal ◽

Mating Tactics

We examined the diving behaviour of breeding male grey seals (Halichoerus grypus) at Sable Island, Nova Scotia, from 1997 to 2001. The proportion of time spent at sea varied between 0 and 78% (N = 30). Males engaged in deep (43.4 ± 3.3 m (mean ± SE), N = 27) diving, and these dives were clustered into bouts, which mostly occurred during long trips (62.2 ± 14.7 h). We suggest that males spent time foraging during deep dives. Shallow diving (5.9 ± 0.1 m, N = 27) accounted for 40.8% of dives, which were also clustered into bouts that mostly occurred during short trips (2.1 ± 0.37 h). We suggest that shallow diving comprised a suite of behaviours, but included little foraging behaviour. Phenotypic traits had little influence on diving behaviour. Further work is required to understand the extent to which foraging behaviour enhances reproductive success, and whether shallow diving is a component of the mating tactics of male grey seals at Sable Island.

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110 EFFECT OF MELATONIN TREATMENT ON LIBIDO AND ENDOCRINE FUNCTION OF DROMEDARY CAMEL BULLS OUT OF THE BREEDING SEASON

Reproduction Fertility and Development ◽

10.1071/rdv29n1ab110 ◽

2017 ◽

Vol 29 (1) ◽

pp. 163 ◽

Cited By ~ 4

Author(s):

A. Swelum ◽

I. Saadeldin ◽

H. Ba-Awadh ◽

A. Alowaimer

Keyword(s):

Breeding Season ◽

Reproductive Performance ◽

Repeated Measures ◽

Endocrine Function ◽

Gland Secretion ◽

Control Group ◽

Dromedary Camel ◽

Testosterone Levels ◽

Significant Difference ◽

Length Changes

The reproductive performance of camels is poor and has remained a major obstacle to the growth of dromedary populations. The limited breeding season is one of the most important causes of the poor reproductive performance. In seasonal animals, melatonin is the chemical messenger that allows the perception of daylight length changes. Commercial melatonin products have been developed for the manipulation of seasonal breeding in animals. The present study aimed to evaluate the influence of melatonin implantation on libido, serum melatonin, and testosterone concentrations in dromedary camels during the non-breeding season (June and July). Ten camel bulls were used in the 35-day-long trial; 5 of them were implanted with 30 Melovine® implant (Ceva, Libourne, France) subcutaneously on Day 0, whereas the other 5 camel bulls remained untreated as a control. Libido was evaluated weekly in response to oestrous-induced female camels treated with oestrogen (1 mL Oestrocon; oestradiol benzoate 5 mg mL−1) 2 days before assessment of libido. Libido was scored as follows: 0 = not interested: the male did not show any libido; 1 = low interested: the male went near the female and showed low frequency of sniffing and flehmen; 2 = interested: the male went near the female, it showed sniffing, flehmen, grinding of teeth/whistling, yawning; 3 = high interested: the male went near the female and was very agitated, it showed sniffing, flehmen, grinding of teeth/whistling, yawning, urination, and tail raising. It stood with open legs, and poll gland secretion and neck rubbing were observed; 4 = excited, like 3, but the male showed blatering and dulaa extrusion, was very excited, stood with open legs, high poll gland secretion and neck rubbing were observed. Blood samples were collected weekly. Serum melatonin and testosterone concentrations were evaluated using commercial ELISA kits. Comparisons among groups were evaluated using repeated-measures ANOVA, using SAS software (SAS Institute Inc., Cary, NC, USA). A difference was considered significant at the P < 0.05 level. The results revealed that at Day 0, all camel bulls in 2 groups had no libido and there was no significant difference in the melatonin or testosterone levels in the 2 groups. The libido increased gradually in the melatonin group and reached the maximum (3–5) at week 4 and week 5. The control group had low libido (0–1) along the trial. Statistically, the libido was significantly higher in the melatonin group than control group. Additionally, testosterone levels were significantly higher in melatonin group than control group, especially in the fourth week of the present trial (565.07 ± 33.04 pg mL−1 and 458.49 ± 25.36 pg mL−1, respectively). In conclusion, melatonin implantation in the non-breeding season significantly improved the libido and the reproductive performance of dromedary camel bulls. Therefore, it may be possible to improve the reproductive efficiency of camels by extending the breeding season through treatment with melatonin during the non-breeding season.

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