@conference {41977,
	title = {Maternal constraint in sheep breeds with diverse birth weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {187-191},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Reciprocal crosses of Shire and Shetland ponies and transferring embryos between small and large breeds of horses and pigs have shown that maternal size, ratherthan foetal genotype, is the primary determinant of birth size. In the present study, 40 Cheviot (C) ewes and 40 Suffolk (S) ewes were split into two groups. Each group was mated to either two Suffolk rams or two Cheviot rams to generate CC, CS, SC and SS lambs. Birth weights differed significantly (P<0.01) between the four lamb genotypes (CC 4.12 {\textpm} 0.21; CS 4.43 {\textpm} 0.23; SC 5.08 {\textpm} 0.19; SS 5.17 {\textpm} 0.19, kg). Furthermore, lower birth weight was significantly (P<0.01) associated with lower maternal circulating plasma placental lactogen (oPL) concentrations in the Cheviot dams at days 90 (C 25.8 {\textpm} 10.0 vs. S 71.8 {\textpm} 11.6, ng/ml) and 110 (C 84.5 {\textpm} 16.8 vs. S 175.9 {\textpm} 19.0, ng/ml) but not at day 130 of gestation. These results indicate that the size of the ewe affects the intrauterine development of her lamb. Moreover, the lower concentrations of oPL in the Cheviot dams may have contributed to the constraint observed in foetal growth.},
	issn = {1176-5283},
	author = {Jenkinson CMC and Kenyon PR and Blair HT and Breier BH and Gluckman PD}
}
@conference {40563,
	title = {Growth-promoting and metabolic actions of recombinant ovine placental lactogen and bovine growth hormone in young lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {59-62},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {It has been shown previously that ovine placental lactogen (oPL) has a  
growth-promoting effect in the growth hormone (GH)-deficient dwarf rat.   
However, this effect has not been verified in an homologous system using  
animals with an intact somatotrophic axis.  To examine the effects of oPL in  
the sheep, we injected lambs with recombinant oPL (0.1 mg/kg liveweight/day,  
n=16) or saline (n=16) for 21 days commencing on day 3 of life and compared  
their effects on body growth and energy intake with those in lambs treated with  
the same dose of recombinant bovine growth hormone (bGH, n=16).   
Circulating concentrations (ng/ml) of hormones in saline- vs bGH- vs oPL- 
treated lambs at day 20 of treatment were (mean{\textpm}SE): oPL, <0.5 vs <0.5 vs  
12.8{\textpm}0.5; GH, 10.8{\textpm}5.0 vs 48.4{\textpm}5.0 vs 12.6{\textpm}5.0, P<0.001; insulin-like growth  
factor-I (IGF-1), 267.6{\textpm}14.4 vs 302.4{\textpm}14.2 vs 291.7{\textpm}14.4.  Average daily gain  
(kg/day) during treatment was significantly (P<0.05) greater in oPL-treated  
lambs (0.28{\textpm}0.01) than in saline-treated (0.25{\textpm}0.01) or bGH-treated  
(0.24{\textpm}0.01) lambs.  Similarly, there were significant (P<0.05) increases in 
total energy intake (over the 21 day treatment period) during treatment with 
oPL (112.5{\textpm}3.5 MJ ME), compared with bGH (102.0{\textpm}3.5 MJ ME) or saline  
(102.0{\textpm}3.5 MJ ME) treatment.  It is concluded that oPL is somatogenic in  
young lambs.  This effect may be mediated by stimulating voluntary feed 
intake rather than by elevating circulating concentrations of IGF-I. },
	issn = {1176-5283},
	author = {Min SH and MacKenzie DDS and Breier BH and McCutcheon SN and Gluckman PD}
}
@conference {40550,
	title = {Influence of insulin-like growth factor-1 (IGF-1) on components of the haematopoietic and lymphatic systems},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {5-8},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Increased thymic weights have been reported in sheep selected for  
resistance to internal parasites and treatment with IGF-1 increases thymic and  
splenic weights in sheep, suggesting that IGF-1 may have a role in regulating  
immune function.  This hypothesis was examined in four experiments using  
mice as a model.  Expt 1 Unselected Swiss mice (n-24) were injected 2 x daily  
with 30 mg/d rhIGF-1 or saline for 26 days from 28 days of age.  IGF-1  
treatment increased spleen weight at a common body weight (118.2 vs 95.9,  
pooled standard error (PSE) = 6.2 mg, P<0.05), but did not affect thymic  
regression (thymic weights at the end of treatment: 85.5 vs 81.9, PSE = 4.0  
mg). Expt 2 Unselected female Swiss mice (n=22, age = 84.8{\textpm}0.8 days) were  
injected 3 x daily with 30 mg/d rhIGF-1 or saline for 17 days.  IGF-1 treatment  
increased thymic weight at a common body weight (78.4 vs 58.0, PSE = 3.0  
mg, P<0.01), but had little effect on splenic weight (180.1 vs 163.0, PSE = 7.5  
mg, P>0.10), Expt 3 Histological sections of spleens from High (H), Control  
(C), and Low (L) IGF-1 selected mice at 30 (n=30) and 120 (n=35) days of age  
were analyzed for the density of megakaryocytes (precursor cells for  
thrombocytes), and the percentage of the area covered by white pulp (lymphatic  
tissue). L mice had, compared to C and H mice, lighter spleens (62.6 vs 76.8 vs  
89.6, PSE = 5.3 mg, at 30d; 60.2 vs 109.5 vs 114.5, PSE = 7.4 mg, at 120d;  
P<0.05), and a lower density of megakaryocytes (9.2 vs 13.4 vs 14.7, PSE = 1.6  
n/mm2, at 30d; 2.1 vs 13.9 vs 14.3, PSE = 2.0 n/mm2, at 120d; P<0.05), but  
were not different in the percentage of the area covered by white pulp (16.1 vs  
14.1 vs 13.4, PSE = 1.3\%, at 30d; 28.3 vs 23.1 vs 23.8, PSE = 2.4\%, at 120d).   
Expt 4 Mice from the three IGF-1 selection lines (n=13 vs n=13 vs n=14 for L  
vs C vs H, age=86.8{\textpm}2.3 days) showed no difference in spleen weights (110.8  
vs 137.4 vs 139.0, PSE = 11.8 mg; P>0.10).  In response to an antigenic  
challenge with sheep red blood cells (SRBC), there was a small effect (P=0.10)  
of selection line on the number of plaque-forming (immunoglobulin M (IgM)- 
producing) cells (PFC) per spleen (880x103 vs 954x103 vs 1187x103, PSE =  
130x103), but the differences in anti-SRBC antibody titres (IgM) in the plasma  
(10.8 vs 11.1 vs 11.7, PSE = 0.6) were not significant.  It is concluded that  
IGF-1 affects splenic and thymic weights independently, that it influences the  
density of megakaryocytes in the spleen, and that it has an effect on the number  
of PFC per spleen in response to a SRBC challenge.  However, the biological  
significance of these effects is still to be established.},
	issn = {1176-5283},
	author = {Kuhn Sherlock B and Morel PCH and Mathis JM and Blair HT and McCutcheon SN and Marbrook J and Breier BH and Gluckman PD}
}
@conference {40531,
	title = {Metabolic changes in sheep divergently selected for plasma IGF-1},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {53},
	year = {1993},
	month = {Jan},
	pages = {381-384},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The detection of small amounts of biologically active material in animals may require quantification of radioactive label. Here we compare several image analysis methods for quantifying relative levels of radioactive probe detected by x-ray film or photographic emulsion. Total RNA "dot blots" and ovine muscle sections were probed for the presence of muscle actin mRNA using 35S-labelled riboprobes. Bound probe was detected by x-ray film in both cases. The probed sections were further exposed to photographic emulsion, while the dot blots were individually quantified by scintillation counting. Bound probe was quantified macroscopically by digitisation of optical density (OD) and thresholding of the x-ray film image. Dot blot image ODs were correlated with scintillation counts (r>0.96), demonstrating that the levels of mRNA detected in tissues by autoradiography are proportional to cellular mRNA concentration. Densitometry of section macroautoradiographic images can therefore be useful in determining relative probe signal at the tissue level. When probe was quantified microscopically by counting silver grains in emulsion autoradiographs, simple thresholding correlated with manual counts (r=0.88) but was unreliable at higher grain densities. Processing of the gray image gave a more direct estimate of silver grain density (r= 0.98).},
	issn = {1176-5283},
	author = {Sherlock RG and Blair HT and Kuhn B and MacKenzie DDS and Breier BH and Gluckman PD and McCutcheon SN}
}
@conference {40316,
	title = {Plasma hormone concentrations in pasture-fed Friesian cows treated with recombinantly-derived bovine somatotropin (bST)},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {235-238},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Dairy farmers often debate the importance of liveweight of  rising 2 year old heifers and the value of various heifer wintering  systems on subsequent production. Lifetime performance of all dairy  cows born on the Taranaki Agricultural Research Station have been  recorded since 1978 on a computerised data base. This data base was  utilised to determine the liveweight gain of heifers and cows over  winter and the effects of this on production in the following season.   Initial analysis of the data showed a significant (P<0.01) age effect on  winter liveweight gain within a mixed age herd of cows. The average  liveweight gain over eight years of the older cows (4 yr +) was 3 times  that of the rising 2 year olds. Further analysis showed a significant  (P<0.05) age effect on the relationship between liveweight at calving  and production of milkfat in the following season. Higher liveweight at  calving resulted in a greater increase in production for 2 year olds  than for older cattle. The conclusion to be drawn from this is that  wintering rising 2 yea old heifers separately from older cows to achieve  higher liveweight may have beneficial effects on the following seasons  production.   A field trial in winter 1990 to test this assumption showed the winter  liveweight gain of rising 2 year old heifers and mature cows, offered  the same herbage allowance, was significantly (P<0.01) higher when  wintered separately than wintered as a mixed age herd. Subsequent milk  solids production from the two-wintering systems was the same despite  different liveweight at calving. Aspects of herd behaviour were  suggested as the cause of the nil response.  },
	issn = {1176-5283},
	author = {McCutcheon SN and Hoogendoorn CJ and Lynch GA and Wickham BW and Breier BH and Gluckman PD}
}
@conference {40352,
	title = {Responses to divergent selection for plasma insulin-like growth factor-1 (IGF-1) in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {417-422},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {No abstract supplied  },
	issn = {1176-5283},
	author = {Morel PCH and Blair HT and McCutcheon SN and Breier BH and Gluckman PD}
}
@conference {40198,
	title = {Regulation of growth by the growth hormone axis},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {50},
	year = {1990},
	month = {Jan},
	pages = {73-79},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The bovine conceptus induces an array of physiological and   biochemical responses that lead to the establishment of pregnancy.   Among the most studied of these is secretion of prostaglandin (PG)   F2alpha (F) from the uterine endometrium. Pregnancy appears to be   associated with laterations in many of the regulatory systems that cause   PGF secretion leading to luteolysis in cyclic animals. The conceptus   secretes an antiluteolytic protein (bovine trophoblast protein-1 complex   [bTP-1] that appears to induce an inhibitor of prostaglandin synthesis.   The bTP-1 antiluteolytic protein is an alphaII interferon. The   secondary effects associated with interferon-like activities (antiviral,   antiproliferative, altered gene expression, immunosuppressive) may   complement development and sustenance of the conceptus. Both ovarian CL   function and follicular activity are altered in early pregnancy.   Changes in follicular activity may reinforce the antiluteolytic signals   from the conceptus leading to maintenance of the CL. Potential   management systems to improve reproductive efficiency that are based on   supplementation with bTP-1-like molecules, controlled ovarian follicular   management, and progesterone therapy are discussed.    },
	issn = {1176-5283},
	author = {Bass JJ and Gluckman PD}
}
@conference {40116,
	title = {The mechanism of action of growth hormone on milk production of ruminants},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {48},
	year = {1988},
	month = {Jan},
	pages = {191-194},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {The effect of management on milk, milkfat and protein production was assessed by analysing information collected from 16 different experimental farmlets run over a 9 year period on the Waimate West Demonstration Farm and the Taranaki Agricultural Research Station. In these trials a wide range of stocking rates (2.7 to 4.5 cows/ha), pasture types (ryegrass, lucerne, tall fescue and phalaris) and management systems were used. Comparisons of production and regression analysis between and within years and treatments failed to detect any significant effects of variations in grazing management, stock rate and cow condition at calving on milkfat or protein production. Information from a relatively wide data base, covering a range of seasons, management systems and pasture types suggests that herd management for maximum protein production needs to be no different than for systems already researched and adopted for milkfat production.},
	issn = {1176-5283},
	author = {Davis SR and Hodgkinson SC and Gluckman PD and Moore LG and Breier BH}
}
